ORGANELLAR GENOME AND ORGANELLAR INHERITENCERanjan Kumar
This document summarizes organellar genomes and inheritance. It discusses the history of discovering DNA in chloroplasts and mitochondria in the 1960s. Key points:
- Chloroplast and mitochondrial DNA are found in plant and animal cells and are inherited separately from nuclear genes.
- Endosymbiotic theory proposes that chloroplasts and mitochondria originated from engulfed photosynthetic and aerobic bacteria, respectively.
- Organellar DNA replication and gene expression occur within the organelles. Uniparental, non-Mendelian inheritance is observed.
- Differences exist between organellar and nuclear DNA as well as between chloroplast and mitochondrial genomes.
This document provides information on organelle DNA, specifically mitochondrial DNA (mtDNA). It discusses the structure and function of mitochondria and cells. It describes how mtDNA is thought to originate from engulfed bacteria in early eukaryotic cells based on the endosymbiotic theory. MtDNA is maternally inherited, exists in high copy number, and lacks recombination. It has a higher mutation rate than nuclear DNA. MtDNA mutations can cause mitochondrial diseases if a tissue-specific threshold of mutations is reached.
The document discusses organellar genomes and their composition. It provides information on several key points:
1. Organellar genomes refer to the genetic material present in organelles like chloroplasts and mitochondria. These genomes are much smaller than nuclear genomes, ranging from 5-200 kb.
2. The organellar genomes mainly contain genes for components involved in respiration and photosynthesis, as well as RNAs and proteins for transcription and translation. DNA makes up a very small percentage, around 0.1%, of the total dry weight of organellar material.
3. Endosymbiotic theory explains the origins of organellar genomes from once free-living prokaryotes that became incorporated into eukaryotic
This document discusses different concepts of genes including:
1. Classical concepts viewed genes as units of heredity, transmission of characters, and mutation.
2. Molecular concepts define genes as the entire nucleic acid sequence required for protein synthesis, including coding and regulatory regions.
3. Genes have a fine structure and can be divided into functional units called cistrons based on complementation testing of mutants.
Chloroplasts are double-membrane organelles found in plant cells that contain chlorophyll and are the site of photosynthesis. Chloroplast DNA is circular and ranges in size from 120,000 to 170,000 base pairs. It contains approximately 120 genes, including genes that encode proteins involved in photosynthesis and the transcription and translation machinery. Chloroplast DNA replication is semi-conservative and there are typically multiple copies of the chloroplast genome within each chloroplast.
The document discusses the differences between prokaryotic and eukaryotic genomes. Prokaryotes generally have a single, circular chromosome while eukaryotes have multiple linear chromosomes within a membrane-bound nucleus. The human genome contains around 3 billion base pairs divided between nuclear and mitochondrial DNA. The nuclear genome encodes around 20,000-25,000 protein-coding genes and is inherited equally from both parents, while mitochondrial DNA is maternally inherited.
Dna content,c value paradox, euchromatin heterochromatin, banding patternArchanaSoni3
DNA content refers to the amount of DNA in an organism's haploid chromosomes. It varies greatly between organisms, with eukaryotes generally having more DNA than prokaryotes. The amount of DNA does not always correlate with an organism's complexity, known as the C-value paradox. This is because eukaryotic DNA contains large amounts of non-coding repetitive sequences. Chromatin exists in two forms - euchromatin, which is less condensed and permits gene expression, and heterochromatin, which is highly condensed and usually silences genes. Heterochromatin forms in specific regions like centromeres and telomeres and is important for chromosome function and stability.
Microbial genetics is a subject area within microbiology and genetic engineering. This involves the study of the genotype of microbial species and also the expression system in the form of phenotypes
ORGANELLAR GENOME AND ORGANELLAR INHERITENCERanjan Kumar
This document summarizes organellar genomes and inheritance. It discusses the history of discovering DNA in chloroplasts and mitochondria in the 1960s. Key points:
- Chloroplast and mitochondrial DNA are found in plant and animal cells and are inherited separately from nuclear genes.
- Endosymbiotic theory proposes that chloroplasts and mitochondria originated from engulfed photosynthetic and aerobic bacteria, respectively.
- Organellar DNA replication and gene expression occur within the organelles. Uniparental, non-Mendelian inheritance is observed.
- Differences exist between organellar and nuclear DNA as well as between chloroplast and mitochondrial genomes.
This document provides information on organelle DNA, specifically mitochondrial DNA (mtDNA). It discusses the structure and function of mitochondria and cells. It describes how mtDNA is thought to originate from engulfed bacteria in early eukaryotic cells based on the endosymbiotic theory. MtDNA is maternally inherited, exists in high copy number, and lacks recombination. It has a higher mutation rate than nuclear DNA. MtDNA mutations can cause mitochondrial diseases if a tissue-specific threshold of mutations is reached.
The document discusses organellar genomes and their composition. It provides information on several key points:
1. Organellar genomes refer to the genetic material present in organelles like chloroplasts and mitochondria. These genomes are much smaller than nuclear genomes, ranging from 5-200 kb.
2. The organellar genomes mainly contain genes for components involved in respiration and photosynthesis, as well as RNAs and proteins for transcription and translation. DNA makes up a very small percentage, around 0.1%, of the total dry weight of organellar material.
3. Endosymbiotic theory explains the origins of organellar genomes from once free-living prokaryotes that became incorporated into eukaryotic
This document discusses different concepts of genes including:
1. Classical concepts viewed genes as units of heredity, transmission of characters, and mutation.
2. Molecular concepts define genes as the entire nucleic acid sequence required for protein synthesis, including coding and regulatory regions.
3. Genes have a fine structure and can be divided into functional units called cistrons based on complementation testing of mutants.
Chloroplasts are double-membrane organelles found in plant cells that contain chlorophyll and are the site of photosynthesis. Chloroplast DNA is circular and ranges in size from 120,000 to 170,000 base pairs. It contains approximately 120 genes, including genes that encode proteins involved in photosynthesis and the transcription and translation machinery. Chloroplast DNA replication is semi-conservative and there are typically multiple copies of the chloroplast genome within each chloroplast.
The document discusses the differences between prokaryotic and eukaryotic genomes. Prokaryotes generally have a single, circular chromosome while eukaryotes have multiple linear chromosomes within a membrane-bound nucleus. The human genome contains around 3 billion base pairs divided between nuclear and mitochondrial DNA. The nuclear genome encodes around 20,000-25,000 protein-coding genes and is inherited equally from both parents, while mitochondrial DNA is maternally inherited.
Dna content,c value paradox, euchromatin heterochromatin, banding patternArchanaSoni3
DNA content refers to the amount of DNA in an organism's haploid chromosomes. It varies greatly between organisms, with eukaryotes generally having more DNA than prokaryotes. The amount of DNA does not always correlate with an organism's complexity, known as the C-value paradox. This is because eukaryotic DNA contains large amounts of non-coding repetitive sequences. Chromatin exists in two forms - euchromatin, which is less condensed and permits gene expression, and heterochromatin, which is highly condensed and usually silences genes. Heterochromatin forms in specific regions like centromeres and telomeres and is important for chromosome function and stability.
Microbial genetics is a subject area within microbiology and genetic engineering. This involves the study of the genotype of microbial species and also the expression system in the form of phenotypes
This document discusses the structure of genes in prokaryotes and eukaryotes. It defines a gene as a sequence of DNA that codes for a specific protein. Prokaryotic genes are continuous with three regions - a promoter, coding sequence, and terminator. Eukaryotic genes can be complex with introns and exons, promoters, and regulatory elements. Key differences are that prokaryotic genes lack introns while eukaryotic genes undergo splicing to remove introns. The document also outlines several characteristics of genes like their transmission from parents to offspring and ability to mutate.
Molecular study of Bacteria in relation to heredity and variationNilakshiKakati1
The document discusses heredity and variation in bacteria through molecular studies. It covers various genetic elements in bacteria like the chromosome, plasmids, bacteriophages, and transposable elements. It also describes different types of mutations that cause genetic variation, and mechanisms of gene transfer between bacteria like transformation, transduction, and conjugation. Fluctuation tests demonstrated that variation in bacteria is due to pre-existing mutations rather than environmental changes.
Structure of DNA. Coiling of DNA. Definitions about genetics. The Gene & The Genetic Code. Gene Mutation. Regulation of gene expression. DNA Functions. Patterns Of Inheritance
Mitochondrial d na powerpoint presentation (4)Khan_Zada
This document discusses mitochondrial DNA (mtDNA), including its characteristics, inheritance, interactions with nuclear DNA, mutations, and role in disease. Some key points:
- MtDNA is a 16.5kb circular chromosome located in mitochondria and encodes 37 genes, including those for oxidative phosphorylation. It is maternally inherited.
- Unlike nuclear DNA, mtDNA replicates randomly during cell division, which can lead to heteroplasmy (mixture of mutant and normal mtDNA). Mutations are more common in mtDNA than nuclear DNA.
- Interactions between mtDNA and nuclear DNA are required as both genomes encode proteins involved in oxidative phosphorylation. Mutations in either genome can cause similar diseases.
- A genetic bottleneck during
This document summarizes key information about mitochondrial DNA (mtDNA). It notes that mtDNA is located in mitochondria and contains genes that encode proteins for oxidative phosphorylation to produce cellular energy. MtDNA is maternally inherited. The human mtDNA genome is small, circular, and encodes 37 genes. MtDNA replication involves DNA polymerase gamma and is essential for mitochondrial function. Larger mtDNA genomes exist in some plants and protists. MtDNA can be used for ancestry tracing and forensic identification but has limitations compared to nuclear DNA.
The document discusses the molecular structure of genes and chromosomes. It describes how DNA is organized into chromosomes, which contain both protein-coding genes and non-coding sequences. Genes contain exons and introns, and in eukaryotes genes are further organized into transcription units. Chromatin compacts the DNA into nucleosomes and higher-order structures like the 30nm fiber. Overall the document provides an overview of the molecular organization and components that make up eukaryotic genes and chromosomes.
This document provides an overview of microbial genetics. It discusses key topics like DNA, RNA, proteins, transcription, translation, gene regulation, and genetic variation. Regarding prokaryotes vs eukaryotes, it notes that prokaryotes lack membrane-bound organelles and their DNA is not sequestered in the nucleus. It also explains processes like DNA replication, transcription, translation, and how gene expression is regulated through operons and repressor/activator proteins binding DNA. The document outlines bacterial mechanisms of genetic variation like mutation and horizontal gene transfer through conjugation, transformation and transduction.
This document discusses chloroplast DNA (cpDNA). Chloroplasts contain their own circular genome of double-stranded DNA ranging from 140-200kb. The cpDNA contains genes that code for proteins involved in photosynthesis as well as rRNA and tRNA. It has a quadripartite structure containing single copy and inverted repeat regions. Tobacco and liverwort were two of the first chloroplast genomes to be sequenced. Molecular studies of cpDNA regions have been useful for plant systematics. Replication of cpDNA is independent of nuclear DNA and involves enzymes like DNA polymerase and helicase.
The document discusses genome structure and genomics. It defines key terms like genome, repetitive DNA, and defines the major classes of repetitive DNA, which constitute around 45% of the human genome. It discusses how DNA denaturation and renaturation kinetics can be used to determine genome complexity and GC content. Cot analysis allows characterization of sequence complexity based on repetitiveness. Eukaryotic genomes have lower gene density and finding genes is more challenging compared to prokaryotes due to introns and other factors.
The document discusses the C-value paradox, which is the lack of relationship between genome size and organism complexity. It provides data on the wide range of genome sizes across different taxonomic groups. Introns and exons are described, with exons comprising the coding sequences and introns being removed from transcripts by splicing. Alternative splicing can generate multiple protein isoforms from a single gene. Repeated sequences, including satellites, minisatellites, microsatellites, transposons, SINEs and LINEs comprise a large portion of eukaryotic genomes.
Junk DNA/ Non-coding DNA and its Importance (Regulatory RNAs, RNA interferen...Pradeep Singh Narwat
The document discusses various types of non-coding DNA sequences, including repetitive sequences, transposons, non-coding RNAs, introns, and pseudogenes. It notes that while genes only make up 2-3% of human DNA, recent projects like ENCODE have found that a much larger portion of non-coding DNA is functionally important, for example through transcriptional and translational regulation of protein-coding sequences. The document outlines different classes of transposons, introns, non-coding RNAs and their various roles in gene expression, epigenetics, and genome evolution.
Gene families are sets of similar genes formed by duplication of an original gene. A gene cluster is a subgroup of a gene family where the genes are located near each other on a chromosome. Examples discussed include haemoglobin gene clusters, histone gene clusters, and ribosomal RNA gene clusters. Haemoglobin genes are expressed at different developmental stages. Myoglobin is related to haemoglobin and encodes oxygen transport in muscle. Histone genes encode structural proteins that package DNA into nucleosomes. Ribosomal RNA genes are present in high copy numbers and encode components of ribosomes.
Genetic recombination involves the exchange of genetic material between chromosomes or DNA molecules. It occurs through two main types - homologous recombination, which exchanges DNA between similar sequences, and non-homologous recombination between dissimilar sequences. Recombination is important for genetic diversity, DNA repair, and proper chromosome segregation during cell division. It can happen during both mitosis and meiosis, but only meiotic recombination shuffles genes from parents to offspring. There are also different mechanisms of recombination, including site-specific, transposition, and various DNA repair pathways that facilitate genetic exchange.
Nuclear Genomes(Short Answers and questions)Zohaib HUSSAIN
1. What did researchers find when they sequenced the centromeres of Arabidopsis? Why was this finding surprising?
Ans: Before the Arabidopsis sequences were obtained it was thought that these repeat sequences were by far the principal component of centromeric DNA. However, Arabidopsis centromeres also contain multiple copies of genome-wide repeats, along with a few genes, the latter at a density of 7–9 per 100 kb compared with 25 genes per 100 kb for the noncentromeric regions of Arabidopsis chromosomes. The discovery that centromeric DNA contains genes was a big surprise because it was thought that these regions were genetically inactive.
2. What differences in gene distribution and repetitive DNA content are seen when yeast and human chromosomes are compared?
Ans. A typical region of a human chromosome will have few genes (most of which will contain introns), several repeated sequences, and a large amount of nonrepetitive, nongenic DNA. Yeast chromosomes have higher gene densities, with very few genes containing introns, and have few repeated sequences and much less nongenic DNA.
3. The human genome contains about 50,000 fewer genes than was predicted by many researchers. Why were these initial predictions so high?
Ans. These early estimates were high because they were based on the supposition that, in most cases, a single gene specifies a single mRNA and a single protein. According to this model, the number of genes in the human genome should be similar to the number of proteins in human cells, leading to the estimates of 80,000–100,000. The discovery that the number of genes is much lower than this indicates that alternative splicing, the process by which exons from a pre-mRNA are assembled in different combinations so that more than one protein can be coded by a single gene is more prevalent than was originally appreciated.
4. What are the different methods used to catalog genes? What are the advantages or disadvantages of these methods?
Ans. Gene catalogs can be based on the known functions of genes, but such catalogs are incomplete because in most genomes many genes have unknown functions. Gene catalogs that are based on the identities of protein domains coded by genes are more comprehensive as these include many genes whose specific functions are unknown.
5. What is the function of the different genes in the human globin gene families?
Ans. The globins are the blood proteins that combine to make hemoglobin, each molecule of hemoglobin being made up of two a-type and two b-type globins.The a-globin cluster is located on chromosome 16 and the b-cluster on chromosome 11. Both clusters contain genes that are expressed at different developmental stages and each includes at least one pseudogene. Note that expression of the a-type gene x2 begins in the embryo and continues during the fetal stage; there is no fetal-specific a-type globin. The q pseudogene is expressed but its protein product is inactive. None of the other p
As a periodontist, it is of utmost importance to understand the genetic basis of inheritance in periodontal diseases be able to relate to the various polymorphisms associated with periodontal diseases. This ppt presents the basics of genetics from the point of view of future understanding of polymorphisms related to periodontal diseases.
chloroplast being the second semi-autonomous organelle of the plant cell also harbours its genome. the presentation includes various characteristic features of this organelle genome along with its functional pecularities and significance
Extra nuclear genome.power point presentationharitha shankar
This document discusses extra nuclear genomes, specifically chloroplast DNA and mitochondrial DNA. It provides details on:
1) Chloroplast DNA is circular DNA ranging from 120-155kb that encodes around 120 genes and is present in multiple copies within chloroplasts.
2) Mitochondrial DNA also exists as circular DNA that varies in size and encodes RNA and some proteins. In mammals it is 16.5kb while in plants it can be over 100kb.
3) Both organelle genomes are transcribed and translated within their respective organelles but rely on nuclear genes for some functions like replication machinery. They have their own genetic codes that differ slightly from nuclear codes.
Mitochondria generate most of a cell's ATP through oxidative phosphorylation. They contain their own genome separate from the nuclear genome. Mitochondria have a double membrane structure with the inner membrane forming folds called cristae. The mitochondrial genome is a circular DNA present in multiple copies that encodes proteins, rRNAs and tRNAs. Mitochondrial DNA is replicated, transcribed and the RNAs processed independently of the nuclear genome. Key processes involve the RNA polymerase, transcription factors and the DNA polymerase for replication. Mutations in mitochondrial DNA can cause human diseases.
This document discusses the structure of genes in prokaryotes and eukaryotes. It defines a gene as a sequence of DNA that codes for a specific protein. Prokaryotic genes are continuous with three regions - a promoter, coding sequence, and terminator. Eukaryotic genes can be complex with introns and exons, promoters, and regulatory elements. Key differences are that prokaryotic genes lack introns while eukaryotic genes undergo splicing to remove introns. The document also outlines several characteristics of genes like their transmission from parents to offspring and ability to mutate.
Molecular study of Bacteria in relation to heredity and variationNilakshiKakati1
The document discusses heredity and variation in bacteria through molecular studies. It covers various genetic elements in bacteria like the chromosome, plasmids, bacteriophages, and transposable elements. It also describes different types of mutations that cause genetic variation, and mechanisms of gene transfer between bacteria like transformation, transduction, and conjugation. Fluctuation tests demonstrated that variation in bacteria is due to pre-existing mutations rather than environmental changes.
Structure of DNA. Coiling of DNA. Definitions about genetics. The Gene & The Genetic Code. Gene Mutation. Regulation of gene expression. DNA Functions. Patterns Of Inheritance
Mitochondrial d na powerpoint presentation (4)Khan_Zada
This document discusses mitochondrial DNA (mtDNA), including its characteristics, inheritance, interactions with nuclear DNA, mutations, and role in disease. Some key points:
- MtDNA is a 16.5kb circular chromosome located in mitochondria and encodes 37 genes, including those for oxidative phosphorylation. It is maternally inherited.
- Unlike nuclear DNA, mtDNA replicates randomly during cell division, which can lead to heteroplasmy (mixture of mutant and normal mtDNA). Mutations are more common in mtDNA than nuclear DNA.
- Interactions between mtDNA and nuclear DNA are required as both genomes encode proteins involved in oxidative phosphorylation. Mutations in either genome can cause similar diseases.
- A genetic bottleneck during
This document summarizes key information about mitochondrial DNA (mtDNA). It notes that mtDNA is located in mitochondria and contains genes that encode proteins for oxidative phosphorylation to produce cellular energy. MtDNA is maternally inherited. The human mtDNA genome is small, circular, and encodes 37 genes. MtDNA replication involves DNA polymerase gamma and is essential for mitochondrial function. Larger mtDNA genomes exist in some plants and protists. MtDNA can be used for ancestry tracing and forensic identification but has limitations compared to nuclear DNA.
The document discusses the molecular structure of genes and chromosomes. It describes how DNA is organized into chromosomes, which contain both protein-coding genes and non-coding sequences. Genes contain exons and introns, and in eukaryotes genes are further organized into transcription units. Chromatin compacts the DNA into nucleosomes and higher-order structures like the 30nm fiber. Overall the document provides an overview of the molecular organization and components that make up eukaryotic genes and chromosomes.
This document provides an overview of microbial genetics. It discusses key topics like DNA, RNA, proteins, transcription, translation, gene regulation, and genetic variation. Regarding prokaryotes vs eukaryotes, it notes that prokaryotes lack membrane-bound organelles and their DNA is not sequestered in the nucleus. It also explains processes like DNA replication, transcription, translation, and how gene expression is regulated through operons and repressor/activator proteins binding DNA. The document outlines bacterial mechanisms of genetic variation like mutation and horizontal gene transfer through conjugation, transformation and transduction.
This document discusses chloroplast DNA (cpDNA). Chloroplasts contain their own circular genome of double-stranded DNA ranging from 140-200kb. The cpDNA contains genes that code for proteins involved in photosynthesis as well as rRNA and tRNA. It has a quadripartite structure containing single copy and inverted repeat regions. Tobacco and liverwort were two of the first chloroplast genomes to be sequenced. Molecular studies of cpDNA regions have been useful for plant systematics. Replication of cpDNA is independent of nuclear DNA and involves enzymes like DNA polymerase and helicase.
The document discusses genome structure and genomics. It defines key terms like genome, repetitive DNA, and defines the major classes of repetitive DNA, which constitute around 45% of the human genome. It discusses how DNA denaturation and renaturation kinetics can be used to determine genome complexity and GC content. Cot analysis allows characterization of sequence complexity based on repetitiveness. Eukaryotic genomes have lower gene density and finding genes is more challenging compared to prokaryotes due to introns and other factors.
The document discusses the C-value paradox, which is the lack of relationship between genome size and organism complexity. It provides data on the wide range of genome sizes across different taxonomic groups. Introns and exons are described, with exons comprising the coding sequences and introns being removed from transcripts by splicing. Alternative splicing can generate multiple protein isoforms from a single gene. Repeated sequences, including satellites, minisatellites, microsatellites, transposons, SINEs and LINEs comprise a large portion of eukaryotic genomes.
Junk DNA/ Non-coding DNA and its Importance (Regulatory RNAs, RNA interferen...Pradeep Singh Narwat
The document discusses various types of non-coding DNA sequences, including repetitive sequences, transposons, non-coding RNAs, introns, and pseudogenes. It notes that while genes only make up 2-3% of human DNA, recent projects like ENCODE have found that a much larger portion of non-coding DNA is functionally important, for example through transcriptional and translational regulation of protein-coding sequences. The document outlines different classes of transposons, introns, non-coding RNAs and their various roles in gene expression, epigenetics, and genome evolution.
Gene families are sets of similar genes formed by duplication of an original gene. A gene cluster is a subgroup of a gene family where the genes are located near each other on a chromosome. Examples discussed include haemoglobin gene clusters, histone gene clusters, and ribosomal RNA gene clusters. Haemoglobin genes are expressed at different developmental stages. Myoglobin is related to haemoglobin and encodes oxygen transport in muscle. Histone genes encode structural proteins that package DNA into nucleosomes. Ribosomal RNA genes are present in high copy numbers and encode components of ribosomes.
Genetic recombination involves the exchange of genetic material between chromosomes or DNA molecules. It occurs through two main types - homologous recombination, which exchanges DNA between similar sequences, and non-homologous recombination between dissimilar sequences. Recombination is important for genetic diversity, DNA repair, and proper chromosome segregation during cell division. It can happen during both mitosis and meiosis, but only meiotic recombination shuffles genes from parents to offspring. There are also different mechanisms of recombination, including site-specific, transposition, and various DNA repair pathways that facilitate genetic exchange.
Nuclear Genomes(Short Answers and questions)Zohaib HUSSAIN
1. What did researchers find when they sequenced the centromeres of Arabidopsis? Why was this finding surprising?
Ans: Before the Arabidopsis sequences were obtained it was thought that these repeat sequences were by far the principal component of centromeric DNA. However, Arabidopsis centromeres also contain multiple copies of genome-wide repeats, along with a few genes, the latter at a density of 7–9 per 100 kb compared with 25 genes per 100 kb for the noncentromeric regions of Arabidopsis chromosomes. The discovery that centromeric DNA contains genes was a big surprise because it was thought that these regions were genetically inactive.
2. What differences in gene distribution and repetitive DNA content are seen when yeast and human chromosomes are compared?
Ans. A typical region of a human chromosome will have few genes (most of which will contain introns), several repeated sequences, and a large amount of nonrepetitive, nongenic DNA. Yeast chromosomes have higher gene densities, with very few genes containing introns, and have few repeated sequences and much less nongenic DNA.
3. The human genome contains about 50,000 fewer genes than was predicted by many researchers. Why were these initial predictions so high?
Ans. These early estimates were high because they were based on the supposition that, in most cases, a single gene specifies a single mRNA and a single protein. According to this model, the number of genes in the human genome should be similar to the number of proteins in human cells, leading to the estimates of 80,000–100,000. The discovery that the number of genes is much lower than this indicates that alternative splicing, the process by which exons from a pre-mRNA are assembled in different combinations so that more than one protein can be coded by a single gene is more prevalent than was originally appreciated.
4. What are the different methods used to catalog genes? What are the advantages or disadvantages of these methods?
Ans. Gene catalogs can be based on the known functions of genes, but such catalogs are incomplete because in most genomes many genes have unknown functions. Gene catalogs that are based on the identities of protein domains coded by genes are more comprehensive as these include many genes whose specific functions are unknown.
5. What is the function of the different genes in the human globin gene families?
Ans. The globins are the blood proteins that combine to make hemoglobin, each molecule of hemoglobin being made up of two a-type and two b-type globins.The a-globin cluster is located on chromosome 16 and the b-cluster on chromosome 11. Both clusters contain genes that are expressed at different developmental stages and each includes at least one pseudogene. Note that expression of the a-type gene x2 begins in the embryo and continues during the fetal stage; there is no fetal-specific a-type globin. The q pseudogene is expressed but its protein product is inactive. None of the other p
As a periodontist, it is of utmost importance to understand the genetic basis of inheritance in periodontal diseases be able to relate to the various polymorphisms associated with periodontal diseases. This ppt presents the basics of genetics from the point of view of future understanding of polymorphisms related to periodontal diseases.
chloroplast being the second semi-autonomous organelle of the plant cell also harbours its genome. the presentation includes various characteristic features of this organelle genome along with its functional pecularities and significance
Extra nuclear genome.power point presentationharitha shankar
This document discusses extra nuclear genomes, specifically chloroplast DNA and mitochondrial DNA. It provides details on:
1) Chloroplast DNA is circular DNA ranging from 120-155kb that encodes around 120 genes and is present in multiple copies within chloroplasts.
2) Mitochondrial DNA also exists as circular DNA that varies in size and encodes RNA and some proteins. In mammals it is 16.5kb while in plants it can be over 100kb.
3) Both organelle genomes are transcribed and translated within their respective organelles but rely on nuclear genes for some functions like replication machinery. They have their own genetic codes that differ slightly from nuclear codes.
Mitochondria generate most of a cell's ATP through oxidative phosphorylation. They contain their own genome separate from the nuclear genome. Mitochondria have a double membrane structure with the inner membrane forming folds called cristae. The mitochondrial genome is a circular DNA present in multiple copies that encodes proteins, rRNAs and tRNAs. Mitochondrial DNA is replicated, transcribed and the RNAs processed independently of the nuclear genome. Key processes involve the RNA polymerase, transcription factors and the DNA polymerase for replication. Mutations in mitochondrial DNA can cause human diseases.
The document discusses the SCRaMbLE technique, which uses the Cre-loxP system to increase phenotypic and genotypic diversity in organisms. The Cre-loxP system was originally discovered in bacteriophage P1, where it directs site-specific recombination of plasmid DNA into bacterial chromosomes. SCRaMbLE was first tested in yeast in 1987 and allows random chromosomal rearrangements by inducing recombination between loxP sites inserted throughout the genome. This technique can be used to determine which gene combinations confer beneficial traits to yeast.
Organization and Regulation of Mitochondrial Protein SynthesisHeena36363
Mitochondria contain their own genome (mtDNA) which encodes some essential subunits of the oxidative phosphorylation complexes, as well as tRNAs and rRNAs required for mitochondrial protein synthesis. Mitochondrial translation requires nuclear-encoded factors and has adapted mechanisms to function within mitochondria. The mitochondrial ribosome (mitoribosome) is specialized for translation within this organelle, having evolved from bacterial ancestors. Translation in mitochondria involves initiation through IF2 and IF3 binding, elongation of the polypeptide chain, and termination. Adaptations allow for membrane insertion of proteins and regulation of mitochondrial protein synthesis.
This document discusses RNA structure and types. It begins by describing the basic components and functions of RNA, including its role in transcription and as an intermediate molecule in protein synthesis. It then discusses the different forms and structures of RNA, including primary, secondary and tertiary structures. The main types of RNA - mRNA, tRNA, rRNA and others like miRNA and siRNA - are then summarized in terms of their roles and characteristics. Applications of RNA interference are also briefly outlined.
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand.
Organellar genomes, such as those found in mitochondria and chloroplasts, can be manipulated. The mitochondria genome is maternally inherited and contains genes that code for proteins involved in respiration. The chloroplast genome is also maternally inherited and contains genes for photosynthesis-related proteins. Methods to transform these genomes include particle bombardment, PEG-mediated transformation, and Agrobacterium-mediated transformation. Manipulating organellar genomes has applications for crop improvement like developing cytoplasmic male sterility.
Ribosomal RNA (rRNA) is a type of RNA that provides the structural scaffold of the ribosome. There are three main types of rRNA - 5S, 16S, and 23S rRNA - that vary in size between species but together can comprise up to 90% of a cell's total RNA. rRNA forms distinctive secondary structures and is organized into operons within genomes. Comparative sequence analysis has revealed highly conserved secondary and tertiary structures that have been largely validated by ribosome crystal structures.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Non-coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. There are several types of ncRNAs including transfer RNA (tRNA), ribosomal RNA (rRNA), and microRNAs. tRNA transfers amino acids to sites of protein synthesis during translation. rRNA forms ribosomes and catalyzes peptide bond formation. ncRNAs are involved in many cellular processes like translation, splicing, and gene regulation. Dysregulation of ncRNAs can cause diseases like cancer.
The document provides an overview of concepts related to genes and protein synthesis. It discusses the classical and modern concepts of genes, how genes are expressed through transcription and translation, and the central dogma of molecular biology whereby DNA is transcribed into RNA which is then translated into protein. Key aspects covered include DNA and RNA structure, the genetic code, transcription initiation and elongation, translation via ribosomes, and termination of protein synthesis.
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cell biology class 17th N ovember mitochondria 2015.pptsubhashree533922
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assignment on inheritance and expressio of organeller dna 1
1. Department of Plant Breeding and Genetics
Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (M.P.)
(2017-18)
Assignment
On
Inheritance and Expression of Organeller DNA
Presented by :
Sarla Kumawat
Ph.D. 1st year
Professor
V.K. Gour
2. Inheritance and Expression of Organeller DNA
History of Organeller DNA
1908– Correns, first presented the evidence for
cytoplasmic inheritance in Mirabilis jalapa.
1908-Baur, first presented the evidence for cytoplasmic
inheritance in Pelargonium zonale.
1924 Jenkins, described the iojap leaf variegation in
maize.
1933 Rhodes, described CMS in Maize
1943 Sonneborn ,kappa particle in Paramoecium
3. Organellar DNA also known as maternal DNA. It
is of two types i.e. Mitochondrial and chloroplast
DNA.
Important features of Organellar DNA
Replicates both in chloroplast and mitochondria
in a semi-conservative fashion.
Liable to mutation.
They are expressed and inherited separately
from nuclear genes.
They are transcribed and translated within the
organelles.
Uni-parental inheritance is observed.
4. Present in multiple copies in each organelle cp-DNA- 20-
40 copies per chloroplast, ~4 copies per mitochondria
(E.g.: Yeast).
1. Mitochondrial DNA:
May be circular or linear.
Size: varies from ~16.5kb to ~100kb.
Human mitochondrial genes contain no introns,
although introns are found in the mitochondria of other
groups (plants, for instance).
2. Chloroplast DNA
Double-stranded
Chloroplasts contain naked circular DNA.
5. Circular, super coiled, and generally not associated
with any proteins.
Size: Varies. 85kb (Codium fragile) to 2000kb
(Acetabularia sp.), Larger than mitochondrial
genomes (80-600 Kb in length).
Each chloroplast contains 10-60 (sometimes 100)
copies of its genome. The gene controlling
cytoplasmic inheritance are present outside the
nucleus and in the cytoplasm, they are known as
plasma gene, cytoplasmic genes, extra chromosomal
genes.
The sum total of genes present in cytoplasm of a cell
is known as Plasmon.
All the genes present in a plastid are known as
Plastoms.
7. Organeller Inheritance
Organeller inheritance are true cytoplasmic
inheritance, concerned with either chloroplast or
mitochondrial traits and are usually associated with
their DNA.
Features of Organellar Inheritance
Governed by organellar genes
Does not exhibits distinct segregation pattern
Reciprocal differences are observed
Show maternal effects
Mapping is difficult
Plasma genes are associated with either cpDNA or
mtDNA.
8. Important features of Organellar Inheritance
Reciprocal differences - As organellar genome
from only on parent, generally the female parent
are transmitted (Uni-parental inheritance).
9. Lack of Segregation
Irregular Segregation in Biparental Inheritance
Somatic Segregation
Association with Organellar DNA
Mutagenesis
Lack of Association with A Parasite, Symbiont or
Virus
Plastid inheritance: Carl Correns (1908) Studied
the inheritance of leaf variegation called
‘albomaculatus’ in the four O clock plant
Mirabilis jalapa.
10. Variegated-shoot phenotypes in four o’clocks
Mixed chloroplasts
White/green
Mutant chloroplast
White
non-photosynthetic
Normal chloroplast
Green
photosynthetic
11.
12. MITOCHONDRAL INHERITANCE
Inheritance pattern governed by mt-DNA is
termed as mitochondrial inheritance.
Examples of Mitochondrial inheritance are as
follows:-
Cytoplasmic Male Sterility in plants
Maize,Sorghum etc.
Pokyness in Neurospora
Petite in Yeast
13. Expression of Organeller DNA
Expression of mitochondrial DNA
Mitochondrial DNA (mtDNA), which encodes
subunits of the oxidative phosphorylation complexes
essential for cellular respiration and ATP production.
Expression, replication, and maintenance of mtDNA
require factors encoded by nuclear genes.
These include not only the primary machinery
involved (eg. transcription and replication
components) but also those in signaling pathways
that mediate or sense alterations in mitochondrial
function in accord with changing cellular needs or
environmental conditions.
14. The basic protein machinery required for
transcription initiation in human mitochondria has
been elucidated after the discovery of two
multifunctional mitochondrial transcription factors, h-
mtTFB1 and h-mtTFB2, that are also rRNA
methyltransferases.
For example, in the D-loop regulatory region there are
four sequence elements (conserved sequence blocks:
CSB I, CSB II, CSB III; and origin of H-strand synthesis:
OH) that are postulated to be important for initiation of
transcription-primed, leading-strand DNA synthesis
according to the asymmetric model of mtDNA replication.
15. This site lies in an unusual region of the
genome where there is a clustering of five
adjacent tRNA genes. Although this site is a
major region of initiation of lagging-strand
synthesis, it appears that other sites on the
molecule may serve as alternative initiation
sites.
Third, one of the first features of mtDNA to be
recognized is the D-loop itself. This is a stable
three-stranded DNA structure of ∼570 to 665
nucleotides in length (in humans) that begins at
OH and extends downstream where it ends at a
few distinct sites.
16. These elements are downstream of the LSP and
are involved in configuring and processing the
LSP transcript to form RNA primers for initiation
by the mtDNA polymerase, Pol γ.
Therefore, the RNA primers for leading-strand
mtDNA replication are generated by POLRMT
(the mitochondrial RNA polymerase). Second,
approximately two-thirds the distance around the
mtDNA molecule from OH is OL, which is a
primary site of initiation of lagging-strand mtDNA
synthesis, according to the asymmetric
replication model.
17. This structure has all of the features of a stalled (or
terminated) leading-strand replication intermediate;
however, whether this is actually the case has not been
strictly determined.
Since its discovery, the significance of the need to
maintain this structure in a subset (a large subset in
some cells) of mtDNA molecules has eluded the field, but
it is logical to assume it is of regulatory importance with
regard to expression, replication, and/or inheritance of
mtDNA.
18. With regard to regulation of mtDNA expression and
maintenance, a key point to re-emphasize is that, except
for the mtDNA-encoded rRNAs and tRNAs, all of the
factors required for transcription, RNA processing,
translation, replication, and repair of mtDNA are encoded
by nuclear genes, translated by cytoplasmic ribosomes,
and imported into mitochondria to their sites of action.
In other words, there is an important and relatively large
subset of the ∼1500 nucleus-encoded proteins in the
mitochondrion that is devoted to mitochondrial gene
expression and mtDNA maintenance.
Signalling pathways must exist to coordinate the activities
of these distinct genetic compartments (the nucleus and
mitochondria) to maintain and modulate mitochondrial
gene expression.
19. Chloroplast gene expression
Chloroplast genomes of extant land plants have only
50 protein-coding genes involved in photosynthesis,
gene expression, lipid metabolism and other
processes, 30 tRNA genes and full sets of rRNA genes.
In spite of their small genomes (0.15 Mbp in land plant
chloroplasts versus 3 Mbp in cyanobacteria),
chloroplast gene expression is regulated by more
complex systems compared to the simple prokaryotic
regulatory system.
Chloroplast gene expression is mediated by two
distinct types of RNA polymerase (RNAP) and is
highly dependent on post-transcriptional regulation.
20. such as the processing of polycistronic transcripts,
intron splicing and RNA editing. Moreover, recent
RNA-sequences analyses of chloroplast transcripts
identified unexpected diversifications of RNA
molecules, such as non-coding and antisense RNAs
(Hotto et al., 2011 and Zhelyazkova et al., 2012)
However, the genes encoded in chloroplast
genomes are insufficient to regulate their
complicated gene expression, and so the chloroplast
gene expression machinery includes various
nucleus-encoded regulatory components.
Chloroplast gene expression is largely dependent on
prokaryotic machineries derived from the ancestral
cyanobacterium.
21. The bacterial multi-subunit RNAP is composed of a
core Rpo complex, which has the catalytic enzyme
activity, and a sigma factor, which recognizes
promoter sequences (Ishihama, 2000). Chloroplasts
contain the bacterial-type RNAP, called plastid-
encoded plastid RNAP (PEP), which shares
functional similarity with the bacterial RNAP (Igloi
and Kossel, 1992;
22. Significance of organeller DNA
Role cytoplasmic organelles in transmission
of characters.
mapping of chloroplast and mitochondrial
genome.
cytoplasmic male sterility.
Mutation of chloroplast-DNA and
mitochondrial-DNA leads to generation of
new variants.
mt-DNA is used for the study of human
evolution.