scholarly journals First description of a widespread Mytilus trossulus-derived bivalve transmissible cancer lineage in M. trossulus itself

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Skazina ◽  
Nelly Odintsova ◽  
Maria Maiorova ◽  
Angelina Ivanova ◽  
Risto Väinölä ◽  
...  

AbstractTwo lineages of bivalve transmissible neoplasia (BTN), BTN1 and BTN2, are known in blue mussels Mytilus. Both lineages derive from the Pacific mussel M. trossulus and are identified primarily by their unique genotypes of the nuclear gene EF1α. BTN1 is found in populations of M. trossulus from the Northeast Pacific, while BTN2 has been detected in populations of other Mytilus species worldwide but not in M. trossulus itself. Here we examined M. trossulus from the Sea of Japan (Northwest Pacific) for the presence of BTN. Using hemocytology and flow cytometry of the hemolymph, we confirmed the presence of disseminated neoplasia in our specimens. Cancerous mussels possessed the BTN2 EF1α genotype and two mitochondrial haplotypes with different recombinant control regions, similar to that of common BTN2 lineages. This is the first report of BTN2 in its original host species M. trossulus. A comparison of all available BTN and M. trossulus COI sequences suggests a common and recent origin of BTN2 diversity in populations of M. trossulus outside the Northeast Pacific, possibly in the Northwest Pacific.

2020 ◽  
Author(s):  
Maria Skazina ◽  
Nelly Odintsova ◽  
Maria Maiorova ◽  
Angelina Ivanova ◽  
Risto Väinölä ◽  
...  

AbstractTwo lineages of bivalve transmissible neoplasia (BTN), BTN1 and BTN2, are known in blue mussels Mytilus. Both lineages derive from the Pacific mussel M. trossulus and are identified primarily by the unique genotypes of the nuclear gene EF1α. BTN1 is found in populations of M. trossulus from the Northeast Pacific, while BTN2 has been detected in populations of other Mytilus species worldwide but not in M. trossulus itself. The aim of our study was to examine mussels M. trossulus from the Sea of Japan (Northwest Pacific) for the presence of BTN. Using hemocytology and flow cytometry of the hemolymph, we confirmed disseminated neoplasia in our specimens. Cancerous mussels possessed the unique BTN2 EF1α genotype and two mitochondrial haplotypes with different recombinant control regions, similar to that of common BTN2 lineages. This is the first report of BTN2 in its original host species M. trossulus populations in West Pacific may be the birthplace of BTN2 and a natural reservoir where it is maintained and whence it spreads worldwide. A comparison of all available BTN and M. trossulus COI sequences suggests a common and recent, though presumably prehistoric origin of BTN2 diversity in populations of M. trossulus outside the Northeast Pacific.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.


1978 ◽  
Vol 10 (1) ◽  
pp. 1-29 ◽  
Author(s):  
Paolo A. Pirazzoli

Evidence of Holocene sea levels higher than the present level have often been reported from the Northwest Pacific. Eustatic interpretations have been propounded, but age and level of the maximum transgression vary with each new analysis. In this investigation, after an inventory of approximately 250 items of data, some of which are new, a tentative synthesis transcending local scale is advanced. The highest levels are reported from Taiwan, where they often reach several tens of meters in altitude. In the Ryûkyûs and in the main islands of the Japanese Archipelago, evidence of recent emergence is found along most of the coasts. Elevation increases towards the oceanic trenches, but former sea levels at above 6 m and even higher may also be recognized along the coasts of the Sea of Japan. In a few areas, such as in the Niigata Plain, marks of Holocene sea levels higher than at present are lacking. On the other hand, in other basins regarded as subsiding, such as those in the Nôbi and the Kantô plains, evidence of recent emergence is quite frequent. In many places, marks of several sea levels indicate that a step-by-step uplift has occurred. All the investigated insular arcs, therefore, seem to be situated in epeirogenic areas formed by several more or less large blocks affected by relative movements. The blocks are larger in the Outer Zone of Southwestern Japan; in the Inner Zone, an intricate network of fault lines marks the boundaries of many smaller independent blocks. During great earthquakes, relative movements of uplift, subsidence, tilting, or undulation occur in one or several blocks, depending on the position of the epicentres. Subsidence, however, must often be simply of a temporary nature, because a long-term uplift trend seems to prevail in most regions, even if it occurs at different rates. This interpretation may explain the cause of the great variety of ages and elevations of the former sea levels (with the oldest ages corresponding to the highest elevations) and the great number of indicators of step-by-step sea-level change. The inference, drawn by several authors, that the Holocene sea level in the Northwest Pacific was higher than at present, is, therefore, reasonable on a local scale, but does not define an eustatic sea level.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2863 ◽  
Author(s):  
Anton Chichvarkhin

A new sea star species,H. djakonovisp.n., was discovered in Rudnaya Bay in the Sea of Japan. This is a sympatric species of the well-known and common speciesHenricia pseudoleviusculaDjakonov, 1958. Both species are similar in body size and proportions, shape of skeletal plates, and life coloration, which distinguishes them from the otherHenriciaspecies inhabiting the Sea of Japan. Nevertheless, these species can be distinguished by their abactinal spines: in both species, they are short and barrel-like, but the new species is the onlyHenriciaspecies in Russian waters of the Pacific that possesses such spines with a massive, smooth, bullet-like tip. The spines inH. pseudoleviusculaare crowned with a variable number of well-developed thorns. About half (<50%) of the abactinal pseudopaxillae in the new species are oval, not crescent-shaped as inH. pseudoleviuscula.


1985 ◽  
Vol 7 (3) ◽  
pp. 379-387 ◽  
Author(s):  
A. G. Rodnikov ◽  
A. G. Gainanov ◽  
B. V. Yermakov ◽  
V. M. Kovylin ◽  
V. A. Seliverstov ◽  
...  

2014 ◽  
Vol 28 (6) ◽  
pp. 628 ◽  
Author(s):  
Steven J. B. Cooper ◽  
Christopher H. S. Watts ◽  
Kathleen M. Saint ◽  
Remko Leijs

Scirtidae is a cosmopolitan group of beetles with aquatic or saproxylic larvae. A large diversity of species has recently been described from Australia, but their systematics is uncertain. There is evidence that current genera are polyphyletic and that Australian species were wrongly placed in northern hemisphere genera. Here we investigate the systematics of Australian Scirtidae using molecular phylogenetic analyses of combined data from the mitochondrial cytochrome c oxidase subunit 1 (COI) and nuclear gene elongation factor 1-α (EF1-α) genes. We also assess the current taxonomy of Australian Scirtidae using partial COI sequences. Bayesian phylogenetic analyses of COI and EF1-α sequence data from 81 taxa show that the Australian genera Contacyphon, Pseudomicrocara and Prionocyphon are polyphyletic. There is no close relationship between Australian and Eurasian genera, with the exception of Scirtes. Phylogenetic analyses of partial COI data from Australian Scirtidae generally support the current α taxonomy, with the exception of several species that may be associated with species complexes. Geographically a high proportion of species lineages are restricted to relict patches of wet forest suggesting that they may be relict populations. The phylogeny and sequence data presented here provide a sound basis for further systematic and biogeographical studies of the Scirtidae.


2007 ◽  
Vol 67 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Masanobu Shishikura ◽  
Tomoo Echigo ◽  
Heitaro Kaneda

AbstractIn this study we utilize marine shell samples from two levels of historically uplifted sessile mollusk assemblages and raised wave-cut benches to evaluate the marine reservoir correction (ΔR) for the Pacific coast of central Japan. Elevation measurements of the uplifted marine shells indicate that the lower assemblage emerged during the 1923 Taisho Kanto earthquake (M7.9), whereas uplift of the upper assemblage is most likely but less confidently ascribed to the 1703 Genroku Kanto earthquake (M8.2). Radiocarbon dating of carefully selected samples from the upper and lower assemblages yielded very similar ΔR values of 82 ± 33 and 77 ± 32 yr, respectively. We regard the former ΔR value as a representative and more reliable value given the uncertainty in correlation of the upper assemblage with the 1703 earthquake. This result is consistent with previously reported ΔR values for the Pacific coast of south-central Japan and areas around the Sea of Japan that are influenced by warm ocean currents. Radiocarbon dating of coseismically uplifted shells can aid in estimating marine reservoir ages in the tectonically active Japan Islands.


1959 ◽  
Vol 37 (6) ◽  
pp. 895-897 ◽  
Author(s):  
L. Margolis

Cyamus balaenopterae Barnard from Balaenoptera acutorostrata and Neocyamus physeteris (Pouchet) from Physeter macrocephalus are reported for the first time from the Pacific Ocean. This is the first record of a cyamid from B. acutorostrata.


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