118-470: Omura (小村) or Ōmura (大村) are Japanese surnames, but may also refer to: Ōmura, Nagasaki , a city located in Nagasaki Prefecture, Japan Ōmura clan , a clan of samurai of Medieval Japan of the province of Hizen Omura's whale ( Balaenoptera omurai ), a species of rorqual about which very little is known Dacun , renamed Ōmura during Japanese rule,
236-738: A "pygmy or regionally distinct" form of Bryde's whale, which was confirmed when one was photographed and biopsied in October 2000 and its tissue sample sent to the Southwest Fisheries Science Center in La Jolla, California . There, its DNA was analyzed and found to be a complete match with a "pygmy Bryde's" sample obtained from the Philippines – later, however, it was discovered samples from the Philippines corresponded to B. omurai and not B. edeni . During marine mammal surveys conducted in
354-593: A 3.2 m (10 ft) female neonate with fetal folds and folded dorsal fin and flukes stranded at Miyazaki , Miyazaki Prefecture , on the eastern coast of Kyushu . Off northwestern Madagascar, six different cow-calf pairs were seen: one in August 2011, three in November 2013, and two in August 2015, suggesting a protracted calving season. The three calves observed in November had bent dorsal fins (indicating that they were fairly young) but did not have fetal folds, while one of
472-550: A 6.4 m (21 ft) male off Goheung in December 2006. A 4.4 m (14 ft) male calf was also caught in small-mesh herring seine nets in the Gulf of Thailand , Songkhla Province, in May 2011, while a 7.5 m (25 ft) whale (thought to likely be an Omura's whale) was caught in fishing gear off Negombo , Sri Lanka, in August 1985. A live whale seen off Sri Lanka in 2017 also had
590-699: A Japanese microbiologist Seiichi Ōmura (大村 清一, 1892-1968), politician and cabinet minister Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Omura . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Omura&oldid=1206939103 " Categories : Disambiguation pages Place name disambiguation pages Disambiguation pages with surname-holder lists Japanese-language surnames Hidden categories: Articles containing Japanese-language text Short description
708-602: A calf in 2013, and alone again in 2015 and 2017, showing that individuals can exhibit strong site fidelity. The six paratypes taken in the Solomon Sea in 1976 reportedly only had krill ( Euphausia diomedeae ) in their stomachs, while crustaceans and fish were found in a 7 m (23 ft) female from Japan. Individuals in Madagascar have been observed lunge feeding on the krill Pseudeuphausia latifrons . Omura's whale produce amplitude-modulated songs of 15-50 Hz with
826-649: A charter boat off Phuket's coast in the Andaman Sea captured a pair of Omura's whales with a drone , one of which was an exceptionally rare all-white Omura whale . As early as the late 19th century, the natives of Lila, Bohol , began hunting whales in the Bohol Sea . By the turn of the century, this had spread to nearby Pamilacan Island and later to Sagay, Camiguin . At Pamilacan, whales were caught as early as January and as late as June, but most were taken in April and May. When
944-550: A complete skeleton, both complete rows of baleen plates, and frozen pieces of muscle, blubber, and kidney collected by T. K. Yamada, M. Oishi, T. Kuramochi, E. Jibiki, and S. Fujioka. The type locality is the Sea of Japan, which may not be representative of the species’ typical range. The paratypes include the eight specimens (five females and three males), NRIFSF1-8 (National Research Institute of Far Seas Fisheries, Fisheries Research Agency, Shizuoka ), collected by Japanese research vessels in
1062-585: A database) to determine maternal lineage. Most often, the comparison is made with the revised Cambridge Reference Sequence . Vilà et al. have published studies tracing the matrilineal descent of domestic dogs from wolves. The concept of the Mitochondrial Eve is based on the same type of analysis, attempting to discover the origin of humanity by tracking the lineage back in time. Entities subject to uniparental inheritance and with little to no recombination may be expected to be subject to Muller's ratchet ,
1180-500: A donor female, and nuclear DNA from the mother and father. In the spindle transfer procedure, the nucleus of an egg is inserted into the cytoplasm of an egg from a donor female which has had its nucleus removed, but still contains the donor female's mtDNA. The composite egg is then fertilized with the male's sperm. The procedure is used when a woman with genetically defective mitochondria wishes to procreate and produce offspring with healthy mitochondria. The first known child to be born as
1298-435: A finding that has been rejected by other scientists. In sexual reproduction , mitochondria are normally inherited exclusively from the mother; the mitochondria in mammalian sperm are usually destroyed by the egg cell after fertilization. Also, mitochondria are present solely in the midpiece, which is used for propelling the sperm cells, and sometimes the midpiece, along with the tail, is lost during fertilization. In 1999 it
SECTION 10
#17328448610941416-545: A healthy human sperm has been reported to contain on average 5 molecules), degradation of sperm mtDNA in the male genital tract and in the fertilized egg; and, at least in a few organisms, failure of sperm mtDNA to enter the egg. Whatever the mechanism, this single parent ( uniparental inheritance ) pattern of mtDNA inheritance is found in most animals, most plants and also in fungi. In a study published in 2018, human babies were reported to inherit mtDNA from both their fathers and their mothers resulting in mtDNA heteroplasmy ,
1534-542: A mutation in mtDNA has been used to help diagnose prostate cancer in patients with negative prostate biopsy . mtDNA alterations can be detected in the bio-fluids of patients with cancer. mtDNA is characterized by the high rate of polymorphisms and mutations. Some of which are increasingly recognized as an important cause of human pathology such as oxidative phosphorylation (OXPHOS) disorders, maternally inherited diabetes and deafness (MIDD), Type 2 diabetes mellitus, Neurodegenerative disease , heart failure and cancer. Though
1652-626: A mutational (contrary to the selective one) explanation for the observation that long-lived species have GC-rich mtDNA: long-lived species become GC-rich simply because of their biased process of mutagenesis. An association between mtDNA mutational spectrum and species-specific life-history traits in mammals opens a possibility to link these factors together discovering new life-history-specific mutagens in different groups of organisms. Deletion breakpoints frequently occur within or near regions showing non-canonical (non-B) conformations, namely hairpins, cruciforms and cloverleaf-like elements. Moreover, there
1770-546: A new species of baleen whale. However, due to the lack of a detailed osteological study and the absence of "conclusive data", the International Whaling Commission decided to consider them only as a regionally distinct group of "small-form Bryde's whale". Despite this declaration, the specific status of the Solomon Sea specimens was supported by a mitochondrial DNA study done by Hideyoshi Yoshida and Hidehiro Kato (1999). The identity of these eight specimens
1888-617: A pair observed feeding within the Sandfly Passage of the Florida Islands on 14 November 2010. In October 2015, an international team of scientists, led by Salvatore Cerchio of the New England Aquarium and Woods Hole Oceanographic Institution , released the first images and field observations of the species from a population off northwestern Madagascar. Forty-four sightings of Omura's whale were made between 2011 and 2014, with
2006-399: A paper on sightings of Omura's whale made off Nosy Be in 1991–1995, 1998, and 2000, including photographs of an aggregation of a dozen whales seen skim and lunge feeding in 40 to 80 m (130 to 260 ft) of water in November 1994 at 13° 26' S, 48° 05' E. In 2017, the first confirmed live sightings of Omura's whale were made off Taiwan and Sri Lanka. On December 31, 2023, tourists on
2124-493: A peak frequency of 36.1 Hz and an average duration of 9.2 seconds. This is sometimes followed by a tonal call of 17 Hz and four seconds in duration. These songs are repeated every two to three minutes, sometimes for as long as thirteen hours. Songs have been recorded off northwest Madagascar year-round, with peak activity from late October to late January and again from late May to late June. Overlapping choruses of several singing individuals have been recorded throughout
2242-412: A quarter of the body length. The pectoral fins are short but slender, being from about 13 to 15 per cent of the body length. The dorsal fin ranges between 7.5 and 20 cm (3.0 and 7.9 in) in height and 18 to 60 cm (7 to 23.5 in) in length for specimens 3.9 to 7.15 m (12.8 to 23.5 ft) in length, and is placed about 57 per cent of the body length back from the tip of the rostrum. It
2360-521: A result of mitochondrial donation was a boy born to a Jordanian couple in Mexico on 6 April 2016. The concept that mtDNA is particularly susceptible to reactive oxygen species generated by the respiratory chain due to its proximity remains controversial. mtDNA does not accumulate any more oxidative base damage than nuclear DNA. It has been reported that at least some types of oxidative DNA damage are repaired more efficiently in mitochondria than they are in
2478-507: A role in the mitochondrial bottleneck, exploiting cell-to-cell variability to ameliorate the inheritance of damaging mutations. According to Justin St. John and colleagues, "At the blastocyst stage, the onset of mtDNA replication is specific to the cells of the trophectoderm . In contrast, the cells of the inner cell mass restrict mtDNA replication until they receive the signals to differentiate to specific cell types." The two strands of
SECTION 20
#17328448610942596-440: A ruling head of the clan of Omura throughout the latter Sengoku Period of Feudal Japan Hideaki Ōmura (大村 秀章, born 1960), a Japanese politician and the governor of Aichi Prefecture Jim K. Omura (born 1940), an electrical engineer and information theorist Masanari Omura ( 大村 真也 , born 1984) , Japanese footballer Norio Omura (小村 徳男, born 1969), a former Japanese football defender Satoshi Omura (大村 智, born 1935),
2714-619: A rural township in Changhua County, Taiwan People [ edit ] Ōmura Masujirō (大村 益次郎, 1824-1869), a Japanese military leader and theorist in Bakumatsu period Japan Ōmura Sumihiro (大村 純熈, 1830-1882), the 13th and final daimyō of Ōmura Domain in Hizen Province, Kyūshū, Japan Ōmura Sumitada (大村 純忠, 1533-1587), a Japanese daimyō lord of the Sengoku period Ōmura Yoshiaki ,
2832-655: A scar on its rostrum suggestive of an entanglement with fishing gear. Two individuals of Omura's whale were victims of ship strike , including the holotype of the species, an 11 m (36 ft) female found off Tsunoshima in the Sea of Japan in September 1998, and a whale brought into Manila Bay on the bow of a ship. Omura's whale is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals. It
2950-435: A species and also for identifying and quantifying the phylogeny (evolutionary relationships; see phylogenetics ) among different species. To do this, biologists determine and then compare the mtDNA sequences from different individuals or species. Data from the comparisons is used to construct a network of relationships among the sequences, which provides an estimate of the relationships among the individuals or species from which
3068-481: A specimen of unknown sex that stranded in 1983 in Phuket Province , Thailand, was 7 m (23.0 ft) in length. Of 16 "Bryde's whales" caught by hunters from Pamilacan between 1991 and 1993, 12 were measured. These cluster into two size categories, nine whales less than 10 m (32.8 ft), and three 12 m (39.4 ft) or more. Later, 85% (24 of 28) of the identified skull specimens examined from
3186-623: A stabilisation or reduction in mutant load between generations. The mechanism underlying the bottleneck is debated, with a recent mathematical and experimental metastudy providing evidence for a combination of the random partitioning of mtDNAs at cell divisions and the random turnover of mtDNA molecules within the cell. Male mitochondrial DNA inheritance has been discovered in Plymouth Rock chickens . Evidence supports rare instances of male mitochondrial inheritance in some mammals as well. Specifically, documented occurrences exist for mice, where
3304-449: A toggle-headed grommet harpoon with a 2.5 m (8.2 ft) wooden shaft similar to the "dolphin irons" used by American whalemen in the mid-19th century, which in turn was either attached to a 140 m (460 ft) rope with a plastic fishing float or a 400 m (1,300 ft) rope with a plastic float or oil drum at the end. After an hour or more, the whale tired, and men took turns cutting it until it died. The boats usually towed
3422-460: A valid species and revealed it to be an early offshoot from the rorqual lineage, diverging much earlier than Bryde's and sei whales . It is perhaps more closely related to its larger relative, the blue whale . In the third edition of Mammal Species of the World , the "species" is relegated to being a synonym of Balaenoptera edeni . However, the authors note that this is subject to a revision of
3540-412: A whale was spotted from shore, between 10 and 20 pump boats (boats with motors originally used for pumps) were launched in chase. When within range, a "hookman" jumped onto the whale's head and stabbed it with a 35-cm-long, 22.5-cm-wide stainless steel hook attached to a heavy line of 30 m (98 ft) with a 2 m (6.6 ft) bamboo spar buoy at the end of it. At Camiguin, they harpooned it with
3658-401: A white chevron on the back, pectoral fins with a white anterior border and inner surface, and flukes with a white ventral surface and black margins. Like fin whales, it also exhibits a white left gape and a dark right gape, a reversal of the asymmetrical pigmentation on the lower jaw. It has a very falcate dorsal fin with a leading edge that gradually slopes into the back, halfway in shape between
Omura - Misplaced Pages Continue
3776-478: Is 61.5 per cent of the body length from the tip of the lower jaw to the umbilicus, whereas it is about 63 per cent from the tip of the lower jaw to the end of the ventral grooves. The flukes are about a quarter to a fifth of the body length in width. Omura's whale is among the smallest of the rorquals – only the two species of minke whale , the common and Antarctic , which reach 9.75 and 10.7 m (32.0 and 35.1 ft) in length, respectively, are smaller. Of
3894-532: Is a linear genome made up of homogeneous DNA molecules (type 5). Great variation in mtDNA gene content and size exists among fungi and plants, although there appears to be a core subset of genes present in all eukaryotes (except for the few that have no mitochondria at all). In Fungi, however, there is no single gene shared among all mitogenomes. Some plant species have enormous mitochondrial genomes, with Silene conica mtDNA containing as many as 11,300,000 base pairs. Surprisingly, even those huge mtDNAs contain
4012-467: Is a well-established marker of oxidative DNA damage. In persons with amyotrophic lateral sclerosis (ALS), the enzymes that normally repair 8-oxoG DNA damages in the mtDNA of spinal motor neurons are impaired. Thus oxidative damage to mtDNA of motor neurons may be a significant factor in the etiology of ALS. Over the past decade, an Israeli research group led by Professor Vadim Fraifeld has shown that strong and significant correlations exist between
4130-440: Is absent in both B. brydei and B. edeni . Unlike B. edeni , the alisphenoid is separate from the squamosal in B. omurai . The head of the first rib is not bifurcated in B. omurai , unlike B. brydei and B. edeni . Omura's whale has a total of 53 vertebrae, including seven cervical (the standard number among mammals), 13 thoracic , 12 lumbar , and 21 caudal . Like all members of its genus, it has only four digits on
4248-457: Is also a photograph (taken between 1915 and 1944) of a whale caught by the villagers of Lamakera that "strongly resembles a young Omura's whale in size and shape". Among the small "Bryde's whale" caught 40 mi off Shionomisaki , Wakayama Prefecture , in June 1976, were two sexually mature females of 7.9 and 8.5 m (26 and 28 ft), both of which are thought to likely be Omura's whale. Of
4366-487: Is data supporting the involvement of helix-distorting intrinsically curved regions and long G-tetrads in eliciting instability events. In addition, higher breakpoint densities were consistently observed within GC-skewed regions and in the close vicinity of the degenerate sequence motif YMMYMNNMMHM. Unlike nuclear DNA, which is inherited from both parents and in which genes are rearranged in the process of recombination , there
4484-531: Is different from Wikidata All article disambiguation pages All disambiguation pages Omura%27s whale Omura's whale or the dwarf fin whale ( Balaenoptera omurai ) is a species of rorqual about which very little is known. Before its formal description, it was referred to as a small, dwarf or pygmy form of Bryde's whale by various sources. The common name and specific epithet commemorate Japanese cetologist Hideo Omura [ jp ] . The scientific description of this whale
4602-542: Is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. In addition, Omura's whale is covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region ( Pacific Cetaceans MOU ). Mitochondrial DNA Mitochondrial DNA ( mtDNA and mDNA )
4720-514: Is observed in bivalve mollusks. In those species, females have only one type of mtDNA (F), whereas males have F type mtDNA in their somatic cells, but M type of mtDNA (which can be as much as 30% divergent) in germline cells. Paternally inherited mitochondria have additionally been reported in some insects such as fruit flies , honeybees , and periodical cicadas . An IVF technique known as mitochondrial donation or mitochondrial replacement therapy (MRT) results in offspring containing mtDNA from
4838-509: Is one hypothesis for why some genes are retained in mtDNA; colocalisation for redox regulation is another, citing the desirability of localised control over mitochondrial machinery. Recent analysis of a wide range of mtDNA genomes suggests that both these features may dictate mitochondrial gene retention. Across all organisms, there are six main mitochondrial genome types, classified by structure (i.e. circular versus linear), size, presence of introns or plasmid like structures , and whether
Omura - Misplaced Pages Continue
4956-540: Is severely degraded. Autosomal cells only have two copies of nuclear DNA, but can have hundreds of copies of mtDNA due to the multiple mitochondria present in each cell. This means highly degraded evidence that would not be beneficial for STR analysis could be used in mtDNA analysis. mtDNA may be present in bones, teeth, or hair, which could be the only remains left in the case of severe degradation. In contrast to STR analysis, mtDNA sequencing uses Sanger sequencing . The known sequence and questioned sequence are both compared to
5074-518: Is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in a eukaryotic cell; most of the DNA is in the cell nucleus , and, in plants and algae, the DNA also is found in plastids , such as chloroplasts . Human mitochondrial DNA was the first significant part of
5192-485: Is the first multicellular organism known to have this absence of aerobic respiration and live completely free of oxygen dependency. There are three different mitochondrial genome types in plants and fungi. The first type is a circular genome that has introns (type 2) and may range from 19 to 1000 kbp in length. The second genome type is a circular genome (about 20–1000 kbp) that also has a plasmid-like structure (1 kb) (type 3). The final genome type found in plants and fungi
5310-404: Is uncertain – they may refer to Omura's whale or the smaller form of Bryde's whale ( B. edeni ). These three individuals were noted to have very small baleen plates – about 22 by 15 cm (8.7 by 5.9 in), about 22 by 16 cm (8.7 by 6.3 in), and 23.5 by 17.5 cm (9.3 by 6.9 in), respectively – with length-breadth quotients of 1.34 to 1.46, within the upper range (1.00-1.43) of
5428-452: Is used in an analogous way to determine the patrilineal history.) This is usually accomplished on human mitochondrial DNA by sequencing the hypervariable control regions (HVR1 or HVR2), and sometimes the complete molecule of the mitochondrial DNA, as a genealogical DNA test . HVR1, for example, consists of about 440 base pairs. These 440 base pairs are compared to the same regions of other individuals (either specific people or subjects in
5546-510: Is usually no change in mtDNA from parent to offspring. Although mtDNA also recombines, it does so with copies of itself within the same mitochondrion. Because of this and because the mutation rate of animal mtDNA is higher than that of nuclear DNA, mtDNA is a powerful tool for tracking ancestry through females ( matrilineage ) and has been used in this role to track the ancestry of many species back hundreds of generations. mtDNA testing can be used by forensic scientists in cases where nuclear DNA
5664-517: The POLG2 gene. The replisome machinery is formed by DNA polymerase, TWINKLE and mitochondrial SSB proteins . TWINKLE is a helicase , which unwinds short stretches of dsDNA in the 5' to 3' direction. All these polypeptides are encoded in the nuclear genome. During embryogenesis , replication of mtDNA is strictly down-regulated from the fertilized oocyte through the preimplantation embryo. The resulting reduction in per-cell copy number of mtDNA plays
5782-646: The Bohol Sea were found to be Omura's whales, whereas only 15% (4 of 28) were what was tentatively called the Indo-Pacific form of Bryde's whale ( B. brydei ). The former size category may be primarily (if not entirely) Omura's whale, whereas the larger whales – one of unknown sex of 12 m (39.4 ft) and two females of 13 m (42.7 ft) – would be the larger, offshore form of Bryde's whale. Of those smaller whales, four males ranged from 6.7 to 9.8 m (22.0 to 32.2 ft), four females ranged from 4.9 to 9.3 m (16.1 to 30.5 ft), and one of unknown sex
5900-407: The Bohol Sea ), Vietnam ( Quảng Ngãi Province ), Malaysia ( Pahang ), Thailand (with sightings and strandings from February, May to June, and November to December; including the provinces of Phang Nga , Phuket , Prachuap Khiri Khan , and Songkhla ), Indonesia (with sightings and strandings from February, April to June, and from September to November; with records from West Sumatra ,
6018-600: The Indo-Pacific and the Atlantic Oceans , primarily in shelf waters between 35° N and 35° S, with the majority of records in the tropics (between 23° 26' N and 23° 26' S). Their range includes southern Japan (with strandings and entanglements recorded in March and from May to October; including the prefectures of Yamaguchi , Miyazaki , Kagawa , Mie , Shizuoka , and Chiba ), South Korea (December to January, from
SECTION 50
#17328448610946136-581: The Solomon Islands , New Caledonia , Sri Lanka (February), the Chagos Archipelago , Iran (September, Strait of Hormuz ), Egypt (April, the northern Red Sea ) northwestern Madagascar (12° 01' S to 19° 23' S, with sightings by researchers from August and October to December, by whale watch operators from April to December, and acoustically detected year-round), Mauritania (November, Trarza Region ), Brazil (September, Ceará ), and in
6254-413: The eukaryotic nucleus during evolution . The reasons mitochondria have retained some genes are debated. The existence in some species of mitochondrion-derived organelles lacking a genome suggests that complete gene loss is possible, and transferring mitochondrial genes to the nucleus has several advantages. The difficulty of targeting remotely-produced hydrophobic protein products to the mitochondrion
6372-586: The human genome to be sequenced. This sequencing revealed that human mtDNA has 16,569 base pairs and encodes 13 proteins . As in other vertebrates, the human mitochondrial genetic code differs slightly from nuclear DNA. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology . It also permits tracing the relationships of populations, and so has become important in anthropology and biogeography . Nuclear and mitochondrial DNA are thought to have separate evolutionary origins, with
6490-403: The manus of each pectoral fin (the third digit is missing). The phalangeal formula is: I-5, II-7, IV-6, V-3. Its appearance resembles the larger fin whale (thus the alternate common names of dwarf fin whale and little fin whale ), both having a dark gray left lower jaw, and on the right side a white mandible patch, a white blaze, a dark eye stripe, a white inter-stripe wash, as well as
6608-463: The provinces of South Jeolla and South Gyeongsang ), China (with strandings from November to February and in August; including the provinces of Zhejiang , Fujian , Guangdong , and Guangxi ), Taiwan (with strandings from November to March and in May; there are also sightings from April to May and July to August), Hong Kong (March), the Philippines ( Manila Bay , Busuanga , and
6726-403: The 118 other "ordinary" Bryde's whales taken in the eastern Indian Ocean, south of Java . As a result of allozyme analysis, their distinctive baleen and small size at physical maturity compared to Bryde's whale, and photographs obtained of the harvested whales (showing their fin whale-like coloration), Shiro Wada and Kenichi Numachi (1991) decided that these eight individuals represented members of
6844-464: The 9 specimens included in the formal description of Omura's whale, but also within the lower range of the Bryde's whale complex (1.2 to 1.33). The holotype of the smaller form of Bryde's whale ( B. edeni ) from Myanmar , though, had baleen plates of 30 by 15 cm (11.8 by 5.9 in), or a length-breadth quotient of exactly 2.0 – within the typical range of the Bryde's whale complex (1.8 to 2.4). Of
6962-698: The Indo-Pacific Bryde's whale ( B. brydei ). This was supported by genetic studies, which found that, based on comparison of published phylogenies, the small "Bryde's whales" from the Philippines correspond to Omura's whale. A monograph from 1923 describes three skulls of balaenopterids taken by native whalers in Indonesia. Later examination of photographs of those skulls by one of the scientists (Tadasu K. Yamada) that had formally described Omura's whale showed that two of them, one from Bangsri, Java , and another from Lamakera , Solor, belonged to B. omurai . There
7080-472: The Indo-Pacific form of B. brydei , but are invisible in dorsal view in B. edeni and the North Pacific form of B. brydei . B. omurai has two small foramina "along the suture between the parietal and squamosal in the posterior wall of the temporal fossa ", which both B. brydei and B. edeni lack. B. omurai has an oblique ridge on the dorsal side of the maxilla near the base of the rostrum, which
7198-410: The Indo-Pacific in the late 1970s. The longest baleen plate (NRIFSF6 includes 18 more baleen plates), an earplug, and a piece of the sixth thoracic vertebra with associated epiphysis were collected from each individual. Omura's whale has several unique skeletal features that distinguish it from its congeners, namely B. brydei and B. edeni . In B. omurai and B. brydei , the posterior end of
SECTION 60
#17328448610947316-453: The Japanese vernacular name of Tsunoshima kujira ( English : Horn Island whale). The holotype is an 11.03 m (36.2 ft) adult female, NSMT-M32505 (National Science Museum, Tokyo), which stranded at Tsunoshima ( 34°21′03″N 130°53′09″E / 34.35083°N 130.88583°E / 34.35083; 130.88583 ) in the southern Sea of Japan on 11 September 1998. It includes
7434-558: The Revised Cambridge Reference Sequence to generate their respective haplotypes. If the known sample sequence and questioned sequence originated from the same matriline, one would expect to see identical sequences and identical differences from the rCRS. Cases arise where there are no known samples to collect and the unknown sequence can be searched in a database such as EMPOP. The Scientific Working Group on DNA Analysis Methods recommends three conclusions for describing
7552-468: The Solomon Islands in 2009 and 2010, what were "most likely" Omura's whales were sighted on three occasions. They were estimated to be 6 to 10 m (20 to 33 ft) in length and lacked obvious auxiliary ridges. The sightings were made very close to shore (within a few hundred meters), one on the west coast of Malaita in November 2009, one on the northwest coast of Guadalcanal in November 2010, and
7670-543: The accumulation of deleterious mutations until functionality is lost. Animal populations of mitochondria avoid this through a developmental process known as the mtDNA bottleneck . The bottleneck exploits random processes in the cell to increase the cell-to-cell variability in mutant load as an organism develops: a single egg cell with some proportion of mutant mtDNA thus produces an embryo in which different cells have different mutant loads. Cell-level selection may then act to remove those cells with more mutant mtDNA, leading to
7788-419: The accumulation of mtDNA damage in several organs of rats. For example, dietary restriction prevented age-related accumulation of mtDNA damage in the cortex and decreased it in the lung and testis. Increased mt DNA damage is a feature of several neurodegenerative diseases . The brains of individuals with Alzheimer's disease have elevated levels of oxidative DNA damage in both nuclear DNA and mtDNA, but
7906-436: The ascending process of the maxilla widens to become squarish, whereas in B. edeni , it is slender and round throughout its length. In B. omurai , this widened posterior portion conceals the premaxilla , which disappears below the maxilla and nasal and does not reach the frontal , whereas in both B. brydei and B. edeni , the premaxilla reaches the frontal. The parietals flare laterally in dorsal view in B. omurai and
8024-598: The calves sighted in August had an erect dorsal fin, indicating that it was older but still probably born that year. These calves were estimated to range in length from 3 to 5 m (9.8 to 16.4 ft). Little is known of the behavior and diet of Omura's whale. Their blow is low and diffuse. After surfacing, the dorsal fin is usually not visible until after the head and splashguard have disappeared and they don't fluke when diving. They have been seen lunge feeding, defecating, and breaching off both Komodo National Park and northwestern Madagascar; they've also been seen rolling at
8142-504: The carcass to Lila for butchering, where it was sold and the meat eaten raw or cooked. Pamilacan hunters alone caught 10 to 20 per year, whereas at Camiguin, they caught them only sporadically. When Maria Louella L. Dolar and colleagues (1994) examined photographs or baleen of the whales caught in the Bohol Sea between 1991 and 1993, they identified them as Bryde's whales; this was supported by osteological examinations of skulls collected from
8260-456: The coding instructions for some proteins, which may have an effect on organism metabolism and/or fitness. Mutations of mitochondrial DNA can lead to a number of illnesses including exercise intolerance and Kearns–Sayre syndrome (KSS), which causes a person to lose full function of heart, eye, and muscle movements. Some evidence suggests that they might be major contributors to the aging process and age-associated pathologies . Particularly in
8378-714: The context of disease, the proportion of mutant mtDNA molecules in a cell is termed heteroplasmy . The within-cell and between-cell distributions of heteroplasmy dictate the onset and severity of disease and are influenced by complicated stochastic processes within the cell and during development. Mutations in mitochondrial tRNAs can be responsible for severe diseases like the MELAS and MERRF syndromes. Mutations in nuclear genes that encode proteins that mitochondria use can also contribute to mitochondrial diseases. These diseases do not follow mitochondrial inheritance patterns, but instead follow Mendelian inheritance patterns. Recently
8496-403: The differences between a known mtDNA sequence and a questioned mtDNA sequence: exclusion for two or more differences between the sequences, inconclusive if there is one nucleotide difference, or cannot exclude if there are no nucleotide differences between the two sequences. The rapid mutation rate (in animals) makes mtDNA useful for assessing genetic relationships of individuals or groups within
8614-626: The differences in animal species maximum life spans in a multiplicative manner (i.e., species maximum life span = their mtDNA GC% * metabolic rate). To support the scientific community in carrying out comparative analyses between mtDNA features and longevity across animals, a dedicated database was built named MitoAge . De novo mutations arise either due to mistakes during DNA replication or due to unrepaired damage caused in turn by endogenous and exogenous mutagens. It has been long believed that mtDNA can be particularly sensitive to damage caused by reactive oxygen species (ROS), however G>T substitutions,
8732-666: The eight individuals taken by Japanese scientific whaling in the 1970s, six were processed aboard the factory ship Tonan Maru No. 2 in the Solomon Sea (9°49'-10°17'S, 157°29'-157°56'E) on 24 October 1976, and two were processed aboard the factory ship Nisshin Maru No. 3 near the Cocos Islands ( 10°51′S 97°02′E / 10.850°S 97.033°E / -10.850; 97.033 and 10°53′S 94°29′E / 10.883°S 94.483°E / -10.883; 94.483 , respectively) on 15 and 17 November 1978. Three of
8850-415: The eight specimens taken during Japanese whaling in the Indo-Pacific, the five females ranged in length from 10.1 to 11.5 m (33.1 to 37.7 ft), while the three males ranged from 9.6 to 10.0 m (31.5 to 32.8 ft). The females ranged in age from perhaps only 9 years (the earplug was damaged or partially lost) for an 11.2 m (36.7 ft) individual to 29 years for the longest female, whereas
8968-624: The ends of the linear DNA ) with different modes of replication, which have made them interesting objects of research because many of these unicellular organisms with linear mtDNA are known pathogens . Most ( bilaterian ) animals have a circular mitochondrial genome. Medusozoa and calcarea clades however include species with linear mitochondrial chromosomes. With a few exceptions, animals have 37 genes in their mitochondrial DNA: 13 for proteins , 22 for tRNAs , and 2 for rRNAs . Mitochondrial genomes for animals average about 16,000 base pairs in length. The anemone Isarachnanthus nocturnus has
9086-403: The genetic distances of distantly related species. Statistical models that treat substitution rates among codon positions separately, can thus be used to simultaneously estimate phylogenies that contain both closely and distantly related species Mitochondrial DNA was admitted into evidence for the first time ever in a United States courtroom in 1996 during State of Tennessee v. Paul Ware . In
9204-422: The genetic material is a singular molecule or collection of homogeneous or heterogeneous molecules. In many unicellular organisms (e.g., the ciliate Tetrahymena and the green alga Chlamydomonas reinhardtii ), and in rare cases also in multicellular organisms (e.g. in some species of Cnidaria ), the mtDNA is linear DNA . Most of these linear mtDNAs possess telomerase -independent telomeres (i.e.,
9322-551: The genus. The database ITIS lists this as a valid taxon, noting a caveat on the disputed systematics of this species, Balaenoptera edeni and Balaenoptera brydei . The six specimens obtained in the Solomon Sea in 1976 were only noted to be smaller at sexual maturity than the "ordinary" Bryde's whales caught off New Zealand , whereas the two caught near the Cocos-Keeling Islands in 1978 were not differentiated from
9440-477: The hallmark of the oxidative damage in the nuclear genome, are very rare in mtDNA and do not increase with age. Comparing the mtDNA mutational spectra of hundreds of mammalian species, it has been recently demonstrated that species with extended lifespans have an increased rate of A>G substitutions on single-stranded heavy chain. This discovery led to the hypothesis that A>G is a mitochondria-specific marker of age-associated oxidative damage. This finding provides
9558-421: The human mitochondrial DNA are distinguished as the heavy strand and the light strand. The heavy strand is rich in guanine and encodes 12 subunits of the oxidative phosphorylation system, two ribosomal RNAs (12S and 16S), and 14 transfer RNAs (tRNAs). The light strand encodes one subunit, and 8 tRNAs. So, altogether mtDNA encodes for two rRNAs, 22 tRNAs, and 13 protein subunits , all of which are involved in
9676-524: The idea is controversial, some evidence suggests a link between aging and mitochondrial genome dysfunction. In essence, mutations in mtDNA upset a careful balance of reactive oxygen species (ROS) production and enzymatic ROS scavenging (by enzymes like superoxide dismutase , catalase , glutathione peroxidase and others). However, some mutations that increase ROS production (e.g., by reducing antioxidant defenses) in worms increase, rather than decrease, their longevity. Also, naked mole rats , rodents about
9794-462: The initiation of the transcription of the heavy and light strands are located in the main non-coding region of the mtDNA called the displacement loop, the D-loop . There is evidence that the transcription of the mitochondrial rRNAs is regulated by the heavy-strand promoter 1 (HSP1), and the transcription of the polycistronic transcripts coding for the protein subunits are regulated by HSP2. Measurement of
9912-558: The largest mitochondrial genome of any animal at 80,923 bp. The smallest known mitochondrial genome in animals belongs to the comb jelly Vallicula multiformis , which consist of 9,961 bp. In February 2020, a jellyfish-related parasite – Henneguya salminicola – was discovered that lacks a mitochondrial genome but retains structures deemed mitochondrion-related organelles. Moreover, nuclear DNA genes involved in aerobic respiration and in mitochondrial DNA replication and transcription were either absent or present only as pseudogenes . This
10030-415: The levels of the mtDNA-encoded RNAs in bovine tissues has shown that there are major differences in the expression of the mitochondrial RNAs relative to total tissue RNA. Among the 12 tissues examined the highest level of expression was observed in heart, followed by brain and steroidogenic tissue samples. As demonstrated by the effect of the trophic hormone ACTH on adrenal cortex cells, the expression of
10148-443: The longevity of species. The application of a mitochondrial-specific ROS scavenger, which lead to a significant longevity of the mice studied, suggests that mitochondria may still be well-implicated in ageing. Extensive research is being conducted to further investigate this link and methods to combat ageing. Presently, gene therapy and nutraceutical supplementation are popular areas of ongoing research. Bjelakovic et al. analyzed
10266-509: The majority in 2013 (thirteen) and 2014 (twenty-five). Forty-two were made off Nosy Iranja and the Ampasindava Peninsula, while only two occurred off Nosy Be . They were observed in open shelf waters that averaged 31 m (102 ft) deep (range: 4 to 202 m, or 13.1 to 662 ft) and were never seen in deep waters off the shelf break or in shallower coastal waters or embayments. In 2018, Pierre Laboute and Philippe Borsa published
10384-424: The male-inherited mitochondria were subsequently rejected. It has also been found in sheep, and in cloned cattle. Rare cases of male mitochondrial inheritance have been documented in humans. Although many of these cases involve cloned embryos or subsequent rejection of the paternal mitochondria, others document in vivo inheritance and persistence under lab conditions. Doubly uniparental inheritance of mtDNA
10502-525: The mitochondrial genes may be strongly regulated by external factors, apparently to enhance the synthesis of mitochondrial proteins necessary for energy production. Interestingly, while the expression of protein-encoding genes was stimulated by ACTH, the levels of the mitochondrial 16S rRNA showed no significant change. In most multicellular organisms , mtDNA is inherited from the mother (maternally inherited). Mechanisms for this include simple dilution (an egg contains on average 200,000 mtDNA molecules, whereas
10620-443: The more gradual slope of the fin whale and the more acute angle of Bryde's and sei whales. Its dorsal fin is also proportionally smaller and less upright than these other species. It typically has a single prominent median ridge on the rostrum, but can have faint lateral ridges, which are more pronounced in calves. Bryde's whale, on the other hand, has three prominent ridges on the rostrum. It has 45 to 95 ventral grooves that extend past
10738-480: The mtDNA base composition and animal species-specific maximum life spans. As demonstrated in their work, higher mtDNA guanine + cytosine content ( GC% ) strongly associates with longer maximum life spans across animal species. An additional observation is that the mtDNA GC% correlation with the maximum life spans is independent of the well-known correlation between animal species metabolic rate and maximum life spans. The mtDNA GC% and resting metabolic rate explain
10856-448: The mtDNA derived from the circular genomes of bacteria engulfed by the ancestors of modern eukaryotic cells. This theory is called the endosymbiotic theory . In the cells of extant organisms, the vast majority of the proteins in the mitochondria (numbering approximately 1500 different types in mammals ) are coded by nuclear DNA , but the genes for some, if not most, of them are thought to be of bacterial origin, having been transferred to
10974-833: The mtDNA has approximately 10-fold higher levels than nuclear DNA. It has been proposed that aged mitochondria is the critical factor in the origin of neurodegeneration in Alzheimer's disease. Analysis of the brains of AD patients suggested an impaired function of the DNA repair pathway, which would cause reduce the overall quality of mtDNA. In Huntington's disease , mutant huntingtin protein causes mitochondrial dysfunction involving inhibition of mitochondrial electron transport , higher levels of reactive oxygen species and increased oxidative stress . Mutant huntingtin protein promotes oxidative damage to mtDNA, as well as nuclear DNA, that may contribute to Huntington's disease pathology . The DNA oxidation product 8-oxoguanine (8-oxoG)
11092-558: The mtDNAs were taken. mtDNA can be used to estimate the relationship between both closely related and distantly related species. Due to the high mutation rate of mtDNA in animals, the 3rd positions of the codons change relatively rapidly, and thus provide information about the genetic distances among closely related individuals or species. On the other hand, the substitution rate of mt-proteins is very low, thus amino acid changes accumulate slowly (with corresponding slow changes at 1st and 2nd codon positions) and thus they provide information about
11210-472: The nucleus. mtDNA is packaged with proteins which appear to be as protective as proteins of the nuclear chromatin. Moreover, mitochondria evolved a unique mechanism which maintains mtDNA integrity through degradation of excessively damaged genomes followed by replication of intact/repaired mtDNA. This mechanism is not present in the nucleus and is enabled by multiple copies of mtDNA present in mitochondria. The outcome of mutation in mtDNA may be an alteration in
11328-487: The oxidative phosphorylation process. Between most (but not all) protein-coding regions, tRNAs are present (see the human mitochondrial genome map ). During transcription, the tRNAs acquire their characteristic L-shape that gets recognized and cleaved by specific enzymes. With the mitochondrial RNA processing, individual mRNA, rRNA, and tRNA sequences are released from the primary transcript. Folded tRNAs therefore act as secondary structure punctuations. The promoters for
11446-466: The plant and fungal genomes also exist in some protists, as do two unique genome types. One of these unique types is a heterogeneous collection of circular DNA molecules (type 4) while the other is a heterogeneous collection of linear molecules (type 6). Genome types 4 and 6 each range from 1–200 kbp in size. The smallest mitochondrial genome sequenced to date is the 5,967 bp mtDNA of the parasite Plasmodium falciparum . Endosymbiotic gene transfer,
11564-495: The process by which genes that were coded in the mitochondrial genome are transferred to the cell's main genome, likely explains why more complex organisms such as humans have smaller mitochondrial genomes than simpler organisms such as protists. Mitochondrial DNA is replicated by the DNA polymerase gamma complex which is composed of a 140 kDa catalytic DNA polymerase encoded by the POLG gene and two 55 kDa accessory subunits encoded by
11682-456: The putative new species to be conducted. As a result of external morphology, osteology, and mitochondrial DNA analysis of two of the harvested whales and the Tsunoshima specimen, Wada, Masayuki Oishi, and Yamada described Balaenoptera omurai in the 20 November 2003 issue of the journal Nature . In honour of the people of Tsunoshima, who helped remove the flesh from the type specimen, it was given
11800-409: The results of 78 studies between 1977 and 2012, involving a total of 296,707 participants, and concluded that antioxidant supplements do not reduce all-cause mortality nor extend lifespan, while some of them, such as beta carotene, vitamin E, and higher doses of vitamin A, may actually increase mortality. In a recent study, it was shown that dietary restriction can reverse ageing alterations by affecting
11918-430: The right side, the front third are yellowish-white, the intermediate 100 plates are bi-colored (dark on the outer side and yellowish-white on the inner side), and the remaining plates in the back were all black, while on the left side, the majority are bi-colored with the remaining back plates being all black like the right side. The average length and width for the nine specimens was 26 by 21.4 cm (10.2 by 8.4 in),
12036-442: The same number and kinds of genes as related plants with much smaller mtDNAs. The genome of the mitochondrion of the cucumber ( Cucumis sativus ) consists of three circular chromosomes (lengths 1556, 84 and 45 kilobases), which are entirely or largely autonomous with regard to their replication . Protists contain the most diverse mitochondrial genomes, with five different types found in this kingdom. Type 2, type 3 and type 5 of
12154-559: The same sites by Dolar, William F. Perrin, and others (1996), who suggested they were a "small form" of Bryde's whale. The specimens were deposited in the collections of the Marine Research Laboratory of Silliman University in Dumaguete , Negros Oriental , Philippines, where they were examined by T. K. Yamada and co-workers (2008). They discovered that 24 of the skulls were actually from Omura's whales, whereas only four were from
12272-557: The seven records from Japan involve bycaught individuals, including a 9.2 m (30 ft) male in Sagami Bay in October 2003, a 10.05 m (33.0 ft) female in Tokyo Bay in May 2004, and a 6.3 m (21 ft) female near Ise Bay in March 2012. Both records from South Korea were individuals taken as bycatch, including a 6.3 m (21 ft) female off Geoje in January 2004 and
12390-500: The size of mice , live about eight times longer than mice despite having reduced, compared to mice, antioxidant defenses and increased oxidative damage to biomolecules. Once, there was thought to be a positive feedback loop at work (a 'Vicious Cycle'); as mitochondrial DNA accumulates genetic damage caused by free radicals, the mitochondria lose function and leak free radicals into the cytosol . A decrease in mitochondrial function reduces overall metabolic efficiency. However, this concept
12508-407: The smallest length-to-breadth quotient (1.22) for any species in its genus. Omura's whale seen off New Caledonia , the Solomon Islands , West Sumatra , and East Kalimantan showed extensive scarring from cookiecutter shark bites, indicating they had ventured into deep waters; whereas those off Madagascar did not exhibit them. The rostrum is flat and V-shaped with the head occupying about
12626-669: The southern Java Sea , Bali , Komodo , the Solor Archipelago , Seram , Raja Ampat Islands , and East Kalimantan ), the Cocos (Keeling) Islands , the Andaman Islands (April), Australia ( Western Australia from Exmouth to north of Darwin in the Northern Territory at about 9° 30' S - 10° S, 130° E), South Australia (January, Gulf St Vincent ), Queensland (November to December, Port Douglas and Mission Beach ),
12744-409: The surface in apparent mating (the last of which allowed the identification of a male) off the former area. Off Madagascar, average group size was only 1.1 individuals (272 individuals in 247 groups), but loose aggregations of as many as a dozen whales could be seen. A total of thirteen cow-calf pairs were observed between 2011 and 2016, including a female first seen in an aggregation in 2012, then with
12862-429: The three females caught in the Solomon Sea, two were ovulating and lactating and one was resting (not lactating, ovulating, or pregnant), while one of the two females caught near the Cocos Islands was accompanied by a calf estimated to be about 3 m (9.8 ft) in length. Nothing is known of the duration of gestation and lactation, and little is known of the timing or extent of breeding seasons. In August 2005,
12980-526: The three males ranged from perhaps 21 years (another damaged or partially lost earplug) for the longest male to 38 years for one of the 9.6 m (31.5 ft) specimens. All were physically mature with the exception of the smallest female. Of individuals found stranded in Taiwan and Thailand between 1983 and 2004, five males ranged in length from 5.13 to 10 m (16.8 to 32.8 ft), while two females were 4.3 and 5.95 m (14.1 and 19.5 ft), respectively –
13098-430: The umbilicus. The type specimen (NSMT-M32505) had 203-208 pairs of baleen plates that were "short and broad with uncurled, stiff, grayish-white fringes", while NRIFSF6 had an estimated 181–190 on the right side – fewer than any other species in its genus. Other specimens of Omura's whale had between 204 and 246 pairs of baleen plates. Like the fin whale, NSMT-M32505 exhibited asymmetrical coloration in its baleen, as well: on
13216-506: The vicinity of the Saint Peter and Saint Paul Archipelago . In 1999 and 2000, an unidentified species of rorqual was repeatedly seen in the waters of Komodo National Park . They were small (most estimated to be only 7 to 10 m (23 to 33 ft) in length) with asymmetrical coloration similar to the fin whale, only had a single prominent ridge on the rostrum, and an extremely hooked dorsal fin. At first, they were tentatively identified as
13334-567: The year as well. Four Omura's whales were satellite -tagged off northwest Madagascar in November 2016. The tags stayed on an average of 42 days (range: 30–58 days). The tagged whales traveled an average of 2,530 km (range: 2,148 to 3,181 km) but remained within a small coastal range of only 230 to 405 km (average: 283 km) off the northwest coast of the island. All whales traversed their entire individual ranges several times, spending most of their time on shelf waters and rarely venturing into deep waters. Omura's whale are found in
13452-521: Was 9.4 m (30.8 ft). Lone individuals seen off Madagascar were estimated to range between 8 and 12 m (26 and 39 ft), while calves were estimated to be between 3 and 5 m (9.8 and 16.4 ft). The identity of three mature specimens (two females and a male) examined by biologist Graham Chittleborough in 1958 at a whaling station in Western Australia , which ranged in length from 10.6 to 11.74 m (34.8 to 38.5 ft),
13570-410: Was conclusively disproved when it was demonstrated that mice, which were genetically altered to accumulate mtDNA mutations at accelerated rate do age prematurely, but their tissues do not produce more ROS as predicted by the 'Vicious Cycle' hypothesis. Supporting a link between longevity and mitochondrial DNA, some studies have found correlations between biochemical properties of the mitochondrial DNA and
13688-529: Was finally resolved in 1998 when an unidentified whale, which had died after colliding with a fishing boat in the Sea of Japan and was towed to Tsunoshima, was examined by Tadasu Yamada, Chief of the Division of Mammals and Birds at the National Science Museum, Tokyo . This specimen closely resembled the individuals caught in the 1970s in external appearance and allowed a complete osteological examination of
13806-456: Was made in Nature in 2003 by three Japanese scientists. They determined the existence of the species by analysing the morphology and mitochondrial DNA of nine individuals – eight caught by Japanese research vessels in the late 1970s in the Indo-Pacific and an adult female collected in 1998 from Tsunoshima , an island in the Sea of Japan . Later, abundant genetic evidence confirmed Omura's whale as
13924-460: Was reported that paternal sperm mitochondria (containing mtDNA) are marked with ubiquitin to select them for later destruction inside the embryo . Some in vitro fertilization techniques, particularly injecting a sperm into an oocyte , may interfere with this. The fact that mitochondrial DNA is mostly maternally inherited enables genealogical researchers to trace maternal lineage far back in time. ( Y-chromosomal DNA , paternally inherited,
#93906