著者
Kawada Shin-ichiro Harada Masashi Obara Yoshitaka Kobayashi Shuji Koyasu Kazuhiro Oda Sen-ichi
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.18, no.7, pp.1003-1010, 2001-09-20
被引用文献数
14 23

A detailed analysis was done on the karyotypes of four species of mole in the genera Euroscaptor and Mogera using a G-banding technique. All four species examined had a chromosome number of 2n = 36, as reported previously. Euroscaptor mizura and M. wogura from Aichi Prefecture had almost the same chromosome constitution and G-banding patterns. These common karyotypes were considered to be equivalent to the hypothetical ancestral karyotype of Mogera, since two distinct genera derived from an ancestor share G-banding homologies. According to this hypothesis, the karyotype of M. imaizumii might have been derived from the ancestral karyotype through pericentric inversion in one pair of acrocentrics, chromosome 11. Two geographically isolated populations of M. tokudae had different karyotypes : the Echigo population had the same karyotype as M. imaizumii, whereas the Sado population had a derivative karyotype that was able to be explained by pericentric inversions in three pairs of acrocentrics, remaining chromosome 11 as subtelocentric. Mogera wogura from South Korea differed considerably in terms of chromosome constitution from the Japanese population of M. wogura. However, we deduced that pericentric and paracentric inversions in four pairs of acrocentrics would explain the karyotype differences between the Japanese and Korean populations. Furthermore, from the morphology of chromosome 11, we can conclude that the Korean mole was derived from primitive M. wogura through four inversions, quite separately from the lineage of M. imaizumii and M. tokudae. Thus, inversion rearrangements appear to have played a major role in the chromosomal evolution of Japanese talpine moles.
著者
Harada Masashi Ando Akiro Tsuchiya Kimiyuki Koyasu Kazuhiro
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.18, no.3, pp.433-442, 2001-04-10
被引用文献数
4 16

Karyotypes of the greater Japanese shrew-mole, Urotrichus talpoides (Talpidae), collected from 57 localities in Japan were studied by conventional, G- and C-band staining techniques to elucidate geographical chromosomal variations, the mechanism of changes in chromosomes, and the distribution patterns of karyotypic races. Shrew-mole samples examined could be divided geographically into two slightly divergent chromosomal forms designated as the western and eastern races. These two karyotypic races had the same diploid number (34) and fundamental number (64), but they had autosomes with different makeups. A comparison of conventional karyotypes showed a distinct intraspecific variation in shape of autosomal pair no. 14 which was classified as subtelocentric in the western race and as metacentric in the eastern race. G- and C-banding analyses revealed that karyotypic variation found in no. 14 pair was involved in pericentric inversion and quantitative changes in constitutive heterochromatin. Intraspecific and geographical variation in chromosomes caused by such karyological events is rare and unique among members of the family Talpidae examined so far. Furthermore, our results demonstrated that the clear boundary between the two parapatric karyotypic races was actually located along the Kurobe-Fuji line in the central part of Honshu, but not along the Owari-Tsuruga isthmian line previously postulated by Tsuchiya (1987,1988). Zoogeographical implications of the boundary of parapatric distribution in U. talpoides are also discussed.
著者
Motokawa Masaharu Suzuki Hitoshi Harada Masashi Lin Liang-Kong Koyasu Kazuhiro Oda Sen-ichi
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.17, no.4, pp.497-504, 2000-05-20
被引用文献数
5 7

Phylogenetic relationships among the East Asian species of the genus Crocidura (Mammalia, Insectivora, Soricidae) were inferred from the partial sequences (402 base pairs) of the mitochondrial cytochrome b gene. Six species of Crocidura and one representative of another insectivoran genus Suncus were examined. In the neighbor joining tree, four distinct lineages were recognized: C. lasiura from northeastern China and Korea, and C. dsinezumi from the main-islands of Japan; C. attenuata from Taiwan; C. watasei from the Amami and Okinawa Groups, and S. murinus from the Miyako Group; and C. suaveolens from Tsushima and Taiwan, and C. sibirica from Central Asia in Russian territory. All these lineages excluding C. lasiura and C. dsinezumi were also recognized by the maximum parsimony analysis. Clustering of C. watasei with S. murinus suggested the non-monophyly of the genus Crocidura as of the present definition. Biogeographical implications of the present results were also discussed.
著者
Tsuchiya Kimiyuki Suzuki Hitoshi Shinohara Akio HARADA Masashi WAKANA Shigeharu SAKAIZUMI Mitsuru HAN Sang-Hoon LIN Liang-Kong KRYUKOV Alexei P.
出版者
The Genetics Society of Japan
雑誌
Genes & genetic systems (ISSN:13417568)
巻号頁・発行日
vol.75, no.1, pp.17-24, 2000-02
被引用文献数
15 42

Taxonomic analysis has previously revealed that the species of moles that inhabit Japan are characterized by exceptional species richness and a high level of endemism. Here, we focused on the evolutionary history of the four Japanese mole species of the genera <i>Euroscapter</i> and <i>Mogera</i>, examining mitochondrial cytochrome <i>b</i> (cyt <i>b</i>) gene sequences and comparing them with those of continental <i>Mogera wogura</i> (Korean and Russian populations), <i>M. insularis</i> from Taiwan, and <i>Talpa europaea</i> and <i>T. altaica</i> from the western and central Eurasian continent, respectively. Our data support the idea that in a radiation center somewhere on the Eurasian continent, a parental stock evolved to modern mole-like morph and radiated several times intermittently during the course of the evolution, spreading its branches to other peripheral geographic domains at each stage of the radiation. Under this hypothesis, the four lineages of Japanese mole species, <i>E. mizura</i>, <i>M. tokudae</i>, <i>M. imaizumii</i>, and <i>M. wogura</i>, could be explained to have immigrated to Japan in this order. <i>Mogera wogura</i> and <i>M. imaizumii</i> showed substantial amounts of geographic variation and somewhat complicated distributions of the cyt <i>b</i> gene types. These intraspecific variations are likely to be associated with the expansion processes of moles in the Japanese Islands during the Pleistocene glacial ages.<br>