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Mizukawa H.,Ehime University | Nomiyama K.,Ehime University | Nakatsu S.,Nakatsu Veterinary Surgery | Yachimori S.,Shikoku Institute of Natural History | And 4 more authors.
Environmental Pollution | Year: 2013

Residue levels and patterns of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), their hydroxylated metabolites (OH-PCBs, OH-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the blood of various terrestrial mammals in Japan, including cats, raccoon dogs, dogs, masked palm civets, foxes, raccoons, badgers, and mongooses were determined. Tri- through penta-chlorinated OH-PCBs were predominant in cat blood, whereas hexa- through octa-chlorinated OH-PCBs were found in other species. High proportion of BDE209 was found in all species, suggesting exposure to municipal waste and soil containing higher levels of deca-BDE products. 6OH-/MeO-BDE47 and 2′OH-/MeO-BDE68 were dominant in all terrestrial mammals. This is first report on the detection of OH-/MeO-PBDEs in the blood of terrestrial mammals. High concentrations of OH-/MeO-PBDEs were found in cats, suggesting the intake of these compounds from seafood. Cats exhibited higher accumulation and specific patterns of OH-PCBs, OH-PBDEs, and MeO-PBDEs, they may be at a high risk from these metabolites. © 2012 Elsevier B.V. All rights reserved.


Ishibashi Y.,Japan Forestry and Forest Products Research Institute | Oi T.,Japan Forestry and Forest Products Research Institute | Oi T.,Ishikawa Prefectural University | Arimoto I.,Hakusan Nature Conservation Center | And 7 more authors.
Conservation Genetics | Year: 2016

In Japan, the black bear, Ursus thibetanus, is distributed on Honshu and Shikoku Islands. Most populations in western Japan declined considerably during the twentieth century, but a few populations are now rebounding due to conservation efforts. Here, we examined the sequence variation in the second exon of the major histocompatibility complex class II DQB gene (270 bp), which is critical for pathogen recognition. We measured variation within six populations in western Japan, including two threatened populations in the Chugoku region on Honshu and one on Shikoku. Eight sequence variants were observed among the examined bears (n = 417), and two to eight variants were retained within populations. Our samples, collected in 2001–2013, retained a smaller number of sequence variants in each population compared with the allelic diversity in an earlier study that examined the same gene and used samples collected mainly during the last century. Many rare variants that were observed previously and may have been maintained by balancing selection have disappeared from recent populations. Although the earlier study suggested a loss of genetic diversity in western Japan, the present study shows that further loss of rare variants has occurred, probably due to genetic drift during the end of the last century. © 2016 Springer Science+Business Media Dordrecht


Inoue T.,Hokkaido University | Kaneko Y.,Tokyo University of Agriculture and Technology | Yamazaki K.,Ibaraki Nature Museum | Anezaki T.,Gunma Museum of Natural History | And 7 more authors.
Conservation Genetics | Year: 2012

The masked palm civet Paguma larvata (Carnivora: Viverridae) in Japan has been phylogeographically considered an introduced species from Taiwan. To reveal the population structures and relationships among the P. larvata populations in Japan, seven compound microsatellite loci were isolated from the genome and genotyped for 287 individuals collected from the field. STRUCTURE analysis and factorial correspondence analysis of genotyping data revealed that animals from Japan were divided into four genetic clusters. Geographic distribution of the genetic clusters partly referred to sampling areas, indicating multiple introductions into distinct areas of Japan or independent founding events leading to the generation of different genetic clusters within introduced populations in Japan. The large genetic differentiation of populations in the Shikoku District from those in other areas within Japan suggests that there were at least two introduction routes into Japan, and a possibility that some founders from areas other than Taiwan were also involved in the introduction into Japan. The genetic variation within Japanese populations were not markedly reduced compared with that of Taiwan. The results indicated that the Japanese populations of P. larvata could have retained moderate genetic diversity during founding events, because of multiple introductions, or a large number or high genetic diversity of founders. Although some individuals in Japan showed a sign of admixture between different clusters, there is no evidence that such an admixture markedly increased the genetic diversity within Japanese populations. © 2012 Springer Science+Business Media B.V.


Tashima S.,Hokkaido University | Kaneko Y.,Tokyo University of Agriculture and Technology | Anezaki T.,Gunma Natural History Museum | Baba M.,Kitakyushu Museum of Natural History and Human History | And 4 more authors.
Mammal Study | Year: 2011

The short interspersed nucleotide elements (SINEs) are specific to the taxa and thought to be one of powerful phylogenetic gene markers. Especially, the SINE sequences, which exist uniquely in genome of order Carnivora, are named CAN-SINEs. Among the Eurasian badgers (genus Meles), a member of the family Mustelidae in order Carnivora, the Japanese badger (M. anakuma) was previously reported to have an insertion of CAN-SINE in the final intron of the zinc finger protein gene on Y chromosome (ZFY). In the present study, we examined occurrence of the CAN-SINE of the ZFY final intron in the Eurasian badgers, and three continental and four Japanese haplotypes were identified from a total of 40 male badgers. Among the Eurasian badger CAN-SINEs, a 12-bp deletion specific to the Japanese haplotypes was found, whereas the 12-bp region (non-deletion) in the continental haplotypes consisted of one 6-bp direct repeat and 6-bp microsatellite-like sequences. Moreover, the continental haplotypes were phylogenetically divided into three lineages: eastern Eurasia, Caucasus and western Eurasia. These genetic differentiations supported the classification recently proposing that genus Meles are grouped into the European badger (M. meles), the Southwest Asian badger (M. canescens), the Northwest & Central Asian badger (M. leucurus) and the Japanese badger (M. anakuna). In addition, the number of adenines in the poly A/T rich tails was polymorphic among all lineages of Eurasian badgers, and geographically variable within the Japanese badgers. © the Mammalogical Society of Japan.


Hoshino K.,Oita Marine Palace Aquarium UMITAMAGO | Hibino Y.,Mie University | Kimura S.,Mie University | Machida Y.,Kochi University | Machida Y.,Shikoku Institute of Natural History
Ichthyological Research | Year: 2011

The worm eels, Muraenichthys okamurai Machida and Ohta 1996 and M. borealis Machida and Shiogaki 1990, both from Japanese waters, have been distinguished by the difference in dentition on the upper jaw and palatal area, and regarded as valid species of Scolecenchelys. A detailed examination of the dentition of the type specimens and recently caught specimens revealed that the difference in the dentition described in the original descriptions is actually intraspecific variation. Apparently M. okamurai represents the juvenile of M. borealis, and the former is its junior subjective synonym. © 2011 The Ichthyological Society of Japan.


Tashima S.,Hokkaido University | Kaneko Y.,Tokyo University of Agriculture and Technology | Anezaki T.,Gunma Museum Natural History | Baba M.,Kitakyushu Museum of Natural History and Human History | And 4 more authors.
Zoological Science | Year: 2011

In the present study, to further understand the phylogenetic relationships among the Eurasian badgers (Meles, Mustelidae, Carnivora), which are distributed widely in the Palearctic, partial sequences of the mitochondrial DNA (mtDNA) control region (539-545 base-pairs) as a maternal genetic marker, and the sex-determining region on the Y-chromosome gene (SRY: 1052-1058 base-pairs), as a paternal genetic marker, were examined. The present study revealed ten SRY haplotypes from 47 males of 112 individuals of the Eurasian Continent and Japan. In addition, 39 mtDNA haplotypes were identified from those animals. From the phylogeography of both the uniparentally inherited genes, four lineages were recognized as Japanese, eastern Eurasian, Caucasian, and western Eurasian. The distribution patterns of the mtDNA lineages showed the existence of a sympatric zone between the eastern and western Eurasian lineages around the Volga River in western Russia. Furthermore, the present study suggested that in the Japanese badgers, the larger genetic differentiation of the Shikoku population was attributable to geographic history in the Japanese islands. © 2011 Zoological Society of Japan.


Masuda R.,Hokkaido University | Lin L.-K.,Tunghai University | Pei K.J.-C.,National Pingtung University of Science and Technology | Chen Y.-J.,CSIC - National Museum of Natural Sciences | And 6 more authors.
Zoological Science | Year: 2010

The source areas of the Japanese populations of the masked palm civet Paguma larvata (Viverridae, Carnivora), an alien species in Japan, have not been identified. In the present study, to reveal their origins and genetic features, we determined the full mitochondrial DNA cytochrome b sequences (1,140 base-pairs) of a total of 206 individuals of P. larvata from the Honshu and Shikoku islands of Japan (186 animals) and Taiwan (20 animals), and investigated their molecular phylogeography and the genetic relationships between populations in these countries. We found that each animal from Japan exhibited one of four haplotypes (JA1, JA2, JA4, and JA5), and that JA1 and JA4 were more frequent in eastern Honshu and Shikokucentral Honshu, respectively. By contrast, six haplotypes consisting of four new types (TW1, TW2, TW3, and TW4) and the previously reported two types (JA1 and JA4) were identified from 20 animals from native populations in Taiwan. Within Taiwan, one haplotype set (JA1, TW1, and TW2) was distributed in the western region, while a second (JA4, TW3, and TW4) was found in the eastern region; these regions are separated by high mountain ranges. Our comparison of haplotype distributions strongly demonstrated that the eastern Japanese populations originated from animals of western Taiwan, and that the western Japanese populations originated from those of eastern Taiwan. In addition, the lower genetic variability and particular distribution patterns of haplotypes in Japan showed founder effects, which may have resulted from multiple introductions of P. larvata to Japan from Taiwan. © 2010 Zoological Society of Japan.


Tashima S.,Hokkaido University | Kaneko Y.,Tokyo University of Agriculture and Technology | Anezaki T.,Gunma Museum Natural History | Baba M.,Kitakyushu Museum of Natural History and Human History | And 2 more authors.
Mammal Study | Year: 2010

To further understand the population structures of the Japanese badgers (Meles anakuma) on the Japanese islands, we analyzed their bi-parentally inherited microsatellites. Based on genotypes of nine microsatellite loci, the badgers were divided into five discrete clusters: three clusters from the Honshu Island, one from Kyushu and one from Shikoku. We propose that this genetic differentiation among badgers from the Honshu, Shikoku and Kyushu Islands is as a consequence of geographical isolation caused by the Seto Inland Sea. Furthermore, the cluster containing individuals from Shikoku was more differentiated from the other clusters, plausibly attributable to the earlier geological separation of the Shikoku Island from the Honshu and Kyushu Islands. The three clusters in Honshu, however, did not correspond precisely with geographical locations. As indicated in previous studies, based on mitochondrial DNA analysis, the genetic relationships within the Japanese badgers might reflect recent population expansion, occurring over a relatively short evolutionary time-scale. The findings preliminarily indicate that the Japanese badgers do not possess the high levels of philopatry seen in the European badger (Meles meles), a closely related species, although further analyses using balanced sample sizes from a wider range is required. © 2010 the Mammalogical Society of Japan.

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