Genome

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An image of the 46 chromosomes making up the diploid genome of a human male (the mitochondrial chromosomes are not shown). UCSC human chromosome colours.png
An image of the 46 chromosomes making up the diploid genome of a human male (the mitochondrial chromosomes are not shown).

In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. [1] It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of junk DNA with no evident function. [2] [3] Almost all eukaryotes have mitochondria and a small mitochondrial genome. [2] Algae and plants also contain chloroplasts with a chloroplast genome.

Contents

The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The Human Genome Project was started in October 1990, and then reported the sequence of the human genome in April 2003, [4] although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. [5]

With advancements in technology that could handle sequencing of the many repetitive sequences found in human DNA that were not fully uncovered by the original Human Genome Project study, scientists reported the first end-to-end human genome sequence in March 2022. [6]

Origin of the term

The term genome was created in 1920 by Hans Winkler, [7] professor of botany at the University of Hamburg, Germany. The website Oxford Dictionaries and the Online Etymology Dictionary suggest the name is a blend of the words gene and chromosome . [8] [9] [10] [11] However, see omics for a more thorough discussion. A few related -ome words already existed, such as biome and rhizome , forming a vocabulary into which genome fits systematically. [12]

Definition

It is very difficult to come up with a precise definition of "genome." It usually refers to the DNA (or sometimes RNA) molecules that carry the genetic information in an organism but sometimes it is difficult to decide which molecules to include in the definition; for example, bacteria usually have one or two large DNA molecules (chromosomes) that contain all of the essential genetic material but they also contain smaller extrachromosomal plasmid molecules that carry important genetic information. The definition of 'genome' that is commonly used in the scientific literature is usually restricted to the large chromosomal DNA molecules in bacteria. [13]

Nuclear genome

Eukaryotic genomes are even more difficult to define because almost all eukaryotic species contain nuclear chromosomes plus extra DNA molecules in the mitochondria. In addition, algae and plants have chloroplast DNA. Most textbooks make a distinction between the nuclear genome and the organelle (mitochondria and chloroplast) genomes so when they speak of, say, the human genome, they are only referring to the genetic material in the nucleus. [2] [14] This is the most common use of 'genome' in the scientific literature.

Ploidy

Most eukaryotes are diploid, meaning that there are two of each chromosome in the nucleus but the 'genome' refers to only one copy of each chromosome. Some eukaryotes have distinctive sex chromosomes, such as the X and Y chromosomes of mammals, so the technical definition of the genome must include both copies of the sex chromosomes. For example, the standard reference genome of humans consists of one copy of each of the 22 autosomes plus one X chromosome and one Y chromosome. [15]

Sequencing and mapping

A genome sequence is the complete list of the nucleotides (A, C, G, and T for DNA genomes) that make up all the chromosomes of an individual or a species. Within a species, the vast majority of nucleotides are identical between individuals, but sequencing multiple individuals is necessary to understand the genetic diversity.

Part of DNA sequence - prototypification of complete genome of virus Part of DNA sequence prototypification of complete genome of virus 5418 nucleotides.gif
Part of DNA sequence – prototypification of complete genome of virus

In 1976, Walter Fiers at the University of Ghent (Belgium) was the first to establish the complete nucleotide sequence of a viral RNA-genome (Bacteriophage MS2). The next year, Fred Sanger completed the first DNA-genome sequence: Phage Φ-X174, of 5386 base pairs. [16] The first bacterial genome to be sequenced was that of Haemophilus influenzae, completed by a team at The Institute for Genomic Research in 1995. A few months later, the first eukaryotic genome was completed, with sequences of the 16 chromosomes of budding yeast Saccharomyces cerevisiae published as the result of a European-led effort begun in the mid-1980s. The first genome sequence for an archaeon, Methanococcus jannaschii , was completed in 1996, again by The Institute for Genomic Research.[ citation needed ]

The development of new technologies has made genome sequencing dramatically cheaper and easier, and the number of complete genome sequences is growing rapidly. The US National Institutes of Health maintains one of several comprehensive databases of genomic information. [17] Among the thousands of completed genome sequencing projects include those for rice, a mouse, the plant Arabidopsis thaliana , the puffer fish, and the bacteria E. coli. In December 2013, scientists first sequenced the entire genome of a Neanderthal, an extinct species of humans. The genome was extracted from the toe bone of a 130,000-year-old Neanderthal found in a Siberian cave. [18] [19]

New sequencing technologies, such as massive parallel sequencing have also opened up the prospect of personal genome sequencing as a diagnostic tool, as pioneered by Manteia Predictive Medicine. A major step toward that goal was the completion in 2007 of the full genome of James D. Watson, one of the co-discoverers of the structure of DNA. [20]

Whereas a genome sequence lists the order of every DNA base in a genome, a genome map identifies the landmarks. A genome map is less detailed than a genome sequence and aids in navigating around the genome. The Human Genome Project was organized to map and to sequence the human genome. A fundamental step in the project was the release of a detailed genomic map by Jean Weissenbach and his team at the Genoscope in Paris. [21] [22]

Reference genome sequences and maps continue to be updated, removing errors and clarifying regions of high allelic complexity. [23] The decreasing cost of genomic mapping has permitted genealogical sites to offer it as a service, [24] to the extent that one may submit one's genome to crowdsourced scientific endeavours such as DNA.LAND at the New York Genome Center, [25] an example both of the economies of scale and of citizen science. [26]

Viral genomes

Viral genomes can be composed of either RNA or DNA. The genomes of RNA viruses can be either single-stranded RNA or double-stranded RNA, and may contain one or more separate RNA molecules (segments: monopartit or multipartit genome). DNA viruses can have either single-stranded or double-stranded genomes. Most DNA virus genomes are composed of a single, linear molecule of DNA, but some are made up of a circular DNA molecule. [27]

Prokaryotic genomes

Prokaryotes and eukaryotes have DNA genomes. Archaea and most bacteria have a single circular chromosome, [28] however, some bacterial species have linear or multiple chromosomes. [29] [30] If the DNA is replicated faster than the bacterial cells divide, multiple copies of the chromosome can be present in a single cell, and if the cells divide faster than the DNA can be replicated, multiple replication of the chromosome is initiated before the division occurs, allowing daughter cells to inherit complete genomes and already partially replicated chromosomes. Most prokaryotes have very little repetitive DNA in their genomes. [31] However, some symbiotic bacteria (e.g. Serratia symbiotica ) have reduced genomes and a high fraction of pseudogenes: only ~40% of their DNA encodes proteins. [32] [33]

Some bacteria have auxiliary genetic material, also part of their genome, which is carried in plasmids. For this, the word genome should not be used as a synonym of chromosome.

Eukaryotic genomes

In a typical human cell, the genome is contained in 22 pairs of autosomes, two sex chromosomes (the female and male variants shown at bottom right), as well as the mitochondrial genome (shown to scale as "MT" at bottom left).
Further information: Karyotype Human karyotype with bands and sub-bands.png
In a typical human cell, the genome is contained in 22 pairs of autosomes, two sex chromosomes (the female and male variants shown at bottom right), as well as the mitochondrial genome (shown to scale as "MT" at bottom left).

Eukaryotic genomes are composed of one or more linear DNA chromosomes. The number of chromosomes varies widely from Jack jumper ants and an asexual nemotode, [34] which each have only one pair, to a fern species that has 720 pairs. [35] It is surprising the amount of DNA that eukaryotic genomes contain compared to other genomes. The amount is even more than what is necessary for DNA protein-coding and noncoding genes due to the fact that eukaryotic genomes show as much as 64,000-fold variation in their sizes. [36] However, this special characteristic is caused by the presence of repetitive DNA, and transposable elements (TEs).

A typical human cell has two copies of each of 22 autosomes, one inherited from each parent, plus two sex chromosomes, making it diploid. Gametes, such as ova, sperm, spores, and pollen, are haploid, meaning they carry only one copy of each chromosome. In addition to the chromosomes in the nucleus, organelles such as the chloroplasts and mitochondria have their own DNA. Mitochondria are sometimes said to have their own genome often referred to as the "mitochondrial genome". The DNA found within the chloroplast may be referred to as the "plastome". Like the bacteria they originated from, mitochondria and chloroplasts have a circular chromosome.

Unlike prokaryotes where exon-intron organization of protein coding genes exists but is rather exceptional, eukaryotes generally have these features in their genes and their genomes contain variable amounts of repetitive DNA. In mammals and plants, the majority of the genome is composed of repetitive DNA. [37]

DNA sequencing

High-throughput technology makes sequencing to assemble new genomes accessible to everyone. Sequence polymorphisms are typically discovered by comparing resequenced isolates to a reference, whereas analyses of coverage depth and mapping topology can provide details regarding structural variations such as chromosomal translocations and segmental duplications.

Coding sequences

DNA sequences that carry the instructions to make proteins are referred to as coding sequences. The proportion of the genome occupied by coding sequences varies widely. A larger genome does not necessarily contain more genes, and the proportion of non-repetitive DNA decreases along with increasing genome size in complex eukaryotes. [37]

Noncoding sequences

Noncoding sequences include introns, sequences for non-coding RNAs, regulatory regions, and repetitive DNA. Noncoding sequences make up 98% of the human genome. There are two categories of repetitive DNA in the genome: tandem repeats and interspersed repeats. [38]

Tandem repeats

Short, non-coding sequences that are repeated head-to-tail are called tandem repeats. Microsatellites consisting of 2–5 basepair repeats, while minisatellite repeats are 30–35 bp. Tandem repeats make up about 4% of the human genome and 9% of the fruit fly genome. [39] Tandem repeats can be functional. For example, telomeres are composed of the tandem repeat TTAGGG in mammals, and they play an important role in protecting the ends of the chromosome.

In other cases, expansions in the number of tandem repeats in exons or introns can cause disease. [40] For example, the human gene huntingtin (Htt) typically contains 6–29 tandem repeats of the nucleotides CAG (encoding a polyglutamine tract). An expansion to over 36 repeats results in Huntington's disease, a neurodegenerative disease. Twenty human disorders are known to result from similar tandem repeat expansions in various genes. The mechanism by which proteins with expanded polygulatamine tracts cause death of neurons is not fully understood. One possibility is that the proteins fail to fold properly and avoid degradation, instead accumulating in aggregates that also sequester important transcription factors, thereby altering gene expression. [40]

Tandem repeats are usually caused by slippage during replication, unequal crossing-over and gene conversion. [41]

Transposable elements

Transposable elements (TEs) are sequences of DNA with a defined structure that are able to change their location in the genome. [39] [31] [42] TEs are categorized as either as a mechanism that replicates by copy-and-paste or as a mechanism that can be excised from the genome and inserted at a new location. In the human genome, there are three important classes of TEs that make up more than 45% of the human DNA; these classes are The long interspersed nuclear elements (LINEs), The interspersed nuclear elements (SINEs), and endogenous retroviruses. These elements have a big potential to modify the genetic control in a host organism. [36]

The movement of TEs is a driving force of genome evolution in eukaryotes because their insertion can disrupt gene functions, homologous recombination between TEs can produce duplications, and TE can shuffle exons and regulatory sequences to new locations. [43]

Retrotransposons

Retrotransposons [44] are found mostly in eukaryotes but not found in prokaryotes. Retrotransposons form a large portion of the genomes of many eukaryotes. A retrotransposon is a transposable element that transposes through an RNA intermediate. Retrotransposons [45] are composed of DNA, but are transcribed into RNA for transposition, then the RNA transcript is copied back to DNA formation with the help of a specific enzyme called reverse transcriptase. A retrotransposon that carries reverse transcriptase in its sequence can trigger its own transposition but retrotransposons that lack a reverse transcriptase must use reverse transcriptase synthesized by another retrotransposon. Retrotransposons can be transcribed into RNA, which are then duplicated at another site into the genome. [46] Retrotransposons can be divided into long terminal repeats (LTRs) and non-long terminal repeats (Non-LTRs). [43]

Long terminal repeats (LTRs) are derived from ancient retroviral infections, so they encode proteins related to retroviral proteins including gag (structural proteins of the virus), pol (reverse transcriptase and integrase), pro (protease), and in some cases env (envelope) genes. [42] These genes are flanked by long repeats at both 5' and 3' ends. It has been reported that LTRs consist of the largest fraction in most plant genome and might account for the huge variation in genome size. [47]

Non-long terminal repeats (Non-LTRs) are classified as long interspersed nuclear elements (LINEs), short interspersed nuclear elements (SINEs), and Penelope-like elements (PLEs). In Dictyostelium discoideum, there is another DIRS-like elements belong to Non-LTRs. Non-LTRs are widely spread in eukaryotic genomes. [48]

Long interspersed elements (LINEs) encode genes for reverse transcriptase and endonuclease, making them autonomous transposable elements. The human genome has around 500,000 LINEs, taking around 17% of the genome. [49]

Short interspersed elements (SINEs) are usually less than 500 base pairs and are non-autonomous, so they rely on the proteins encoded by LINEs for transposition. [50] The Alu element is the most common SINE found in primates. It is about 350 base pairs and occupies about 11% of the human genome with around 1,500,000 copies. [43]

DNA transposons

DNA transposons encode a transposase enzyme between inverted terminal repeats. When expressed, the transposase recognizes the terminal inverted repeats that flank the transposon and catalyzes its excision and reinsertion in a new site. [39] This cut-and-paste mechanism typically reinserts transposons near their original location (within 100 kb). [43] DNA transposons are found in bacteria and make up 3% of the human genome and 12% of the genome of the roundworm C. elegans. [43]

Genome size

Log-log plot of the total number of annotated proteins in genomes submitted to GenBank as a function of genome size Genome size vs protein count.svg
Log–log plot of the total number of annotated proteins in genomes submitted to GenBank as a function of genome size

Genome size is the total number of the DNA base pairs in one copy of a haploid genome. Genome size varies widely across species. Invertebrates have small genomes, this is also correlated to a small number of transposable elements. Fish and Amphibians have intermediate-size genomes, and birds have relatively small genomes but it has been suggested that birds lost a substantial portion of their genomes during the phase of transition to flight.  Before this loss, DNA methylation allows the adequate expansion of the genome. [36]

In humans, the nuclear genome comprises approximately 3.1 billion nucleotides of DNA, divided into 24 linear molecules, the shortest 45 000 000 nucleotides in length and the longest 248 000 000 nucleotides, each contained in a different chromosome. [51] There is no clear and consistent correlation between morphological complexity and genome size in either prokaryotes or lower eukaryotes. [37] [52] Genome size is largely a function of the expansion and contraction of repetitive DNA elements.

Since genomes are very complex, one research strategy is to reduce the number of genes in a genome to the bare minimum and still have the organism in question survive. There is experimental work being done on minimal genomes for single cell organisms as well as minimal genomes for multi-cellular organisms (see developmental biology). The work is both in vivo and in silico . [53] [54]

Genome size differences due to transposable elements

Comparison among genome sizes Genome sizes.png
Comparison among genome sizes

There are many enormous differences in size in genomes, specially mentioned before in the multicellular eukaryotic genomes. Much of this is due to the differing abundances of transposable elements, which evolve by creating new copies of themselves in the chromosomes. [36] Eukaryote genomes often contain many thousands of copies of these elements, most of which have acquired mutations that make them defective. Here is a table of some significant or representative genomes. See #See also for lists of sequenced genomes.

Organism typeOrganismGenome size
(base pairs)
Approx. no. of genesNote
Virus Porcine circovirus type 11,7591.8 kBSmallest viruses replicating autonomously in eukaryotic cells [55]
Virus Bacteriophage MS2 3,5693.6 kBFirst sequenced RNA-genome [56]
Virus SV40 5,2245.2 kB [57]
Virus Phage Φ-X174 5,3865.4 kBFirst sequenced DNA-genome [58]
Virus HIV 9,7499.7 kB [59]
Virus Phage λ 48,50248.5 kBOften used as a vector for the cloning of recombinant DNA

[60] [61] [62]

Virus Megavirus 1,259,1971.3 MBUntil 2013 the largest known viral genome [63]
Virus Pandoravirus salinus 2,470,0002.47 MBLargest known viral genome. [64]
Eukaryotic organelle Human mitochondrion 16,56916.6 kB [65]
Bacterium Nasuia deltocephalinicola (strain NAS-ALF)112,091112 kB137Smallest known non-viral genome. Symbiont of leafhoppers. [66]
Bacterium Carsonella ruddii 159,662160 kBAn endosymbiont of psyllid insects
Bacterium Buchnera aphidicola 600,000600 kBAn endosymbiont of aphids [67]
Bacterium Wigglesworthia glossinidia 700,000700 kBA symbiont in the gut of the tsetse fly
Bacteriumcyanobacterium Prochlorococcus spp. (1.7 Mb)1,700,0001.7 MB1,884Smallest known cyanobacterium genome. One of the primary photosynthesizers on Earth. [68] [69]
Bacterium Haemophilus influenzae 1,830,0001.8 MBFirst genome of a living organism sequenced, July 1995 [70]
Bacterium Escherichia coli 4,600,0004.6 MB4,288 [71]
Bacterium – cyanobacterium Nostoc punctiforme 9,000,0009 MB7,4327432 open reading frames [72]
Bacterium Solibacter usitatus (strain Ellin 6076)9,970,00010 MB [73]
Bacterium Sorangium cellulosum 13,033,77913 MB9,367Largest known bacterial genome [74] [75]
Amoeboid Polychaos dubium ("Amoeba" dubia)670,000,000,000670 GBLargest known genome. [76] (Disputed) [77]
Plant Genlisea tuberosa 61,000,00061 MBSmallest recorded flowering plant genome, 2014 [78]
Plant Arabidopsis thaliana 135,000,000 [79] 135 MB27,655 [80] First plant genome sequenced, December 2000 [81]
Plant Populus trichocarpa 480,000,000480 MB73,013First tree genome sequenced, September 2006 [82]
Plant Pinus taeda (Loblolly pine)22,180,000,00022.18 GB50,172 Gymnosperms generally have much larger genomes than angiosperms [83] [84]
Plant Fritillaria assyriaca 130,000,000,000130 GB
Plant Paris japonica (Japanese-native, order Liliales)150,000,000,000150 GBFormer largest plant genome known [85]
Plantmoss Physcomitrella patens 480,000,000480 MBFirst genome of a bryophyte sequenced, January 2008 [86]
Fungusyeast Saccharomyces cerevisiae 12,100,00012.1 MB6,294First eukaryotic genome sequenced, 1996 [87]
Fungus Aspergillus nidulans 30,000,00030 MB9,541 [88]
Nematode Pratylenchus coffeae 20,000,00020 MB [89] Smallest animal genome known [90]
Nematode Caenorhabditis elegans 100,300,000100 MB19,000First multicellular animal genome sequenced, December 1998 [91]
Insect Belgica antarctica (Antarctic midge)99,000,00099 MBSmallest insect genome sequenced thus far, likely an adaptation to an extreme environment [92]
Insect Drosophila melanogaster (fruit fly)175,000,000175 MB13,600Size variation based on strain (175–180 Mb; standard y w strain is 175 Mb) [93]
Insect Apis mellifera (honey bee)236,000,000236 MB10,157 [94]
Insect Bombyx mori (silk moth)432,000,000432 MB14,62314,623 predicted genes [95]
Insect Solenopsis invicta (fire ant)480,000,000480 MB16,569 [96]
Crustacean Antarctic krill 48,010,000,00048 GB23,00070-92% repetitive DNA [97]
Amphibian Neuse River waterdog 118,000,000,000118 GBLargest tetrapod genome sequenced as of 2022 [98]
Amphibian Ornate burrowing frog 1,060,000,0001.06 GBSmallest known frog genome [99]
Lizard Armadillo girdled lizard 3,930,000,0003.93 GBLargest known squamate genome [100]
Mammal Plains viscacha rat 8,400,000,0008.4 GBLargest known mammalian genome [101]
Mammal Mus musculus 2,700,000,0002.7 GB20,210 [102]
Mammal Pan paniscus 3,286,640,0003.3 GB20,000Bonobo – estimated genome size 3.29 billion bp [103]
Mammal Homo sapiens 3,117,000,0003.1 GB20,000Homo sapiens genome size estimated at 3.12 Gbp in 2022 [51]

Initial sequencing and analysis of the human genome [104]

Bird Gallus gallus 1,043,000,0001.0 GB20,000 [105]
Fish Tetraodon nigroviridis (type of puffer fish)385,000,000390 MBSmallest vertebrate genome known, estimated to be 340 Mb [106] [107] – 385 Mb [108]
Fish Protopterus aethiopicus (marbled lungfish)130,000,000,000130 GBLargest vertebrate genome known [109] [110] [111]
Plant Tmesipteris truncata (fern ally)160,000,000,000160 GBLargest plant genome known [112]

Genomic alterations

All the cells of an organism originate from a single cell, so they are expected to have identical genomes; however, in some cases, differences arise. Both the process of copying DNA during cell division and exposure to environmental mutagens can result in mutations in somatic cells. In some cases, such mutations lead to cancer because they cause cells to divide more quickly and invade surrounding tissues. [113] In certain lymphocytes in the human immune system, V(D)J recombination generates different genomic sequences such that each cell produces a unique antibody or T cell receptors.

During meiosis, diploid cells divide twice to produce haploid germ cells. During this process, recombination results in a reshuffling of the genetic material from homologous chromosomes so each gamete has a unique genome.

Genome-wide reprogramming

Genome-wide reprogramming in mouse primordial germ cells involves epigenetic imprint erasure leading to totipotency. Reprogramming is facilitated by active DNA demethylation, a process that entails the DNA base excision repair pathway. [114] This pathway is employed in the erasure of CpG methylation (5mC) in primordial germ cells. The erasure of 5mC occurs via its conversion to 5-hydroxymethylcytosine (5hmC) driven by high levels of the ten-eleven dioxygenase enzymes TET1 and TET2. [115]

Genome evolution

Genomes are more than the sum of an organism's genes and have traits that may be measured and studied without reference to the details of any particular genes and their products. Researchers compare traits such as karyotype (chromosome number), genome size, gene order, codon usage bias, and GC-content to determine what mechanisms could have produced the great variety of genomes that exist today (for recent overviews, see Brown 2002; Saccone and Pesole 2003; Benfey and Protopapas 2004; Gibson and Muse 2004; Reese 2004; Gregory 2005).

Duplications play a major role in shaping the genome. Duplication may range from extension of short tandem repeats, to duplication of a cluster of genes, and all the way to duplication of entire chromosomes or even entire genomes. Such duplications are probably fundamental to the creation of genetic novelty.

Horizontal gene transfer is invoked to explain how there is often an extreme similarity between small portions of the genomes of two organisms that are otherwise very distantly related. Horizontal gene transfer seems to be common among many microbes. Also, eukaryotic cells seem to have experienced a transfer of some genetic material from their chloroplast and mitochondrial genomes to their nuclear chromosomes. Recent empirical data suggest an important role of viruses and sub-viral RNA-networks to represent a main driving role to generate genetic novelty and natural genome editing.

In fiction

Works of science fiction illustrate concerns about the availability of genome sequences.

Michael Crichton's 1990 novel Jurassic Park and the subsequent film tell the story of a billionaire who creates a theme park of cloned dinosaurs on a remote island, with disastrous outcomes. A geneticist extracts dinosaur DNA from the blood of ancient mosquitoes and fills in the gaps with DNA from modern species to create several species of dinosaurs. A chaos theorist is asked to give his expert opinion on the safety of engineering an ecosystem with the dinosaurs, and he repeatedly warns that the outcomes of the project will be unpredictable and ultimately uncontrollable. These warnings about the perils of using genomic information are a major theme of the book.

The 1997 film Gattaca is set in a futurist society where genomes of children are engineered to contain the most ideal combination of their parents' traits, and metrics such as risk of heart disease and predicted life expectancy are documented for each person based on their genome. People conceived outside of the eugenics program, known as "In-Valids" suffer discrimination and are relegated to menial occupations. The protagonist of the film is an In-Valid who works to defy the supposed genetic odds and achieve his dream of working as a space navigator. The film warns against a future where genomic information fuels prejudice and extreme class differences between those who can and cannot afford genetically engineered children. [116]

See also

Related Research Articles

<span class="mw-page-title-main">Transposable element</span> Semiparasitic DNA sequence

A transposable element is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material. In the human genome, L1 and Alu elements are two examples. Barbara McClintock's discovery of them earned her a Nobel Prize in 1983. Its importance in personalized medicine is becoming increasingly relevant, as well as gaining more attention in data analytics given the difficulty of analysis in very high dimensional spaces.

<span class="mw-page-title-main">Human genome</span> Complete set of nucleic acid sequences for humans

The human genome is a complete set of nucleic acid sequences for humans, encoded as the DNA within each of the 24 distinct chromosomes in the cell nucleus. A small DNA molecule is found within individual mitochondria. These are usually treated separately as the nuclear genome and the mitochondrial genome. Human genomes include both protein-coding DNA sequences and various types of DNA that does not encode proteins. The latter is a diverse category that includes DNA coding for non-translated RNA, such as that for ribosomal RNA, transfer RNA, ribozymes, small nuclear RNAs, and several types of regulatory RNAs. It also includes promoters and their associated gene-regulatory elements, DNA playing structural and replicatory roles, such as scaffolding regions, telomeres, centromeres, and origins of replication, plus large numbers of transposable elements, inserted viral DNA, non-functional pseudogenes and simple, highly repetitive sequences. Introns make up a large percentage of non-coding DNA. Some of this non-coding DNA is non-functional junk DNA, such as pseudogenes, but there is no firm consensus on the total amount of junk DNA.

Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules. Other functional regions of the non-coding DNA fraction include regulatory sequences that control gene expression; scaffold attachment regions; origins of DNA replication; centromeres; and telomeres. Some non-coding regions appear to be mostly nonfunctional, such as introns, pseudogenes, intergenic DNA, and fragments of transposons and viruses. Regions that are completely nonfunctional are called junk DNA.

Molecular evolution describes how inherited DNA and/or RNA change over evolutionary time, and the consequences of this for proteins and other components of cells and organisms. Molecular evolution is the basis of phylogenetic approaches to describing the tree of life. Molecular evolution overlaps with population genetics, especially on shorter timescales. Topics in molecular evolution include the origins of new genes, the genetic nature of complex traits, the genetic basis of adaptation and speciation, the evolution of development, and patterns and processes underlying genomic changes during evolution.

Repeated sequences are short or long patterns that occur in multiple copies throughout the genome. In many organisms, a significant fraction of the genomic DNA is repetitive, with over two-thirds of the sequence consisting of repetitive elements in humans. Some of these repeated sequences are necessary for maintaining important genome structures such as telomeres or centromeres.

<span class="mw-page-title-main">Retrotransposon</span> Type of genetic component

Retrotransposons are mobile elements which move in the host genome by converting their transcribed RNA into DNA through the reverse transcription. Thus, they differ from Class II transposable elements, or DNA transposons, in utilizing an RNA intermediate for the transposition and leaving the transposition donor site unchanged.

<span class="mw-page-title-main">Epigenome</span> Biological term

In biology, the epigenome of an organism is the collection of chemical changes to its DNA and histone proteins that affects when, where, and how the DNA is expressed; these changes can be passed down to an organism's offspring via transgenerational epigenetic inheritance. Changes to the epigenome can result in changes to the structure of chromatin and changes to the function of the genome. The human epigenome, including DNA methylation and histone modification, is maintained through cell division. The epigenome is essential for normal development and cellular differentiation, enabling cells with the same genetic code to perform different functions. The human epigenome is dynamic and can be influenced by environmental factors such as diet, stress, and toxins.

<span class="mw-page-title-main">Genome size</span> Amount of DNA contained in a genome

Genome size is the total amount of DNA contained within one copy of a single complete genome. It is typically measured in terms of mass in picograms or less frequently in daltons, or as the total number of nucleotide base pairs, usually in megabases. One picogram is equal to 978 megabases. In diploid organisms, genome size is often used interchangeably with the term C-value.

Extrachromosomal DNA is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell. Most DNA in an individual genome is found in chromosomes contained in the nucleus. Multiple forms of extrachromosomal DNA exist, and, while some of these serve important biological functions, they can also play a role in diseases such as cancer.

<span class="mw-page-title-main">Gene</span> Sequence of DNA or RNA that codes for an RNA or protein product

In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes.

Exon shuffling is a molecular mechanism for the formation of new genes. It is a process through which two or more exons from different genes can be brought together ectopically, or the same exon can be duplicated, to create a new exon-intron structure. There are different mechanisms through which exon shuffling occurs: transposon mediated exon shuffling, crossover during sexual recombination of parental genomes and illegitimate recombination.

<span class="mw-page-title-main">Mobile genetic elements</span> DNA sequence whose position in the genome is variable

Mobile genetic elements (MGEs), sometimes called selfish genetic elements, are a type of genetic material that can move around within a genome, or that can be transferred from one species or replicon to another. MGEs are found in all organisms. In humans, approximately 50% of the genome is thought to be MGEs. MGEs play a distinct role in evolution. Gene duplication events can also happen through the mechanism of MGEs. MGEs can also cause mutations in protein coding regions, which alters the protein functions. These mechanisms can also rearrange genes in the host genome generating variation. These mechanism can increase fitness by gaining new or additional functions. An example of MGEs in evolutionary context are that virulence factors and antibiotic resistance genes of MGEs can be transported to share genetic code with neighboring bacteria. However, MGEs can also decrease fitness by introducing disease-causing alleles or mutations. The set of MGEs in an organism is called a mobilome, which is composed of a large number of plasmids, transposons and viruses.

In the fields of bioinformatics and computational biology, Genome survey sequences (GSS) are nucleotide sequences similar to expressed sequence tags (ESTs) that the only difference is that most of them are genomic in origin, rather than mRNA.

<span class="mw-page-title-main">LTR retrotransposon</span> Class I transposable element

LTR retrotransposons are class I transposable elements (TEs) characterized by the presence of long terminal repeats (LTRs) directly flanking an internal coding region. As retrotransposons, they mobilize through reverse transcription of their mRNA and integration of the newly created cDNA into another genomic location. Their mechanism of retrotransposition is shared with retroviruses, with the difference that the rate of horizontal transfer in LTR-retrotransposons is much lower than the vertical transfer by passing active TE insertions to the progeny. LTR retrotransposons that form virus-like particles are classified under Ortervirales.

<span class="mw-page-title-main">Genome evolution</span> Process by which a genome changes in structure or size over time

Genome evolution is the process by which a genome changes in structure (sequence) or size over time. The study of genome evolution involves multiple fields such as structural analysis of the genome, the study of genomic parasites, gene and ancient genome duplications, polyploidy, and comparative genomics. Genome evolution is a constantly changing and evolving field due to the steadily growing number of sequenced genomes, both prokaryotic and eukaryotic, available to the scientific community and the public at large.

<span class="mw-page-title-main">Periannan Senapathy</span>

Periannan Senapathy is a molecular biologist, geneticist, author and entrepreneur. He is the founder, president and chief scientific officer at Genome International Corporation, a biotechnology, bioinformatics, and information technology firm based in Madison, Wisconsin, which develops computational genomics applications of next-generation DNA sequencing (NGS) and clinical decision support systems for analyzing patient genome data that aids in diagnosis and treatment of diseases.

<span class="mw-page-title-main">Long interspersed nuclear element</span>

Long interspersed nuclear elements (LINEs) are a group of non-LTR retrotransposons that are widespread in the genome of many eukaryotes. LINEs contain an internal Pol II promoter to initiate transcription into mRNA, and encode one or two proteins, ORF1 and ORF2. The functional domains present within ORF1 vary greatly among LINEs, but often exhibit RNA/DNA binding activity. ORF2 is essential to successful retrotransposition, and encodes a protein with both reverse transcriptase and endonuclease activity.

<span class="mw-page-title-main">Short interspersed nuclear element</span>

Short interspersed nuclear elements (SINEs) are non-autonomous, non-coding transposable elements (TEs) that are about 100 to 700 base pairs in length. They are a class of retrotransposons, DNA elements that amplify themselves throughout eukaryotic genomes, often through RNA intermediates. SINEs compose about 13% of the mammalian genome.

DNA transposons are DNA sequences, sometimes referred to "jumping genes", that can move and integrate to different locations within the genome. They are class II transposable elements (TEs) that move through a DNA intermediate, as opposed to class I TEs, retrotransposons, that move through an RNA intermediate. DNA transposons can move in the DNA of an organism via a single-or double-stranded DNA intermediate. DNA transposons have been found in both prokaryotic and eukaryotic organisms. They can make up a significant portion of an organism's genome, particularly in eukaryotes. In prokaryotes, TE's can facilitate the horizontal transfer of antibiotic resistance or other genes associated with virulence. After replicating and propagating in a host, all transposon copies become inactivated and are lost unless the transposon passes to a genome by starting a new life cycle with horizontal transfer. It is important to note that DNA transposons do not randomly insert themselves into the genome, but rather show preference for specific sites.

The G-value paradox arises from the lack of correlation between the number of protein-coding genes among eukaryotes and their relative biological complexity. The microscopic nematode Caenorhabditis elegans, for example, is composed of only a thousand cells but has about the same number of genes as a human. Researchers suggest resolution of the paradox may lie in mechanisms such as alternative splicing and complex gene regulation that make the genes of humans and other complex eukaryotes relatively more productive.

References

  1. Roth, Stephanie Clare (1 July 2019). "What is genomic medicine?". Journal of the Medical Library Association. 107 (3). University Library System, University of Pittsburgh: 442–448. doi:10.5195/jmla.2019.604. ISSN   1558-9439. PMC   6579593 . PMID   31258451.
  2. 1 2 3 Graur, Dan; Sater, Amy K.; Cooper, Tim F. (2016). Molecular and Genome Evolution. Sinauer Associates, Inc. ISBN   9781605354699. OCLC   951474209.
  3. Brosius, J (2009). "The Fragmented Gene". Annals of the New York Academy of Sciences. 1178 (1): 186–93. Bibcode:2009NYASA1178..186B. doi:10.1111/j.1749-6632.2009.05004.x. PMID   19845638. S2CID   8279434.
  4. "The Human Genome Project". Genome.gov. Retrieved 29 April 2023.
  5. "First complete sequence of a human genome". National Institutes of Health (NIH). 11 April 2022. Archived from the original on 14 April 2023. Retrieved 29 April 2023.
  6. Hartley, Gabrielle (31 March 2022). "The Human Genome Project pieced together only 92% of the DNA – now scientists have finally filled in the remaining 8%". TheConversation.org. The Conversation US, Inc. Retrieved 4 April 2022.
  7. Winkler HL (1920). Verbreitung und Ursache der Parthenogenesis im Pflanzen- und Tierreiche. Jena: Verlag Fischer.
  8. "definition of Genome in Oxford dictionary". Archived from the original on 1 March 2014. Retrieved 25 March 2014.
  9. "genome" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)
  10. "genome". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 24 August 2022.
  11. Harper, Douglas. "genome". Online Etymology Dictionary .
  12. Lederberg J, McCray AT (2001). "'Ome Sweet 'Omics – A Genealogical Treasury of Words" (PDF). The Scientist. 15 (7). Archived from the original (PDF) on 29 September 2006.
  13. Kirchberger PC, Schmidt ML, and Ochman H (2020). "The ingenuity of bacterial genomes". Annual Review of Microbiology. 74: 815–834. doi:10.1146/annurev-micro-020518-115822. PMID   32692614. S2CID   220699395.
  14. Brown, TA (2018). Genomes 4. New York, NY, USA: Garland Science. ISBN   9780815345084.
  15. "Ensembl Human Assembly and gene annotation (GRCh38)". Ensembl. Retrieved 30 May 2022.
  16. "All about genes". beowulf.org.uk.
  17. "Genome Home". 8 December 2010. Retrieved 27 January 2011.
  18. Zimmer C (18 December 2013). "Toe Fossil Provides Complete Neanderthal Genome" . The New York Times . Archived from the original on 2 January 2022. Retrieved 18 December 2013.
  19. Prüfer K, Racimo F, Patterson N, Jay F, Sankararaman S, Sawyer S, et al. (January 2014). "The complete genome sequence of a Neanderthal from the Altai Mountains". Nature. 505 (7481): 43–49. Bibcode:2014Natur.505...43P. doi:10.1038/nature12886. PMC   4031459 . PMID   24352235.
  20. Wade N (31 May 2007). "Genome of DNA Pioneer Is Deciphered". The New York Times. Retrieved 2 April 2010.
  21. "What's a Genome?". Genomenewsnetwork.org. 15 January 2003. Retrieved 27 January 2011.
  22. "Mapping Factsheet". 29 March 2004. Archived from the original on 19 July 2010. Retrieved 27 January 2011.
  23. Genome Reference Consortium. "Assembling the Genome" . Retrieved 23 August 2016.
  24. Kaplan, Sarah (17 April 2016). "How do your 20,000 genes determine so many wildly different traits? They multitask". The Washington Post. Retrieved 27 August 2016.
  25. Check Hayden, Erika (2015). "Scientists hope to attract millions to 'DNA.LAND'". Nature. doi:10.1038/nature.2015.18514. S2CID   211729308.
  26. Zimmer, Carl (25 July 2016). "Game of Genomes, Episode 13: Answers and Questions". STAT. Retrieved 27 August 2016.
  27. Gelderblom, Hans R. (1996). Structure and Classification of Viruses (4th ed.). Galveston, TX: The University of Texas Medical Branch at Galveston. ISBN   9780963117212. PMID   21413309.
  28. Samson RY, Bell SD (2014). "Archaeal chromosome biology". Journal of Molecular Microbiology and Biotechnology. 24 (5–6): 420–27. doi:10.1159/000368854. PMC   5175462 . PMID   25732343.
  29. Chaconas G, Chen CW (2005). "Replication of Linear Bacterial Chromosomes: No Longer Going Around in Circles". The Bacterial Chromosome. pp. 525–540. doi:10.1128/9781555817640.ch29. ISBN   9781555812324.
  30. "Bacterial Chromosomes". Microbial Genetics. 2002.
  31. 1 2 Koonin EV, Wolf YI (July 2010). "Constraints and plasticity in genome and molecular-phenome evolution". Nature Reviews. Genetics. 11 (7): 487–98. doi:10.1038/nrg2810. PMC   3273317 . PMID   20548290.
  32. McCutcheon JP, Moran NA (November 2011). "Extreme genome reduction in symbiotic bacteria". Nature Reviews. Microbiology. 10 (1): 13–26. doi:10.1038/nrmicro2670. PMID   22064560. S2CID   7175976.
  33. Land M, Hauser L, Jun SR, Nookaew I, Leuze MR, Ahn TH, Karpinets T, Lund O, Kora G, Wassenaar T, Poudel S, Ussery DW (March 2015). "Insights from 20 years of bacterial genome sequencing". Functional & Integrative Genomics. 15 (2): 141–61. doi:10.1007/s10142-015-0433-4. PMC   4361730 . PMID   25722247.
  34. "Scientists sequence asexual tiny worm whose lineage stretches back 18 million years". ScienceDaily. Retrieved 7 November 2017.
  35. Khandelwal S (March 1990). "Chromosome evolution in the genus Ophioglossum L.". Botanical Journal of the Linnean Society. 102 (3): 205–17. doi:10.1111/j.1095-8339.1990.tb01876.x.
  36. 1 2 3 4 Zhou, Wanding; Liang, Gangning; Molloy, Peter L.; Jones, Peter A. (11 August 2020). "DNA methylation enables transposable element-driven genome expansion". Proceedings of the National Academy of Sciences of the United States of America. 117 (32): 19359–19366. Bibcode:2020PNAS..11719359Z. doi: 10.1073/pnas.1921719117 . ISSN   1091-6490. PMC   7431005 . PMID   32719115.
  37. 1 2 3 Lewin B (2004). Genes VIII (8th ed.). Upper Saddle River, NJ: Pearson/Prentice Hall. ISBN   978-0-13-143981-8.
  38. Stojanovic N, ed. (2007). Computational genomics : current methods. Wymondham: Horizon Bioscience. ISBN   978-1-904933-30-4.
  39. 1 2 3 Padeken J, Zeller P, Gasser SM (April 2015). "Repeat DNA in genome organization and stability". Current Opinion in Genetics & Development. 31: 12–19. doi:10.1016/j.gde.2015.03.009. PMID   25917896.
  40. 1 2 Usdin K (July 2008). "The biological effects of simple tandem repeats: lessons from the repeat expansion diseases". Genome Research. 18 (7): 1011–19. doi:10.1101/gr.070409.107. PMC   3960014 . PMID   18593815.
  41. Li YC, Korol AB, Fahima T, Beiles A, Nevo E (December 2002). "Microsatellites: genomic distribution, putative functions and mutational mechanisms: a review". Molecular Ecology. 11 (12): 2453–65. Bibcode:2002MolEc..11.2453L. doi: 10.1046/j.1365-294X.2002.01643.x . PMID   12453231. S2CID   23606208.
  42. 1 2 Wessler SR (November 2006). "Transposable elements and the evolution of eukaryotic genomes". Proceedings of the National Academy of Sciences of the United States of America. 103 (47): 17600–01. Bibcode:2006PNAS..10317600W. doi: 10.1073/pnas.0607612103 . PMC   1693792 . PMID   17101965.
  43. 1 2 3 4 5 Kazazian HH (March 2004). "Mobile elements: drivers of genome evolution". Science. 303 (5664): 1626–32. Bibcode:2004Sci...303.1626K. doi:10.1126/science.1089670. PMID   15016989. S2CID   1956932.
  44. "Transposon | genetics". Encyclopedia Britannica. Retrieved 5 December 2020.
  45. Sanders, Mark Frederick (2019). Genetic Analysis: an integrated approach third edition. New York: Pearson, always learning, and mastering. p. 425. ISBN   9780134605173.
  46. Deininger PL, Moran JV, Batzer MA, Kazazian HH (December 2003). "Mobile elements and mammalian genome evolution". Current Opinion in Genetics & Development. 13 (6): 651–58. doi:10.1016/j.gde.2003.10.013. PMID   14638329.
  47. Kidwell MG, Lisch DR (March 2000). "Transposable elements and host genome evolution". Trends in Ecology & Evolution. 15 (3): 95–99. doi:10.1016/S0169-5347(99)01817-0. PMID   10675923.
  48. Richard GF, Kerrest A, Dujon B (December 2008). "Comparative genomics and molecular dynamics of DNA repeats in eukaryotes". Microbiology and Molecular Biology Reviews. 72 (4): 686–727. doi:10.1128/MMBR.00011-08. PMC   2593564 . PMID   19052325.
  49. Cordaux R, Batzer MA (October 2009). "The impact of retrotransposons on human genome evolution". Nature Reviews. Genetics. 10 (10): 691–703. doi:10.1038/nrg2640. PMC   2884099 . PMID   19763152.
  50. Han JS, Boeke JD (August 2005). "LINE-1 retrotransposons: modulators of quantity and quality of mammalian gene expression?". BioEssays. 27 (8): 775–84. doi:10.1002/bies.20257. PMID   16015595. S2CID   26424042.
  51. 1 2 Nurk, Sergey; et al. (31 March 2022). "The complete sequence of a human genome" (PDF). Science. 376 (6588): 44–53. Bibcode:2022Sci...376...44N. doi:10.1126/science.abj6987. PMC   9186530 . PMID   35357919. S2CID   235233625. Archived (PDF) from the original on 26 May 2022.
  52. Gregory TR, Nicol JA, Tamm H, Kullman B, Kullman K, Leitch IJ, Murray BG, Kapraun DF, Greilhuber J, Bennett MD (January 2007). "Eukaryotic genome size databases". Nucleic Acids Research. 35 (Database issue): D332–38. doi:10.1093/nar/gkl828. PMC   1669731 . PMID   17090588.
  53. Glass JI, Assad-Garcia N, Alperovich N, Yooseph S, Lewis MR, Maruf M, Hutchison CA, Smith HO, Venter JC (January 2006). "Essential genes of a minimal bacterium". Proceedings of the National Academy of Sciences of the United States of America. 103 (2): 425–30. Bibcode:2006PNAS..103..425G. doi: 10.1073/pnas.0510013103 . PMC   1324956 . PMID   16407165.
  54. Forster AC, Church GM (2006). "Towards synthesis of a minimal cell". Molecular Systems Biology. 2 (1): 45. doi:10.1038/msb4100090. PMC   1681520 . PMID   16924266.
  55. Mankertz P (2008). "Molecular Biology of Porcine Circoviruses". Animal Viruses: Molecular Biology. Caister Academic Press. ISBN   978-1-904455-22-6.
  56. Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M (April 1976). "Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". Nature. 260 (5551): 500–07. Bibcode:1976Natur.260..500F. doi:10.1038/260500a0. PMID   1264203. S2CID   4289674.
  57. Fiers W, Contreras R, Haegemann G, Rogiers R, Van de Voorde A, Van Heuverswyn H, Van Herreweghe J, Volckaert G, Ysebaert M (May 1978). "Complete nucleotide sequence of SV40 DNA". Nature. 273 (5658): 113–20. Bibcode:1978Natur.273..113F. doi:10.1038/273113a0. PMID   205802. S2CID   1634424.
  58. Sanger F, Air GM, Barrell BG, Brown NL, Coulson AR, Fiddes CA, Hutchison CA, Slocombe PM, Smith M (February 1977). "Nucleotide sequence of bacteriophage phi X174 DNA". Nature. 265 (5596): 687–95. Bibcode:1977Natur.265..687S. doi:10.1038/265687a0. PMID   870828. S2CID   4206886.
  59. "Virology – Human Immunodeficiency Virus And Aids, Structure: The Genome And Proteins of HIV". Pathmicro.med.sc.edu. 1 July 2010. Retrieved 27 January 2011.
  60. Thomason L, Court DL, Bubunenko M, Costantino N, Wilson H, Datta S, Oppenheim A (April 2007). "Recombineering: Genetic Engineering in Bacteria Using Homologous Recombination". Current Protocols in Molecular Biology. Chapter 1: Unit 1.16. doi:10.1002/0471142727.mb0116s78. ISBN   978-0-471-14272-0. PMID   18265390. S2CID   490362.
  61. Court DL, Oppenheim AB, Adhya SL (January 2007). "A new look at bacteriophage lambda genetic networks". Journal of Bacteriology. 189 (2): 298–304. doi:10.1128/JB.01215-06. PMC   1797383 . PMID   17085553.
  62. Sanger F, Coulson AR, Hong GF, Hill DF, Petersen GB (December 1982). "Nucleotide sequence of bacteriophage lambda DNA". Journal of Molecular Biology. 162 (4): 729–73. doi:10.1016/0022-2836(82)90546-0. PMID   6221115.
  63. Legendre M, Arslan D, Abergel C, Claverie JM (January 2012). "Genomics of Megavirus and the elusive fourth domain of Life". Communicative & Integrative Biology. 5 (1): 102–06. doi:10.4161/cib.18624. PMC   3291303 . PMID   22482024.
  64. Philippe N, Legendre M, Doutre G, Couté Y, Poirot O, Lescot M, Arslan D, Seltzer V, Bertaux L, Bruley C, Garin J, Claverie JM, Abergel C (July 2013). "Pandoraviruses: amoeba viruses with genomes up to 2.5 Mb reaching that of parasitic eukaryotes" (PDF). Science. 341 (6143): 281–86. Bibcode:2013Sci...341..281P. doi:10.1126/science.1239181. PMID   23869018. S2CID   16877147.
  65. Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden R, Young IG (April 1981). "Sequence and organization of the human mitochondrial genome". Nature. 290 (5806): 457–65. Bibcode:1981Natur.290..457A. doi:10.1038/290457a0. PMID   7219534. S2CID   4355527.
  66. Bennett GM, Moran NA (5 August 2013). "Small, smaller, smallest: the origins and evolution of ancient dual symbioses in a Phloem-feeding insect". Genome Biology and Evolution. 5 (9): 1675–88. doi:10.1093/gbe/evt118. PMC   3787670 . PMID   23918810.
  67. Shigenobu S, Watanabe H, Hattori M, Sakaki Y, Ishikawa H (September 2000). "Genome sequence of the endocellular bacterial symbiont of aphids Buchnera sp. APS". Nature. 407 (6800): 81–86. Bibcode:2000Natur.407...81S. doi: 10.1038/35024074 . PMID   10993077.
  68. Rocap G, Larimer FW, Lamerdin J, Malfatti S, Chain P, Ahlgren NA, et al. (August 2003). "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation". Nature. 424 (6952): 1042–47. Bibcode:2003Natur.424.1042R. doi: 10.1038/nature01947 . PMID   12917642. S2CID   4344597.
  69. Dufresne A, Salanoubat M, Partensky F, Artiguenave F, Axmann IM, Barbe V, et al. (August 2003). "Genome sequence of the cyanobacterium Prochlorococcus marinus SS120, a nearly minimal oxyphototrophic genome". Proceedings of the National Academy of Sciences of the United States of America. 100 (17): 10020–25. Bibcode:2003PNAS..10010020D. doi: 10.1073/pnas.1733211100 . PMC   187748 . PMID   12917486.
  70. Fleischmann RD, Adams MD, White O, Clayton RA, Kirkness EF, Kerlavage AR, Bult CJ, Tomb JF, Dougherty BA, Merrick JM (July 1995). "Whole-genome random sequencing and assembly of Haemophilus influenzae Rd". Science. 269 (5223): 496–512. Bibcode:1995Sci...269..496F. doi:10.1126/science.7542800. PMID   7542800. S2CID   10423613.
  71. Blattner FR, Plunkett G, Bloch CA, Perna NT, Burland V, Riley M, et al. (September 1997). "The complete genome sequence of Escherichia coli K-12". Science. 277 (5331): 1453–62. doi: 10.1126/science.277.5331.1453 . PMID   9278503.
  72. Meeks JC, Elhai J, Thiel T, Potts M, Larimer F, Lamerdin J, Predki P, Atlas R (2001). "An overview of the genome of Nostoc punctiforme, a multicellular, symbiotic cyanobacterium". Photosynthesis Research. 70 (1): 85–106. doi:10.1023/A:1013840025518. PMID   16228364. S2CID   8752382.
  73. Challacombe JF, Eichorst SA, Hauser L, Land M, Xie G, Kuske CR (15 September 2011). Steinke D (ed.). "Biological consequences of ancient gene acquisition and duplication in the large genome of Candidatus Solibacter usitatus Ellin6076". PLOS ONE. 6 (9): e24882. Bibcode:2011PLoSO...624882C. doi: 10.1371/journal.pone.0024882 . PMC   3174227 . PMID   21949776.
  74. Schneiker, Susanne; Perlova, Olena; Kaiser, Olaf; Gerth, Klaus; Alici, Aysel; Altmeyer, Matthias O; Bartels, Daniela; Bekel, Thomas; Beyer, Stefan; Bode, Edna; Bode, Helge B; Bolten, Christoph J; Choudhuri, Jomuna V; Doss, Sabrina; Elnakady, Yasser A (November 2007). "Complete genome sequence of the myxobacterium Sorangium cellulosum". Nature Biotechnology. 25 (11): 1281–1289. doi: 10.1038/nbt1354 . ISSN   1087-0156.
  75. "Largest known bacterial genome size - Bacteria Sorangium cellulosum - BNID 104469". bionumbers.hms.harvard.edu. Retrieved 2 May 2024.
  76. Parfrey LW, Lahr DJ, Katz LA (April 2008). "The dynamic nature of eukaryotic genomes". Molecular Biology and Evolution. 25 (4): 787–94. doi:10.1093/molbev/msn032. PMC   2933061 . PMID   18258610.
  77. ScienceShot: Biggest Genome Ever Archived 11 October 2010 at the Wayback Machine , comments: "The measurement for Amoeba dubia and other protozoa which have been reported to have very large genomes were made in the 1960s using a rough biochemical approach which is now considered to be an unreliable method for accurate genome size determinations."
  78. Fleischmann A, Michael TP, Rivadavia F, Sousa A, Wang W, Temsch EM, Greilhuber J, Müller KF, Heubl G (December 2014). "Evolution of genome size and chromosome number in the carnivorous plant genus Genlisea (Lentibulariaceae), with a new estimate of the minimum genome size in angiosperms". Annals of Botany. 114 (8): 1651–63. doi:10.1093/aob/mcu189. PMC   4649684 . PMID   25274549.
  79. "Genome Assembly". The Arabidopsis Information Resource (TAIR).
  80. "Details - Arabidopsis thaliana - Ensembl Genomes 40". plants.ensembl.org.
  81. Greilhuber J, Borsch T, Müller K, Worberg A, Porembski S, Barthlott W (November 2006). "Smallest angiosperm genomes found in lentibulariaceae, with chromosomes of bacterial size". Plant Biology. 8 (6): 770–77. Bibcode:2006PlBio...8..770G. doi:10.1055/s-2006-924101. PMID   17203433. S2CID   260252929.
  82. Tuskan GA, Difazio S, Jansson S, Bohlmann J, Grigoriev I, Hellsten U, et al. (September 2006). "The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)" (PDF). Science. 313 (5793): 1596–604. Bibcode:2006Sci...313.1596T. doi:10.1126/science.1128691. OSTI   901819. PMID   16973872. S2CID   7717980.
  83. Zimin, Aleksey; Stevens, Kristian; et al. (March 2014). "Sequencing and Assembly of the 22-Gb Loblolly Pine Genome". Genetics. 196 (3): 875–890. doi:10.1534/genetics.113.159715. PMC   3948813 . PMID   24653210.
  84. Neale, David B; et al. (March 2014). "Decoding the massive genome of loblolly pine using haploid DNA and novel assembly strategies". Genome Biology. 15 (3): R59. doi: 10.1186/gb-2014-15-3-r59 . PMC   4053751 . PMID   24647006.
  85. Pellicer J, Fay MF, Leitch IJ (15 September 2010). "The largest eukaryotic genome of them all?". Botanical Journal of the Linnean Society. 164 (1): 10–15. doi: 10.1111/j.1095-8339.2010.01072.x .
  86. Lang D, Zimmer AD, Rensing SA, Reski R (October 2008). "Exploring plant biodiversity: the Physcomitrella genome and beyond". Trends in Plant Science. 13 (10): 542–49. doi:10.1016/j.tplants.2008.07.002. PMID   18762443.
  87. "Saccharomyces Genome Database". Yeastgenome.org. Retrieved 27 January 2011.
  88. Galagan JE, Calvo SE, Cuomo C, Ma LJ, Wortman JR, Batzoglou S, et al. (December 2005). "Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae". Nature. 438 (7071): 1105–15. Bibcode:2005Natur.438.1105G. doi: 10.1038/nature04341 . PMID   16372000.
  89. Leroy S, Bouamer S, Morand S, Fargette M (2007). "Genome size of plant-parasitic nematodes". Nematology. 9 (3): 449–50. doi:10.1163/156854107781352089.
  90. Gregory TR (2005). "Animal Genome Size Database". Gregory, T.R. (2016). Animal Genome Size Database.
  91. The C. elegans Sequencing Consortium (December 1998). "Genome sequence of the nematode C. elegans: a platform for investigating biology". Science. 282 (5396): 2012–18. Bibcode:1998Sci...282.2012.. doi:10.1126/science.282.5396.2012. PMID   9851916. S2CID   16873716.
  92. Kelley, Joanna L.; Peyton, Justin T.; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M.; Yee, Muh-Ching; Johnston, J. Spencer; Bustamante, Carlos D.; Lee, Richard E.; Denlinger, David L. (12 August 2014). "Compact genome of the Antarctic midge is likely an adaptation to an extreme environment". Nature Communications. 5: 4611. Bibcode:2014NatCo...5.4611K. doi:10.1038/ncomms5611. ISSN   2041-1723. PMC   4164542 . PMID   25118180.
  93. Ellis LL, Huang W, Quinn AM, Ahuja A, Alfrejd B, Gomez FE, Hjelmen CE, Moore KL, Mackay TF, Johnston JS, Tarone AM (July 2014). "Intrapopulation genome size variation in D. melanogaster reflects life history variation and plasticity". PLOS Genetics. 10 (7): e1004522. doi: 10.1371/journal.pgen.1004522 . PMC   4109859 . PMID   25057905.
  94. Honeybee Genome Sequencing Consortium (October 2006). "Insights into social insects from the genome of the honeybee Apis mellifera". Nature. 443 (7114): 931–49. Bibcode:2006Natur.443..931T. doi:10.1038/nature05260. PMC   2048586 . PMID   17073008.
  95. The International Silkworm Genome (December 2008). "The genome of a lepidopteran model insect, the silkworm Bombyx mori". Insect Biochemistry and Molecular Biology. 38 (12): 1036–45. doi:10.1016/j.ibmb.2008.11.004. PMID   19121390.
  96. Wurm Y, Wang J, Riba-Grognuz O, Corona M, Nygaard S, Hunt BG, et al. (April 2011). "The genome of the fire ant Solenopsis invicta". Proceedings of the National Academy of Sciences of the United States of America. 108 (14): 5679–84. Bibcode:2011PNAS..108.5679W. doi: 10.1073/pnas.1009690108 . PMC   3078418 . PMID   21282665.
  97. Shao, Changwei; Sun, Shuai; Liu, Kaiqiang; Wang, Jiahao; Li, Shuo; Liu, Qun; Deagle, Bruce E.; Seim, Inge; Biscontin, Alberto; Wang, Qian; Liu, Xin; Kawaguchi, So; Liu, Yalin; Jarman, Simon; Wang, Yue (16 March 2023). "The enormous repetitive Antarctic krill genome reveals environmental adaptations and population insights". Cell Glish. 186 (6): 1279–1294.e19. doi: 10.1016/j.cell.2023.02.005 . hdl: 11577/3472081 . ISSN   0092-8674. PMID   36868220. S2CID   257286259.
  98. "Junk DNA Deforms Salamander Bodies". Scientific American . February 2022. Archived from the original on 22 May 2023.
  99. A bird-like genome from a frog - PNAS
  100. Ecological factors and parity mode correlate with genome size variation in squamate reptiles
  101. Evolution of the Largest Mammalian Genome
  102. Church DM, Goodstadt L, Hillier LW, Zody MC, Goldstein S, She X, et al. (May 2009). Roberts RJ (ed.). "Lineage-specific biology revealed by a finished genome assembly of the mouse". PLOS Biology. 7 (5): e1000112. doi: 10.1371/journal.pbio.1000112 . PMC   2680341 . PMID   19468303.
  103. "Pan paniscus (pygmy chimpanzee)". nih.gov. Retrieved 30 June 2016.
  104. Venter JC, Adams MD, Myers EW, Li PW, Mural RJ, Sutton GG, et al. (February 2001). "The sequence of the human genome". Science. 291 (5507): 1304–51. Bibcode:2001Sci...291.1304V. doi: 10.1126/science.1058040 . PMID   11181995.
  105. International Chicken Genome Sequencing Consortium (December 2004). "Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution". Nature. 432 (7018): 695–716. Bibcode:2004Natur.432..695C. doi: 10.1038/nature03154 . ISSN   0028-0836. PMID   15592404.
  106. Roest Crollius H, Jaillon O, Dasilva C, Ozouf-Costaz C, Fizames C, Fischer C, Bouneau L, Billault A, Quetier F, Saurin W, Bernot A, Weissenbach J (July 2000). "Characterization and repeat analysis of the compact genome of the freshwater pufferfish Tetraodon nigroviridis". Genome Research. 10 (7): 939–49. doi:10.1101/gr.10.7.939. PMC   310905 . PMID   10899143.
  107. Jaillon O, Aury JM, Brunet F, Petit JL, Stange-Thomann N, Mauceli E, et al. (October 2004). "Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype". Nature. 431 (7011): 946–57. Bibcode:2004Natur.431..946J. doi: 10.1038/nature03025 . PMID   15496914.
  108. "Tetraodon Project Information". Archived from the original on 26 September 2012. Retrieved 17 October 2012.
  109. Leitch, I J (August 2007). "Genome sizes through the ages". Heredity. 99 (2): 121–122. doi:10.1038/sj.hdy.6800981. ISSN   0018-067X.
  110. "Genome size and chromosome number database we - Various - BNID 100597". bionumbers.hms.harvard.edu. Retrieved 17 August 2024.
  111. "Animal Genome Size Database:: Statistics". www.genomesize.com. Retrieved 17 August 2024.
  112. Zimmer, Carl (31 May 2024). "Scientists Find the Largest Known Genome Inside a Small Plant - A fern from a Pacific island carries 50 times as much DNA as humans do". The New York Times . Archived from the original on 31 May 2024. Retrieved 1 June 2024.
  113. Martincorena I, Campbell PJ (September 2015). "Somatic mutation in cancer and normal cells". Science. 349 (6255): 1483–89. Bibcode:2015Sci...349.1483M. doi:10.1126/science.aab4082. PMID   26404825. S2CID   13945473.
  114. Hajkova P, Jeffries SJ, Lee C, Miller N, Jackson SP, Surani MA (July 2010). "Genome-wide reprogramming in the mouse germ line entails the base excision repair pathway". Science. 329 (5987): 78–82. Bibcode:2010Sci...329...78H. doi:10.1126/science.1187945. PMC   3863715 . PMID   20595612.
  115. Hackett JA, Sengupta R, Zylicz JJ, Murakami K, Lee C, Down TA, Surani MA (January 2013). "Germline DNA demethylation dynamics and imprint erasure through 5-hydroxymethylcytosine". Science. 339 (6118): 448–52. Bibcode:2013Sci...339..448H. doi:10.1126/science.1229277. PMC   3847602 . PMID   23223451.
  116. "Gattaca (movie)". Rotten Tomatoes. 24 October 1997.

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