Papers - SHINOHARA Akio
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Individual differences in torpor expression in adult mice are related to relative birth mass.
Kato GA, Sakamoto SH, Eto T, Okubo Y, Shinohara A, Morita T, Koshimoto C
The Journal of experimental biology 221 ( Pt 12 ) 2018.6
Language：Japanese Publishing type：Research paper (scientific journal)
DOI： 10.1242/jeb.171983
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Nakamura T., Ichii O., Irie T., Mizoguchi T., Shinohara A., Kouguchi H., Sunden Y., Otsuka-Kanazawa S., Elewa Y., Koshimoto C., Nagasaki K., Kon Y.
Histology and Histopathology 33 ( 6 ) 555 - 565 2018.6
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Histology and Histopathology
© 2018, Histology and Histopathology. All rights reserved. Pharyngeal pouches in mammals develop into specific derivatives. If the differentiation of the pharyngeal pouches is anomalous, their remnants can result in cysts, sinuses, and fistulae in the differentiated organs or around the neck. In the present study, we found several pharyngeal pouch remnants, such as cystic structures in thymus and parathyroid gland and fossulae extended from the piriform fossa, in the inbred cotton rats maintained at Hokkaido Institute of Public Health (HIS/Hiph) and University of Miyazaki (HIS/Mz). In HIS/Hiph, the fossulae extended from the apex of the piriform fossa into the thyroid glands and were lined with stratified squamous and cuboidal epithelium. Calcitonin-positive C-cells were present within their epithelium in HIS/Hiph. In contrast, the fossulae of HIS/Mz ran outside the thyroid glands toward the parathyroid glands; they were lined with columnar ciliated epithelium and a few goblet cells, but had no C-cells, which was consistent with the cystic structures in the thymus and the parathyroid gland. These results indicated that the fossulae were a remnant of the ultimobranchial body in HIS/Hiph and of the thymopharyngeal duct in HIS/Mz. Thus, the fossulae of the piriform fossa resembled the piriform sinus fistula in human. In conclusion, cotton rats frequently possessed pharyngeal pouch remnants, including the piriform sinus fistula, and therefore, might serve as a novel model to elucidate the mechanisms of pharyngeal pouch development.
DOI： 10.14670/HH-11-946
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徳之島産ケナガネズミDiplothrix legataの精子形成に関する組織学的基礎情報 Reviewed
加藤悟郎，城ヶ原貴通，後藤嘉輝，篠原明男，越本知大
哺乳類科学 57 ( 2 ) 217 - 220 2017.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Protein restriction does not affect body temperature pattern in female mice. Reviewed
Kato GA, Shichijo H, Takahashi T, Shinohara A, Morita T, Koshimoto C
Experimental Animals 2017.6
Language：English Publishing type：Research paper (scientific journal)
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Comparative Morphology of the Penis and Clitoris in Four Species of Moles (Talpidae)
Sinclair A., Glickman S., Catania K., Shinohara A., Baskin L., Cunha G.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 328 ( 3 ) 275 - 294 2017.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
© 2017 Wiley Periodicals, Inc. The penile and clitoral anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles. Using histology, three-dimensional reconstruction, and morphometric analysis, sexual dimorphism was examined with regard to a nine feature masculine trait score that included perineal appendage length (prepuce), anogenital distance, and presence/absence of bone. The presence/absence of ovotestes was discordant in all four mole species for sex differentiation features. For many sex differentiation features, discordance with ovotestes was observed in at least one mole species. The degree of concordance with ovotestes was highest for hairy-tailed moles and lowest for broad-footed moles. In relationship to phylogenetic clade, sex differentiation features also did not correlate with the similarity/divergence of the features and presence/absence of ovotestes. Hairy-tailed and Japanese shrew moles reside in separated clades, but they exhibit a high degree of congruence. Broad-footed and hairy-tailed moles reside within the same clade but had one of the lowest correlations in features and presence/absence of ovotestes. Thus, phylogenetic affinity and the presence/absence of ovotestes are poor predictors for most sex differentiation features within mole external genitalia.
DOI： 10.1002/jez.b.22732
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Talpid mole phylogeny unites shrew moles and illuminates overlooked cryptic species diversity Reviewed
H. Kai, A. Shinohara, K.M. Helgen, M.S. Springer, J. Xue-Long and K.L. Campbell
Molecular Biology and Evolution 34 ( 1 ) 78 - 87 2017.1
Language：English Publishing type：Research paper (scientific journal)
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Mole ghrelin: cDNA cloning, gene expression, and diverse molecular forms in Mogera imaizumii Reviewed
M. Satou, H. Kaiya, Y. Nishi, A. Shinohara, S-i. Kawada, M. Miyazato, K. Kangawa, H. Sugimoto
General and Comparative Endocrinology 232 199 - 210 2016.6
Language：English Publishing type：Research paper (scientific journal)
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Shinohara A., Uchida E., Shichijo H., Sakamoto S., Morita T., Koshimoto C.
Mammalian Biology 81 ( 1 ) 46 - 52 2016.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Mammalian Biology
© 2014. The mammalian gastrointestinal tract has evolved to facilitate food utilisation. Hamsters within the subfamily Cricetinae (Rodentia, Cricetidae) have a compartmentalised stomach consisting of a forestomach and a glandular stomach. The role of the forestomach in hamsters has long been discussed. In this study, we evaluated the microflora and volatile fatty acid contents of the large forestomach and caecum of a greater long-tailed hamster (Tscherskia triton). The estimated bacterial biodiversity in the forestomach based on 16S rRNA library sequencing analyses was low (sequence n=226, Shannon index H'=2.12) compared to that in the rumen of ruminants. In contrast, the bacterial diversity in the caecum was very high (n=259, H'=4.45), and comparable to that of other hindgut fermenters. The forestomach bacterial flora was dominated by Lactobacillus spp. (179/226 clones), and high concentrations of lactic acid were observed in the forestomach. These results indicate that the forestomach does not function like the rumen of ruminants, but that lactic acid fermentation does take place in this compartment. The caecum is thought to play a more important role in food digestion via fermentation by symbiotic microbes than the forestomach. When all cloned 16S rRNA gene sequences n(=485) were grouped into operational taxonomic units (OTUs) with 97% similarity, the majority of clones isolated from the forestomach contents were also present in the caecum (85.4%), although fewer clones isolated from the caecum contents shared OTUs with clones from the forestomach (19.3%). Based on these results, we hypothesise that bacteria were transferred from the caecum to the forestomach by coprophagy.
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Microbial diversity in forestomach and caecum contents of the greater long-tailed hamster Tscherskia triton (Rodentia: Cricetidae) Reviewed
A. Shinohara, E. Uchida, H. Shichijo, S. H. Sakamoto, T. Morita, C. Koshimoto
Mammalian Biology 81 ( 1 ) 46 - 52 2016.1
Language：English Publishing type：Research paper (scientific journal)
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Shinohara A., Kawada S., Son N., Can D., Sakamoto S., Koshimoto C.
Raffles Bulletin of Zoology 63 366 - 375 2015.9
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Raffles Bulletin of Zoology
© National University of Singapore. Until 2008, three species of fossorial moles (tribe Talpini, Talpidae, Lipotyphla, Mammalia) were recognised in Vietnam: Euroscaptor longirostris from the northern highlands, E. parvidens from the southern Annamese mountains and Mogera latouchei from the northern lowlands. Recently, a new species (Eursocaptor subanura) was described from northern Vietnam. This new mole is externally similar to E. parvidens, but the skull and dental characters are rather similar to E. longirostris. In this study, we determined the complete mitochondrial cytochrome b (Cytb; 1140 bp), partial mitochondrial 12S ribosomal RNA (12S; ca. 850 bp) and partial nuclear recombination activating gene 1 (Rag1; 1010 bp) gene sequences of 19 specimens of E. subanura collected from three localities in northern Vietnam and estimated the phylogenetic relationships among the Southeast Asian moles. Our results strongly support the full species status of E. subanura and that it is a sister taxon to E. parvidens of central Vietnam, but not E. longirostris of northern Vietnam. Although we analysed samples from only three localities, intraspecies diversity in E. subanura was lower than in the other two species. These results suggest that E. subanura diverged from E. parvidens and that it is a relict species that survived past climatic changes.
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The effects of maternal presence on natal dispersal are seasonally flexible in an asocial rodent
Sakamoto S., Eto T., Okubo Y., Shinohara A., Morita T., Koshimoto C.
Behavioral Ecology and Sociobiology 69 ( 7 ) 1075 - 1084 2015.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Behavioral Ecology and Sociobiology
© 2015, Springer-Verlag Berlin Heidelberg. In mammals, social tolerance among females, the philopatric sex, is formed through continued physical proximity between kin after offspring are weaned. However, the benefits of continued close association may be outweighed by costs such as local resource competition and risk of inbreeding. We hypothesized that for ‘philopatric females’, a flexible tendency towards either natal dispersal or philopatry is an important behavioral response to changes in social conditions. We examined this using an asocial rodent, Apodemus speciosus, which exhibits two discrete breeding seasons, one in spring and the second in autumn. Daughters and mothers were shown to recognize each other as kin at the time of weaning in both seasons. In spring, some mothers reproduced twice, and some first-litter daughters matured and reproduced in the same season. In autumn, however, only mothers reproduced, and there were no second litters. In spring, the proportion of natal dispersers was higher among weaned offspring whose mother remained present than those whose mother was absent, while in autumn, natal dispersal was more frequent when the mother was absent than when she remained. Sons dispersed earlier than their female littermates. Population density alone is insufficient to explain these patterns. We suggest that variable levels of reproductive competition between female kin result in seasonal differences in female natal dispersal. Breeding condition can be modulated by environmental factors, and the promotion of reproductive activity of females in spring may cause natal dispersal of daughters, while the inhibition of reproductive activity in autumn may permit philopatry.
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The future of Mammalian Molecular Phylogenetics
Shinohara Akio, Sato Jun J., Yonezawa Takahiro, He Kai, Imai Hiroo
Honyurui Kagaku (Mammalian Science) 55 ( 1 ) 98 - 99 2015
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Mammal Society of Japan
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A comparison of the diet and fine-scale distribution of sympatric Tibetan and red foxes in Qinghai, P. R. China Reviewed
H. Tsukada, W. Li, H. Duo, Z. Guo, Y. Fu, M. Peng, X. Shen, J. Jing, A. Yuan, M. Ni, S. He, F. Huang, K. Feng, K. Ishikawa, I. Kobayashi, A. Shinohara, N. Nonaka
Wildlife Biology 20 ( 6 ) 356 - 361 2014.12
Language：English Publishing type：Research paper (scientific journal)
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Susceptibility of muridae cell lines to ecotropic murine leukemia virus and the cationic amino acid transporter 1 viral receptor sequences: implications for evolution of the viral receptor Reviewed
K. Kakoki, A. Shinohara, M. Izumida, Y. Koizumi, E. Honda, G. Kato, T. Igawa, H. Sakai, H. Hayashi, T. Matsuyama, T. Morita, C. Koshimoto and Y. Kubo
Virus Gene 48 ( 3 ) 448 - 456 2014.6
Language：English Publishing type：Research paper (scientific journal)
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Molecular phylogeny of East and Southeast Asian fossorial moles (Lipotyphla, Talpidae) Reviewed
A. Shinohara, S-I. Kawada, N. T. Son, C. Koshimoto, H. Endo, D. N. Can and H. Suzuki
Journal of Mammalogy 95 ( 3 ) 455 - 466 2014.6
Language：English Publishing type：Research paper (scientific journal)
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Tsukada H., Li W., Duo H., Guo Z., Fu Y., Peng M., Shen X., Jing J., Yuan A., Ni M., He S., Huang F., Feng K., Ishikawa K., Kobayashi I., Shinohara A., Nonaka N.
Wildlife Biology 20 ( 6 ) 356 - 361 2014.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Wildlife Biology
© 2014 The Authors. We compared the diet and the spatial distribution of the Tibetan fox Vulpes ferrilata and the red fox Vulpes vulpes in the Tibetan plateau, to elucidate mechanisms of coexistence for these two sympatric canids and to clarify their roles as definitive hosts for zoonotic Echinococcus parasites. Diet and fine-scale distribution patterns were assessed by fecal DNA analysis. A total of 45 fecal samples (15 belonging to Tibetan fox, 30 belonging to red fox were collected from 15 sites into three of which contained only Tibetan fox feces, six only red fox feces, and six contained feces of both species. The abundance of pika burrows, a key prey item for both species, did not differ among the sites. Food composition analysis, estimated using a point-frame method, revealed slight but insignificant differences between the two species. Tibetan foxes consumed primarily mammals, whereas red foxes consumed primarily insects. The dietary range of the Tibetan fox was narrower than that of the red fox but there was little dietary overlap between the two species. These findings suggest that the weak partitioning of food resources between Tibetan and red foxes can facilitate their coexistence even within the same habitat where they share the same key prey items, i.e. small mammals such as pikas. These dietary differences between the two fox species also suggest that the Tibetan fox is a more important definitive host for Echinococcus on the Tibetan plateau than is the red fox.
DOI： 10.2981/wlb.00066
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Kakoki K., Shinohara A., Izumida M., Koizumi Y., Honda E., Kato G., Igawa T., Sakai H., Hayashi H., Matsuyama T., Morita T., Koshimoto C., Kubo Y.
Virus Genes 48 ( 3 ) 448 - 456 2014.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Virus Genes
Ecotropic murine leukemia viruses (Eco-MLVs) infect mouse and rat, but not other mammalian cells, and gain access for infection through binding the cationic amino acid transporter 1 (CAT1). Glycosylation of the rat and hamster CAT1s inhibits Eco-MLV infection, and treatment of rat and hamster cells with a glycosylation inhibitor, tunicamycin, enhances Eco-MLV infection. Although the mouse CAT1 is also glycosylated, it does not inhibit Eco-MLV infection. Comparison of amino acid sequences between the rat and mouse CAT1s shows amino acid insertions in the rat protein near the Eco-MLV-binding motif. In addition to the insertion present in the rat CAT1, the hamster CAT1 has additional amino acid insertions. In contrast, tunicamycin treatment of mink and human cells does not elevate the infection, because their CAT1s do not have the Eco-MLV-binding motif. To define the evolutionary pathway of the Eco-MLV receptor, we analyzed CAT1 sequences and susceptibility to Eco-MLV infection of other several murinae animals, including the southern vole (Microtus rossiaemeridionalis), large Japanese field mouse (Apodemus speciosus), and Eurasian harvest mouse ( Micromys minutus). Eco-MLV infection was enhanced by tunicamycin in these cells, and their CAT1 sequences have the insertions like the hamster CAT1. Phylogenetic analysis of mammalian CAT1s suggested that the ancestral CAT1 does not have the Eco-MLV-binding motif, like the human CAT1, and the mouse CAT1 is thought to be generated by the amino acid deletions in the third extracellular loop of CAT1. © Springer Science+Business Media 2014.
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He K., Shinohara A., Jiang X., Campbell K.
Molecular Phylogenetics and Evolution 70 ( 1 ) 513 - 521 2014.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Molecular Phylogenetics and Evolution
The tribe Talpini is a group of strictly subterranean moles distributed across the Eurasian Continent whose phylogenetic relationships and taxonomy remain unresolved. Here we report a multi-locus nuclear-mitochondrial DNA dataset (9468. bp) from 11 talpine species encompassing all five recognized genera, together with analyses of their divergence times and evolutionary affinities inferred from maximum likelihood and Bayesian approaches. Our results finely resolved all relationships except the root of the four recognized Asian genera, which was placed sister to the genus Talpa. With respect to the Asian clade, we moreover provide the first molecular support for a sister-taxon relationship between Parascaptor and Scaptochirus and confirm that the genus Euroscaptor is paraphyletic. Further, and despite a relatively small sample size (22 specimens), our species delimitation analyses support the existence of at least two genetically distinct, and hence potentially cryptic species. Taken together, these findings argue that generic status should be given to E. mizura and illustrate that the taxonomic diversity of the tribe Talpini in mountainous regions of southwestern China and Southeast Asia is underestimated. Finally, results of our divergence time analyses support a rapid radiation of the endemic Asian genera in the late-Miocene, which temporally corresponds with enhanced aridity and cooling arising from a significant uplift of the Himalayan-Tibetan plateau. © 2013 Elsevier Inc.
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Molecular phylogeny of East and Southeast Asian fossorial moles (Lipotyphla, Talpidae)
Shinohara A., Kawada S., Son N., Koshimoto C., Endo H., Can D., Suzuki H.
Journal of Mammalogy 95 ( 3 ) 455 - 466 2014.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Mammalogy
The diversity of fossorial moles in East and Southeast Asia is contained in the 2 species-rich genera Mogera (8 species) and Euroscaptor (8 or more species), and the 3 monospecific genera Scapanulus, Scaptochirus, and Parascaptor. To better understand the evolution and biogeography of these fossorial moles, we conducted molecular phylogenetic analyses using mitochondrial cytochrome-b (Cytb; 1,140 base pairs [bp]) and 12S rRNA (approximately 830 bp) and nuclear recombination activating gene 1 (Rag1; 1,010 bp) gene sequences from 5 species of Euroscaptor, 6 of Mogera, and the single species of Scaptochirus. Phylogenetic estimates revealed 5 distinct lineages of East and Southeast Asian fossorial moles: Mogera, Scaptochirus, Euroscaptor mizura, E. parvidens, and E. malayana-E. klossi-E. longirostris. Our results support the monophyly of Mogera but not Euroscaptor, indicating a need for taxonomic revision of the latter genus. We hypothesize that Mogera originated in the central portion of its range and then dispersed to peripheral islands, such as Taiwan and the Japanese Islands. The fragmented distribution of Southeast Asian Euroscaptor presumably arose from habitat competition (invasion) from Mogera species, long-range dispersal, vicariance events, or a combination of these, explaining the high species richness of fossorial moles in this region. © 2014 American Society of Mammalogists.
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Maeda Y., Funagayama M., Shinohara A., Koshimoto C., Furusawa H., Nakahara H., Yamaguchi Y., Saitoh T., Yamamoto T., Komaki K.
Journal of Physiology and Biochemistry 70 ( 3 ) 849 - 855 2014.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Physiology and Biochemistry
© 2014, University of Navarra. The influence of human serum albumin (HSA) on the bile acid-mediated inhibition of liver microsomal type 1 11β-hydroxysteroid dehydrogenase (11β-HSD1) was studied in vitro. A rat liver microsomal fraction was prepared, and the 11β-HSD1 enzyme activity in the presence of various concentrations of bile acids and HSA was determined using hydrocortisone as the substrate. The products of the reaction were extracted and analyzed using high-performance liquid chromatography. The magnitude of the inhibition decreased with the addition of HSA in a dose-dependent manner. Four percent human albumin decreased the inhibitory effects of 100 μM chenodeoxycholic acid and lithocholic acid from 89.9 ± 5.6 to 54.5 ± 6.1 % and from 83.8 ± 4.8 to 20.8 ± 4.2 %, respectively. In contrast, ursodeoxycholic acid and deoxycholic acid showed no inhibitory effect on the enzyme activity in the presence of 4 % human serum albumin, and the addition of 1 % γ-globulin to the assay mixture in the presence of bile acids did not affect the enzyme activity. Our in vitro study showed that the addition of HSA ameliorated the inhibition of 11β-HSD1 and that the magnitude of the change is dependent on the species of bile acid, presumably based on the numbers of hydroxyl groups. These results suggest that HSA seems to protect the bile acid-mediated inhibition of 11β-HSD1 in the healthy subject. On the other hand, in the patients with obstructive biliary diseases, not only elevated serum bile acid but also the accompanying hypoalbuminemia is important to evaluate the pathophysiology of the bile acid-mediated inhibition of 11β-HSD1 of the disease.