Genomic imprinting refers to the differential expression of genes based on whether they are inherited from the mother or father. It is found only in placental mammals and involves around 20 identified genes related to fetal growth and brain development. Genomic imprinting is thought to have evolved due to conflict between maternal and paternal genes over the allocation of maternal resources during fetal development.
Genomic imprinting is an epigenetic process where genes are expressed differently based on their parental origin. Imprinted genes make up a small minority of genes and are often clustered together in the genome. They are regulated by DNA methylation and other epigenetic marks which are established in the germline and maintained throughout development. Imprinted genes play important roles in growth and development. The parent-of-origin specific expression of imprinted genes is thought to have evolved from parental conflicts over resource allocation during fetal development.
Chromatin remodeling refers to dynamic changes in chromatin structure that occur in cells. There are several classes of chromatin remodeling complexes that use ATP hydrolysis to alter nucleosome positioning in different ways: 1) Nucleosome sliding, 2) Ejection of histone dimers or octamers, and 3) Replacement of core histones with histone variants. Disorders can result if chromatin remodeling is disrupted. Techniques like chromatin immunoprecipitation sequencing are used to study chromatin structure.
Genetic mapping involves determining the location of genes and DNA markers on chromosomes. There are different types of mapping including genetic mapping which looks at linkage and inheritance, physical mapping which determines exact positions, and comparative mapping between species. Key techniques include linkage analysis using crosses and pedigrees, radiation hybrid mapping, restriction mapping, and somatic cell hybrid mapping. The goal is to construct genetic linkage maps that order markers based on recombination frequency to identify the location of genes.
1. Chromatin remodeling is the process by which chromatin structure is dynamically modified to allow access of DNA for processes like transcription.
2. There are two main types of chromatin remodeling - covalent histone modification and ATP-dependent chromatin remodeling complexes.
3. ATP-dependent complexes use energy from ATP hydrolysis to move, eject, or restructure nucleosomes, allowing access to DNA.
4. Examples of chromatin remodeling complexes include SWI/SNF, ISWI, CHD, and INO80 families, which have different activities like nucleosome sliding or histone variant exchange.
The document summarizes Drosophila development and genetics. It discusses Drosophila's life cycle, egg polarity genes that establish the dorsal-ventral and anterior-posterior axes, segmentation genes that determine body segments, and homeotic genes that specify segment identity. It also mentions genetic mutations in Drosophila that are named after their phenotypes, such as brown eye color (bw) and vestigial wings (vg). Drosophila has been a useful model organism for genetic analysis due to its short life cycle, large progeny numbers, and techniques like balancer chromosomes that help preserve gene linkages.
This document discusses mitochondrial inheritance in humans. It begins by describing mitochondria and their role in cellular respiration and ATP synthesis. Mitochondrial DNA is circular and encodes for proteins, tRNAs and rRNAs. Mutations can occur in mtDNA and be heteroplasmic. Mitochondrial disorders are maternally inherited and can result from mutations in mtDNA or nuclear DNA. Common syndromes include MELAS, MERRF and LHON. Diagnosis involves family history, clinical evaluation, biochemical testing, muscle biopsy and genetic testing. Treatment focuses on symptom management and supplementation. Mitochondrial defects can impact female and male fertility by reducing ATP production necessary for processes like oocyte maturation and sperm motility. New therapies involving
Both in prokaryotes and eukaryotes, newly synthesized proteins must be delivered to their correct subcellular locations. Secretory proteins have an N-terminal signal peptide that targets them to the endoplasmic reticulum, where they are translocated and modified. Transport vesicles then carry proteins from the ER to the Golgi complex for further modification. From the Golgi, vesicles transport proteins either to other organelles or fuse with the plasma membrane to release proteins outside the cell. Correct protein targeting and trafficking is essential for cellular function.
Segmentation in Drosophila melanogaster Shreya Ahuja
All human beings, no matter how different we look, have a certain basic body plan established in us (for instance, all of us have our heads are placed right above our shoulders with arms stretching out from either side). Drosophila is no exception. This presentation talks about establishment of the body plan in Drosophila, how and when the different Segmentation Genes are expressed in Drosophila to give rise to its segmented body pattern.
Genomic imprinting is an epigenetic process where genes are expressed differently based on their parental origin. Imprinted genes make up a small minority of genes and are often clustered together in the genome. They are regulated by DNA methylation and other epigenetic marks which are established in the germline and maintained throughout development. Imprinted genes play important roles in growth and development. The parent-of-origin specific expression of imprinted genes is thought to have evolved from parental conflicts over resource allocation during fetal development.
Chromatin remodeling refers to dynamic changes in chromatin structure that occur in cells. There are several classes of chromatin remodeling complexes that use ATP hydrolysis to alter nucleosome positioning in different ways: 1) Nucleosome sliding, 2) Ejection of histone dimers or octamers, and 3) Replacement of core histones with histone variants. Disorders can result if chromatin remodeling is disrupted. Techniques like chromatin immunoprecipitation sequencing are used to study chromatin structure.
Genetic mapping involves determining the location of genes and DNA markers on chromosomes. There are different types of mapping including genetic mapping which looks at linkage and inheritance, physical mapping which determines exact positions, and comparative mapping between species. Key techniques include linkage analysis using crosses and pedigrees, radiation hybrid mapping, restriction mapping, and somatic cell hybrid mapping. The goal is to construct genetic linkage maps that order markers based on recombination frequency to identify the location of genes.
1. Chromatin remodeling is the process by which chromatin structure is dynamically modified to allow access of DNA for processes like transcription.
2. There are two main types of chromatin remodeling - covalent histone modification and ATP-dependent chromatin remodeling complexes.
3. ATP-dependent complexes use energy from ATP hydrolysis to move, eject, or restructure nucleosomes, allowing access to DNA.
4. Examples of chromatin remodeling complexes include SWI/SNF, ISWI, CHD, and INO80 families, which have different activities like nucleosome sliding or histone variant exchange.
The document summarizes Drosophila development and genetics. It discusses Drosophila's life cycle, egg polarity genes that establish the dorsal-ventral and anterior-posterior axes, segmentation genes that determine body segments, and homeotic genes that specify segment identity. It also mentions genetic mutations in Drosophila that are named after their phenotypes, such as brown eye color (bw) and vestigial wings (vg). Drosophila has been a useful model organism for genetic analysis due to its short life cycle, large progeny numbers, and techniques like balancer chromosomes that help preserve gene linkages.
This document discusses mitochondrial inheritance in humans. It begins by describing mitochondria and their role in cellular respiration and ATP synthesis. Mitochondrial DNA is circular and encodes for proteins, tRNAs and rRNAs. Mutations can occur in mtDNA and be heteroplasmic. Mitochondrial disorders are maternally inherited and can result from mutations in mtDNA or nuclear DNA. Common syndromes include MELAS, MERRF and LHON. Diagnosis involves family history, clinical evaluation, biochemical testing, muscle biopsy and genetic testing. Treatment focuses on symptom management and supplementation. Mitochondrial defects can impact female and male fertility by reducing ATP production necessary for processes like oocyte maturation and sperm motility. New therapies involving
Both in prokaryotes and eukaryotes, newly synthesized proteins must be delivered to their correct subcellular locations. Secretory proteins have an N-terminal signal peptide that targets them to the endoplasmic reticulum, where they are translocated and modified. Transport vesicles then carry proteins from the ER to the Golgi complex for further modification. From the Golgi, vesicles transport proteins either to other organelles or fuse with the plasma membrane to release proteins outside the cell. Correct protein targeting and trafficking is essential for cellular function.
Segmentation in Drosophila melanogaster Shreya Ahuja
All human beings, no matter how different we look, have a certain basic body plan established in us (for instance, all of us have our heads are placed right above our shoulders with arms stretching out from either side). Drosophila is no exception. This presentation talks about establishment of the body plan in Drosophila, how and when the different Segmentation Genes are expressed in Drosophila to give rise to its segmented body pattern.
This document discusses quantitative genetics and the concepts of phenotypic value, genotypic value, environmental deviation, and population mean. It explains that quantitative traits are controlled by multiple genes and their inheritance is called quantitative or polygenic inheritance. The phenotypic value of an individual is determined by the sum of their genotypic value and environmental deviation. The population mean genotypic value, which is equal to the population mean phenotypic value if environmental deviations average to zero, can be calculated based on allele frequencies at loci and their additive and dominance effects.
RECOMBINATION MOLECULAR BIOLOGY PPT UPDATED new.pptxSabahat Ali
This ppt is about recombination and where it occurs. Types of recombination and models of recombination along with many factors in prokaryotic and eukaryotic recombination
This document discusses key concepts in population genetics, including defining a population as a group of the same species living in a specific area. It provides an example of studying the genetics of a population of racers lizards, looking at the frequency of dominant and recessive alleles for stripe color. The values for p (frequency of dominant allele) and q (frequency of recessive allele) are calculated based on observing 110 lizards with the dominant white stripe allele out of 200 total alleles observed. This yields values of p=0.55 and q=0.45 for this population.
The major histocompatibility complex (MHC) plays a key role in the immune system by presenting antigens and distinguishing self from non-self. It is located on chromosome 6 in humans and contains genes like HLA that determine disease susceptibility. MHC molecules come in two classes: class I present intracellular peptides and class II present extracellular peptides. Variants in MHC genes can increase risk for certain diseases, like a variant in HLA-DQ increasing susceptibility to type 1 diabetes. Loss of MHC diversity in some populations like cheetahs can also lead to increased disease emergence due to a less broad range of antigens recognized.
Translation is the process by which the genetic code in mRNA is used to direct the synthesis of proteins. It involves three main steps - initiation, elongation, and termination. Initiation requires the small and large ribosomal subunits to assemble around an mRNA molecule along with initiator tRNA and other initiation factors. Elongation then adds amino acids one by one to the growing polypeptide chain according to the mRNA codons. Termination occurs when a stop codon is reached, causing the ribosome to dissociate and release the complete protein.
This document discusses genotype-environment interaction. It begins by defining genotype-environment interaction as different genotypes responding differently to environmental variation. It then covers the history of debates around this topic. It explains that phenotype results from both genotype and environment. Several epidemiological models of genotype-environment interaction are presented. The document discusses methods of analyzing interaction, including twin and adoption studies as well as molecular analyses. It addresses modeling interaction statistically and provides some examples, like skin cancer risk with sun exposure. The significance of understanding genotype-environment interaction is explained, like improving disease prevention.
Introduction to Real Time PCR (Q-PCR/qPCR/qrt-PCR): qPCR Technology Webinar S...QIAGEN
This slidedeck introduces the concepts of real-time PCR and how to conduct a real-time PCR assay. The topics that are covered include an overview of real-time PCR chemistries, protocols, quantification methods, real-time PCR applications and factors for success.
Knockout mice are genetically engineered mice where one or more genes have been inactivated through gene knockout. They are important animal models for studying the role of genes with unknown functions. By causing a specific gene to be inactive in mice and observing differences in behavior or health, researchers can infer the probable function of that gene. Transgenic mice have foreign or modified genes added, which are then integrated randomly into the mouse genome, allowing the study of these additional genes. Both knockout and transgenic mice are useful models for studying human genetic diseases.
hox genes and its role in development both in human and drosophila . homeotic genes. homeobox genes. developmental biology. different types of homeotic genes in drosophila and human. deficiencydiseases due to lack of hox genes in human
1. Genetic linkage maps show the relative locations of DNA markers along chromosomes, while physical maps show the exact positions of genes and sequences.
2. Major methods for genetic mapping are RFLPs, microsatellites, and SNPs, while physical mapping uses restriction fingerprinting, chromosome walking, STS mapping, and FISH.
3. Gene mapping is useful for locating gene positions, estimating genetic risk, and has aided in fully sequencing genomes like yeast, worms, flies, mice, and humans.
Population genetics focuses on the frequencies and distribution of genes in populations. It combines Darwin's theory of evolution with Mendelian genetics and molecular biology. There are several forces that can change allelic and genotypic frequencies in a population over time, including mutation, natural selection, migration between populations, and genetic drift. Hardy-Weinberg equilibrium describes the relationship between gene and genotypic frequencies in a population, where the frequencies will remain constant from generation to generation if these evolutionary forces are not present.
The document discusses how DNA is packed into eukaryotic chromosomes. DNA first wraps around histone proteins to form nucleosomes, compacting the DNA 7-fold. Nucleosomes then interact to form a 30nm fiber compacting the DNA another 7-fold. Additional compaction occurs through interactions between the 30nm fiber and the nuclear matrix, forming radial loop domains that attach to the nuclear lamina and internal matrix, further condensing the DNA. This hierarchical packaging allows the long eukaryotic chromosomes to fit within the nucleus.
This document provides an overview of transposable elements (TEs). It discusses that TEs are DNA sequences that can move within genomes. There are two major classes of TEs - retrotransposons which move via an RNA intermediate, and DNA transposons which move directly through a cut-and-paste or copy-and-paste mechanism. The document outlines different types of TEs found in bacteria, eukaryotes, and the human genome. It also discusses the impact of TEs in causing mutations and their applications in genetic engineering and mutagenesis experiments.
The document summarizes early development in Drosophila, including embryogenesis, fate determination, and patterning. It discusses how Drosophila undergo holometabolous development through distinct larva, pupa, and adult stages. It then details the processes of fertilization, cleavage, gastrulation, and segmentation that establish the body plan. Key genes that pattern the anterior-posterior and dorsal-ventral axes are also summarized, including maternal effect genes, gap genes, pair-rule genes, segment polarity genes, and homeotic genes.
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
Transposons are segments of DNA that can change position within a genome, causing mutations. There are two types: DNA transposons, which move directly between positions, and retrotransposons, which are transcribed to RNA and then reverse transcribed to DNA before inserting elsewhere. Transposons move via either a "cut and paste" mechanism or a "copy and paste" mechanism. They have been useful research tools for mutagenesis and studying gene expression, but can also cause genetic diseases.
This document discusses quantitative genetics and the concepts of phenotypic value, genotypic value, environmental deviation, and population mean. It explains that quantitative traits are controlled by multiple genes and their inheritance is called quantitative or polygenic inheritance. The phenotypic value of an individual is determined by the sum of their genotypic value and environmental deviation. The population mean genotypic value, which is equal to the population mean phenotypic value if environmental deviations average to zero, can be calculated based on allele frequencies at loci and their additive and dominance effects.
RECOMBINATION MOLECULAR BIOLOGY PPT UPDATED new.pptxSabahat Ali
This ppt is about recombination and where it occurs. Types of recombination and models of recombination along with many factors in prokaryotic and eukaryotic recombination
This document discusses key concepts in population genetics, including defining a population as a group of the same species living in a specific area. It provides an example of studying the genetics of a population of racers lizards, looking at the frequency of dominant and recessive alleles for stripe color. The values for p (frequency of dominant allele) and q (frequency of recessive allele) are calculated based on observing 110 lizards with the dominant white stripe allele out of 200 total alleles observed. This yields values of p=0.55 and q=0.45 for this population.
The major histocompatibility complex (MHC) plays a key role in the immune system by presenting antigens and distinguishing self from non-self. It is located on chromosome 6 in humans and contains genes like HLA that determine disease susceptibility. MHC molecules come in two classes: class I present intracellular peptides and class II present extracellular peptides. Variants in MHC genes can increase risk for certain diseases, like a variant in HLA-DQ increasing susceptibility to type 1 diabetes. Loss of MHC diversity in some populations like cheetahs can also lead to increased disease emergence due to a less broad range of antigens recognized.
Translation is the process by which the genetic code in mRNA is used to direct the synthesis of proteins. It involves three main steps - initiation, elongation, and termination. Initiation requires the small and large ribosomal subunits to assemble around an mRNA molecule along with initiator tRNA and other initiation factors. Elongation then adds amino acids one by one to the growing polypeptide chain according to the mRNA codons. Termination occurs when a stop codon is reached, causing the ribosome to dissociate and release the complete protein.
This document discusses genotype-environment interaction. It begins by defining genotype-environment interaction as different genotypes responding differently to environmental variation. It then covers the history of debates around this topic. It explains that phenotype results from both genotype and environment. Several epidemiological models of genotype-environment interaction are presented. The document discusses methods of analyzing interaction, including twin and adoption studies as well as molecular analyses. It addresses modeling interaction statistically and provides some examples, like skin cancer risk with sun exposure. The significance of understanding genotype-environment interaction is explained, like improving disease prevention.
Introduction to Real Time PCR (Q-PCR/qPCR/qrt-PCR): qPCR Technology Webinar S...QIAGEN
This slidedeck introduces the concepts of real-time PCR and how to conduct a real-time PCR assay. The topics that are covered include an overview of real-time PCR chemistries, protocols, quantification methods, real-time PCR applications and factors for success.
Knockout mice are genetically engineered mice where one or more genes have been inactivated through gene knockout. They are important animal models for studying the role of genes with unknown functions. By causing a specific gene to be inactive in mice and observing differences in behavior or health, researchers can infer the probable function of that gene. Transgenic mice have foreign or modified genes added, which are then integrated randomly into the mouse genome, allowing the study of these additional genes. Both knockout and transgenic mice are useful models for studying human genetic diseases.
hox genes and its role in development both in human and drosophila . homeotic genes. homeobox genes. developmental biology. different types of homeotic genes in drosophila and human. deficiencydiseases due to lack of hox genes in human
1. Genetic linkage maps show the relative locations of DNA markers along chromosomes, while physical maps show the exact positions of genes and sequences.
2. Major methods for genetic mapping are RFLPs, microsatellites, and SNPs, while physical mapping uses restriction fingerprinting, chromosome walking, STS mapping, and FISH.
3. Gene mapping is useful for locating gene positions, estimating genetic risk, and has aided in fully sequencing genomes like yeast, worms, flies, mice, and humans.
Population genetics focuses on the frequencies and distribution of genes in populations. It combines Darwin's theory of evolution with Mendelian genetics and molecular biology. There are several forces that can change allelic and genotypic frequencies in a population over time, including mutation, natural selection, migration between populations, and genetic drift. Hardy-Weinberg equilibrium describes the relationship between gene and genotypic frequencies in a population, where the frequencies will remain constant from generation to generation if these evolutionary forces are not present.
The document discusses how DNA is packed into eukaryotic chromosomes. DNA first wraps around histone proteins to form nucleosomes, compacting the DNA 7-fold. Nucleosomes then interact to form a 30nm fiber compacting the DNA another 7-fold. Additional compaction occurs through interactions between the 30nm fiber and the nuclear matrix, forming radial loop domains that attach to the nuclear lamina and internal matrix, further condensing the DNA. This hierarchical packaging allows the long eukaryotic chromosomes to fit within the nucleus.
This document provides an overview of transposable elements (TEs). It discusses that TEs are DNA sequences that can move within genomes. There are two major classes of TEs - retrotransposons which move via an RNA intermediate, and DNA transposons which move directly through a cut-and-paste or copy-and-paste mechanism. The document outlines different types of TEs found in bacteria, eukaryotes, and the human genome. It also discusses the impact of TEs in causing mutations and their applications in genetic engineering and mutagenesis experiments.
The document summarizes early development in Drosophila, including embryogenesis, fate determination, and patterning. It discusses how Drosophila undergo holometabolous development through distinct larva, pupa, and adult stages. It then details the processes of fertilization, cleavage, gastrulation, and segmentation that establish the body plan. Key genes that pattern the anterior-posterior and dorsal-ventral axes are also summarized, including maternal effect genes, gap genes, pair-rule genes, segment polarity genes, and homeotic genes.
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
Transposons are segments of DNA that can change position within a genome, causing mutations. There are two types: DNA transposons, which move directly between positions, and retrotransposons, which are transcribed to RNA and then reverse transcribed to DNA before inserting elsewhere. Transposons move via either a "cut and paste" mechanism or a "copy and paste" mechanism. They have been useful research tools for mutagenesis and studying gene expression, but can also cause genetic diseases.
Non mendelian inheritance / cytoplasmic inheritance / Extranuclear InheritanceMahammed Faizan
Inheritance of traits from parents to off springs from cytoplasmic organelle genetic material is known as extra nuclear inheritance.
it is mainly responsible due to DNA present in cytoplasmic organelle.
total genes present in cytoplasm is know as as plasmon.
Mouse zar1 like (xm 359149) colocalizes with m-rna processing components and ...wujunbo1015
1. The study identified a mouse gene, Zar1l, that encodes a ZAR1-like protein called ZAR1L. 2. ZAR1L is predominantly expressed in oocytes and zygotes. When ectopically expressed, ZAR1L localizes to cytoplasmic foci in late two-cell stage embryos. 3. Expression of a dominant-negative ZAR1L C-terminal mutant induced two-cell stage embryonic arrest, accompanied by abnormal epigenetic modifications and downregulation of chromatin factors.
This document discusses inheritance and provides examples of cytoplasmic inheritance. It describes Mendelian inheritance where genes located on chromosomes segregate in predictable ratios. Non-Mendelian inheritance involves genes located in the cytoplasm that are transmitted from the female parent only, with no segregation in F2 generations. Examples discussed include chloroplast inheritance in Mirabilis jalapa, kappa particles determining toxicity in Paramoecium, and shell coiling determined by cytoplasmic proteins in snails. Cytoplasmic male sterility is also summarized, where mitochondrial mutations cause pollen to be non-functional but are maternally inherited.
This document discusses Mendelian and non-Mendelian inheritance. It provides examples of cytoplasmic inheritance including the inheritance of chloroplast genes in Mirabilis jalapa, where the phenotype is determined by the genotype of the female parent through cytoplasmic/plastid transmission, not the genes in the nucleus. It also discusses inheritance involving cytoplasmic particles like kappa particles in Paramecium, which are transmitted maternally but whose production is controlled by nuclear genes. The key differences between Mendelian and non-Mendelian inheritance are summarized in a table.
Molecular tools in reproductive research document discusses:
1. Molecular tools like genomics, proteomics, and RNA interference can provide insights into the underlying mechanisms of fertility and infertility.
2. These tools allow understanding of genetic variation and provide methods to enhance fertility and improve diagnosis of fertility disorders.
3. The document discusses applications of genetic markers, genomics, proteomics, and RNA interference in studying reproductive processes in male and female animals as well as embryonic development.
1. The document discusses various examples of extra-chromosomal or cytoplasmic inheritance, including chloroplast mutations in four o'clock plants causing leaf variegation, mitochondrial mutations in yeast, and maternal effects on shell coiling in snails.
2. It also describes infective heredity through kappa particles transmitted cytoplasmically in Paramecium. The kappa particles can kill sensitive Paramecium strains and are transmitted from parent to offspring depending on nuclear genes.
3. Cytoplasmic inheritance involves transmission of hereditary material like genes located in organelles like chloroplasts and mitochondria, rather than in the cell nucleus, and can be purely maternal.
The document summarizes research identifying genes required for cytoplasmic localization in early C. elegans embryos. Key findings include:
1) Mutations in maternal effect genes disrupted cytoplasmic localization, leading to defects like equal first cleavage, altered second cleavages, abnormal P granule localization, abnormal cell differentiation, and sterility.
2) Genes identified included par-1, par-2, par-3, and par-4. Mutations caused mispositioning of spindles, altered cleavage timing, and improper P granule localization.
3) The par genes appear to function in a common process governing cleavage patterning, intestinal differentiation, and P granule localization, and their mutation
Epigenetics and genomic imprinting mustHussein Sabit
This document discusses epigenetics and its role in cancer. It begins by defining epigenetics as changes in gene expression that do not involve changes to the DNA sequence. These epigenetic changes can be influenced by environmental factors and can be passed down to daughter cells or offspring. The document then covers various epigenetic mechanisms including DNA methylation and histone modifications, and how they regulate gene expression and cellular differentiation. It discusses examples of how epigenetics contributes to normal development and diseases like cancer. The summary concludes that epigenetics demonstrates that DNA is not solely responsible for our fate, and that environmental influences can also impact our genes.
GENOMIC IMPRINTING ;the process by which only one copy ofnandanasanthosh1601
Genomic imprinting is a process where genes are expressed differently depending on whether they are inherited from the mother or the father. A key example is the Igf2 gene in mice and humans, which is only expressed when inherited paternally. This leads to conflicting interests between maternal and paternal genes regarding resource allocation to offspring. Genomic imprinting is regulated by epigenetic mechanisms like DNA methylation and histone modifications. Imprinting control regions establish parent-specific methylation patterns and control imprinted gene clusters. Diseases like Angelman and Beckwith-Wiedemann syndromes result from dysregulation of imprinted genes. The size differences between ligers and tigons are also due to parental genomic imprinting
A RESEARCH ON GENOMIC IMPRINTINGGenomic imprinting is the epig.docxransayo
A RESEARCH ON GENOMIC IMPRINTING
Genomic imprinting is the epigenetic phenomenon mostly occurring in gametogenesis. It has independently evolved in flowering plants and mammals. In both organisms, imprinting occurs in the embryo-nourishing tissues; the endosperm and the placenta respectively. Imprinting genes regulate the transfer of nutrients to developing progeny (Beery & Workman, 2011).The genomic imprinting usually occurs when both the maternal and the paternal alleles are present but one allele expresses itself while the other remains inactive ( Engel, N. 2015). Gene imprinting is believed to be important in regulation of growth in embryo and neonate
Experiments on androgenotes and gynogenotes , which are produced by nuclear transplantation, are used to create basis of genomic imprinting. The zygotes from androgenotes and gynogenotes were formed but neither type could undergo more development. From this situation, it is possible to suggest that the maternal and paternal effects are complimentary(Morgan, Li, & O’Neill, 2009). Each genome contains different viable and necessary properties. Another evidence that genomic imprinting has a major role in growth and development comes from a research by Li et al(1993).
Optimal method for gene imprinting is DNA methylation, which is carried out with enzyme DNA methyltransferase in mammals. DNA MTase acts on the DNA sequence 5’-6pG-3’. Primarily higher eukaryotes have CpG islands in their genomes. The islands are hardly methylated in the animal cells, this could be due to the bound transcription factors that block DNA MTase. Those sequences which are methylated are normally not active. Some research also show that methylated sequences can be active (Madek, 1974).
The importance of DNA methylation was demonstrated in the study of mammalian development(Li et al, 1993). They postulated that if mutation was introduced to the DNA MTase gene in embryonic stem cell of a mice, methylation of CpG would be abnormal and the gene expression would be affected (“DNA methylation and demethylation dynamics,” 2015). Gene mutation of DNA MTase was caused by homologous recombination and Southern blot analysis affirmed this (Wilkins, 2010). The genes used were insulin-like growth factors; H19, lgf2 and lgf2 receptor; lgf2r.
Normally H19 gene, whih is a maternal allele, is expressed while the paternal allele is inactive. Inactive paternal allele is methylated but the maternal allele is not; this should be noted carefully. RNase and Northern blot analysis essays procedures demonstrated the effects of decreased levels of DNA methylation on mutant mice. It was brought to light that typical DNA methylation is a requirement to keep for the paternal allele inactive for the H19 gene (Mightiness of science, 2016)
The lgf2 is opposite of the H19 gene in that it is expressed only in a methylated paternal allele. As a result, it is expressed in mice having deficient MTase activity. It is expected that the lgf2 gene wil.
Genic or genetic male sterility
- B- line (maintainer line which is male fertile Ms)
- The F1 hybrid obtained from the cross between A and B line
will be male fertile.
Genic or genetic male sterility
Genomic imprinting is an epigenetic phenomenon where genes are differentially expressed based on whether they are inherited from the father or mother. It results in the silencing of one parental allele. Imprinting occurs through DNA methylation and histone modifications and is regulated by imprinting control regions. Disruptions to imprinting through uniparental disomy can cause Prader-Willi syndrome, Angelman syndrome, Beckwith-Wiedemann syndrome and cancer. Imprinting is found primarily in mammals and is thought to have evolved from parent-offspring conflict over resource allocation during development.
Drosophila Melanogaster Genome And its developmental processSubhradeep sarkar
The document summarizes key aspects of the Drosophila genome and life cycle. It notes that Drosophila has advantages for genetic studies like a short life cycle and small genome. Its genome contains around 13,600 genes located on four chromosomes. The life cycle involves an egg, larva, pupa and adult stages. Segmentation and homeotic genes play important roles in development by dividing the body into segments and specifying segment identities. Maternal effect, gap, pair-rule and segment polarity genes control segmentation in a hierarchical manner. Homeotic complexes like bithorax determine body part identities in each segment.
This presentation on Epigenetics is most advanced and evidence based one. Its Very helpful for Genetics students and research fellows, Reproductive Medicine specialist, Reproductive Biologist, Infertility practitioners
Prader Willi syndrome and Genetics and differentialsebinroshan07
This document discusses Prader-Willi syndrome (PWS), including its history, genetics, causes, diagnostic features, genetic testing, and recurrence risk. PWS is caused by the loss of expression of paternal genes in the 15q11-q13 region, which can occur due to deletions, uniparental disomy, or imprinting defects. Key diagnostic features include hypotonia, developmental delay, hypogonadism, hyperphagia leading to obesity, and a characteristic facial gestalt. Genetic testing methods like methylation studies, FISH, CMA, and sequencing can help determine the specific genetic cause. The recurrence risk is usually low but increases to 50% for familial imprinting center defects
Gregor Mendel conducted experiments with pea plants between 1856-1863. He found that when he cross-pollinated pea plants with distinct traits, the offspring displayed only one of the parental traits, and this trait was passed down predictably in future generations. His experiments demonstrated that traits are passed from parents to offspring through discrete units of inheritance, now known as genes, and established the fundamental principles of genetics including dominance, segregation of alleles, and independent assortment. Mendel's work formed the foundation of classical genetics.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Microbial interaction
Microorganisms interacts with each other and can be physically associated with another organisms in a variety of ways.
One organism can be located on the surface of another organism as an ectobiont or located within another organism as endobiont.
Microbial interaction may be positive such as mutualism, proto-cooperation, commensalism or may be negative such as parasitism, predation or competition
Types of microbial interaction
Positive interaction: mutualism, proto-cooperation, commensalism
Negative interaction: Ammensalism (antagonism), parasitism, predation, competition
I. Mutualism:
It is defined as the relationship in which each organism in interaction gets benefits from association. It is an obligatory relationship in which mutualist and host are metabolically dependent on each other.
Mutualistic relationship is very specific where one member of association cannot be replaced by another species.
Mutualism require close physical contact between interacting organisms.
Relationship of mutualism allows organisms to exist in habitat that could not occupied by either species alone.
Mutualistic relationship between organisms allows them to act as a single organism.
Examples of mutualism:
i. Lichens:
Lichens are excellent example of mutualism.
They are the association of specific fungi and certain genus of algae. In lichen, fungal partner is called mycobiont and algal partner is called
II. Syntrophism:
It is an association in which the growth of one organism either depends on or improved by the substrate provided by another organism.
In syntrophism both organism in association gets benefits.
Compound A
Utilized by population 1
Compound B
Utilized by population 2
Compound C
utilized by both Population 1+2
Products
In this theoretical example of syntrophism, population 1 is able to utilize and metabolize compound A, forming compound B but cannot metabolize beyond compound B without co-operation of population 2. Population 2is unable to utilize compound A but it can metabolize compound B forming compound C. Then both population 1 and 2 are able to carry out metabolic reaction which leads to formation of end product that neither population could produce alone.
Examples of syntrophism:
i. Methanogenic ecosystem in sludge digester
Methane produced by methanogenic bacteria depends upon interspecies hydrogen transfer by other fermentative bacteria.
Anaerobic fermentative bacteria generate CO2 and H2 utilizing carbohydrates which is then utilized by methanogenic bacteria (Methanobacter) to produce methane.
ii. Lactobacillus arobinosus and Enterococcus faecalis:
In the minimal media, Lactobacillus arobinosus and Enterococcus faecalis are able to grow together but not alone.
The synergistic relationship between E. faecalis and L. arobinosus occurs in which E. faecalis require folic acid
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills MN
By harnessing the power of High Flux Vacuum Membrane Distillation, Travis Hills from MN envisions a future where clean and safe drinking water is accessible to all, regardless of geographical location or economic status.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
The cost of acquiring information by natural selectionCarl Bergstrom
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
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.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
The debris of the ‘last major merger’ is dynamically young
Imprinting.ppt
1. Genomic Imprinting
•Definition- Differential expression of
two parental alleles
• Only occurs in eutherians (placental,
nonmarsupial) mammals
• Not in other vertebrates
•Of 20-some identified genes, most are
involved in
1. Fetal growth
• Igf2, IgF2r, H19, Grb1
2. Brain development
• Prader-Willi syndrome (PS), Angelman syndromes (AS),
Peg1/Mest
2.
3.
4.
5.
6. Genomic-imprinting conflict
What is genomic imprinting and why has it evolved?
Expression of a gene depending on whether inherited
from father or mother
Main arenas of imprinting effects on human health:
-Placenta
-Brain
-Carcinogenesis
-Stem cells
-In vitro fertilization
from dad from mom
7. • In experiments on mice
maternal and
paternal
pronuclei
normal mouse
both
paternal
pronuclei
The placenta is
huge, the embryo
is undeveloped
both
matern
al
pronucl
ei
The embryo is
formed, the placenta
is underdeveloped
9. CONFLICT THEORY OF IMPRINTING
-> abundant support from empirical studies of imprinted
genes and growth, in mice and humans
(1) IGF2-IGF2R (Haig & Graham 1991 Cell)
(2) CDKN1C (Andrews et al. 2007 BMC Dev Biol)
(3) GRB10 (Charalambous et al. 2003 PNAS)
Beckwith-
Wiedemann
Syndrome
Silver-
Russell
syndrome
Mighty mouse
Normal sized
human
2 doses IGF2
1 dose IGF2
0 doses IGF2
10. Genomic imprinting
the unequal expression of the maternal and paternal alleles of a gene
XX
X
Y
Maternal allele
Patternal allele
Patternal
allele
Matternal
allele
11. • Two major clusters of imprinted genes have been identified in
humans, one on the short (p) arm of chromosome 11 (at
position 11p15) and another on the long (q) arm of chromosome
15 (in the region 15q11 to 15q13).
20. Paternally expressed imprinted genes that function as growth
promoters (i.e., Igf2, Peg1, Peg3, Rasgrf1, Dlk1) and show
growth retardation in embryos deficient for the gene. There
are also maternally expressed imprinted genes that function
as growth repressors (i.e., Igf2r, Gnas, Cdkn1c, H19, Grb10),
as shown by a growth enhancement in embryos deficient for
the gene.
21. Categories of imprinted genes
1. Fetal growth genes- Insulin-like growth
factor-like II (IGF2) response pathway
• IGF2
• Igf2r
• Grb10
• H19
• Gnas
• Rasgrf
• Mash2
• Why?- Embryo develops in a parasite-like
relationship with mother.
23. Prader-Willi Syndrome
• 1 in 15,000 live births
• mostly sporatic
• deletion at 15 q11-q13
• diagnosis at 2 years
• compulsive overeaters
24. A typical Prader-Willi patient
Prader Willi Syndrome- Due to
paternal chromosome deletion
25. • 1 in 25,000 live births
• mostly sporatic
• 80 % have deletion at 15q11-q13
• Specifically mutation of UBE3A gene
Angelman Syndrome
26. Angelman Syndrome
•Speech impairment
•None or minimal use of words
•Receptive and non-verbal communication skills higher than
verbal ones
•Movement or balance disorder, usually ataxia of gait
•Behavioral uniqueness: any combination of frequent
laughter/smiling; apparent happy demeanor
•easily excitable personality, often with hand flapping
movements; hypermotoric behavior; short attention span
28. Parent Offspring Conflict Hypothesis (Haig
hypothesis)
• Conflict between male and female over allocation
of maternal resources to offspring
• Dad uses imprinting to direct all resources to
immediate offspring (not future litters)
• Mom uses imprinting to allocate resources to
multiple litters
• Thus, predict paternally expressed genes would
promote growth, maternally expressed genes should
slow it down
• Prediction mostly hold true
• Example- Igf2 (paternally expressed)-if defective=40%
reduction in growth
29. Parent Offspring Conflict Hypothesis (Haig
hypothesis)
Example – The Igf2 gene and its receptor Igf2r
•Igf2 (paternally expressed)-if defective=40%
reduction in growth
•Igf2r (Igf2 receptor)- if defective=increase growth
•Igf2-/Igf2r- = normal
Another test- Ask if imprinting fails to occur in a monogomous
species
The Beach mouse is entirely monogomous
….but imprinting still occurs, contrary to model
31. How are imprinted genes silenced?
S. Tilghman, Cell 96:185
Dnmt-/- mice-
Many imprinted genes
(e.g. H19) reactivated
..but, Igf2 and Igf2r are
silenced
Mechanism- Methylation interferes with transcription factor binding
Problems with model-
1. Promoters of silent Igf2 and Igf2r alleles are unmethylated
2. One gene, Mash2, is unaffected by loss of methylation
32. How are imprinted genes silenced?
S. Tilghman, Cell 96:185
Mechanism-
Promoters compete
for a single
enhancer
Problem with model-
Both H19 and Igf2 are expressed if H19 gene replaced
with luciferase
Igf2 H19
33. How are imprinted genes silenced?
S. Tilghman, Cell 96:185
Epigenetic marker binds to
unmethylated DNA
Mechanism-
Methylation serves two
purposes
1. Inactivate a gene (e.g.
H19)
2. Prevent binding of
epigenetic marker so
that Igf2 is activated
Igf2 H19
Epigenetic insulator prevents enhancer from “talking to” Igf2
Evidence in support: if delete insulator element- both Igf2 and H19 expressed
34. Evidence for chromatin boundary mechanism
Deletion of ICR- both genes expressed
Identify protein (called CTCF) that binds ICR
CTCF cannot bind methylated DNA
Thorvaldsen and Bartolmei, Science 288:2145, 2000
35. How are imprinted genes silenced?
S. Tilghman, Cell 96:185
Mechanism- Antisense
transcription of
unmethylated
chromosome blocks
sense strand transcription
Mechanism- Antisense
RNA blocks sense strand
transcription