This document provides a summary of a report on genetic diseases. It discusses processes that occur inside the nucleus including replication, transcription, epigenetics, and splicing. Replication allows DNA to duplicate for cell division. Transcription produces pre-mRNA from DNA. Epigenetics involves methyl groups that can prevent gene expression without altering DNA. Splicing matures pre-mRNA into mRNA. The document also examines repair mechanisms during replication that can avoid genetic disorders caused by mutations.
Dr. Elizabeth Blackburn gives a lecture on telomeres and telomerase, and their implications for aging and age-related diseases. She explains that telomeres are repetitive DNA sequences that cap the ends of chromosomes and protect genetic material. Telomerase is an enzyme that adds telomere sequences to chromosomes to maintain their length during cell division. Studies show genetics play a role in longevity, and stress and caregiving can impact telomere length by reducing telomerase activity and increasing oxidative stress. Shorter telomeres are associated with increased mortality and disease susceptibility.
1) Identical twins have the same DNA sequence but can become increasingly different over time with subtle differences in personalities, appearances, behaviors, and disease susceptibilities.
2) This is due to differences in their "epigenome" or how they use their DNA through epigenetic modifications like DNA methylation and histone modifications rather than changes to the DNA sequence.
3) A study of 512 adolescent twins found differences in DNA methylation profiles of imprinted genes between genetically identical twins, supporting the role of environment in influencing epigenetics and contributing to differences between twins.
Epigenetics is the study of changes in gene expression that do not involve changes to the underlying DNA sequence. It involves mechanisms like DNA methylation and histone modification that turn genes on and off. Epigenetic markers can be inherited from parents and influence traits and disease risk. While the genome contains the basic instructions, the epigenome controls which genes are expressed and when. Epigenetic changes may be influenced by environmental factors and can affect health by triggering conditions like cancer.
The document discusses epigenetics, which is the study of changes in gene expression that are not caused by changes in DNA sequence. An epigenome consists of molecular "switches" that turn genes on and off in response to environmental factors like diet, stress, and lifestyle choices. Experiments have found links between early life experiences like famine or smoking and health outcomes in later generations through epigenetic mechanisms. Scientists are researching epigenetics to develop new drugs that can manipulate epigenomes to treat diseases.
DNA contains genetic instructions used by organisms. It is a double-stranded molecule that replicates through unwinding by helicase. The leading strand replicates continuously while the lagging strand replicates discontinuously in fragments called Okazaki fragments. DNA replication ensures genetic material is passed from parent to daughter cells.
Epigenetics refers to modifications that occur on top of genes in response to environmental factors like diet and stress. These modifications involve chemical tags that can turn genes on or off without altering the underlying genetic code. Studies show these epigenetic tags can be inherited from parents and influence stress response and tolerance in offspring. The environment can thus change our genes across generations through epigenetic mechanisms.
This study explored the relationship between physical activity levels, telomere length, and telomerase activity in immune cells of older adults. The researchers found that moderate physical activity was associated with longer telomere length compared to low and high activity levels. No relationship was observed between activity level and telomerase enzyme activity. Additionally, individuals with the hTERT TT genotype had greater telomerase activity than other genotypes, and the TT genotype combined with high activity was associated with even greater telomerase activity. The findings suggest moderate physical activity may benefit telomere length while higher levels may not provide the same benefits.
Telomeres are protective structures at the end of chromosomes that shorten each time a cell divides. Telomerase is an enzyme that adds DNA bases to telomeres and maintains their length. In cancer cells, telomerase is often overexpressed, allowing cells to proliferate indefinitely by preventing telomere shortening. Maintaining telomere length through telomerase activity is key to cellular immortality and unchecked growth, making telomerase a potential target for anti-cancer therapies.
Dr. Elizabeth Blackburn gives a lecture on telomeres and telomerase, and their implications for aging and age-related diseases. She explains that telomeres are repetitive DNA sequences that cap the ends of chromosomes and protect genetic material. Telomerase is an enzyme that adds telomere sequences to chromosomes to maintain their length during cell division. Studies show genetics play a role in longevity, and stress and caregiving can impact telomere length by reducing telomerase activity and increasing oxidative stress. Shorter telomeres are associated with increased mortality and disease susceptibility.
1) Identical twins have the same DNA sequence but can become increasingly different over time with subtle differences in personalities, appearances, behaviors, and disease susceptibilities.
2) This is due to differences in their "epigenome" or how they use their DNA through epigenetic modifications like DNA methylation and histone modifications rather than changes to the DNA sequence.
3) A study of 512 adolescent twins found differences in DNA methylation profiles of imprinted genes between genetically identical twins, supporting the role of environment in influencing epigenetics and contributing to differences between twins.
Epigenetics is the study of changes in gene expression that do not involve changes to the underlying DNA sequence. It involves mechanisms like DNA methylation and histone modification that turn genes on and off. Epigenetic markers can be inherited from parents and influence traits and disease risk. While the genome contains the basic instructions, the epigenome controls which genes are expressed and when. Epigenetic changes may be influenced by environmental factors and can affect health by triggering conditions like cancer.
The document discusses epigenetics, which is the study of changes in gene expression that are not caused by changes in DNA sequence. An epigenome consists of molecular "switches" that turn genes on and off in response to environmental factors like diet, stress, and lifestyle choices. Experiments have found links between early life experiences like famine or smoking and health outcomes in later generations through epigenetic mechanisms. Scientists are researching epigenetics to develop new drugs that can manipulate epigenomes to treat diseases.
DNA contains genetic instructions used by organisms. It is a double-stranded molecule that replicates through unwinding by helicase. The leading strand replicates continuously while the lagging strand replicates discontinuously in fragments called Okazaki fragments. DNA replication ensures genetic material is passed from parent to daughter cells.
Epigenetics refers to modifications that occur on top of genes in response to environmental factors like diet and stress. These modifications involve chemical tags that can turn genes on or off without altering the underlying genetic code. Studies show these epigenetic tags can be inherited from parents and influence stress response and tolerance in offspring. The environment can thus change our genes across generations through epigenetic mechanisms.
This study explored the relationship between physical activity levels, telomere length, and telomerase activity in immune cells of older adults. The researchers found that moderate physical activity was associated with longer telomere length compared to low and high activity levels. No relationship was observed between activity level and telomerase enzyme activity. Additionally, individuals with the hTERT TT genotype had greater telomerase activity than other genotypes, and the TT genotype combined with high activity was associated with even greater telomerase activity. The findings suggest moderate physical activity may benefit telomere length while higher levels may not provide the same benefits.
Telomeres are protective structures at the end of chromosomes that shorten each time a cell divides. Telomerase is an enzyme that adds DNA bases to telomeres and maintains their length. In cancer cells, telomerase is often overexpressed, allowing cells to proliferate indefinitely by preventing telomere shortening. Maintaining telomere length through telomerase activity is key to cellular immortality and unchecked growth, making telomerase a potential target for anti-cancer therapies.
Epigenetics is the study of heritable changes in gene expression that occur without alterations to the underlying DNA sequence. These changes are mediated by mechanisms like DNA methylation, histone modification, and microRNA and can be influenced by environmental factors. While identical twins have the same DNA, differences in lifestyle and health habits over time can result in variations in how their genes are expressed through epigenetic modifications.
This document provides an introduction to genetics. It discusses how genetics is the study of heredity and variation. Key figures who contributed to genetics are mentioned, including Charles Darwin, Gregor Mendel, and scientists who confirmed that DNA is the genetic material like Oswald Avery. The main branches and scopes of genetics are also outlined, such as cytogenetics, molecular genetics, genomics, and proteomics. Different methods for genetic study are described, including pedigree analysis, karyotyping, planned experimental breeding, and twin studies. The document concludes with discussing applications of genetics in fields like medicine, agriculture, and genetic counseling.
Early maternal alcohol consumption alters hippocampal dna methylation, gene e...BARRY STANLEY 2 fasd
Early gestational alcohol exposure in mice alters hippocampal DNA methylation and gene expression, as well as brain structure in offspring. The study used a mouse model where dams consumed 10% ethanol during early gestation. Genome-wide analysis revealed altered expression of 23 genes and 3 microRNAs in the hippocampus of adolescent offspring. DNA methylation changes were also observed upstream of some candidate genes. Expression of some candidate genes was also altered in bone marrow and olfactory epithelium tissues of offspring. MRI analysis found the left hippocampus was enlarged and left olfactory bulb decreased in volume in adult ethanol-exposed offspring, indicating brain asymmetry. The results support the hypothesis that early ethanol exposure disrupts epigenetic programming in embryos, leading to long
Primer on Epigenetics given at the IRSF family conference 2011Christopher Wynder
My presentation for the families of Rett syndrome patients.
This serves as a basic primer on what epigenetics is without deep details on the science.
Appropriate for all levels of education.
For more information contact the author: crwynder@gmail.com
Epigenetics refers to factors above genetics that determine which genes are expressed. The epigenome controls which genes are expressed more than others through mechanisms like methyl groups binding to DNA and histone proteins winding DNA more or less tightly. Epigenetic changes can occur throughout life in response to environmental factors like diet, stress, and lifestyle, and some changes can be passed down from parents to children. While scientists originally thought epigenetic tags were removed before reproduction, it is now understood that some tags can be inherited intergenerationally.
Telomeres play an important role in cellular aging and division. A study found that women with phobic anxiety had shorter telomeres, suggesting anxiety is a risk factor for accelerated aging. In cancer cells, telomerase remains active, allowing indefinite division by regenerating telomeres. Researchers discovered a protein complex that normally inhibits telomerase; in cancer it is delayed, allowing telomerase to extend telomeres and confer immortality. Understanding these processes may lead to new prevention and treatment strategies for diseases of aging and cancer.
Brian Dias studied how fear responses in mice to certain smells can be inherited by subsequent generations through epigenetic mechanisms. He found that mice exposed to acetophenone and given electric shocks would become fearful of the smell, and pass this fear response down to offspring and grandchildren through changes in DNA methylation related to olfactory receptor genes, without altering the DNA sequence. While some evidence suggests environmental exposures can influence later generations epigenetically in plants and animals, the mechanisms of this transgenerational epigenetic inheritance are not fully understood. Explaining how these effects get encoded in sperm or egg cells and transmitted between generations remains an area of ongoing research.
This document discusses genetics and genes. It provides background on DNA, chromosomes, genes, and how genes create proteins but not behaviors or preferences. The document argues that genes have little to do with sexuality and that same-sex attraction is too common to be caused by single genes or genetic errors. Environmental and chance factors are suggested to be stronger influences on sexual preferences than indirect and weak genetic factors.
TA-65 Telomerase Activator - Is it a key to unlocking the longevity puzzle?Ivan Joksimovic
TA-65 is a natural supplement without any active ingredients added. The only way to lengthen telomeres is through the activation of an enzyme called telomerase. Currently the only way to activate telomerase is to take TA-65 supplement. The telomerase-activating potency of TA-65 has been independently proven in rigorous tests by Geron and Sierra Sciences, two biotech companies specializing in telomere biology.
Telomeres are protective pieces of DNA material at the ends of chromosomes. Like the plastic tips on shoelaces, telomeres prevent chromosome ends from fraying and sticking to each other, which would damage genetic information to cause cancer, other diseases or premature ageing.
Evidence clearly shows that people with long telomeres age healthier and live longer.
Every time a cell divides, the telomeres get shorter. After they get too short, the cell no longer can divide and becomes inactive or dies. This process is related with aging and age related diseases.
Without telomeres, the protective caps at the chromosome - the part containing genes essential for life - would get shorter each time a cell divides. Cell division is needed so we can grow new skin, blood, bone and other cells when needed.
The only way to lengthen telomeres is through the activation of an enzyme called telomerase. Currently the only way to activate telomerase is to take TA-65 supplement.
Telomerase is natural enzyme that stabilizes telomere length by adding DNA repeats (TTAGGG) onto the telomeric ends of the chromosomes, thus compensating for the loss of telomeres when cell divide.
Buy TA-65 now for the best price!
http://www.ta65doctor.com/products-page/
www.ta65doctor.com
DNA replication is the process by which DNA copies itself. It occurs during the cell's interphase stage. The DNA double helix unwinds due to breaking of hydrogen bonds between nitrogenous bases. The enzyme DNA helicase unwinds and unzips the DNA molecule. New nucleotides are then linked together by DNA polymerase to make identical copies of the DNA strands. This results in two identical DNA molecules from the original single DNA molecule.
Telomerase Activation: The Key to Unlocking the Aging Puzzle
The presentation discusses telomeres and telomerase, and their role in cellular aging and longevity. It notes that telomeres protect chromosome ends and shorten with each cell division, acting as a biological clock for aging. Telomerase is an enzyme that can rebuild telomere length, counteracting their shortening. Studies show telomerase activation can rejuvenate cells and tissues in mice, reducing biomarkers of aging without increasing cancer risk. Preliminary human studies suggest telomerase activation may provide benefits like improved immunity and bone density. The presentation promotes further research on telomerase activation as a way to potentially treat aging and age-related diseases
Disruption of histone methylation in developing sperm impairs offspring healt...BARRY STANLEY 2 fasd
Science
www.sciencemag.org
Published Online October 8 2015
Science 6 November 2015:
Vol. 350 no. 6261
DOI: 10.1126/science.aab2006
RESEARCH ARTICLE
Disruption of histone methylation in developing sperm impairs
offspring health transgenerationally
Keith Siklenka1,*, Serap Erkek2,3,*,†,‡, Maren Godmann4,§, Romain Lambrot4, Serge McGraw5||,
Christine Lafleur4, Tamara Cohen4, Jianguo Xia4,6, Matthew Suderman7, Michael Hallett8,
Jacquetta Trasler5,9, Antoine H. F. M. Peters2,3,*,¶, Sarah Kimmins1,4,*,¶
Alcohol is not mentioned, but is relevant to the subject.
The next step required is research into the contribution that trasgenerational epegentics of the father makes to the maternal prenatal alcohol exposure effects on the developing fetus.
Barry Stanley
TA 65 - Telomeres and Telomerase - Los Angeles 2015telomerescience
This document provides an overview of a workshop on telomeres and telomerase activation held in Los Angeles in 2015. It discusses telomere biology, factors that impact telomere length, lifestyle interventions and supplements that may help maintain telomere length, and clinical evidence on the effects of telomerase activation. Specifically, it summarizes evidence that telomerase activation through supplements like TA-65 has been shown to reverse cellular aging in mice and improve immune function, metabolic health, and psychological outcomes in human studies. It also discusses how stress, lifestyle factors, and diseases like depression are associated with shorter telomere length.
1) The document provides an overview of Chapter 12 which discusses DNA technology and genomics. It covers topics like gene cloning, genetically modified organisms, DNA profiling, and genomics.
2) Key concepts include how genes can be cloned using recombinant DNA techniques involving restriction enzymes and plasmids. Genetically modified organisms are being used to develop crops with improved traits.
3) DNA profiling uses techniques like short tandem repeat analysis to produce DNA profiles for forensic identification. The Human Genome Project revealed that most human DNA does not consist of genes.
Dr. Al Sears explains the Nobel Prize winning breakthrough telomere technology. This opened the way for Harvard researcher, Dr. Ronal DePinho to find a way to activate telomerase. Telomerase is the enzyme that signals your telomeres to grow longer, unfortunately, it shuts down while you are still in your mother's womb.
Once Nobel Prize winning research identified that telomeres are the protective tips at each end of the strands of your DNA, and as your cells replicate, gradully your telomeres grow shorter. They are the "aging-clocks" inside your DNA.
Once Dr. DePinho found a way to reactivate the telomerase enzyme, he turned old mice into young mice again.
Not long after, scientists discovered ways to do this in humans as well, and today, the discovery of the telomere and telomerase are the most important anti-aging breakthrough of our time.
Early gestational alcohol exposure in mice alters hippocampal gene expression and DNA methylation, leading to changes in brain structure. The study found 23 genes and 3 microRNAs with altered expression in the hippocampus of adolescent offspring exposed to alcohol during early gestation. DNA methylation was also altered in CpG islands upstream of three candidate genes. Expression of two of these genes was also upregulated in the main olfactory epithelium and bone marrow of exposed offspring, supporting the hypothesis that early epigenetic changes affect multiple tissue types. Magnetic resonance imaging found asymmetries in brain structures of adult exposed offspring, including enlarged left hippocampus and smaller left olfactory bulb. The results suggest early alcohol exposure induces long-term epigenetic and
Telomeres are repetitive nucleotide sequences located at the ends of chromosomes that protect them from deterioration. They consist of the sequence TTAGGG repeated hundreds to thousands of times. Each time a cell divides, the telomeres shorten due to an inability to fully replicate chromosome ends. This represents a biological clock for cell division. Telomerase is an enzyme that adds telomere sequences and prevents shortening, allowing cells to avoid replicative senescence or death. In cancer cells, telomerase is often reactivated, allowing unlimited cell division by maintaining telomere length. Telomeres play a key role in cellular aging and are also implicated in many diseases.
Telomerase its role in aging and cancerHimadri Nath
Telomeres are repetitive DNA sequences at the ends of chromosomes that protect chromosomal DNA from degradation. Telomerase is an enzyme that adds telomere repeats to the ends of chromosomes to overcome replication-induced shortening. In normal cells, telomerase is inactive and telomeres shorten with each cell division, eventually leading to senescence. Cancer cells maintain telomere length through telomerase reactivation, allowing unlimited proliferation. Studies found telomerase expressed in 90% of human tumors but not normal tissues, supporting its role in immortality.
The document discusses various cellular processes and organelle functions including homeostasis, permeability, energy production, cell transport, and protein synthesis. It also covers DNA structure and genetic inheritance through processes like replication, transcription, and translation. Key cellular and genetic concepts like mutations, variation, and interrelationships between organ systems are examined.
The document discusses telomerase, an enzyme that repairs telomeres and prevents their shortening during cell division. It provides a brief history of telomerase discovery and defines telomeres as repetitive DNA sequences that protect chromosome ends. Telomerase extends telomeres by using an RNA template to add DNA nucleotides. This prevents loss of genetic material during DNA replication and solves the "end replication problem". Telomerase is active in cancer cells, maintaining telomere length and conferring immortality, but is less active in normal cells, leading to telomere shortening with age. The document concludes that telomerase resets the cellular aging clock by restoring telomere length.
La informática se define como la automatización del manejo de la información. La informática ha transformado rápidamente las sociedades actuales debido a su rápido crecimiento. Existen diversas ramas de la informática como la teoría de la computación, teoría de la información, algoritmos y estructuras de datos. Las computadoras son máquinas capaces de efectuar operaciones mediante programas y pueden ser analógicas o digitales.
Mohamed Ali Hassan Mohamed Wahba is a professional football coach from Egypt seeking a coaching position. He has over 30 years of experience coaching at both the youth and senior levels in Egypt, UAE, Qatar, and other countries. He holds the highest coaching licenses from AFC, CAF, and FA and has worked with renowned coaches like Wiel Coerver. His career highlights include serving as the technical director for Al Nasr FC in Dubai and head coach of Suez Canal Club. He aims to develop players' skills and help teams succeed through strategic coaching.
Epigenetics is the study of heritable changes in gene expression that occur without alterations to the underlying DNA sequence. These changes are mediated by mechanisms like DNA methylation, histone modification, and microRNA and can be influenced by environmental factors. While identical twins have the same DNA, differences in lifestyle and health habits over time can result in variations in how their genes are expressed through epigenetic modifications.
This document provides an introduction to genetics. It discusses how genetics is the study of heredity and variation. Key figures who contributed to genetics are mentioned, including Charles Darwin, Gregor Mendel, and scientists who confirmed that DNA is the genetic material like Oswald Avery. The main branches and scopes of genetics are also outlined, such as cytogenetics, molecular genetics, genomics, and proteomics. Different methods for genetic study are described, including pedigree analysis, karyotyping, planned experimental breeding, and twin studies. The document concludes with discussing applications of genetics in fields like medicine, agriculture, and genetic counseling.
Early maternal alcohol consumption alters hippocampal dna methylation, gene e...BARRY STANLEY 2 fasd
Early gestational alcohol exposure in mice alters hippocampal DNA methylation and gene expression, as well as brain structure in offspring. The study used a mouse model where dams consumed 10% ethanol during early gestation. Genome-wide analysis revealed altered expression of 23 genes and 3 microRNAs in the hippocampus of adolescent offspring. DNA methylation changes were also observed upstream of some candidate genes. Expression of some candidate genes was also altered in bone marrow and olfactory epithelium tissues of offspring. MRI analysis found the left hippocampus was enlarged and left olfactory bulb decreased in volume in adult ethanol-exposed offspring, indicating brain asymmetry. The results support the hypothesis that early ethanol exposure disrupts epigenetic programming in embryos, leading to long
Primer on Epigenetics given at the IRSF family conference 2011Christopher Wynder
My presentation for the families of Rett syndrome patients.
This serves as a basic primer on what epigenetics is without deep details on the science.
Appropriate for all levels of education.
For more information contact the author: crwynder@gmail.com
Epigenetics refers to factors above genetics that determine which genes are expressed. The epigenome controls which genes are expressed more than others through mechanisms like methyl groups binding to DNA and histone proteins winding DNA more or less tightly. Epigenetic changes can occur throughout life in response to environmental factors like diet, stress, and lifestyle, and some changes can be passed down from parents to children. While scientists originally thought epigenetic tags were removed before reproduction, it is now understood that some tags can be inherited intergenerationally.
Telomeres play an important role in cellular aging and division. A study found that women with phobic anxiety had shorter telomeres, suggesting anxiety is a risk factor for accelerated aging. In cancer cells, telomerase remains active, allowing indefinite division by regenerating telomeres. Researchers discovered a protein complex that normally inhibits telomerase; in cancer it is delayed, allowing telomerase to extend telomeres and confer immortality. Understanding these processes may lead to new prevention and treatment strategies for diseases of aging and cancer.
Brian Dias studied how fear responses in mice to certain smells can be inherited by subsequent generations through epigenetic mechanisms. He found that mice exposed to acetophenone and given electric shocks would become fearful of the smell, and pass this fear response down to offspring and grandchildren through changes in DNA methylation related to olfactory receptor genes, without altering the DNA sequence. While some evidence suggests environmental exposures can influence later generations epigenetically in plants and animals, the mechanisms of this transgenerational epigenetic inheritance are not fully understood. Explaining how these effects get encoded in sperm or egg cells and transmitted between generations remains an area of ongoing research.
This document discusses genetics and genes. It provides background on DNA, chromosomes, genes, and how genes create proteins but not behaviors or preferences. The document argues that genes have little to do with sexuality and that same-sex attraction is too common to be caused by single genes or genetic errors. Environmental and chance factors are suggested to be stronger influences on sexual preferences than indirect and weak genetic factors.
TA-65 Telomerase Activator - Is it a key to unlocking the longevity puzzle?Ivan Joksimovic
TA-65 is a natural supplement without any active ingredients added. The only way to lengthen telomeres is through the activation of an enzyme called telomerase. Currently the only way to activate telomerase is to take TA-65 supplement. The telomerase-activating potency of TA-65 has been independently proven in rigorous tests by Geron and Sierra Sciences, two biotech companies specializing in telomere biology.
Telomeres are protective pieces of DNA material at the ends of chromosomes. Like the plastic tips on shoelaces, telomeres prevent chromosome ends from fraying and sticking to each other, which would damage genetic information to cause cancer, other diseases or premature ageing.
Evidence clearly shows that people with long telomeres age healthier and live longer.
Every time a cell divides, the telomeres get shorter. After they get too short, the cell no longer can divide and becomes inactive or dies. This process is related with aging and age related diseases.
Without telomeres, the protective caps at the chromosome - the part containing genes essential for life - would get shorter each time a cell divides. Cell division is needed so we can grow new skin, blood, bone and other cells when needed.
The only way to lengthen telomeres is through the activation of an enzyme called telomerase. Currently the only way to activate telomerase is to take TA-65 supplement.
Telomerase is natural enzyme that stabilizes telomere length by adding DNA repeats (TTAGGG) onto the telomeric ends of the chromosomes, thus compensating for the loss of telomeres when cell divide.
Buy TA-65 now for the best price!
http://www.ta65doctor.com/products-page/
www.ta65doctor.com
DNA replication is the process by which DNA copies itself. It occurs during the cell's interphase stage. The DNA double helix unwinds due to breaking of hydrogen bonds between nitrogenous bases. The enzyme DNA helicase unwinds and unzips the DNA molecule. New nucleotides are then linked together by DNA polymerase to make identical copies of the DNA strands. This results in two identical DNA molecules from the original single DNA molecule.
Telomerase Activation: The Key to Unlocking the Aging Puzzle
The presentation discusses telomeres and telomerase, and their role in cellular aging and longevity. It notes that telomeres protect chromosome ends and shorten with each cell division, acting as a biological clock for aging. Telomerase is an enzyme that can rebuild telomere length, counteracting their shortening. Studies show telomerase activation can rejuvenate cells and tissues in mice, reducing biomarkers of aging without increasing cancer risk. Preliminary human studies suggest telomerase activation may provide benefits like improved immunity and bone density. The presentation promotes further research on telomerase activation as a way to potentially treat aging and age-related diseases
Disruption of histone methylation in developing sperm impairs offspring healt...BARRY STANLEY 2 fasd
Science
www.sciencemag.org
Published Online October 8 2015
Science 6 November 2015:
Vol. 350 no. 6261
DOI: 10.1126/science.aab2006
RESEARCH ARTICLE
Disruption of histone methylation in developing sperm impairs
offspring health transgenerationally
Keith Siklenka1,*, Serap Erkek2,3,*,†,‡, Maren Godmann4,§, Romain Lambrot4, Serge McGraw5||,
Christine Lafleur4, Tamara Cohen4, Jianguo Xia4,6, Matthew Suderman7, Michael Hallett8,
Jacquetta Trasler5,9, Antoine H. F. M. Peters2,3,*,¶, Sarah Kimmins1,4,*,¶
Alcohol is not mentioned, but is relevant to the subject.
The next step required is research into the contribution that trasgenerational epegentics of the father makes to the maternal prenatal alcohol exposure effects on the developing fetus.
Barry Stanley
TA 65 - Telomeres and Telomerase - Los Angeles 2015telomerescience
This document provides an overview of a workshop on telomeres and telomerase activation held in Los Angeles in 2015. It discusses telomere biology, factors that impact telomere length, lifestyle interventions and supplements that may help maintain telomere length, and clinical evidence on the effects of telomerase activation. Specifically, it summarizes evidence that telomerase activation through supplements like TA-65 has been shown to reverse cellular aging in mice and improve immune function, metabolic health, and psychological outcomes in human studies. It also discusses how stress, lifestyle factors, and diseases like depression are associated with shorter telomere length.
1) The document provides an overview of Chapter 12 which discusses DNA technology and genomics. It covers topics like gene cloning, genetically modified organisms, DNA profiling, and genomics.
2) Key concepts include how genes can be cloned using recombinant DNA techniques involving restriction enzymes and plasmids. Genetically modified organisms are being used to develop crops with improved traits.
3) DNA profiling uses techniques like short tandem repeat analysis to produce DNA profiles for forensic identification. The Human Genome Project revealed that most human DNA does not consist of genes.
Dr. Al Sears explains the Nobel Prize winning breakthrough telomere technology. This opened the way for Harvard researcher, Dr. Ronal DePinho to find a way to activate telomerase. Telomerase is the enzyme that signals your telomeres to grow longer, unfortunately, it shuts down while you are still in your mother's womb.
Once Nobel Prize winning research identified that telomeres are the protective tips at each end of the strands of your DNA, and as your cells replicate, gradully your telomeres grow shorter. They are the "aging-clocks" inside your DNA.
Once Dr. DePinho found a way to reactivate the telomerase enzyme, he turned old mice into young mice again.
Not long after, scientists discovered ways to do this in humans as well, and today, the discovery of the telomere and telomerase are the most important anti-aging breakthrough of our time.
Early gestational alcohol exposure in mice alters hippocampal gene expression and DNA methylation, leading to changes in brain structure. The study found 23 genes and 3 microRNAs with altered expression in the hippocampus of adolescent offspring exposed to alcohol during early gestation. DNA methylation was also altered in CpG islands upstream of three candidate genes. Expression of two of these genes was also upregulated in the main olfactory epithelium and bone marrow of exposed offspring, supporting the hypothesis that early epigenetic changes affect multiple tissue types. Magnetic resonance imaging found asymmetries in brain structures of adult exposed offspring, including enlarged left hippocampus and smaller left olfactory bulb. The results suggest early alcohol exposure induces long-term epigenetic and
Telomeres are repetitive nucleotide sequences located at the ends of chromosomes that protect them from deterioration. They consist of the sequence TTAGGG repeated hundreds to thousands of times. Each time a cell divides, the telomeres shorten due to an inability to fully replicate chromosome ends. This represents a biological clock for cell division. Telomerase is an enzyme that adds telomere sequences and prevents shortening, allowing cells to avoid replicative senescence or death. In cancer cells, telomerase is often reactivated, allowing unlimited cell division by maintaining telomere length. Telomeres play a key role in cellular aging and are also implicated in many diseases.
Telomerase its role in aging and cancerHimadri Nath
Telomeres are repetitive DNA sequences at the ends of chromosomes that protect chromosomal DNA from degradation. Telomerase is an enzyme that adds telomere repeats to the ends of chromosomes to overcome replication-induced shortening. In normal cells, telomerase is inactive and telomeres shorten with each cell division, eventually leading to senescence. Cancer cells maintain telomere length through telomerase reactivation, allowing unlimited proliferation. Studies found telomerase expressed in 90% of human tumors but not normal tissues, supporting its role in immortality.
The document discusses various cellular processes and organelle functions including homeostasis, permeability, energy production, cell transport, and protein synthesis. It also covers DNA structure and genetic inheritance through processes like replication, transcription, and translation. Key cellular and genetic concepts like mutations, variation, and interrelationships between organ systems are examined.
The document discusses telomerase, an enzyme that repairs telomeres and prevents their shortening during cell division. It provides a brief history of telomerase discovery and defines telomeres as repetitive DNA sequences that protect chromosome ends. Telomerase extends telomeres by using an RNA template to add DNA nucleotides. This prevents loss of genetic material during DNA replication and solves the "end replication problem". Telomerase is active in cancer cells, maintaining telomere length and conferring immortality, but is less active in normal cells, leading to telomere shortening with age. The document concludes that telomerase resets the cellular aging clock by restoring telomere length.
La informática se define como la automatización del manejo de la información. La informática ha transformado rápidamente las sociedades actuales debido a su rápido crecimiento. Existen diversas ramas de la informática como la teoría de la computación, teoría de la información, algoritmos y estructuras de datos. Las computadoras son máquinas capaces de efectuar operaciones mediante programas y pueden ser analógicas o digitales.
Mohamed Ali Hassan Mohamed Wahba is a professional football coach from Egypt seeking a coaching position. He has over 30 years of experience coaching at both the youth and senior levels in Egypt, UAE, Qatar, and other countries. He holds the highest coaching licenses from AFC, CAF, and FA and has worked with renowned coaches like Wiel Coerver. His career highlights include serving as the technical director for Al Nasr FC in Dubai and head coach of Suez Canal Club. He aims to develop players' skills and help teams succeed through strategic coaching.
Las didácticas contemporáneas promueven un aprendizaje activo donde tanto el profesor como los estudiantes juegan un papel importante. Estas didácticas ayudan a los estudiantes a aprender resolviendo problemas de manera colaborativa bajo la guía del profesor. Aunque estas didácticas tienen beneficios como una retención mayor, su aplicación en algunas instituciones es difícil debido a factores sociales y económicos.
This document outlines a pilot study that aims to develop a reliable measure of frustration for use in electroencephalogram (EEG) research. The study involved 30 participants completing an object selection task designed to induce frustration through increasing rates of false feedback. Participants' affective states and behaviors were measured using a mood checklist and observations. Preliminary results found that reaction times increased as the percentage of false feedback increased, suggesting frustration was induced. The document provides background on defining and measuring frustration, and discusses potential applications of frustration research in education and occupational psychology.
Tecnologias de la informacion al. ma. lauralaura lopez
Este documento presenta un cuadro comparativo de tres tecnologías de la información: Dropbox, Slideshare y YouTube. Dropbox permite crear, almacenar y sincronizar archivos en la nube de forma gratuita hasta 2 GB. Slideshare es un sitio para compartir presentaciones de diapositivas de forma gratuita hasta 100 MB. YouTube es una plataforma para crear y ver videos de forma gratuita con un límite de 2 minutos y 2 GB por video. Las tres plataformas requieren registro con una cuenta y ofrecen almacenamiento gratuito limitado.
Para subir documentos a SlideShare, seleccionar la opción "Subir" en la parte superior derecha después de ingresar al sitio, cargar el archivo deseado y completar los detalles requeridos como título, descripción e información del autor. Finalmente, publicar el documento para que esté disponible para otros usuarios en la plataforma.
Este documento presenta un resumen de 3 oraciones sobre virus de computadora. Explica que los virus de computadora se originaron teóricamente en 1949 y que el primer virus práctico fue escrito en 1972. Luego describe brevemente los métodos de propagación de virus, como correos electrónicos y redes, y los métodos de protección como antivirus y actualizaciones automáticas. Finalmente, define varios tipos de virus como troyanos, gusanos, bombas lógicas y hoaxes.
This document is a curriculum vitae for Mustafa Osama Tewfik Elgamal. It includes his personal details like name, date of birth, address, and contact information. It then lists his educational qualifications which is a bachelor's degree in civil engineering from Tanta University in 2014. It provides details of his work experience including working as a junior site engineer on hotel and building construction projects where he inspected architectural and structural site works. It also lists courses taken in AutoCAD and structural analysis software as well as languages spoken.
Cellular defense against fatal associations between proteins
and DNA
Date:
July 3, 2014
DNA 'replication fork' reconstituted for the first time
Date:
July 9, 2014
DNA replication involves copying genetic material to produce new DNA molecules. Errors can occur during this process due to DNA polymerase, the enzyme responsible for DNA replication. A new study tracked DNA polymerase enzymes and found they can leave behind scaffolding sections during replication that contain errors. These scaffolds become trapped in regulatory regions of DNA and can lead to genetic diseases and cancer by altering important genetic switches. Understanding where errors occur provides insight into disease development and could help researchers develop more targeted treatments.
The DNA is the basis of our genetic code, we could almost say that we are all made of DNA; therefore all studies are trying to understand this important part of us. Over time, they have discovered that DNA contains all the instructions that control the development and function of every cell in our body. What we know is that the DNA is able to divide itself, replicating and giving two daughter strands which contain exactly the same information from DNA mother. Then these are transcribed into RNA and finally translated into proteins, this is what we know as the central dogma of genetic information.
Although nature seems to be so perfect there are some cases where this beautiful process fails, and this is where certain diseases are originated and can cause multiple problems. Scientists are increasingly closer to find answers and perhaps their studies can help in the future.
New treatments for Alzheimer's, autism and depression, could be developed.
It could be the starting point for future researches on genes involved in these diseases.
Knowing which genes are involved, people who are not sick yet, might prevent some disease.
These findings help us understand how diseases work and where they come from.
Encourages doctors and scientists to find more about this genes, to achieve excellent results that could benefit many people.
It gives us hope and determination to achieve incredible things in this medicine area; we know that humans are able to find and develop things that we have never imagine.
We know that DNA is the basis of everything, thus if we understand certain parts of it and what is involved on it, we would be able to control many diseases that affects society nowadays.
With these discovery we would be contributing to industry and researches.
new hypothesis could change the way we see things, and would make researchers focused in other cell structures such as ribosomes.
The cause of some diseases might not be in the DNA, but on the malfunctioning of ribosomes, in that way we must look for the real cause of them.
In my opinion this is a big step for medicine, although there is not yet a certain result, and they have to investigate more about the genes, they have a great part of the investigation that can guide them to find the solution to multiple diseases. I think that this kind of researches benefit a lot our society, because they are trying to improve people’s life, by finding the different places of de brain where illnesses are originated. With this project we can start thinking on possible cures and treatments for Alzheimer's, autism, depression and other disorders.
It's good to start investigating on other cellular structures that may be quite involved in the most complex processes of DNA. Scientists may have never wondered what real role of ribosome is. Thinking about new hypotheses and that maybe the ribosome is the central point is crazy but good, because they could be right.
Scientists have developed new methods to study DNA structure and mutations. One study showed how smoking can chemically alter DNA building blocks, leading to mutations, and researchers created artificial counterparts to detect specific mutation sites. Another found that DNA replication leaves about 1.5% of "scaffold" sequences unremoved, in regulatory gene switches, causing diseases. Understanding these scaffolds may help find disease-causing mutations, aiding treatment.
1) Scientists have reconstituted the DNA "replication fork" for the first time, allowing them to study the complex process of DNA duplication.
2) Researchers discovered that an enzyme involved in metabolizing carbohydrates, pyruvate dehydrogenase complex (PDC), is present in the nucleus and can acetylate histones to regulate DNA replication and gene expression.
3) Understanding how DNA replicates and is regulated could help scientists develop treatments for diseases like cancer by controlling genetic and epigenetic processes involved in uncontrolled cell growth.
Replication Fork and Sweet Genes(Molecular Biology Folding)Ana Cristina Toro
1) Scientists have reconstituted the DNA "replication fork" for the first time, allowing them to study the complex process of DNA duplication.
2) Researchers discovered that an enzyme involved in metabolizing carbohydrates, pyruvate dehydrogenase complex (PDC), is present in the nucleus and can acetylate histones to regulate DNA replication and gene expression.
3) These findings help explain how metabolism and DNA regulation are linked, with potential applications for understanding diseases like cancer where DNA replication is disrupted.
Circumventing Traditional Bottlenecks In Glioblastoma...Melanie Smith
This study investigated whether the nonstructural protein 2B of human rhinovirus 16 (HRV16) induces an endoplasmic reticulum (ER) stress response. A HRV16 2B fusion protein with GFP was expressed in baby hamster kidney (BHK) cells. Results showed HRV16 2B induced high expression of the ER chaperone GRP78 in a time-dependent manner and activated the PERK-eIF2α signaling pathway, leading to increased expression of p-PERK, p-eIF2α, and CHOP. HRV16 2B decreased expression of p-IRE1 and ATF6 p50. This demonstrated for the first time that the PER
In September 1944, the Netherlands was still under Nazi control near the end of World War II. The Allied Forces attempted to liberate the country with a railway strike, but this failed. In response, the German government imposed a food embargo on the Netherlands, coinciding with a harsh winter that led to poor crops. This caused a famine, with daily calorie intake dropping drastically from over 2,300 to just 1,000 initially.
The first document discusses the organization of DNA into chromosomes and the cell cycle. It explains that DNA must be packaged into chromosomes to fit in the nucleus, and that the cell cycle has four phases: G1, S, G2, and M. Mitosis results in two identical daughter cells.
The second document summarizes research finding that slow stem cell division can cause neurological disorders like microcephaly by producing too few neurons. Delayed stem cell division was shown to reduce neuron production in mice lacking a protein involved in gene expression.
The third document covers two related investigations. One showed that the tumor suppressor protein p53, which is mutated in over 50% of cancers, can suppress DNA damage at telomer
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Epigenetics refers to modifications to DNA that change gene expression without altering the DNA sequence. These modifications, such as methylation, can be inherited and influence traits in offspring. Experiments show that environmental factors like chemical exposure, diet, and stress experienced by parents or grandparents can cause epigenetic changes leading to disease in subsequent generations, despite those generations not directly experiencing the original stressor. Further research on epigenetics may lead to new treatments for diseases and insights into disorders that differ between identical twins.
Epigenetics refers to modifications to DNA that change gene expression without altering the DNA sequence. These modifications, such as methylation, can be inherited and influence traits in offspring. Experiments show that environmental factors like chemical exposure, diet, and stress experienced by parents or grandparents can cause epigenetic changes leading to disease in subsequent generations, despite those generations not directly experiencing the original stressor. Further research on epigenetics may lead to new treatments for diseases and insights into disorders that differ between identical twins.
This document summarizes two scientific studies on chromosome defects and genetic diseases. The first study discovered a chromosome therapy technique to correct severe chromosome defects by replacing an abnormal ring chromosome with a normal duplicated chromosome in stem cells. This could help repair birth defects. The second study found that analyzing chromatin architecture, the organization of DNA and proteins in chromosomes, could help identify regulatory DNA anomalies and better diagnose genetic diseases, since DNA sequencing alone is insufficient. This discovery paves the way for improved understanding and diagnosis of many genetic conditions.
This document discusses germline mutations, which can be passed down from parents to offspring. It analyzes data from a study on BRCA mutations in women diagnosed with breast cancer. The data shows more cases of BRCA1 mutations than BRCA2, and more deaths caused by BRCA1. This suggests BRCA1 is a more common and dangerous mutation. A woman with a mutated BRCA1 gene has an 18% risk of dying from cancer. Preventative surgeries may be effective, but more data on patients' family histories is needed to fully evaluate this.
This document discusses germline mutations, which can be passed down from parents to offspring. It analyzes data from a study on BRCA mutations in women diagnosed with breast cancer. The data shows more cases of BRCA1 mutations than BRCA2, and more deaths caused by BRCA1. This suggests BRCA1 is a more common and dangerous mutation. A woman with a mutated BRCA1 gene has an 18% risk of dying from cancer. Germline mutations can be inherited due to genes developing over generations within families with breast cancer history.
The document discusses three scientific seminars attended by the author on topics related to human health and energy production. The first seminar was on how genes in the inner ear may be related to cancer and how calcium signaling could be regulated to help treat cancer. The second discussed DNA damage sensing and repair to maintain genome stability. The third presented research on genetically modifying microorganisms to produce hydrocarbons as a sustainable alternative to fossil fuels. The author argues that this type of scientific research is important for improving human health and developing renewable energy sources.
This document discusses how cells can combat chromosome imbalance and discusses potential medical applications. It describes how researchers discovered that when cells detect genetic problems in their chromosomes, they signal nearby natural killer cells to destroy them, preventing conditions like cancer. The document also discusses how new technologies may help treat diseases like Parkinson's by using synthetic materials or coded DNA to signal stem cells to proliferate or differentiate into targeted cell types like neurons. This could help develop regenerative treatments for neurodegenerative diseases and other conditions.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
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Contents
Introduction & Generality about genetic
I- Inside the nucleus
1. Replication
2. Transcription and epigenetic
3. Splicing
II- Inside the cytoplasm
1. Translation
2. Mutations without consequences
3. Proteins’ role
III- External actions
1. Conditionnal expression
2. Environment and lifestyle
3. Therapy
Conclusion
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INTRODUCTION
&
GENERALITY ABOUT
GENETIC
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Introduction
Genetic is a very vast and very complex field. Thanks to the new technologies
and the researches of very important people in the past centuries, scientists discover
new things and new questions arise. Those last years, researches have progressed a
lot and very fast thanks to the technology. Now, a lot of new things have been
discovered, for instance there is the replication of the DNA, the synthesis of a protein
or themystery of the epigenetic. All cell of our body are in constant activity, in this
way human beings develop themselves in a perfect harmony. However, nothing is
perfect and during the unremitting activity of our cell, it is possible that some
mistakes happen and generate what we call: genetic diseases. Nevertheless, it exists
systems that fix these errors or some ways to avoid their expression. So, a question
appears : In what ways the expression of a genetic disease could be avoided even
though there is a mutation within genetic program ?
Generality about genetic
Humans beings are built from billions and billions of cells. These cells are
constituted of a nucleus, the cytoplasm itself is made up of a many small organisms
for instance there are the mitochondria or the vacuole, and the plasma membrane.
The genetic information is located inside the nucleus and chromosomes are the
genetic information’s shelves. Chromosomes are long threads of DNA, they are
always present inside the nucleus, either they are visible either they are invisible.
Human beings are made of 23 pairs of chromosome and when they are visible, they
are known as « double », they have two chromatids, in other words two arms
combined by one centromere. We are able to classify them, in a descending order of
size, it is called a karyotype. Among the 46 chromosomes, they are two sexual
chromosomes called X and Y, XX define a female and XY a male. DNA is made up of
a two complementary strand rolled-up as a double helix; it is a succession of
nucleotide. Apiece nucleotide is built of phosphate, deoxyribose and base : A for
adenine, T for thymine, C for cytosine and G for guanine. These are complementary
base-pairing. A genetic information correspond to an unique location on a
chromosome for precise character, defined as a gene, some of them can have
different versions : alleles. For instance, there is the eyes colour.
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INSIDE THE
NUCLEUS
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1. Replication
Genes are tiny parts of the DNA, which code for proteins but also have the
genetic information for any living-being. But from DNA to proteins or from a stem
cell to two identical daughter cells there are a few mechanisms that we must talk
about because they can, without a doubt, avoid a serious genetic disorder. Before
talking about those mechanism we ought to talk about the replication which is, has
we can probably say, responsible of life if we forget the details. The replication is the
system which enables the DNA to duplicate so the other mechanism can make the
division of the stem cell in two perfectly identical daughter cells to form a living-
being. Here we will mostly talk about human-beings. On the diagram, the DNA is
opened thanks to an enzyme called the DNA polymerase.When the DNA molecule is
opened, free nucleotides will form a new strand, the non-template strand. The free
nucleotides will match the previous one (A-T / T-A / C-G / G-C). The result of the
replication is, as we know, two identical DNA molecules.
Previously we talked about how we could avoid a genetic disorder when there
is a genetic modification, also called a mutation in the DNA, so now we are going to
show the different mechanisms insidethe replication that repair the mutations. Even
though some mutations can be repaired, not all of them can be. In fact, if the
mutations are too important and damage too much the DNA, the replication can be
stopped leading to more mutations and sometimes the death of the human-being
touched by those alterations.
The first mechanism that we have is the “recombinational repair”, which is a
mechanism happening during the replication that fixes the DNA damages. This
repair system happens probably more often than we think. In fact, when your skin is
too much exposed to the Ultraviolet, called UV, our DNA undergoes some mutations
causing thymine dimers. Those dimers can be very dangerous because they change
our DNA and can cause disorders and cancers. When the thymine dimers are in our
DNA, the replication is blocked and our body has to find a way to fix it. The
“recombinational repair” can begin to do its work. The first thing we have to know is
that it can only work if one of the two strands of the parental DNA is not damaged.
When the DNA polymerase has avoided the dimers, there is a gap on the new strand
because the DNA polymerase was not able to match the new nucleotides with the
dimers. In that case, a matching part on the healthy strand is used to fill the gap in
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question leaving a new gap on the parental strand but it will be filled again by the
polymerase.
The second mechanism happening during the replication is the “error-prone
repair”. This mechanism happens when there are mutations in the DNA just as the
“recombinational repair” system but instead of using a part of the healthy parental
strand, the gap we saw previously is filled with a new DNA that has being
synthetized. As the DNA has been synthetized with a damaged DNA, this system
fails most of the time and causes some mutations even more serious.
Sometimes, those mechanisms to repair the damaged DNA do not work. For
example, the xerodermapigmentosum is a genetic disorder that affects the repair
system. When a person who suffers from this disorder is too much exposed to the
UV,the thymine dimers appearing in the DNA cannot be repaired. Thereason to this
issue is a mutation on the gene that produces the enzyme XPf that has to repair the
dimers in the DNA and this mutation make the enzyme XPf non-functional leading
to more mutations, skin cancer and death of this individual.
2. Transcription and epigenetic
The pre-mRNA is synthesized during the transcription.
This process happens during the interphase. On only one of the two DNA strand and
according to a reading direction. Moreover, only genes are transcribed, that’s why if
there is a modification on a noncoding part of the DNA there won’t be any
consequences during the protein synthesis. However, Scientists don’t know if there
could have other consequences. They haven’t paid attention to those parts for a long
time that’s why they called it “the junk DNA”.
First, RNA polymerase breaks the hydrogen liaisons to open the DNA
molecule. Then this enzyme sets free nucleotides by complementarity on the
transcribed DNA strand. Several pre-mRNA are transcribed at the same time, thanks
to this, there is a lot of proteins which are made faster.
However, some mutations on the DNA may not have any consequences.
Actually, if a methyl group (CH3) place themselves on a gene it won’t express
because the RNA-polymerase couldn’t reach the DNA molecule. The pre-mRNA
couldn’t be transcribed. This mechanism is named epigenetic. Genes on which the
methyl group are situated are determined by the environment, but that doesn’t alter
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DNA sequence. However those marks can stay on the DNA even if the signal which
had initiated it, isn’t present anymore. Moreover epigenetic has a role in the cell
specialization, it show to the cell which gene has to be turned on. The epigenetic is
retained during the cell division. However during the gamete manufacture
epigenetic is suppressed to permit the embryo’s development, but the epigenetic is
hereditary. That means some gene still have epigenetic. Actually, scientists disagree
on that point.
This heredity was proved by a study about starvation in Holland in the winter
of 1944-1945. Actually, the study says than grandchildren of people who knew
starvation are most likely to have diabetes whereas they have never known that.
Women who were pregnant during this winter have had children smaller than usual
and it is not surprising. But these children’s babies didn’t weigh a lot either. So the
starvation’s consequences would affect women’s grandchildren who had known it.
Moreover, a study showed that there were a great number of obese people in this
population whereas neither their nutrition, neither their way of living can explain it.
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However, epigenetic anomalies can contribute to develop diseases. As for
instance if a methyl group is on a tumor suppressive gene which couldn’t express and
couldn’t avoid a tumor.
3. L’épissage
L’épissage correspond à la maturation de l’ARN, c’est-à-dire que l’ARN
prémessager va donner lieu, suite à plusieurs processus à des ARN messagers. Il
existe deux épissages différents : l’épissage constitutif et l’épissage alternatif,
cependant pour plus de la moitié des gènes humains, ils se superposent. Le premier
épissage a pour but de supprimer les introns, soit les parties non-codantes du gène
transcrit. Quant au second, il élimine certains exons et conserve les autres, soit les
parties codantes, afin de former un ARN messager mature et apte à être traduit. De
ce fait, à partir d’un seul ARN prémessager, on peut obtenir plusieurs ARN messager
qui coderont donc chacun pour une protéine. Le génome humain est composé
d’environ 25 000 gènes, or on estime le nombre ARN messager aux alentours de
100 000, l’épissage permettrait donc en moyenne de donner lieu à partir d’un ARN
prémessager à quatre ARN messagers. Ces nombreuses protéines issues à l’origine
de la transcription d’un seul gène sont nommées isoformes protéiques.
L’épissage se fait à l’aide de séquences d’ARN présentes dans l’ARN
prémessager. Les premières séquences agissent en cis, soit de l’intérieur de l’ARN
prémessager, tandis que les autres agissent en trans, donc de l’extérieur. Les
séquences cis ont une influence à distance sur l’épissage, elles se situent entre les
introns et les exons.Il faut savoir qu’un intron commence toujours par une guanine et
un uracile et termine de mêmetoujours par une adénine et une guanine,ils sont ainsi
facilement repérables. Grâce à plusieurs complexes, qui vont d’abord identifier
l’intron, puis le replier avant de l’éliminer, l’épissage constitutif va pouvoir avoir lieu,
une fois supprimé, l’intron est nommé intron excisé. Pour ce qui est de l’épissage
alternatif, les processus sont semblables, mais bien plus complexes. Cependant, au
lieu de replier uniquement l’intron, les agents responsables de l’épissage vont replier
un exon entouré de deux introns, puis les éliminer. En fonction des différentes sortes
de cellules, les exons qui s’expriment ne sont pas les mêmes, ce phénomène
s’appelle la différenciation.
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Certaines mutations silencieuses, qui n’ont aucun effet sur la synthèse
protéique, car le codon code toujours pour le même acide aminé malgré son
changement, peuvent cependant avoir un effet sur les épissages.Quelles soient dans
les introns ou les exons, cela peut modifier les informations dans les séquences cis et
modifier ainsi l’épissage.Les ARN messagers ne sont plus les mêmes et les nouveaux
isoformes pourraient voir leur fonction changer par rapport à l’original. Plusieurs
maladies découlent de ces mutations dites silencieuses, comme la maladie
d’Alzheimer où la protéine tau, deviennent anormales suite à l’insertion de l’exon 10.
Ces protéines s’accumulent alors dans le cytoplasme des cellules des neurones et en
perturbent le fonctionnement.
L’épissage est un système très complexe qui se déroule après la transcription.
Grâce à l’épissage constitutif, qui élimine les introns, et l’épissage alternatif, qui
élimine également certains exons, on peut obtenir un grand nombre de protéines
dites isoformes, à partir d’un seul ARN prémessager. Toutefois les mutations
silencieuses peuvent avoir ici des conséquences sur l’épissage et donner lieu à des
maladies génétiques.
After its maturation, the mRNA associates with some proteins to create a
ribonucleic complex which is named hnRNP or heterogeneous nuclear
ribonucleoprotein. This facility enables the mRNA’s migration by the nuclear
pore to the ribosomes.
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INSIDE THE
CYTOPLASM
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1. Translation
The translation is a mechanism that occurs in the cytosol, which is a part of
the cytoplasm. In fact, it follows the migration where the mRNA goes from the
nucleus to the cytoplasm. The principal role of the translation is to create proteins.
To get this result there are different stages that have to happen in order.
The first stage out of three is the initiation. When the mRNA is in the cytosol,
the small subunit ribosome will get attached to the mRNA from the beginning of it,
to start the translation initiation. As the small subunit ribosome gets to the initiation
site, the tRNA comes to match the first codon with an anti-codon. The tRNA is a
molecule containing an anti-codon that matches to the mRNA’s codons and it also
has an amino acid. Most of the time, the first codon is an AUG it means that the anti-
codon is UAC and the amino acid is methionine (met). As the first tRNA has matched
the first codon, the large subunit ribosome comes over it to create the to different
part of the ribosome, the peptidyl (P) site and the aminoacile (A) site. The initiation is
now finished and the second stage can begin.
The second and most important stage is the elongation, where the ribosome
moves codon per codon, to translate the mRNA into a protein. When the ribosome
moves to the next codon, a new tRNA enters the ribosome at the A site to binds with
the mRNA codon then moves to the P site and leave the ribosome. Before it
completely leaves it, the tRNA’s amino acid is transferred back to the A site to give it
to the new entering tRNA to form a polypeptide. This mechanism continues until the
next stage, the termination.
The termination is the last stage of the translation. When the ribosome has
moved along the mRNA and gets to the end, the last codon will immediately stop
the translation. The reason is that the last codon is a “stop-codon” and no tRNA
exists to translate it. So when the “stop codon” is detected, a release factor will enter
the ribosome and stop all the actions. The translation is finished and the ribosome
lets the polypeptide go. The polypeptide will form a protein by itself or thanks to
other polypeptides.
Sometimes, the translation is not made correctly because of mutations derived
from other mechanism such as the transcription, the replication of the DNA
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previously, or the replication when the individual was still an egg cell. The result of a
non-correct translation can be the synthesis of the wrong protein, of a non-working
protein or the translation can be blocked and the protein will not be created.
Fortunately, there is a chance that the mutation(s) are silent and without
consequences.
2. Les mutations sans conséquences
Une mutation est une modification de la séquence de nucléotides, elle peut
avoir lieu de façon spontanée au cours del’interphase,lors dela réplication de l’ADN ,
mais aussi lors de la transcription. Cependant, certaines erreurs échappent aux
systèmes de réparation et se transmettent à toutes les cellules issues des divisions
cellulaires. Les modifications peuvent aboutir à de graves conséquences comme
entrainer la mort de la cellule ou modifier le fonctionnement de celle-ci, mais
d’autres demeurent sans conséquences.
On distingue parmi les mutations sans conséquences, les mutations
silencieuses. Ces dernières n’ont pas d’impact sur la synthèse protéique puisque le
code génétique est redondant, c’est-à-dire qu’un même acide aminé peut être
synthétisé à partir de différentes combinaisons d’acides aminés, soit les codons. Par
exemple, la leucine est synthétisée à partir des six codons suivants : TTA, TTG, CTT,
CTC,CTA et CTG. Les deux sortes de modifications pouvant être silencieuses sont les
mutations par substitution et les mutations par inversion. La première correspond à
l’échange d’un nucléotide par un autre et la seconde est, comme son nom l’indique,
l’inversion de deux nucléotides placés côte à côte. Effectivement, si l’échange d’un
nucléotide donne un codon codant pour le même acide aminé, cela n’aura pas
d’impact. Si la séquence d’ARN est CTT, qui code pour une leucine et que sur la
séquence mutée, le dernier T est un A, cela donnera CTA qui code également pour
une leucine. De même pour l’inversion, si la séquence D’ARN est CTTA, les trois
derniers nucléotides codant pour uneleucine, et qu’il y a une inversion entre leC et le
T, le codon sera désormais CTA, qui code aussi pour une leucine.
Elle sera aussi sans conséquence si elle touche un gène qui ne sera pas traduit
dans la cellule où elle se trouve ou si la mutation touche un gène dont l’allèle est
récessif, donc qui ne sera pas celui qui s’exprime, comme la mucoviscidose où il faut
être homozygote pour être atteint de la maladie.
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De plus, lorsqu’une mutation induit le changement d’un acide aminé, dans
certain cas, si le nouvel acide aminé a les mêmes propriétés que l’ancien ou en
fonction de sa place dans la chaine, cela peut ne pas avoir d’effet. Par exemple, pour
le cas de la drépanocytose, maladie génétique qui est du à l’échange d’un acide
aminé hydrophile par un hydrophobe situé à l’extérieur de la chaine bêta, cela
provoque un changement de la forme des globules rouges. Si l’ erreur avait donné
lieu à un autre acide aminé hydrophile ou s’il était situé à l’intérieur de la chaine, cela
n’aurait pas eu d’impact sur la forme des globules rouges.
Les mutations sont des phénomènes rares qui se produisent lors du cycle
cellulaire, bien qu’il existe plusieurs systèmes de réparation de l’ADN efficaces,
quelques erreurs perdurent. Cependant, toutes n’ont pas de conséquences sur la
cellule. En effet, dans certains cas, comme par exemple si la mutation netouche pas
un gène ou bien si la mutation est dite silencieuse.
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3. Proteins’ role
Proteins are very varied and have an important role in our organism. As actine
which take part in the muscular contraction, it is a functional movement.
But this one has also other functions. Indeed, it has a structural role, the actine
protein is present in the cytoskeleton, a fibrous layout which is in every cells. This
structure serves to bring a minimal stiffness to cells. Actine serves to generate
internals movements. As, for instance the chromosome displacement during the
cellular division.
However there are others proteins like DNA polymerase which has an
enzymatic function, as antibody which has a defensive role, or the insulin that has a
hormonal function.
When a protein is mutated, there can be serious consequences even if only
one amino acid is different from the original protein. Take the case of
phenylketonuria (PH), this disease appears because of a mutation in the gene PAH
coding for the phenylalanine hydroxylase protein. Because of this disease, the
transformation of the indispensable amino acid phenylalanine present in the food
into tyrosine, a non-essential amino acid cannot happen. That’s why there is a
surplus of phenylalanine in the blood which can involve a lot of consequences. As, for
instance the irreversible and progressive neuron deterioration which can lead to
intellectual deficiency and behavioral disorder. But this surplus involves growth
lateness, spasm, eczema or vomiting. Moreover, the tyrosine lake leads to pale hair
and skin. Fortunately, those symptoms can be avoid or reduce. If the disease is
detect enough early. Well, in France all the people who are sick are known thanks to
the phenylalanine concentration test which is carried out on infants at their third
day. So a diet poor in phenylalanine is put in place for sick people.
The phenotype is all the characteristics that are observables on a person.
We can observe it at different scales. They are: the organism level, it is the
macroscopic phenotype, the cell level that explain what happened in the cell and
the molecule level, it is in the protein.
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EXTERNAL
ACTIONS
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1. Expression conditionnelle
Certaines maladies n’apparaissent que dans des conditions précises comme
l’élévation de la température ou le niveau d’hydratation.
C’est le cas par exemple de la drépanocytose, les effets ne se produisent que
dans un milieu faible en dioxygène. Cette maladie est due à une mutation du gène
codant pour la chaine d’acide aminé bêta del’hémoglobine sur le chromosome11.La
mutation intervient sur le 17ème
nucléotide du gène (T devient A) ce qui influence le
sixième codon et donc le sixième acide aminé. L’acide aminé original était un acide
glutamique mais, il devient alors une valine. Malheureusement, ces deux acides
aminés ne se comportent pas de la même façon. Effectivement, le nouvel acide
aminé, contrairement à l’ancien est hydrophobe.
Lorsqu’une personne fait du sport, plus de dioxygène circule dans le sang mais
après que le sang soit passé dans les muscles, la concentration en dioxygène est
moins importante quelorsque l’organisme est au repos.L’acide aminéevalinequi est
à l’extérieur de la chaine forme alors une liaison hydrophobe avec la phénylalanine
en position 85 et la leucine en position 88. . Il se crée une chaine de bêta-globine
morbide qui se colle à la paroi du globule rouge désoxygéné. Le globule rouge prend
alors la forme d’une faucille. Cette forme réduit leur souplesse, c’est pourquoi
lorsqu’ils doivent passer dans des petits capillaires, ils se cassent. A cause de ce
phénomène, il n’y a pas un grand nombre de globules rouges dans le sang des
drépanocytaires, et les hématies qui restent transportent moins de dioxygène que la
normale. De plus, lors de l’hémolyse des globules rouges l’hémoglobine est relâchée
dans le sang ce qui détruit le monoxyde d’azote. Une molécule permettant la
dilatation des vaisseaux et donc un bon flux sanguin. La destruction des hématies
relâche aussi de l’hème, une substance nocive pour l’endothélium des vaisseaux
sanguins. L’anémie, un manque de globules rouges est l’un des premiers
symptômes. Elle peut se traduire par une pâleur et de la fatigue. Cependant elle peut
être aggravée si la rate s’épuise dans la destruction de globules rouges ou si, dans les
cas les plus extrêmes, la production des globules rouges s’arrête. Il y a aussi de fortes
douleurs au niveau des articulations et des os dû à l’obstruction des vaisseaux
sanguins. Chez les bébés et les nourrissons, il peut y avoir des gonflements
douloureux des pieds et des mains. Il y a des risques d’AVC plus élevés durant ces
crises. Elles peuvent aussi affecter les poumons compromettant ainsi l’oxygénation
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de tout l’organisme. Les risques d’infections sont plus présent et au fil des années, il
peut y avoir des complications sur quasiment toutes les organes, cette maladie peut
aussi engendrer un retard de croissance. Pour traiter cette maladie, il faut tout
d’abord prévenir les infections en administrant plus d’antibiotiques et de vaccins. Il
faut aussi mettre en place un régime et une bonne hydratation afin d’éviter les crises
douloureuses. Lors d’anémie, on peut faire des transfusions sanguines, et dans les
cas les plus graves de drépanocytaires, on peut aussi faire des greffes de moelle
osseuse, mais seulement s’il y a des donneurs compatibles. De plus, lors des crises
vaso-occlusives, les antalgiques et dans les cas les plus extrêmes, de la morphine
peuvent soulager les malades. Cependant, des chercheurs sont en train d’élabor er
des traitements géniques afin de greffer des gènes sains dans les cellules souches
des drépanocytaires.
2. Environment and lifestyle
The environment or the lifestyle can affect some genetic diseases, these
diseases are known as “multifunctional”. They are for the most part polygenic, in
other words several gene are concerned. The environment is defined by what we
can’t act on, that is pollution or else climate amongst others. As for lifestyle, it is
quite the reverse, on what we can act, as nutrition or practice of sport. Consequently
it is possible to reduce the chances to be suffering to this kind of disease or, when
someone suffers from a genetic disorder, it can restrict its expression.
Phenylketonuria (PKU) is a rare genetic disease of metabolism; people
affected by this disorder have an abnormal accumulation of an amino acid, the
phenylalanine. The excess of this amino acid, present in foodstuffs especially in
proteins, cause a progressive and irreversible destruction of neurons, which leads to
a serious mental retardation. It is foreseeable to prevent the symptoms of
phenylketonuria if during the childhood; a very strict diet is set up. In that case, the
symptoms of this disease won’t appear, but following accurate amount and
forbidden food like meat, fish or cereal is compulsory in order to keep the rate of
phenylalanine in conformity. Following this strict diet after a screening can also
regulates the rate of phenylalanine and in this way, symptoms can be less important.
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In this way, it is possible to avoid the symptoms of some genetic diseases or at
least reduce the seriousness of these symptoms. As far as multifunctional diseases,
people can have genetic predispositions but in the same way as phenylketonuria or
other genetic disorders, a specific lifestyle or another environment can prevent the
symptoms to happen. For example there is the Alzheimer’s disease, however
scientists are caring out extensive research to discover the kind of lifestyle that
influences it.
3. Therapy
The last way to avoid and cure a genetic disorder is of course the therapy.
Today, therapy becomes very important in the medical world because, thanks to the
medical progress, we have discovered new ways to treat disorders formerly
incurable. We call this experimental therapy, the gene therapy because the genetic
disorder is treated with genes only. This therapy has been used for a long time, in
fact in 1989, there was the first successful DNA transfer in the human body and year
later it was used by another scientist for a therapeutic use. At the moment we can
count three different approaches to use this therapy still experimental.
The first way is to deactivate the mutated gene. It’s called the gene silencing
and it’s not an easy approach. This therapy is used to fix genes in the human DNA
when there is a mutation. To avoid the serious consequences produced by a
mutation, this gene silencing’s goal is to prevent the transcription thanks to a “triple-
helix-forming oligonucleotide “. We know that the DNA molecule is a double helix
but when a gene is mutated, we use an oligonucleotide, which is a short DNA
molecule, to form a triple-helix and then block the transcription of the mutated
gene.
The second way is similar as the first one because it is also a gene silencing
therapy. Contrary to the first way to deactivate the mutated gene, a new DNA strand
is not added, it’s a ribozyme, which is an RNA molecule, and also an enzyme presents
in the ribosome during the translation. This time, the translation will be prevented.
After the transcription, the mutated strand has become a mutated mRNA but the
ribozyme has specific role : it will get attached to the mutated mRNA and will
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destroy it. Since there is no more mRNA, the translation cannot happen. Moreover
there is no more mutation.
The last approach is to modify the individual’s immune cells to give them another
role, which is, according to theNational Center for Research Resources: “(that) When
returned to the patient, these modified cells will find and destroy any cells that carry
the antigen.”
Today the gene therapy is getting more popular and successes are frequent
especially for blood disorders, hereditary diseases, hemophilia ect… Maybe
someday, it will even be possible to heal any genetic disorders
Conclusion
By way of conclusion, the genetic disease’s expression can be avoided thanks
to a lot of mechanisms in the cell or in the organism level. In the nucleus, repairs
systems prevent mutations, while epigenetic and splicing may avoid them to
express. Likewise, in the cytoplasm, the genetic code’s repetition can avoid a change
of amino acid. Moreover, the same behavior between two amino acids can reduce
the consequences. And a healthy way of living, a good environment and sometimes
a therapy can reduce or stop the disease’s expression.
En ouverture nous allons parler d’un moyen, encore en train de se développer,
permettant d’éviter que les maladies génétiques graves, rares et héréditaires
netouchent un foetus lors de son développement dans l’utérus de la mère. En effet,
d’après le TIME de janvier 2003, des scientifiques américains ont mis au point une
techniquepour retirer le noyau de la cellule œuf de l'utérus puis l'introduire dans une
autre cellule œuf humain en prenant soin de ne pas laisser l’ADN mitochondrial, car
c’est cet ADN qui provoque les maladies du même nom/mitochondriale… D’après
des études, nous pouvons compter qu’un enfant sur 10,000 est atteint de ce genre de
maladie, qui se trouve incurable et peut engendrer des maladies neurologiques, des
malformations et bien d’autres maladies. Cette nouvelle technique et une avancée
primordiale pour le monde de la recherche mais également le monde de la
médecine.