The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

Margaret F. Docker - One of the best experts on this subject based on the ideXlab platform.

  • The evolution of lamprey (Petromyzontida) life history and the origin of metamorphosis
    Reviews in Fish Biology and Fisheries, 2018
    Co-Authors: Thomas M. Evans, Philippe Janvier, Margaret F. Docker
    Abstract:

    Modern lampreys (Petromyzontiformes) are one of two lineages of surviving jawless fishes (agnathans), and are thus of critical importance to understanding the evolution of the vertebrates. Although their fossil record is meager, it appears they have remained morphologically conserved for at least 360 million years, but the origin of their multi-stage life history is unclear. Unlike hagfishes, the other extant group of jawless fishes, which exhibit direct development, all modern lampreys possess a complex life cycle which includes a long-lived freshwater larval (or ammocoete) period, followed by a true metamorphosis into a sexually-immature juvenile and then mature adult which differ dramatically in their morphology and ecology from the larva. Because of their basal position, it is critical to understand when the extant lamprey life history evolved, and if such a life history was present in the last common ancestor of agnathans and gnathostomes. Recent discoveries in paleontology, genomic analyses, and developmental biology are providing insights into this problem. The current review synthesizes these findings and concludes that the ancestral lamprey life cycle followed a direct development. We suggest that the larval period was short and relatively limited if present at all, but that the juvenile included modern larval traits; over the course of evolution, differential selection pressures throughout the lifetime produced distinct larval and juvenile/adult periods. Each period required the dramatically different morphologies seen in modern lampreys, ultimately requiring a true metamorphosis to accommodate the large changes in the body plan and to maximize the efficiency of each life period. As a result, modern lamprey life histories are a patchwork of ancestral and derived characters.

  • variations in the presence of chloride cells in the gills of lampreys Petromyzontiformes and their evolutionary implications
    Journal of Fish Biology, 2015
    Co-Authors: Helmut Bartels, Margaret F. Docker, M Krappe, M M White, C Wrede, I C Potter
    Abstract:

    Although confined to fresh water, non-parasitic species of lampreys and the landlocked parasitic sea lamprey, all of which were derived relatively recently from anadromous ancestors, still develop chloride cells, whose function in their ancestors was for osmoregulation in marine waters during the adult parasitic phase. In contrast, such cells are not developed by the non-parasitic least brook lamprey Lampetra aepyptera, which has been separated from its ancestor for >2 million years, nor by the freshwater parasitic species of the genus Ichthyomyzon. The length of time that a non-parasitic species or landlocked parasitic form or species has spent in fresh water is thus considered the overriding factor determining whether chloride cells are developed by those lampreys.

  • genetic diversity endemism and phylogeny of lampreys within the genus lampetra sensu stricto Petromyzontiformes petromyzontidae in western north america
    Journal of Fish Biology, 2012
    Co-Authors: David A Boguski, Damon H Goodman, S B Reid, Margaret F. Docker
    Abstract:

    : Phylogenetic structure of four Lampetra species from the Pacific drainage of North America (western brook lamprey Lampetra richardsoni, Pacific brook lamprey Lampetra pacifica, river lamprey Lampetra ayresii and Kern brook lamprey Lampetra hubbsi) and unidentified Lampetra specimens (referred to as Lampetra sp.) from 36 locations was estimated using the mitochondrial cytochrome b gene. Maximum parsimony and Bayesian inferences did not correspond with any taxonomic scheme proposed to date. Rather, although L. richardsoni (from Alaska to California) and L. ayresii (from British Columbia to California) together constituted a well-supported clade distinct from several genetically divergent Lampetra populations in Oregon and California, these two species were not reciprocally monophyletic. The genetically divergent populations included L. pacifica (from the Columbia River basin) and L. hubbsi (from the Kern River basin) and four Lampetra sp. populations in Oregon (Siuslaw River and Fourmile Creek) and California (Kelsey and Mark West Creeks). These four Lampetra sp. populations showed genetic divergence between 2.3 and 5.7% from any known species (and up to 8.0% from each other), and may represent morphologically cryptic and thus previously undescribed species. A fifth population (from Paynes Creek, California) may represent a range extension of L. hubbsi into the Upper Sacramento River.

  • Microsatellite DNA analysis of parapatric lamprey (Entosphenus spp.) populations: implications for evolution, taxonomy, and conservation of a Canadian endemic
    Canadian Journal of Zoology, 2012
    Co-Authors: Eric B. Taylor, Les N. Harris, Erin K. Spice, Margaret F. Docker
    Abstract:

    Parapatric freshwater and anadromous parasitic lampreys (Petromyzontiformes) from southwestern Vancouver Is- land, British Columbia, have been described as distinct taxa (Vancouver lamprey (Entosphenus macrostomus (Beamish, 1982)) and Pacific lamprey (Entosphenus tridentatus (Richardson, 1836)), respectively), using morphology, life history, and physiology. We tested for genetic differentiation at microsatellite DNA loci between these taxa and similar freshwater para- sitic lampreys from two other lakes. The number of alleles and expected heterozygosity averaged 3.8 and 0.50, respectively, across loci and populations, and anadromous populations were more variable than freshwater populations. Population sub- division was moderate (FST = 0.096, P < 0.001) and 3% of the total variation was found between taxa and 1.7% was found among populations within taxa (both P < 0.001). Parapatric freshwater and anadromous parasitic lampreys separated by a maximum of 40 km were more distinct (mean FST = 0.042) than were anadromous populations located 800 km from one another (mean FST = 0.012). Localities within lakes with parasitic freshwater lampreys, however, showed little differentiation (FST = 0.0-0.08). Our data support recognizing E. macrostomus and E. tridentatus as distinct species, but similar levels of differentiation between these taxa and other freshwater parasitic lampreys suggest a species complex where the taxonomy re- mains unclear.

  • validity of lampetra pacifica Petromyzontiformes petromyzontidae a brook lamprey described from the lower columbia river basin
    Zootaxa, 2011
    Co-Authors: Stewart B Reid, David A Boguski, Damon H Goodman, Margaret F. Docker
    Abstract:

    The Pacific Brook Lamprey, Lampetra pacifica Vladykov, 1973 was described from the lower Columbia River Basin near Portland, Oregon. Subsequently, L. pacifica has generally been treated as a junior synonym of the Western Brook Lamprey, L. richardsoni Vladykov and Follett, 1965, a species described from the Fraser River Drainage east of Vancouver, British Columbia. We reexamine the available morphological data used by previous authors (trunk myomere counts), report on recent collections from the Columbia Basin, and reinterpret the trunk myomere data in the context of recent genetic sampling from the same populations. Populations of L. pacifica are distinguished from those of L. richardsoni by trunk myomere counts of 53–60 (means 59), respectively, and by genetic sequence divergence (cyt b) of 2.85 to 3.20%. We find no support for placing L. pacifica in the synonymy of L. richardsoni and recognize L. pacifica as a valid species. However, we recognize that there is considerable unresolved diversity in the western North American lampreys and recommend restriction of L. pacifica to the Columbia Basin, suggesting that unresolved populations of Lampetra brook (non-parasitic) lampreys outside the basin with mean trunk myomere counts below 59 be referred to as L. cf. pacifica, until further systematic information is available.

I C Potter - One of the best experts on this subject based on the ideXlab platform.

  • variations in the presence of chloride cells in the gills of lampreys Petromyzontiformes and their evolutionary implications
    Journal of Fish Biology, 2015
    Co-Authors: Helmut Bartels, Margaret F. Docker, M Krappe, M M White, C Wrede, I C Potter
    Abstract:

    Although confined to fresh water, non-parasitic species of lampreys and the landlocked parasitic sea lamprey, all of which were derived relatively recently from anadromous ancestors, still develop chloride cells, whose function in their ancestors was for osmoregulation in marine waters during the adult parasitic phase. In contrast, such cells are not developed by the non-parasitic least brook lamprey Lampetra aepyptera, which has been separated from its ancestor for >2 million years, nor by the freshwater parasitic species of the genus Ichthyomyzon. The length of time that a non-parasitic species or landlocked parasitic form or species has spent in fresh water is thus considered the overriding factor determining whether chloride cells are developed by those lampreys.

  • novel relationships among lampreys Petromyzontiformes revealed by a taxonomically comprehensive molecular data set
    Lang N.J. Roe K.J. Renaud C.B. Gill H.S. Potter I.C. Freyhof J. Naseka A.M. Cochran P. Pérez H.E. Habit E.M. Kuhajda B.R. Neely D.A. Reshetnikov Y.S. , 2009
    Co-Authors: Nicholas J Lang, Claude B. Renaud, Howard S Gill, I C Potter, Jorg Freyhof, Alexander M Naseka, Philip A Cochran, Hector Espinosa Perez, Evelyn Habit, Bernard R Kuhajda
    Abstract:

    The systematics of lampreys was investigated using complete mitochondrial cytochrome b sequences from all genera and nearly all recognized species. The families Geotriidae and Petromyzontidae are monophyletic, but the family Mordaciidae was resolved as two divergent lineages at the base of the tree. Within Petromyzontidae, the nonparasitic Lethenteron sp. S and Okkelbergia aepyptera were recognized as distinct lineages, Lethenteron morii and Lampetra zanandreai were moved to new genera, a sister species relationship was recovered between Caspiomyzon wagneri and Eudontomyzon hellenicus, and a clade was recovered inclusive of Entosphenus hubbsi and western North American Lampetra (L. ayresii and L. richardsoni). The placement of E. hellenicus as the sister species to C. wagneri reduces the number of genera comprised entirely of parasitic species to two, Geotria and Petromyzon. The recognition of distinct lineages for O. aepyptera and Lethenteron sp. S recognizes, for the first time, lineages comprised entirely of nonparasitic species. Apart from the results mentioned above, monophyly was supported for the multi-specific genera Entosphenus, Eudontomyzon, Ichthyomyzon, Lampetra (restricted to European species), and Lethenteron. Intergeneric relationships within Petromyzontidae were poorly resolved, but separate clades inclusive of Entosphenus and Tetrapleurodon (subfamily Entospheninae) and one comprised of Eudontomyzon, Lampetra, and Okkelbergia were recovered.

  • phylogeny of living parasitic lampreys Petromyzontiformes based on morphological data
    Copeia, 2003
    Co-Authors: Howard S Gill, Claude B. Renaud, Francois Chapleau, Richard L Mayden, I C Potter
    Abstract:

    Abstract Relationships among the 18 extant species of parasitic lamprey (Petromyzontiformes) were determined using a cladistic analysis of 32 mainly morphological characters. Because previous analyses support all known fossils as phylogenetically older or the same age as living lampreys, a composite agnathan fossil was used as an outgroup. A consensus of three equally parsimonious trees revealed a trichotomy between a monophyletic northern hemisphere clade and the southern hemisphere genera Geotria and Mordacia. The monophyletic status of the northern hemisphere lampreys and their classification in a single family Petromyzontidae was corroborated. It is suggested that the two southern hemisphere lamprey genera be retained as distinct families. Among northern hemisphere species, Ichthyomyzon and Petromyzon form a monophyletic group sister to the remaining genera. Caspiomyzon is sister to Tetrapleurodon + Entosphenus + Lethenteron + Eudontomyzon + Lampetra, with Tetrapleurodon in turn being sister to a grou...

  • the structure of mordacia mordax insulin supports the monophyly of the Petromyzontiformes and an ancient divergence of mordaciidae and geotriidae
    Comparative Biochemistry and Physiology B, 2001
    Co-Authors: J M Conlon, Yuqi Wang, I C Potter
    Abstract:

    The phylogenetic relationships between the two southern hemisphere lamprey families (Geotriidae and Mordaciidae) and their northern hemisphere counterparts (Petromyzontidae) are unresolved. Insulin was isolated from an extract of islet-containing intestinal tissue from ammocoetes of the Australian lamprey, Mordacia mordax. Its primary structure was established as A-chain: GIVEQCCHRK10CSIYDMENYC20N and B-chain: SALMGTGGTH10LCGSHLVEAL20YVVCGQRGFF30 YTP[SKG]. Although the residues in parentheses are only tentatively assigned, mass spectrometry supports the proposed sequence and demonstrates that Mordacia proinsulin, unlike proinsulin from Geotria australis, is fully processed to mature insulin. Insulins from M. mordax and G. australis and from the northern hemisphere lampreys Petromyzon marinus and Lampetra fluviatilis share a pentapeptide extension to N-terminus of the B-chain (Ser-Ala-Leu-Xaa-Gly) that has never been found in the insulins of any other vertebrate class. This observation provides support for the claim that the Petromyzontiformes constitute a monophyletic group. M. mordax insulin differs from that of G. australis by 18 amino acid residues but by only four residues from the common sequence of P. marinus and L. fluviatilis insulin. These data are consistent with the view that Geotriidae and Mordaciidae have been separated for a long period and suggest that G. australis insulin has undergone an accelerated rate of molecular evolution.

Claude B. Renaud - One of the best experts on this subject based on the ideXlab platform.

  • The taxonomy, phylogeny and distribution of lampreys
    Lampreys: Biology Conservation and Control, 2014
    Co-Authors: Ian C. Potter, Claude B. Renaud, Howard S Gill, Dalal Haoucher
    Abstract:

    The lampreys (Petromyzontiformes), one of the two surviving groups of agnathan (jawless) vertebrates, currently consist of 41 recognized species. This group has an antitropical distribution, with the 37 species of Northern Hemisphere lampreys assigned to the Petromyzontidae, whereas the four species of Southern Hemisphere lampreys are separated into either the Geotriidae (one species) or Mordaciidae (three species). All lamprey species have a blind and microphagous, burrowing larva (ammocoete), which spends a number of years in the soft sediment of creeks and rivers, after which it undergoes a radical metamorphosis. Eighteen lamprey species then embark on an adult parasitic phase (nine at sea and nine in fresh water) during which they increase markedly in size, whereas the other 23 species do not feed as adults and remain in fresh water. On the basis of morphology, 17 of the 23 non-parasitic species each evolved from a particular parasitic species whose descendants are still represented in the contemporary fauna. The remaining six non-parasitic species, the so-called “southern relict” species, have no obvious potential ancestral parasitic species, implying they have diverged markedly from their parasitic ancestor or that the parasitic ancestor is now extinct. Many of the main taxonomic characteristics reside in features that are associated with parasitic feeding, for example, the type and arrangement of the teeth on the suctorial disc and tongue-like piston. The phylogenetic relationships, derived by maximum parsimony analyses of morphological and anatomical data for the 18 parasitic species, were similar in most respects to those obtained by subjecting molecular data (cytochrome b mitochondrial DNA sequence data) for those species to Bayesian analyses. However, in contrast to the results of morphological analyses, the genera Eudontomyzon and Lampetra were not monophyletic when using molecular analyses. When non-parasitic species were included in the molecular analyses, some of the six relict non-parasitic species formed clades with parasitic species which, from their morphology, had been allocated by taxonomists to different genera. More genes, and particularly nuclear genes, should be used to help resolve the basis for these differences between the morphological and molecular phylogenies.

  • eudontomyzon graecus a new nonparasitic lamprey species from greece Petromyzontiformes petromyzontidae
    Zootaxa, 2010
    Co-Authors: Claude B. Renaud, Panos S Economidis
    Abstract:

    Eudontomyzon graecus, sp. n., a nonparasitic lamprey from Greece, is restricted to the Louros River drainage, Ionian Sea basin, Epirus Periphery. It is distinguished from Eudontomyzon hellenicus, the other nonparasitic Greek brook lamprey, occurring allopatrically in the Strymon River drainage, Aegean Sea basin, Central Macedonia Periphery, by possessing at the adult stage a relatively longer tail and a greater number of bicuspid teeth in both the first row of anterials and posterials, and at the ammocoete stage, by a relatively shorter trunk and longer tail and a less pigmented upper lip, tongue precursor bulb and lateral aspects of the elastic ridge. Taken individually, these three adult and five larval characters, varied in their diagnostic power from 71 to 88% for the adults and from 91 to 97% for the ammocoetes. However, in combination, these characters provide sufficient evidence to justify recognition of this new species, in addition to the wide distance (ca 400 km) separating it from its closest extant relative, as well as its independent origin.

  • lethenteron ninae a new nonparasitic lamprey species from the north eastern black sea basin Petromyzontiformes petromyzontidae
    Zootaxa, 2009
    Co-Authors: Alexander M Naseka, Sako B Tuniyev, Claude B. Renaud
    Abstract:

    Lethenteron ninae sp. n., a nonparasitic lamprey, is described from rivers of western Transcaucasia in Russia and Abkhazia. It is distinguished from the other species of Lampetrinae in Europe and west Asia (Black Sea basin) by the combination of the following character states: adults with a dark blotch near the apex of the second dorsal fin; exolaterals absent; posterials either absent or more commonly present in a single incomplete row of 3–7 teeth (a toothless gap in the middle); transverse lingual lamina with 9–15 unicuspid teeth, the median one markedly enlarged; supraoral lamina with two unicuspid teeth separated by a toothless bridge; 1–2 rows of anterials, usually 2; first row of anterials with 5–7 unicuspid teeth; oral fimbriae, 69–99; trunk myomeres in both ammocoetes and adults, 56–62; and in ammocoetes, trunk not mottled and tongue precursor bulb clearly triangular, with a wide base and a pointed apex bearing few cirri.

  • novel relationships among lampreys Petromyzontiformes revealed by a taxonomically comprehensive molecular data set
    Lang N.J. Roe K.J. Renaud C.B. Gill H.S. Potter I.C. Freyhof J. Naseka A.M. Cochran P. Pérez H.E. Habit E.M. Kuhajda B.R. Neely D.A. Reshetnikov Y.S. , 2009
    Co-Authors: Nicholas J Lang, Claude B. Renaud, Howard S Gill, I C Potter, Jorg Freyhof, Alexander M Naseka, Philip A Cochran, Hector Espinosa Perez, Evelyn Habit, Bernard R Kuhajda
    Abstract:

    The systematics of lampreys was investigated using complete mitochondrial cytochrome b sequences from all genera and nearly all recognized species. The families Geotriidae and Petromyzontidae are monophyletic, but the family Mordaciidae was resolved as two divergent lineages at the base of the tree. Within Petromyzontidae, the nonparasitic Lethenteron sp. S and Okkelbergia aepyptera were recognized as distinct lineages, Lethenteron morii and Lampetra zanandreai were moved to new genera, a sister species relationship was recovered between Caspiomyzon wagneri and Eudontomyzon hellenicus, and a clade was recovered inclusive of Entosphenus hubbsi and western North American Lampetra (L. ayresii and L. richardsoni). The placement of E. hellenicus as the sister species to C. wagneri reduces the number of genera comprised entirely of parasitic species to two, Geotria and Petromyzon. The recognition of distinct lineages for O. aepyptera and Lethenteron sp. S recognizes, for the first time, lineages comprised entirely of nonparasitic species. Apart from the results mentioned above, monophyly was supported for the multi-specific genera Entosphenus, Eudontomyzon, Ichthyomyzon, Lampetra (restricted to European species), and Lethenteron. Intergeneric relationships within Petromyzontidae were poorly resolved, but separate clades inclusive of Entosphenus and Tetrapleurodon (subfamily Entospheninae) and one comprised of Eudontomyzon, Lampetra, and Okkelbergia were recovered.

  • phylogeny of living parasitic lampreys Petromyzontiformes based on morphological data
    Copeia, 2003
    Co-Authors: Howard S Gill, Claude B. Renaud, Francois Chapleau, Richard L Mayden, I C Potter
    Abstract:

    Abstract Relationships among the 18 extant species of parasitic lamprey (Petromyzontiformes) were determined using a cladistic analysis of 32 mainly morphological characters. Because previous analyses support all known fossils as phylogenetically older or the same age as living lampreys, a composite agnathan fossil was used as an outgroup. A consensus of three equally parsimonious trees revealed a trichotomy between a monophyletic northern hemisphere clade and the southern hemisphere genera Geotria and Mordacia. The monophyletic status of the northern hemisphere lampreys and their classification in a single family Petromyzontidae was corroborated. It is suggested that the two southern hemisphere lamprey genera be retained as distinct families. Among northern hemisphere species, Ichthyomyzon and Petromyzon form a monophyletic group sister to the remaining genera. Caspiomyzon is sister to Tetrapleurodon + Entosphenus + Lethenteron + Eudontomyzon + Lampetra, with Tetrapleurodon in turn being sister to a grou...

Carl B. Schreck - One of the best experts on this subject based on the ideXlab platform.

  • Maturation characteristics and life-history strategies of the Pacific lamprey, Entosphenus tridentatus
    Canadian Journal of Zoology, 2013
    Co-Authors: Benjamin J. Clemens, Stan Van De Wetering, Stacia A. Sower, Carl B. Schreck
    Abstract:

    Lampreys (Petromyzontiformes) have persisted over millennia and now suffer a recent decline in abundance. Complex life histories may have factored in their persistence; anthropogenic perturbations in their demise. The complexity of life histories of lampreys is not understood, particularly for the anadromous Pacific lamprey, Entosphenus tridentatus Gairdner, 1836. Our goals were to describe the maturation timing and associated characteristics of adult Pacific lamprey, and to test the null hypothesis that different life histories do not exist. Females exhibited early vitellogenesis – early maturation stages; males exhibited spermatogonia – spermatozoa. Cluster analyses revealed an “immature” group and a “maturing–mature” group for each sex. We found statistically significant differences between these groups in the relationships between (i) body mass and total length in males; (ii) Fulton’s condition factor and liver lipids in males; (iii) the gonadosomatic index (GSI) and liver lipids in females; (iv) GSI ...

  • incidence of male intersex in adult pacific lamprey entosphenus tridentatus with a brief discussion of intersex vs hermaphroditism in lampreys Petromyzontiformes
    Canadian Journal of Zoology, 2012
    Co-Authors: Benjamin J. Clemens, Stan Van De Wetering, Stacia A. Sower, Carl B. Schreck
    Abstract:

    We report the incidence of male intersex in adult Pacific lamprey (Entosphenus tridentatus (Richardson, 1836)) during their pre-spawning migration in fresh water. Although "hermaphrodites" have been suggested in other adult lampreys, this is the first detailed description and discussion of this phenomenon. A total of 0.5% of our adult Pacific lamprey from Willamette Falls (2 out of 427 adults) were intersex, with oocytes in the testes. This phenomenon was identifiable only by histological examination. The testes of the intersex males were immature, in the beginning stages of meiosis. One intersex male possessed primary growth or perinucleolar stage oocytes loosely interspersed throughout the testes, and the other pos- sessed at least 6 mid-vitellogenic oocytes (0.6 mm, mean long diameter) separate from the testes. Because premetamorphic lamprey can possess both female and male gonial cells, we hypothesize that intersex is a remnant larval trait and that these fish failed to fully develop into males during metamorphosis. Resume : Nous rendons compte de l'incidence d'intersexualite chez des mâles adultes de lamproie du Pacifique (Entosphe- nus tridentatus (Richardson, 1836)) durant leur migration en eau douce precedant le frai. Bien que la presence « d'herma- phrodites » ait ete suggeree chez d'autres lamproies adultes, il s'agit des premieres description et discussion detaillees de ce phenomene. Au total, 0,5 % des lamproies du Pacifique adultes de Willamette Falls recensees (2 individus sur 427 adultes) etaient intersexuelles, presentant des oocytes dans les testicules. Ce phenomene n'est observable que par un examen histolo- gique. Les testicules des mâles intersexuels etaient immatures, aux stades initiaux de la meiose. Un mâle intersexuel posse- dait des oocytes au stade de croissance primaire ou perinucleolaire dissemines ca et la dans les testicules et l'autre possedait au moins six oocytes a des stades intermediaires de la vitellogenese (diametre long moyen de 0,6 mm) separes des testicu- les. Etant donne que la lamproie premetamorphique peut presenter des cellules goniales femelles et mâles, nous avons emis l'hypothese que l'intersexualite est un caractere larvaire residuel et que ces poissons ne se sont pas developpes complete- ment en individus mâles durant la metamorphose. Mots-cles : intersexualite, gonochoriste, poisson primitif, reproduction, maturation, cyclostomes. (Traduit par la Redaction)

Hwa Kun Byeon - One of the best experts on this subject based on the ideXlab platform.

  • complete mitochondrial genome of the sand lamprey lampetra reissneri Petromyzontiformes petromyzontidae
    Mitochondrial DNA, 2013
    Co-Authors: Daesik Hwang, Hwa Kun Byeon
    Abstract:

    The complete mitochondrial genome was sequenced from the river lamprey, Lampetra reissneri. The genome sequence was 16,197 bp in size, and the gene order and contents were identical to those of the congeneric species Lampetra japonica. However, L. reissneri had two incomplete control regions with a rearrangement of mitochondrial genomic organization compared with other fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), only one gene (CO1) had an incomplete stop codon. The base composition of L. reissneri showed anti-G bias (12.99% and 4.49%) on the 2nd and 3rd position of PCGs, respectively.

  • complete mitochondrial genome of the river lamprey lampetra japonica Petromyzontiformes petromyzonidae
    Mitochondrial DNA, 2013
    Co-Authors: Daesik Hwang, Hwa Kun Byeon
    Abstract:

    The complete mitochondrial genome was sequenced from the river lamprey, Lampetra japonica. The genome sequence was 16,267 bp in size, and the gene order and contents were identical with the genera Lampetra reissneri. However, L. japonica has two control regions with different mitochondrial genomic organization compared to other previously reported fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), 1 gene (CO1) had incomplete stop codon. The base composition of L. japonica showed anti-G bias (4.65%) on the third position of PCGs.