Search

Your search keyword '"Goto, Mutsuo"' showing total 126 results
Start Over Author "Goto, Mutsuo"
126 results on '"Goto, Mutsuo"'

1. Population genetic structure of Bryde's whales (Balaenoptera brydei) on the central and western North Pacific feeding grounds

Author

Taguchi, Mioko, Goto, Mutsuo, Matsuoka, Koji, Tiedemann, Ralph, and Pastene, Luis A.

Subjects
North Pacific Ocean -- Natural history, Animal populations -- Research, Genetic research, Population genetics -- Research, Earth sciences
Abstract

The genetic structure of Bryde's whale (Balaenoptera brydei) on the central and western North Pacific feeding grounds was investigated using a total of 1195 mitochondrial control region sequences and 1182 microsatellite genotypes at 17 loci in specimens collected from three longitudinal areas, 1W (135[degrees]E-165[degrees]E), 1E (165[degrees]E-180[degrees]), and 2 (180[degrees]-155[degrees]W). Genetic diversities were similar among areas and a haplotype network did not show any geographic structure, while an analysis of molecular variance found evidence of genetic structure in this species. Pairwise [F.sub.ST] and [G'.sub.ST] estimates and heterogeneity tests attributed this structure to weak but significant differentiation between areas 1W/1E and 2. A Mantel test and a high-resolution analysis of genetic diversity statistics showed a weak spatial cline of genetic differentiation. These findings could be reconciled by two possible stock structure scenarios: (1) a single population with kin-association affecting feeding ground preference and (2) two populations with feeding ground preference for either area 1W or area 2. An estimated dispersal rate between areas 1W and 2 indicates that both scenarios should be considered as a precautionary principle in stock assessments. Key words: stock structure, stock assessment, fisheries management, conservation, cetacean, Introduction Bryde's whale (Balaenoptera brydei) is a medium-sized baleen whale found year-round in the tropical and warm temperate waters of major oceans between approximately 40[degrees] N and 40[degrees]S (Kato and [...]

Published
2023
Full Text
View/download PDF

16. The Evolution of Unusually Small Amelogenin Genes in Cetaceans; Pseudogenization, X–Y Gene Conversion, and Feeding Strategy.

Author

Kawasaki, Kazuhiko, Mikami, Masato, Goto, Mutsuo, Shindo, Junji, Amano, Masao, and Ishiyama, Mikio

Subjects
GENE conversion, CETACEA, AMELOGENIN, AMELOBLASTS, DENTAL enamel, SEX chromosomes
Abstract

Among extant cetaceans, mysticetes are filter feeders that do not possess teeth and use their baleen for feeding, while most odontocetes are considered suction feeders, which capture prey by suction without biting or chewing with teeth. In the present study, we address the functionality of amelogenin (AMEL) genes in cetaceans. AMEL encodes a protein that is specifically involved in dental enamel formation and is located on the sex chromosomes in eutherians. The X-copy AMELX is functional in enamel-bearing eutherians, whereas the Y-copy AMELY appears to have undergone decay and was completely lost in some species. Consistent with these premises, we detected various deleterious mutations and/or non-canonical splice junctions in AMELX of mysticetes and four suction feeding odontocetes, Delphinapterus leucas, Monodon monoceros, Kogia breviceps, and Physeter macrocephalus, and in AMELY of mysticetes and odontocetes. Regardless of the functionality, both AMELX and AMELY are equally and unusually small in cetaceans, and even their functional AMELX genes presumably encode a degenerate core region, which is thought to be essential for enamel matrix assembly and enamel crystal growth. Furthermore, our results suggest that the most recent common ancestors of extant cetaceans had functional AMELX and AMELY, both of which are similar to AMELX of Platanista minor. Similar small AMELX and AMELY in archaic cetaceans can be explained by gene conversion between AMELX and AMELY. We speculate that common ancestors of modern cetaceans employed a degenerate AMELX, transferred from a decaying AMELY by gene conversion, at an early stage of their transition to suction feeders. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

18. Radiation and speciation of pelagic organisms during periods of global warming: the case of the common minke whale, Balaenoptera acutorostrata

Author

Pastene, Luis A., Goto, Mutsuo, Kanda, Naohisa, Zerbini, Alexandre N., Kerem, Dan, Watanabe, Kazuo, Bessho, Yoshitaka, Hasegawa, Masami, Nielsen, Rasmus, Larsen, Finn, Palsboll, Per J., and Palsbøll lab

Subjects
SUBDIVISION, MIGRATION, CIRCULATION, phylogeography, global warming, EVOLUTION, NORTH-ATLANTIC, MODEL, expansion, speciation, DIVERGENCE, CONTROL REGION, Cetacea, MITOCHONDRIAL-DNA SEQUENCES, MAXIMUM-LIKELIHOOD
Abstract

How do populations of highly mobile species inhabiting open environments become reproductively isolated and evolve into new species? We test the hypothesis that elevated ocean-surface temperatures can facilitate allopatry among pelagic populations and thus promote speciation. Oceanographic modelling has shown that increasing surface temperatures cause localization and reduction of upwelling, leading to fragmentation of feeding areas critical to pelagic species. We test our hypothesis by genetic analyses of populations of two closely related baleen whales, the Antarctic minke whale (Balaenoptera bonaerensis) and common minke whale (Balaenoptera acutorostrata) whose current distributions and migration patterns extent are largely determined by areas of consistent upwelling with high primary production. Phylogeographic and population genetic analyses of mitochondrial DNA control-region nucleotide sequences collected from 467 whales sampled in four different ocean basins were employed to infer the evolutionary relationship among populations of B. acutorostrata by rooting an intraspecific phylogeny with a population of B. bonaerensis. Our findings suggest that the two species diverged in the Southern Hemisphere less than 5 million years ago (Ma). This estimate places the speciation event during a period of extended global warming in the Pliocene. We propose that elevated ocean temperatures in the period facilitated allopatric speciation by disrupting the continuous belt of upwelling maintained by the Antarctic Circumpolar Current. Our analyses revealed that the current populations of B. acutorostrata likely diverged after the Pliocene some 1.5 Ma when global temperatures had decreased and presumably coinciding with the re-establishment of the polar-equatorial temperature gradient that ultimately drives upwelling. In most population samples, we detected genetic signatures of exponential population expansions, consistent with the notion of increasing carrying capacity after the Pliocene. Our hypothesis that prolonged periods of global warming facilitate speciation in pelagic marine species that depend on upwelling should be tested by comparative analyses in other pelagic species.

Published
2007

19. Migration of Antarctic Minke Whales to the Arctic

Author

Glover, Kevin A., primary, Kanda, Naohisa, additional, Haug, Tore, additional, Pastene, Luis A., additional, Øien, Nils, additional, Goto, Mutsuo, additional, Seliussen, Bjørghild B., additional, and Skaug, Hans J., additional

Published
2010
Full Text
View/download PDF

37. Report of the Working Group on DNA.

Author

Skaug, Hans Julius, Kanda, Naohisa, Goto, Mutsuo, Pampoulie, Christophe, and Vikingsson, Gisli A.

Subjects
ANNUAL meetings, COMMITTEE reports, CETACEA
Abstract

The article presents the Report of the Working Group on DNA about its agendas and other issues discussed at the International Whaling Commission (IWC) Scientific Committee Annual Meeting held in Agadir, Morocco from May 30 to June 11, 2010. The proposed amendments to address inconsistencies in taxonomic distinctions for cetacean species made by GenBank are tackled. The recommendations of the working group on the adoption of a standard format for national DNA registers are detailed. The specifications for the development or maintenance of a diagnostic DNA register or tissue archive are also detailed which include the minimum laboratory requirements and conditions for sample collection and tissue analysis.

Published
2011

38. Report of the Working Group on the Pre-Implementation Assessment of Western North Pacific Common Minke Whales.

Author

Kanda, N., An, Y. R., Miyashita, T., Baker, C. S., Pastene, Luis A., Goto, Mutsuo, Kanda, Naohisa, Wade, P., Hatanaka, H., Pastene, L. A., Gunnlaugsson, T., Park, J. Y., Choi, S. G., and Rock, Y. R.

Subjects
COMMITTEE reports, WHALING, FISH population measurement, FISHERY management, FISH stocking, CONFERENCES & conventions
Abstract

The article presents the Report of the Working Group on the Pre-Implementation Assessment of Western North Pacific Common Minke Whales about its agendas and other issues discussed at a pre-meeting of the International Whaling Commission (IWC) Scientific Committee held in Agadir, Morocco from May 28-29, 2010. Previous discussions on stock structure for western North Pacific common minke whales was recalled at the pre-meeting. Some topics tackled included the uncertainties in reports of commercial catches of these minke whales, whale abundance estimates by Korea and Japan and the plans of both countries for future sighting surveys. The working group reviewed the IWC Scientific Assessment Group (SAG) Report on the application of the Revised Management Procedure (RMP) to data for these whales.

Published
2011

49. Sequence Variation in the Tbx4 Gene in Marine Mammals.

Author

Onbe, Kaori, Nishida, Shin, Sone, Emi, Kanda, Naohisa, Goto, Mutsuo, Pastene, Luis A., Tanabe, Shinsuke, and Koike, Hiroko

Abstract

The amino-acid sequences of the T-domain region of the Tbx4 gene, which is required for hindlimb development, are 100% identical in humans and mice. Cetaceans have lost most of their hindlimb structure, although hindlimb buds are present in very early cetacean embryos. To examine whether the Tbx4 gene has the same function in cetaceans as in other mammals, we analyzed Tbx4 sequences from cetaceans, dugong, artiodactyls and marine carnivores. A total of 39 primers were designed using human and dog Tbx4 nucleotide sequences. Exons 3, 4, 5, 6, 7, and 8 of the Tbx4 genes from cetaceans, artiodactyls, and marine carnivores were sequenced. Non-synonymous substitution sites were detected in the T-domain regions from some cetacean species, but were not detected in those from artiodactyls, the dugong, or the carnivores. The C-terminal regions contained a number of non-synonymous substitutions. Although some indels were present, they were in groups of three nucleotides and therefore did not cause frame shifts. The dN/ds values for the T-domain and C-terminal regions of the cetacean and artiodactylous Tbx4 genes were much lower than 1, indicating that the Tbx4 gene maintains it function in cetaceans, although full expression leading to hindlimb development is suppressed. [ABSTRACT FROM AUTHOR]

Published
2007
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results