Papers - SHINOHARA Akio
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Myoglobin primary structure reveals multiple convergent transitions to semi-aquatic life in the world’s smallest mammalian divers Reviewed International coauthorship
He K., Eastman T.G., Czolacz H., Li S., Shinohara A., Kawada S.I., Springer M.S., Berenbrink M., Campbell K.L.
eLife 10 2021.5
Language：English Publishing type：Research paper (scientific journal) Publisher：eLife
The speciose mammalian order Eulipotyphla (moles, shrews, hedgehogs, solenodons) combines an unusual diversity of semi-aquatic, semi-fossorial, and fossorial forms that arose from terrestrial forbearers. However, our understanding of the ecomorphological pathways leading to these lifestyles has been confounded by a fragmentary fossil record, unresolved phylogenetic relationships, and potential morphological convergence, calling for novel approaches. The net surface charge of the oxygen-storing muscle protein myoglobin (ZMb ), which can be readily determined from its primary structure, provides an objective target to address this question due to mechanistic linkages with myoglobin concentration. Here, we generate a comprehensive 71 species molecular phylogeny that resolves previously intractable intra-family relationships and then ancestrally reconstruct ZMb evolution to identify ancient lifestyle transitions based on protein sequence alone. Our phylogenetically informed analyses confidently resolve fossorial habits having evolved twice in talpid moles and reveal five independent secondary aquatic transitions in the order housing the world’s smallest endothermic divers.
DOI： 10.7554/eLife.66797
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Daily Torpor Induced by Food Restriction in the Chinese Hamster, Cricetulus griseus Reviewed
Mika Masaki, Yuki Suetsugi, Chihiro Koshimoto, Tetsuo Morita, Akio Shinohara
Mammal Study 50 ( 3 ) 2025.4
Authorship：Last author, Corresponding author Publishing type：Research paper (scientific journal)
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Spontaneous daily torpor observed in the greater long-tailed hamster (<i>Tsherskia triton</i>) Reviewed
Masaki Mika, Morita Tetsuo, Koshimoto Chihiro, Shinohara Akio
Honyurui Kagaku (Mammalian Science) 65 ( 1 ) 9 - 17 2025.2
Authorship：Last author, Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Mammal Society of Japan
To overcome severe environmental conditions such as cold or food shortage, many small mammals utilize hibernation or daily torpor. Hamsters (subfamily Cricetinae) are a well-known group using hibernation and daily torpor. Interestingly, among hamsters, hibernators tend to have relatively larger body sizes. In contrast, species that use daily torpor have a small body size, although some hamsters still remain unknown in torpor characteristics. In this study, we attempted to induce torpor in the greater long-tailed hamster (<i>Tscherskia triton</i>), which has a large body size among hamsters, by exposing them to condition that mimic winter (short photoperiod 8L:16D and low temperature 5°C). We successfully observed a spontaneous decrease in body temperature, and the duration of the torpor bout did not exceed 24 hours. Therefore, it was revealed for the first time that the greater long-tailed hamster is a heterothermic mammal that utilizes spontaneous daily torpor.
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Ishiniwa H., Okano T., Endoh D., Hirayama H., Yoshioka A., Yokohata Y., Shindo J., Koshimoto C., Shinohara A., Sakamoto S.H., Tamaoki M., Onuma M.
Scientific Reports 14 ( 1 ) 29706 2024.12
Language：English Publishing type：Research paper (scientific journal) Publisher：Scientific Reports
The Fukushima Daiichi Nuclear Power Plant accident caused the release of large amounts of radioactive material into the environment. Radiation from radionuclides cause DNA lesions, mainly via oxidation, which adversely affect wild organisms by damaging their germ cells. Here, we investigated the effects of radiation on the reproductive organs of Japanese field mice (Apodemus speciosus) by estimating the dose rate of radiation exposure, the accumulation of DNA lesions, and the expression of DNA repair enzymes. In highly contaminated areas, mouse testes received a radiation dose rate > 0.1 mGy/d. According to the International Commission on Radiological Protection, there is a very low probability of effects in the reference rat species at this exposure level. The results of the current study do not definitively conclude that the expression of 8-oxoguanine DNA glycosylase 1 and superoxide dismutase in mouse testes increase with dose rate and lifetime dose. However, 8-hydroxy-2′-deoxyguanosine accumulation increases in a dose rate- and lifetime dose-dependent manner in mouse testes, but is not observed in the sperm of the cauda epididymis. These results suggest that, although DNA lesions occurred in male germ cells of Fukushima mice, most were successfully repaired by DNA repair enzymes at the observed gene expression level.
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Optimization of inhaled anesthesia for <i>Octodon degus</i> using electroencephalography
IKAI Yuki, NAGURA-KATO Goro A., SAKAMOTO Shinsuke H., SHINOHARA Akio, KOSHIMOTO Chihiro
Experimental Animals advpub ( 0 ) 93 - 103 2024.8
Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Association for Laboratory Animal Science
Physiological responses to inhaled anesthetics vary among species. Therefore, a precise anesthetic technique is important for each individual species. In this study, we focused on the degu (<i>Octodon degus</i>), a small herbivorous rodent. Degus have recently begun to be used as laboratory models for brain research because of certain human-like characteristics, such as spontaneous development of Alzheimer’s disease. In this study, we evaluated appropriate induction and maintenance anesthesia conditions for isoflurane and sevoflurane in degus by a stimulation test, electroencephalography (EEG), minimum alveolar concentration (MAC), and vital signs. During induction, more rapid time to loss of the righting reflex and deeper anesthesia in degus were observed in isoflurane. The MAC value for degus were 1.75 ± 0.0% in isoflurane and 2.25 ± 0.27% in sevoflurane. Whereas some degus were awake during maintenance anesthesia using both anesthetics at concentrations of ≤2%, no rats were awake when using sevoflurane at a concentration of 2%. The duration of the total flat EEG, a measure of the depth of maintenance anesthesia, was longer for isoflurane than for sevoflurane. Furthermore, higher concentrations of both anesthetics suppressed the respiratory rate in degus. These new findings regarding inhalation anesthesia in degus will contribute to future developments in the fields of laboratory animals and veterinary medicine.
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Uno Y, Matsubara K, Inoue J, Inazawa J, Shinohara A, Koshimoto C, Ichiyanagi K, Matsuda Y
Cytogenetic and genome research 163 ( 1-2 ) 42 - 51 2023.11
Language：English Publishing type：Research paper (scientific journal) Publisher：Cytogenetic and Genome Research
Constitutive heterochromatin, consisting of repetitive sequences, diverges very rapidly; therefore, its nucleotide sequences and chromosomal distributions are often largely different, even between closely related species. The chromosome C-banding patterns of two Gerbillinae species, Meriones unguiculatus and Gerbillus perpallidus, vary greatly, even though they belong to the same subfamily. To understand the evolution of C-positive heterochromatin in these species, we isolated highly repetitive sequences, determined their nucleotide sequences, and characterized them using chromosomal and filter hybridization. We obtained a centromeric repeat (MUN-HaeIII) and a chromosome 13-specific repeat (MUN-EcoRI) from M. unguiculatus. We also isolated a centromeric/ pericentromeric repeat (GPE-MBD) and an interspersed-type repeat that was predominantly amplified in the X and Y chromosomes (GPE-EcoRI) from G. perpallidus. GPE-MBD was found to contain a 17-bp motif that is essential for binding to the centromere-associated protein CENP-B. This indicates that it may play a role in the formation of a specified structure and/or function of centromeres. The nucleotide sequences of the three sequence families, except GPE-EcoRI, were conserved only in Gerbillinae. GPE-EcoRI was derived from the long interspersed nuclear elements 1 retrotransposon and showed sequence homology throughout Muridae and Cricetidae species, indicating that the repeat sequence occurred at least in the common ancestor of Muridae and Cricetidae. Due to a lack of assembly data of highly repetitive sequences constituting heterochromatin in whole-genome sequences of vertebrate species published to date, the knowledge obtained in this study provides useful information for a deep understanding of the evolution of repetitive sequences in not only rodents but also in mammals.
DOI： 10.1159/000533716
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Kaneko C., Shinohara A., Kikuchi T., Tokuda A., Irie T., Yamada K., Misawa N., Yoshida A.
Mammalian Biology 103 ( 4 ) 363 - 373 2023.8
Publishing type：Research paper (scientific journal) Publisher：Mammalian Biology
The Japanese badger (Meles anakuma) and the Japanese raccoon dog (Nyctereutes procyonoides viverrinus) are common wild animals in Japan. They are opportunistic omnivores that share similar foods and environments. Previous study has reported a difference in the isolation rates of a specific genus of bacteria from fecal samples of these animals inhabiting the same areas in Japan. This study hypothesized that badgers and raccoon dogs have different gut microbiota, which leads to different metabolisms of nutrients despite their similar ecological niches. This study aimed to verify this hypothesis by comparatively analyzing the gut microbiota of these species. Bacterial 16S rRNA amplicon sequencing analysis was performed using colonic contents collected from 12 badgers and 12 raccoon dogs. As a result, the gut microbiota in badgers and raccoon dogs were completely distinct. Phylum Firmicutes was the most abundant, followed by Proteobacteria, almost without Bacteroidota in badgers. In contrast, Firmicutes and Bacteroidota were abundant in raccoon dogs. Many species-characteristic bacterial taxonomic features were identified in each animal’s gut microbiota. Moreover, raccoon dogs exhibited richer and more diverse species in their gut microbiota than badgers. This study revealed that badgers and raccoon dogs have distinct gut microbiota, which possibly drives different metabolism, though they share similar foods and environments. Considering anatomical feature that badger lacks a cecum which raccoon dog has, the distinct structure of gut microbiota in badger and raccoon dog could be attributed to the differences in the physical structure of the gastrointestinal tract, even though diet and inhabiting environments are quite similar.
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Ukyo R, Shinohara A, Koshimoto C, Nagura-Kato GA, Ieiri S, Tsuzuki Y, Sakamoto SH
Scientific reports 13 ( 1 ) 9518 2023.6
Language：English Publishing type：Research paper (scientific journal) Publisher：Scientific Reports
Social separation is thought to induce a strong stress response in social juvenile mammals, but little is known about how this response might vary throughout the development. The present study examines the long-term effects of early-life stress (ELS) induced by social separation on individual behaviors later in life using the social and precocious species Octodon degus. Four experimental groups were established a positive control group of mothers and siblings from six litters comprised the socially housed (SH) group, while pups from seven litters were randomly assigned to three treatments: pups experiencing no separation (NS) treatment while their siblings did; repeated bouts of consecutive separation (CS); intermittent separation (IS). We analyzed the effects of separation treatment on the frequency and duration of freezing, rearing and grooming behaviors. ELS was correlated with higher hyperactivity, and hyperactivity increased with more frequent separation. However, the behavioral trend of the NS group changed to hyperactive in long-term observation. The findings suggest that the NS group was indirectly affected by ELS. In addition, suggesting ELS acts to converge an individual’s behavioral tendencies in a certain direction.
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Okabe S., Shinohara A., Motokawa M.
Zoologischer Anzeiger 303 38 - 46 2023.3
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Zoologischer Anzeiger
The island rule has been generally studied as a morphological evolution between continents and islands. Recently, an evolution between islands of the larger main islands and smaller peripheral islands in Japan has been implied. This study revealed island–island biogeography and examined the island rule between islands. We studied the skull morphology of the greater Japanese shrew mole Urotrichus talpoides Temminck, 1841 (Eulipotyphla: Talpidae). Univariate and multivariate analyses were conducted on the basis of 20 measurements obtained from 296 specimens. Our results revealed morphological differences among islands, in the overall skull size, distance of the fourth premolar to the third molar in the upper and lower jaws (P4M3 and P4M3), and the slender–robust proportion of the rostrum and braincase. P4M3 and P4M3 were commonly larger in the peripheral island populations than in the main island populations. By contrast, the overall skull size and proportion of the rostrum and braincase diverged among the peripheral islands. Therefore, gigantism of P4M3 and P4M3 was suggested in the peripheral island populations, and the island rule was partially supported; however, the island–island morphological evolution should be considered to have a different direction from the island rule due to divergent morphology in small–large skull size and slender–robust proportion among peripheral island populations.
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Abe Y, Toyama K, Shinohara A, Nagura-Kato GA, Ikai Y, Koshimoto C, Spin JM, Hato N
Anatomical science international 98 ( 3 ) 426 - 433 2022.12
Language：English Publishing type：Research paper (scientific journal) Publisher：Anatomical Science International
The Mongolian gerbil has historically been useful for brain ischemia experiments, owing to the gerbil’s uniquely underdeveloped circle of Willis (CoW). This led to a gerbil model of cochlear ischemia being generated in our unit. However, we have found that the usual severe hearing loss seen in this model was not being induced consistently in recent experiments using the MON/Jms/GbsSlc gerbil (the sole commercially available gerbil in Japan). We set out to evaluate the posterior communicating artery (PcomA) in MON/Jms/GbsSlc, to re-establish whether this strain is appropriate for ischemia models. Having found that this unique feature is often lost, we then attempted to breed for the characteristic absent PcomA. India-ink perfusion revealed that the percentage of intact bilateral PcomA (“communicating type”) in the MON/Jms/GbsSlc gerbil was 57%; unilateral only (“unilateral communicating type”) was 39%; and completely absent PcomA (“non-communicating type”) was 4%. We were able to obtain few examples of the indigenous old aged Japanese UNG/Mz gerbil strain (at University of Miyazaki). Unfortunately, the pure UNG/Mz female was too elderly for mating. Therefore, selective breeding crosses between MON/Jms/GbsSlc and male UNG/Mz were carried out. After five generations of selective breeding, the percentage of non-communicating type gerbils was significantly higher in the newly generated strain, MON/Jms/SlcMz (F6 generation; 63%) than in the MON/Jms/GbsSlc gerbil. Bilateral common carotid artery occlusion surgery demonstrated that the cerebral blood flow was significantly reduced in MON/Jms/SlcMz compared with MON/Jms/GbsSlc (p < 0.0001) and induced more hippocampal injuries in MON/Jms/SlcMz than in MON/Jms/GbsSlc (p < 0.01). In conclusion, the commercially available MON/Jms/GbsSlc gerbil can easily regain PcomA, and we established a new gerbil strain (MON/Jms/SlcMz) displaying non-PcomA.
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Volatile fatty acids and microflora composition in the digestive tract of the East European vole (Microtus levis) Reviewed
Ikemoto-Kobayashi, M., Shinohara, A., Jogahara, T., Oda, S. & Mekada, K
Naturalistae 26 7 - 13 2022.2
Language：English Publishing type：Research paper (bulletin of university, research institution)
Other Link： http://www1.ous.ac.jp/garden/naturalistae26.html
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Nakamoto A., Harada M., Mitsuhashi R., Tsuchiya K., Kryukov A.P., Shinohara A., Suzuki H.
Zoological Letters 7 ( 1 ) 2 2021.12
Language：English Publishing type：Research paper (scientific journal) Publisher：Zoological Letters
Quaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent. Network construction with the Cytb sequences revealed 10 star-shaped clusters with apparent geographic affinity. Mismatch distribution analysis showed that modes of pairwise nucleotide differences (τ values) were grouped into five classes in terms of the level, implying the occurrence of five stages for rapid expansion. It is conceivable that severe cold periods and subsequent warm periods during the late Quaternary were responsible for the population expansion events. The first and third oldest events included island-derived haplotypes, indicative of the involvement of land bridge formation between remote islands, hence suggesting an association of the ends of the penultimate (PGM, ca. 130,000 years ago) and last (LGM, ca. 15,000 years ago) glacial maxima, respectively. Since the third event was followed by the fourth, it is plausible that the termination of the Younger Dryas and subsequent abrupt warming ca. 11,500 years ago facilitated the fourth expansion event. The second event most likely corresponded to early marine isotope stage (MIS) 3 (ca. 53,000 years ago) when the glaciation and subsequent warming period were predicted to have influenced biodiversity. Utilization of the critical times of 130,000, 53,000, 15,000, and 11,500 years ago as calibration points yielded evolutionary rates of 0.03, 0.045, 0.10 and 0.10 substitutions/site/million years, respectively, showing a time-dependent manner whose pattern was similar to that seen in small rodents reported in our previous studies. The age of the fifth expansion event was calculated to be 5800 years ago with a rate of 0.10 substitutions/site/million years ago during the mid-Holocene, suggestive of the influence of humans or other unspecified reasons, such as the Jomon marine transgression.
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Shinya Okabe, Akio Shinohara, Masaharu Motokawa
Mammal Study 46 ( 4 ) 309 - 315 2021.8
Language：English Publishing type：Research paper (scientific journal) Publisher：Mammalogical Society of Japan
Abstract. Dental anomalies in the greater Japanese shrew mole Urotrichus talpoides Temminck, 1841 (Eulipotyphla: Talpidae) were examined, based on 1001 specimens. We followed the dental formula of U. talpoides I 2/1, C 1/1, P 4/3, M 3/3 = 36, which is adopted by the most recent Japanese researchers, and found dental anomalies in 17 specimens involving 12 instances of absent tooth, four of extra tooth, and one of connate tooth. Of these, the following dental anomalies are reported in U. talpoides for the first time: extra tooth posterior to the upper canine (C1), extra tooth posterior to the upper second premolar (P2), extra teeth on the inner sides of the upper fourth premolars (P4), and connate tooth on the lower canine (C1). The most frequently observed dental anomaly was the absent tooth on C(52.9%), whereas the others were not common (< 11.8%). Our results indicate that dental anomalies in U. talpoides in Urotrichini possess the different pattern from those in species in Scalopini and Talpini. On the other hand, alternative hypothesis of dental formula I 3/2, C 1/1, P 3/2, M 3/3 = 36 explains the observed anomaly pattern in line with the general trend of dental anomalies in Talpini and Scalopini.
DOI： 10.3106/ms2020-0095
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Md Rashedul Islam, Osamu Ichii, Teppei Nakamura, Takao Irie, Akio Shinohara, Md Abdul Masum, Yuki Otani, Takashi Namba, Tsolmon Chuluunbaatar, Yaser Hosny Ali Elewa, Yasuhiro Kon
Animals 11 ( 6 ) 1768 - 1768 2021.6
Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG
Most mammalian ovarian follicles contain only a single oocyte having a single nucleus. However, two or more oocytes and nuclei are observed within one follicle and one oocyte, respectively, in several species, including cotton rat (CR, Sigmodon hispidus). The present study compared ovarian histology, focusing on folliculogenesis, between two inbred CR strains, HIS/Hiph and HIS/Mz. At 4 weeks of age, ovarian sections from both the strains were analyzed histologically. Multi-oocyte follicles (MOFs) and double-nucleated oocytes (DNOs) were observed in all stages of developing follicles in HIS/Hiph, whereas HIS/Mz had MOFs up to secondary stages and lacked DNOs. The estimated total follicles in HIS/Mz were almost half that of HIS/Hiph, but interstitial cells were well developed in HIS/Mz. Furthermore, immunostaining revealed no clear strain differences in the appearance of oocytes positive for Ki67, PCNA, and p63 in MOF or DNOs; no cell death was observed in these oocytes. Ultrastructural analysis revealed more abundant mitochondrial clouds in oocytes of HIS/Hiph than HIS/Mz. Thus, we clarified the strain differences in the CR ovary. These findings indicate that early events during folliculogenesis affect the unique ovarian phenotypes found in CRs, including MOFs or DNOs, and their strain differences.
DOI： 10.3390/ani11061768
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Yagishita-Kyo N., Ikai Y., Uekita T., Shinohara A., Koshimoto C., Yoshikawa K., Maruyama K., Yagishita S.
Biochemical and Biophysical Research Communications 551 54 - 62 2021.4
Language：English Publishing type：Research paper (scientific journal) Publisher：Biochemical and Biophysical Research Communications
Octodon degus is said to be one of the most human-like rodents because of its improved cognitive function. Focusing on its high sociality, we cloned and characterized some sociality-related genes of degus, in order to establish degus as a highly socialized animal model in molecular biology. We cloned degus Neurexin and Neuroligin as sociality-related genes, which are genetically related to autism spectrum disorder in human. According to our results, amino acid sequences of Neurexin and Neuroligin expressed in degus brain, are highly conserved to that of human sequences. Most notably, degus Neuroligin4 is highly similar to human Neuroligin4X, which is one of the most important autism-related genes, whereas mouse Neuroligin4 is known to be poorly similar to human Neuroligin4X. Furthermore, our work also indicated that testosterone directly binds to degus Neurexin and intercepts intercellular Neurexin-Neuroligin binding. Moreover, it is of high interest that testosterone is another key molecule of the higher incidence of autism in male. These results indicated that degus has the potential for animal model of sociality, and furthermore may promote understanding toward the pathogenic mechanism of autism.
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Evaluation index of epilepsy-like seizures observed in common degu (<i>Octodon degus</i>) Reviewed
Ikai Yuki, Shinohara Akio, Nagura-Kato Goro A., Shichijo Hiroki, Koshimoto Chihiro
Honyurui Kagaku (Mammalian Science) 61 ( 1 ) 3 - 11 2021.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Mammal Society of Japan
The common degu (<i>Octodon degus</i>), originally native to South America, is now widely used as an experimental animal owing to several unique characteristics: common degus are highly social and use vocal sounds as communication tools. Importantly, their brain function is more complex than other laboratory rodents, making them a good model in the field of neuroscience. We established a colony of laboratory common degus and observed epilepsy-like seizures. We subsequently analyzed the process, strength, and duration of seizures by video recording. We examined 35 video images from 16 individuals (7 females and 9 males). The seizures began as abnormalities in the body parts (step 1), and then systemic tonic-clonic seizure (step 2) was observed. Following step 2, a short period of stillness (step 3) usually occurred, and then systemic tonic seizure occurred again (step 4). Ultimately, stillness (step 5) continued until recovery. We found sex-based differences in the strength and duration of seizures and observed large individual differences as well. Our results suggest that common degus have the potential to be used as a disease model for epilepsy.
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新潟県新潟市江南区および五泉市近郊におけるエチゴモグラMogera etigoとアズマモグラM. imaizumiiの分布，2019年の現状 Reviewed
佐藤雄大，江藤 毅，篠原明男
哺乳類科学 61 ( 1 ) 29 - 37 2021.1
Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal)
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Sato Takahiro, Eto Takeshi, Shinohara Akio
Honyurui Kagaku (Mammalian Science) 61 ( 1 ) 29 - 37 2021
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Mammal Society of Japan
The distributions of <i>Mogera etigo</i> and <i>Mogera imaizumii</i> were examined in two areas of the Echigo Plain, Niigata Prefecture. The first survey area was in the paddy fields of the southern region of the Kounan area, Niigata city. The second was in the paddy fields in the surroundings of central Gosen city. In the Kounan area, burrows of <i>M. imaizumii</i> were observed for the first time, but the distributions of <i>M. etigo</i> were reduced compared with those noted in the previous studies. These results suggest that <i>M. etigo</i> have disappeared in at least some regions of their previous range and/or have been displaced by <i>M. imaizumii</i>. In the eastern parts of Gosen city, the burrows of both moles were sympatrically observed. In contrast, the burrows of <i>M. etigo</i> found in the western regions were individually isolated. The isolated <i>M. etigo</i> might disappear if habitat alteration and/or competitive exclusion by <i>M. imaizumii</i> occurs.
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Shinohara A., Nohara M., Kondo Y., Jogahara T., Nagura-Kato G., Izawa M., Koshimoto C.
Experimental Animals 68 ( 4 ) 531 - 539 2019
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Experimental Animals
© 2019 Japanese Association for Laboratory Animal Science. The Asian house shrew, Suncus murinus, is an insectivore (Eulipotyphla, Mammalia) and an important laboratory animal for life-science studies. The gastrointestinal tract of Suncus is simple: the length of the entire intestine is very short relative to body size, the large intestine is quite short, and there are no fermentative chambers such as the forestomach or cecum. These features imply that Suncus has a different nutritional physiology from those of humans and mice, but little is known about whether Suncus utilizes microbial fermentation in the large (LI) or small (SI) intestine. In addition, domestication may affect the gastrointestinal microbial diversity of Suncus. Therefore, we compared the gastrointestinal microbial diversity of Suncus between laboratory and wild Suncus and between the SI and LI (i.e., four groups: Lab-LI, Lab-SI, Wild-LI, and Wild-SI) using bacterial 16S rRNA gene library sequencing analyses with a sub-cloning method. We obtained 759 cloned sequences (176, 174, 195, and 214 from the Lab-LI, Lab-SI, Wild-LI, and Wild-SI samples, respectively), which revealed that the gastrointestinal microbiota of Suncus is rich in Firmicutes (mostly lactic acid bacteria), with few Bacteroidetes. We observed different bacterial communities according to intestinal region in laboratory Suncus, but not in wild Suncus. Furthermore, the gastrointestinal microbial diversity estimates were lower in laboratory Suncus than in wild Suncus. These results imply that Suncus uses lactic acid fermentation in the gut, and that the domestication process altered the gastrointestinal bacterial diversity.
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ヨーロッパモリネズミにおける尿を用いたストレスホルモンの測定
前山健太、篠原明男、仮屋博敬、川辺俊晃、城ヶ原貴通、名倉（加藤）悟郎、坂本信介、越本知大
九州実験動物雑誌 39 29 - 38 2019
Language：Japanese Publishing type：Research paper (scientific journal)