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74-414: Ehrlichia is a genus of Rickettsiales bacteria that are transmitted to vertebrates by ticks. These bacteria cause the disease ehrlichiosis , which is considered zoonotic , because the main reservoirs for the disease are animals. Ehrlichia species are obligately intracellular pathogens and are transported between cells through the host cell filopodia during initial stages of infection, whereas in

148-498: A population bottleneck , or, in some cases, natural selection , can lead to fixation. The classic example of a unitary pseudogene is the gene that presumably coded the enzyme L-gulono-γ-lactone oxidase (GULO) in primates. In all mammals studied besides primates (except guinea pigs), GULO aids in the biosynthesis of ascorbic acid (vitamin C), but it exists as a disabled gene (GULOP) in humans and other primates. Another more recent example of

222-695: A combination of similarity or homology to a known gene, together with a loss of some functionality. That is, although every pseudogene has a DNA sequence that is similar to some functional gene, they are usually unable to produce functional final protein products. Pseudogenes are sometimes difficult to identify and characterize in genomes, because the two requirements of similarity and loss of functionality are usually implied through sequence alignments rather than biologically proven. Pseudogenes for RNA genes are usually more difficult to discover as they do not need to be translated and thus do not have "reading frames". A number of rRNA pseudogenes have been identified on

296-411: A criterion to establish them as non-essential. Lopes-Marques et al. define polymorphic pseudogenes as genes that carry a LoF allele with a frequency higher than 1% (in global or certain sub-populations) and without overt pathogenic consequences when homozygous. While the vast majority of pseudogenes have lost their function, some cases have emerged in which a pseudogene either re-gained its original or

370-549: A disabled gene links the deactivation of the caspase 12 gene (through a nonsense mutation ) to positive selection in humans. Some pseudogenes are still intact in some individuals but inactivated (mutated) in others. Abascal et al. have called these pseudogenes "polymorphic". They are often homozygous for loss-of-function (LoF) variants, that is, in many people both copies are inactive. Polymorphic pseudogenes often represent non-essential (or dispensable) genes, as opposed to essential genes, and their frequent mutations are actually

444-409: A duplicated gene's functionality usually has little effect on an organism's fitness , since an intact functional copy still exists. According to some evolutionary models, shared duplicated pseudogenes indicate the evolutionary relatedness of humans and the other primates. If pseudogenization is due to gene duplication, it usually occurs in the first few million years after the gene duplication, provided

518-426: A fitness advantage that kept this lineage going. Unique glycoproteins and major outer membrane proteins can be expressed variously using 25 different genes. The glycoproteins are important targets of the host immune response, attachment to the host cell, and other features in the immune response. The more outer-membrane protein genes that can be expressed, the higher the chance the organism can avoid being recognized by

592-436: A gene from being normally transcribed or translated , and thus the gene may become less- or non-functional or "deactivated". These are the same mechanisms by which non-processed genes become pseudogenes, but the difference in this case is that the gene was not duplicated before pseudogenization. Normally, such a pseudogene would be unlikely to become fixed in a population, but various population effects, such as genetic drift ,

666-567: A larger variety of hosts. Heartwater , caused by E. ruminantium , is a prevalent tick-borne disease of livestock in Africa and the Caribbean, but also threatens the American mainland. Three strains have arisen from this species due to evolutionary change in their genomes. When sequencing their genomes, many active genomic modifications have occurred, such as high substitution rates, truncated genes, and

740-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

814-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

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888-685: A profound effect on the fitness of an organism. The survival of Ehrlichia depends greatly on the immune response of its host. With a higher range of outer membrane proteins, the parasite can evade the immune system of the host more effectively and establish persistent infection. The most pronounced evidence of evolution in the genome size of Erhlichia is the presence of tandem repeats , which vary highly among individuals and species. Over time, individuals may expand or contract parts of their genes and alleles , which adds genetic variation and may sometimes affect phenotype . Ehrlichia and its closely related genus Anaplasma show extreme diversity in

962-493: A pseudogene and will be either unexpressed or functionless. This kind of evolutionary fate is shown by population genetic modeling and also by genome analysis . According to evolutionary context, these pseudogenes will either be deleted or become so distinct from the parental genes so that they will no longer be identifiable. Relatively young pseudogenes can be recognized due to their sequence similarity. Various mutations (such as indels and nonsense mutations ) can prevent

1036-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

1110-504: A role in regulating protein-coding transcripts, as reviewed. One of the many examples is psiPPM1K. Processing of RNAs transcribed from psiPPM1K yield siRNAs that can act to suppress the most common type of liver cancer, hepatocellular carcinoma . This and much other research has led to considerable excitement about the possibility of targeting pseudogenes with/as therapeutic agents piRNAs . Some piRNAs are derived from pseudogenes located in piRNA clusters. Those piRNAs regulate genes via

1184-473: A similar function or evolved a new function. In the human genome , a number of examples have been identified that were originally classified as pseudogenes but later discovered to have a functional, although not necessarily protein-coding, role. Examples include the following: The rapid proliferation of DNA sequencing technologies has led to the identification of many apparent pseudogenes using gene prediction techniques. Pseudogenes are often identified by

1258-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1332-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

1406-558: A type of junk DNA . Most non-bacterial genomes contain many pseudogenes, often as many as functional genes. This is not surprising, since various biological processes are expected to accidentally create pseudogenes, and there are no specialized mechanisms to remove them from genomes. Eventually pseudogenes may be deleted from their genomes by chance of DNA replication or DNA repair errors, or they may accumulate so many mutational changes that they are no longer recognizable as former genes. Analysis of these degeneration events helps clarify

1480-637: Is a fairly common event that has had a huge impact on the composition of the genome. For example, somewhere between 30 and 44% of the human genome consists of repetitive elements such as SINEs and LINEs (see retrotransposons ). In the process of retrotransposition, a portion of the mRNA or hnRNA transcript of a gene is spontaneously reverse transcribed back into DNA and inserted into chromosomal DNA. Although retrotransposons usually create copies of themselves, it has been shown in an in vitro system that they can create retrotransposed copies of random genes, too. Once these pseudogenes are inserted back into

1554-508: Is another common and important process in the evolution of genomes. A copy of a functional gene may arise as a result of a gene duplication event caused by homologous recombination at, for example, repetitive SINE sequences on misaligned chromosomes and subsequently acquire mutations that cause the copy to lose the original gene's function. Duplicated pseudogenes usually have all the same characteristics as genes, including an intact exon - intron structure and regulatory sequences. The loss of

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1628-479: Is common truncation of the 5' end relative to the parent sequence, which is a result of the relatively non-processive retrotransposition mechanism that creates processed pseudogenes. Processed pseudogenes are continually being created in primates. Human populations, for example, have distinct sets of processed pseudogenes across its individuals. It has been shown that processed pseudogenes accumulate mutations faster than non-processed pseudogenes. Gene duplication

1702-418: Is currently named Ehrlichia ruminantium . In 1945, an "infection and treatment" method for livestock was developed. This is still the only commercially available "vaccine" against the disease, which is not a true vaccine, but intentional exposure to the disease with monitoring and antibiotic treatment if needed. In 1985, the organism was first propagated reliably in tissue culture. A new species of Ehrlichia

1776-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

1850-416: Is found only in neurons . This finding of tissue-specific biologically-functional genes that could have been classified as pseudogenes by in silico analysis complicates the analysis of sequence data. Another Drosophilia pseudo-pseudogene is jingwei , which encodes a functional alcohol dehydrogenase enzyme in vivo . As of 2012, it appeared that there are approximately 12,000–14,000 pseudogenes in

1924-671: Is not an order to which functional genes are lost first. For example, the oldest pseudogenes in Mycobacterium leprae are in RNA polymerases and the biosynthesis of secondary metabolites while the oldest ones in Shigella flexneri and Shigella typhi are in DNA replication , recombination, and repair . Since most bacteria that carry pseudogenes are either symbionts or obligate intracellular parasites, genome size eventually reduces. An extreme example

1998-541: Is observed less frequently than E. chaffeensis. During 2008–2012, 4,613 cases of E. chaffeensis infections were reported through the National Notifiable Diseases Surveillance System (NNDSS). The incidence rate (IR) was 3.2 cases per million person-years (PYs). The hospitalization rate (HR) was 57% and the case fatality rate (CFR) was 1%. During that same time, 55 cases of E. ewingii infections were reported through NNDSS. The national IR

2072-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

2146-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

2220-466: Is the genome of Mycobacterium leprae , an obligate parasite and the causative agent of leprosy . It has been reported to have 1,133 pseudogenes which give rise to approximately 50% of its transcriptome . The effect of pseudogenes and genome reduction can be further seen when compared to Mycobacterium marinum , a pathogen from the same family. Mycobacteirum marinum has a larger genome compared to Mycobacterium leprae because it can survive outside

2294-406: Is thought to originate from gene duplication events, followed by the fusion and fission of resulting paralogs of the gene. These duplication, fusion, and fission events form multiple gene copies and fragments, which are able to accumulate mutations. These copies and fragments of membrane proteins can then recombine, through a process called gene conversion , resulting in a new gene variant. This has

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2368-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

2442-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

2516-451: The codon for the initiating methionine and thus prevents translation of the normal PTEN protein. In spite of that, PTENP1 appears to play a role in oncogenesis . The 3' UTR of PTENP1 mRNA functions as a decoy of PTEN mRNA by targeting micro RNAs due to its similarity to the PTEN gene, and overexpression of the 3' UTR resulted in an increase of PTEN protein level. That is, overexpression of

2590-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

2664-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

2738-772: The Eastern and Southeastern United States, while A. phagocytophilum is spread by the Ixodes scapularis tick in the Upper Midwest; 1,518 cases of E. chaffeensis were recorded in southeastern, south-central and mid-Atlantic areas of the country in 2013. Despite the first cases of "E. ewingii" appearing in the Missouri in the year 1999, this strain was not reportable to health officials until 2008. Since 2008, there have been reported human cases of E. ewingii in Oklahoma, Arkansas and Tennessee though it

2812-901: The PTENP1 3' UTR leads to increased regulation and suppression of cancerous tumors. The biology of this system is basically the inverse of the BRAF system described above. Potogenes . Pseudogenes can, over evolutionary time scales, participate in gene conversion and other mutational events that may give rise to new or newly functional genes. This has led to the concept that pseudo genes could be viewed as pot ogenes: pot ential genes for evolutionary diversification. Pseudogenes are found in bacteria . Most are found in bacteria that are not free-living; that is, they are either symbionts or obligate intracellular parasites . Thus, they do not require many genes that are needed by free-living bacteria, such as gene associated with metabolism and DNA repair. However, there

2886-406: The amount of BRAF protein is kept under control in cells through the action of miRNA. In normal situations, the amount of RNA from BRAF and the pseudogene BRAFP1 compete for miRNA, but the balance of the 2 RNAs is such that cells grow normally. However, when BRAFP1 RNA expression is increased (either experimentally or by natural mutations), less miRNA is available to control the expression of BRAF, and

2960-440: The appearance of a premature stop codon in a predicted mRNA sequence, which would, in theory, prevent synthesis ( translation ) of the normal protein product of the original gene. There have been some reports of translational readthrough of such premature stop codons in mammals. As alluded to in the figure above, a small amount of the protein product of such readthrough may still be recognizable and function at some level. If so,

3034-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

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3108-495: The basis of changes in rDNA array ends. Pseudogenes can complicate molecular genetic studies. For example, amplification of a gene by PCR may simultaneously amplify a pseudogene that shares similar sequences. This is known as PCR bias or amplification bias. Similarly, pseudogenes are sometimes annotated as genes in genome sequences. Processed pseudogenes often pose a problem for gene prediction programs, often being misidentified as real genes or exons. It has been proposed that

3182-453: The effects of non-selective processes in genomes. Pseudogene sequences may be transcribed into RNA at low levels, due to promoter elements inherited from the ancestral gene or arising by new mutations. Although most of these transcripts will have no more functional significance than chance transcripts from other parts of the genome, some have given rise to beneficial regulatory RNAs and new proteins. Pseudogenes are usually characterized by

3256-485: The final stages of infection, the pathogen ruptures the host cell membrane. The genus Ehrlichia is named after German microbiologist Paul Ehrlich . The first ehrlichial disease was recognized in South Africa during the 19th century. Its tick-borne nature was determined in 1900. The organism itself was demonstrated in 1925 when it was recognized to be a Rickettsia . It was initially named Rickettsia ruminantium , and

3330-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

3404-409: The functions lost due to reductive evolution, and this contributes to its need for a host. Natural selection may not be the reason for small genomes. Despite there being multiple strains of ehrlichiosis, only two species, E. chaffeensis and E. ewingii , are currently known to cause the disease in humans. Amblyomma americanum ticks spread E. chaffeensis and E. ewingii bacterial infection in

3478-402: The gene has not been subjected to any selection pressure . Gene duplication generates functional redundancy and it is not normally advantageous to carry two identical genes. Mutations that disrupt either the structure or the function of either of the two genes are not deleterious and will not be removed through the selection process. As a result, the gene that has been mutated gradually becomes

3552-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

3626-575: The genome, they usually contain a poly-A tail , and usually have had their introns spliced out ; these are both hallmark features of cDNAs . However, because they are derived from an RNA product, processed pseudogenes also lack the upstream promoters of normal genes; thus, they are considered "dead on arrival", becoming non-functional pseudogenes immediately upon the retrotransposition event. However, these insertions occasionally contribute exons to existing genes, usually via alternatively spliced transcripts. A further characteristic of processed pseudogenes

3700-399: The host's immune system. Also, reductive evolution is present in E. canis . The genome has had a severe loss of metabolic pathway enzymes compared to its ancestors. Reductive evolution in obligate intracellular pathogens is usually the direct result of genetic drift in small populations, low recombination rates, and high mutation rates. The host metabolic pathway enzymes take control of

3774-560: The host; therefore, the genome must contain the genes needed to do so. Although genome reduction focuses on what genes are not needed by getting rid of pseudogenes, selective pressures from the host can sway what is kept. In the case of a symbiont from the Verrucomicrobiota phylum, there are seven additional copies of the gene coding the mandelalide pathway. The host, species from Lissoclinum , use mandelalides as part of its defense mechanism. The relationship between epistasis and

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3848-729: The human genome. A 2016 proteogenomics analysis using mass spectrometry of peptides identified at least 19,262 human proteins produced from 16,271 genes or clusters of genes, with 8 new protein-coding genes identified that were previously considered pseudogenes. An earlier analysis found that human PGAM4 (phosphoglycerate mutase), previously thought to be a pseudogene, is not only functional, but also causes infertility if mutated. A number of pseudo-pseudogenes were also found in prokaryotes, where some stop codon substitutions in essential genes appear to be retained, even positively selected for. siRNAs . Some endogenous siRNAs appear to be derived from pseudogenes, and thus some pseudogenes play

3922-470: The identification of processed pseudogenes can help improve the accuracy of gene prediction methods. In 2014, 140 human pseudogenes have been shown to be translated. However, the function, if any, of the protein products is unknown. There are four main types of pseudogenes, all with distinct mechanisms of origin and characteristic features. The classifications of pseudogenes are as follows: In higher eukaryotes , particularly mammals , retrotransposition

3996-422: The increased amount of BRAF protein causes cancer. This sort of competition for regulatory elements by RNAs that are endogenous to the genome has given rise to the term ce RNA . PTEN . The PTEN gene is a known tumor suppressor gene . The PTEN pseudogene, PTENP1 is a processed pseudogene that is very similar in its genetic sequence to the wild-type gene. However, PTENP1 has a missense mutation which eliminates

4070-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

4144-714: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Pseudogenes Pseudogenes are nonfunctional segments of DNA that resemble functional genes . Most arise as superfluous copies of functional genes, either directly by gene duplication or indirectly by reverse transcription of an mRNA transcript. Pseudogenes are usually identified when genome sequence analysis finds gene-like sequences that lack regulatory sequences needed for transcription or translation , or whose coding sequences are obviously defective due to frameshifts or premature stop codons . Pseudogenes are

4218-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

4292-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

4366-476: The nonsynonymous mutations. E. canis is a small, obligate-intracellular, tick-transmitted, Gram-negative α-proteobacterium. This species is responsible for the globally distributed canine monocytic ehrlichiosis . E. canis also shows evolution in its complex membrane structures and immune evasion strategies. These evolutionary features are derived traits that do not show up in the previous lineages, which may indicate that these features may have contributed to

4440-412: The piRNA pathway in mammalian testes and are crucial for limiting transposable element damage to the genome. microRNAs . There are many reports of pseudogene transcripts acting as microRNA decoys. Perhaps the earliest definitive example of such a pseudogene involved in cancer is the pseudogene of BRAF . The BRAF gene is a proto-oncogene that, when mutated, is associated with many cancers. Normally,

4514-477: The presence of pseudogenes and tandem repeats. When analyzing substitution rates between the three strains in 888 orthologous coding DNA sequences, three coding DNA sequences were biased towards nonsynonymous substitutions that affect phenotype. In contrast, 181 coding DNA sequences were biased towards synonymous substitutions, which do not affect phenotype. This indicates that selection pressure to maintain protein function existed, and this selection acted against

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4588-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

4662-461: The pseudogene can be subject to natural selection . That appears to have happened during the evolution of Drosophila species . In 2016 it was reported that four predicted pseudogenes in multiple Drosophila species actually encode proteins with biologically important functions, "suggesting that such 'pseudo-pseudogenes' could represent a widespread phenomenon". For example, the functional protein (a glutamate olfactory receptor ) from gene Ir75a

4736-466: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

4810-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

4884-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

4958-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

5032-402: The structure and content of their genomes. This diversity is direct result of rare clones with extreme genomes that emerged by chance after repeated bottleneck events, and this diversity persists because of the lack of selective constraints on rapid growth inside the host tissue. The evolutionary changes in the outer membrane proteins have led to the emergence of new strains that can infect

5106-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

5180-510: The transmitting vector of the E. muris strain in these states. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

5254-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

5328-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

5402-415: Was 0.04 cases per million PY. The HR was 77% and the case fatality rate was 0%. In Minnesota and Wisconsin, four people reported symptoms that are associated with ehrlichiosis, and upon further research, neither of these cases was found to be E. chaffeensis or E. ewingii , but instead it was revealed as a new species, similar in genetic makeup to E. muris . Ixodes scapularis ticks are hypothesized to be

5476-905: Was discovered inside the deer tick Ixodes scapularis . This newly found organism has only been isolated from deer ticks in Wisconsin and Minnesota in the USA. The species is known as Ehrlichia Wisconsin HM543746 . The following species have been effectively and validly published: The following species have been published, but are not valid according to the Bacteriological Code : The following species have been published as candidatus species: The Ehrlichia genome contains many different variants of genes that encode outer membrane proteins , which have gone through intense modification over long periods of time. The great diversity in outer membrane protein genes

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