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85-414: 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

170-435: A frameshift mutation ). Point mutations that occur in non-coding sequences are most often without consequences, although there are exceptions. If the mutated base pair is in the promoter sequence of a gene, then the expression of the gene may change. Also, if the mutation occurs in the splicing site of an intron , then this may interfere with correct splicing of the transcribed pre-mRNA . By altering just one amino acid,

255-402: A change to one amino acid in the protein is not detrimental to the organism as a whole. Most proteins can withstand one or two point mutations before their function changes. Non-conservative mutations result in an amino acid change that has different properties than the wild type . The protein may lose its function, which can result in a disease in the organism. For example, sickle-cell disease

340-491: A codon coding for the amino acid glycine may be changed to a stop codon, causing the proteins that should have been produced to be deformed and unable to complete their intended tasks. Because the mutations can affect the DNA and thus the chromatin , it can prohibit mitosis from occurring due to the lack of a complete chromosome. Problems can also arise during the processes of transcription and replication of DNA. These all prohibit

425-535: A fatty substance called GM2 ganglioside in nerve cells. Mutations in the HEXA gene disrupt the activity of beta-hexosaminidase A, preventing the breakdown of the fatty substances. As a result, the fatty substances accumulate to deadly levels in the brain and spinal cord. The buildup of GM2 ganglioside causes progressive damage to the nerve cells. This is the cause of the signs and symptoms of Tay-Sachs disease. In molecular biology , repeat-induced point mutation or RIP

510-426: 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

595-581: 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

680-651: 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

765-628: 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,

850-420: A non-conservative (missense) mutation. Silent mutations code for the same amino acid (a " synonymous substitution "). A silent mutation does not affect the functioning of the protein . A single nucleotide can change, but the new codon specifies the same amino acid, resulting in an unmutated protein. This type of change is called synonymous change since the old and new codon code for the same amino acid. This

935-685: 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

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1020-415: A protein depending on where the mutation occurs in the amino acid sequence of the protein. If the mutation occurs in the region of the gene that is responsible for coding for the protein, the amino acid may be altered. This slight change in the sequence of amino acids can cause a change in the function, activation of the protein meaning how it binds with a given enzyme, where the protein will be located within

1105-436: A purine with a pyrimidine or vice versa. There is a systematic difference in mutation rates for transitions (Alpha) and transversions (Beta). Transition mutations are about ten times more common than transversions. Nonsense mutations include stop-gain and start-loss. Stop-gain is a mutation that results in a premature termination codon ( a stop was gained ), which signals the end of translation. This interruption causes

1190-409: 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

1275-427: 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. ;

1360-455: 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

1445-420: A transcript's AUG start codon, resulting in the reduction or elimination of protein production. Missense mutations code for a different amino acid. A missense mutation changes a codon so that a different protein is created, a non-synonymous change. Conservative mutations result in an amino acid change. However, the properties of the amino acid remain the same (e.g., hydrophobic, hydrophilic, etc.). At times,

1530-446: Is a chart depicting the first thirteen amino acids in the normal and abnormal sickle cell polypeptide chain. The cause of Tay–Sachs disease is a genetic defect that is passed from parent to child. This genetic defect is located in the HEXA gene, which is found on chromosome 15. The HEXA gene makes part of an enzyme called beta-hexosaminidase A, which plays a critical role in the nervous system. This enzyme helps break down

1615-542: Is a process by which DNA accumulates G : C to A : T transition mutations. Genomic evidence indicates that RIP occurs or has occurred in a variety of fungi while experimental evidence indicates that RIP is active in Neurospora crassa , Podospora anserina , Magnaporthe grisea , Leptosphaeria maculans , Gibberella zeae and Nectria haematococca . In Neurospora crassa , sequences mutated by RIP are often methylated de novo . RIP occurs during

1700-507: Is a template for the creation of the complementary strand. A single point mutation can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for. Point mutations may arise from spontaneous mutations that occur during DNA replication . The rate of mutation may be increased by mutagens . Mutagens can be physical, such as radiation from UV rays , X-rays or extreme heat, or chemical (molecules that misplace base pairs or disrupt

1785-405: Is believed to have evolved as a defense mechanism against transposable elements , which resemble parasites by invading and multiplying within the genome. RIP creates multiple missense and nonsense mutations in the coding sequence. This hypermutation of G-C to A-T in repetitive sequences eliminates functional gene products of the sequence (if there were any to begin with). In addition, many of

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1870-597: Is caused by a single point mutation (a missense mutation) in the beta- hemoglobin gene that converts a GAG codon into GUG, which encodes the amino acid valine rather than glutamic acid . The protein may also exhibit a "gain of function" or become activated, such is the case with the mutation changing a valine to glutamic acid in the BRAF gene; this leads to an activation of the RAF protein which causes unlimited proliferative signalling in cancer cells. These are both examples of

1955-603: Is caused by point mutations in the Neurofibromin 1 or Neurofibromin 2 gene. Sickle-cell anemia is caused by a point mutation in the β-globin chain of hemoglobin, causing the hydrophilic amino acid glutamic acid to be replaced with the hydrophobic amino acid valine at the sixth position. The β-globin gene is found on the short arm of chromosome 11. The association of two wild-type α-globin subunits with two mutant β-globin subunits forms hemoglobin S (HbS). Under low-oxygen conditions (being at high altitude, for example),

2040-547: Is created from the genetic information on the HBB, or "hemoglobin, beta" gene found on chromosome 11p15.5. A single point mutation in this polypeptide chain, which is 147 amino acids long, results in the disease known as Sickle Cell Anemia. Sickle-cell anemia is an autosomal recessive disorder that affects 1 in 500 African Americans, and is one of the most common blood disorders in the United States. The single replacement of

2125-418: 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

2210-612: 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

2295-559: 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

2380-405: Is possible because 64 codons specify only 20 amino acids. Different codons can lead to differential protein expression levels, however. Sometimes the term point mutation is used to describe insertions or deletions of a single base pair (which has more of an adverse effect on the synthesized protein due to the nucleotides' still being read in triplets, but in different frames: a mutation called

2465-460: 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,

2550-474: 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

2635-522: Is the only known protein essential for RIP. It is a DNA methyltransferease-like protein, that when mutated or knocked out results in loss of RIP. Deletion of the rid homolog in Aspergillus nidulans , dmtA , results in loss of fertility while deletion of the rid homolog in Ascobolus immersens , masc1 , results in fertility defects and loss of methylation induced premeiotically (MIP) . RIP

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2720-406: 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

2805-621: 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

2890-824: 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;

2975-419: 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 ,

3060-404: 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,

3145-511: The C-bearing nucleotides become methylated , thus decreasing transcription. Because RIP is so efficient at detecting and mutating repeats, fungal biologists often use it as a tool for mutagenesis . A second copy of a single-copy gene is first transformed into the genome . The fungus must then mate and go through its sexual cycle to activate the RIP machinery. Many different mutations within

3230-798: 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

3315-463: The absence of a polar amino acid at position six of the β-globin chain promotes the non-covalent polymerisation (aggregation) of hemoglobin, which distorts red blood cells into a sickle shape and decreases their elasticity. Hemoglobin is a protein found in red blood cells, and is responsible for the transportation of oxygen through the body. There are two subunits that make up the hemoglobin protein: beta-globins and alpha-globins . Beta-hemoglobin

3400-442: 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

3485-400: The cell from reproduction and thus lead to the death of the cell. Long-term effects can be a permanent changing of a chromosome, which can lead to a mutation. These mutations can be either beneficial or detrimental. Cancer is an example of how they can be detrimental. Other effects of point mutations, or single nucleotide polymorphisms in DNA, depend on the location of the mutation within

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3570-427: The cell, or the amount of free energy stored within the protein. If the mutation occurs in the region of the gene where transcriptional machinery binds to the protein, the mutation can affect the way in which transcription factors bind to the protein. The mechanisms of transcription bind to a protein through recognition of short nucleotide sequences. A mutation in this region may alter these sequences and, thus, change

3655-480: The downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect (e.g. synonymous mutations ) to deleterious effects (e.g. frameshift mutations ), with regard to protein production, composition, and function. Point mutations usually take place during DNA replication . DNA replication occurs when one double-stranded DNA molecule creates two single strands of DNA, each of which

3740-589: The duplicated gene are obtained from even a single fertilization event so that inactivated alleles, usually due to nonsense mutations , as well as alleles containing missense mutations can be obtained. The cellular reproduction process of meiosis was discovered by Oscar Hertwig in 1876. Mitosis was discovered several years later in 1882 by Walther Flemming . Hertwig studied sea urchins, and noticed that each egg contained one nucleus prior to fertilization and two nuclei after. This discovery proved that one spermatozoon could fertilize an egg, and therefore proved

3825-409: The entire peptide may change, thereby changing the entire protein. The new protein is called a protein variant . If the original protein functions in cellular reproduction then this single point mutation can change the entire process of cellular reproduction for this organism. Point germline mutations can lead to beneficial as well as harmful traits or diseases. This leads to adaptations based on

3910-469: The environment where the organism lives. An advantageous mutation can create an advantage for that organism and lead to the trait's being passed down from generation to generation, improving and benefiting the entire population. The scientific theory of evolution is greatly dependent on point mutations in cells . The theory explains the diversity and history of living organisms on Earth. In relation to point mutations, it states that beneficial mutations allow

3995-422: The evolutionary conservation assuming that changes at conserved positions tend to be more deleterious. While majority of methods provide a binary classification of effects of mutations into damaging and benign, a new level of annotation is needed to offer an explanation of why and how these mutations damage proteins. Moreover, if the mutation occurs in the region of the gene where transcriptional machinery binds to

4080-491: 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

4165-446: 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

4250-409: 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

4335-551: The gene. For example, if the mutation occurs in the region of the gene responsible for coding, the amino acid sequence of the encoded protein may be altered, causing a change in the function, protein localization, stability of the protein or protein complex. Many methods have been proposed to predict the effects of missense mutations on proteins. Machine learning algorithms train their models to distinguish known disease-associated from neutral mutations whereas other methods do not explicitly train their models but almost all methods exploit

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4420-737: 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,

4505-574: The helical shape of DNA). Mutagens associated with cancers are often studied to learn about cancer and its prevention. There are multiple ways for point mutations to occur. First, ultraviolet (UV) light and higher-frequency light have ionizing capability, which in turn can affect DNA. Reactive oxygen molecules with free radicals, which are a byproduct of cellular metabolism, can also be very harmful to DNA. These reactants can lead to both single-stranded and double-stranded DNA breaks. Third, bonds in DNA eventually degrade, which creates another problem to keep

4590-399: 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

4675-425: The integrity of DNA to a high standard. There can also be replication errors that lead to substitution, insertion, or deletion mutations. In 1959 Ernst Freese coined the terms "transitions" or "transversions" to categorize different types of point mutations. Transitions are replacement of a purine base with another purine or replacement of a pyrimidine with another pyrimidine. Transversions are replacement of

4760-633: 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,

4845-401: 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. Point mutation A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on

4930-403: 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

5015-428: 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

5100-476: 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

5185-432: The organism to thrive and reproduce, thereby passing its positively affected mutated genes on to the next generation. On the other hand, harmful mutations cause the organism to die or be less likely to reproduce in a phenomenon known as natural selection . There are different short-term and long-term effects that can arise from mutations. Smaller ones would be a halting of the cell cycle at numerous points. This means that

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5270-410: The original start site, in-frame within the processed transcript and downstream to a ribosomal binding site, it can be used to initiate translation. The likely effect is additional amino acids added to the amino terminus of the original protein. Frame-shift mutations are also possible in start-gain mutations, but typically do not affect translation of the original protein. Start-loss is a point mutation in

5355-508: The phytopathogenic fungus L. maculans , RIP mutations are found in single copy regions, adjacent to the repeated elements. These regions are either non-coding regions or genes encoding small secreted proteins including avirulence genes. The degree of RIP within these single copy regions was proportional to their proximity to repetitive elements. Rep and Kistler have speculated that the presence of highly repetitive regions containing transposons, may promote mutation of resident effector genes. So

5440-477: 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

5525-465: The presence of effector genes within such regions is suggested to promote their adaptation and diversification when exposed to strong selection pressure. As RIP mutation is traditionally observed to be restricted to repetitive regions and not single copy regions, Fudal et al. suggested that leakage of RIP mutation might occur within a relatively short distance of a RIP-affected repeat. Indeed, this has been reported in N. crassa whereby leakage of RIP

5610-496: The process of meiosis. Hermann Fol continued Hertwig's research by testing the effects of injecting several spermatozoa into an egg, and found that the process did not work with more than one spermatozoon. Flemming began his research of cell division starting in 1868. The study of cells was an increasingly popular topic in this time period. By 1873, Schneider had already begun to describe the steps of cell division. Flemming furthered this description in 1874 and 1875 as he explained

5695-406: The protein to be abnormally shortened. The number of amino acids lost mediates the impact on the protein's functionality and whether it will function whatsoever. Stop-loss is a mutation in the original termination codon ( a stop was lost ), resulting in abnormal extension of a protein's carboxyl terminus. Start-gain creates an AUG start codon upstream of the original start site. If the new AUG is near

5780-408: The protein, the mutation can affect the binding of the transcription factors because the short nucleotide sequences recognized by the transcription factors will be altered. Mutations in this region can affect rate of efficiency of gene transcription, which in turn can alter levels of mRNA and, thus, protein levels in general. Point mutations can have several effects on the behavior and reproduction of

5865-541: 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

5950-470: 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

6035-408: 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

6120-542: The sexual stage in haploid nuclei after fertilization but prior to meiotic DNA replication . In Neurospora crassa , repeat sequences of at least 400 base pairs in length are vulnerable to RIP. Repeats with as low as 80% nucleotide identity may also be subject to RIP. Though the exact mechanism of repeat recognition and mutagenesis are poorly understood, RIP results in repeated sequences undergoing multiple transition mutations . The RIP mutations do not seem to be limited to repeated sequences. Indeed, for example, in

6205-457: The sixth amino acid in the beta-globin, glutamic acid, with valine results in deformed red blood cells. These sickle-shaped cells cannot carry nearly as much oxygen as normal red blood cells and they get caught more easily in the capillaries, cutting off blood supply to vital organs. The single nucleotide change in the beta-globin means that even the smallest of exertions on the part of the carrier results in severe pain and even heart attack. Below

6290-497: 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,

6375-412: 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

6460-488: The steps in more detail. He also argued with Schneider's findings that the nucleus separated into rod-like structures by suggesting that the nucleus actually separated into threads that in turn separated. Flemming concluded that cells replicate through cell division, to be more specific mitosis. Matthew Meselson and Franklin Stahl are credited with the discovery of DNA replication . Watson and Crick acknowledged that

6545-402: 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

6630-403: 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

6715-510: 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

6800-576: 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

6885-429: 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

6970-596: The way the transcription factors bind to the protein. Mutations in this region can affect the efficiency of gene transcription, which controls both the levels of mRNA and overall protein levels. Point mutations in multiple tumor suppressor proteins cause cancer . For instance, point mutations in Adenomatous Polyposis Coli promote tumorigenesis. A novel assay, Fast parallel proteolysis (FASTpp) , might help swift screening of specific stability defects in individual cancer patients. Neurofibromatosis

7055-415: 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

7140-406: Was detected in single copy sequences at least 930 bp from the boundary of neighbouring duplicated sequences. To elucidate the mechanism of detection of repeated sequences leading to RIP may allow to understand how the flanking sequences may also be affected. RIP causes G : C to A : T transition mutations within repeats, however, the mechanism that detects the repeated sequences is unknown. RID

7225-927: 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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