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Likidkarnchanakornkij J, Jindatip D, Wannaprasert T. Morphology of the digestive system of the lesser bamboo rat (Cannomys badius). Anat Histol Embryol 2023; 52:944-955. [PMID: 37559462 DOI: 10.1111/ahe.12954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/11/2023]
Abstract
The lesser bamboo rat is a fossorial rodent within the monotypic genus Cannomys, family Spalacidae and is found in Indochina. The present work provides the first detailed description of the morphology of its digestive system, as examined by gross dissection and histological examination. The oesophagus was lined by a heavily keratinized epithelium and contained mostly striated muscles in the muscularis externa. The stomach was of the unilocular-hemiglandular type with a cornified squamous area at the fundus separated from the glandular area by the limiting ridge. The length ratio of the small intestine to the entire intestine was relatively low compared to that in other rodents. The caecum contained five to seven haustra and numerous lymphoid tissues, but no distinct appendix. Within the long colon, two non-papillated longitudinal folds forming a colonic groove, V-shaped mucosal folds like fishbones and abundant goblet cells were apparent. A five-lobed liver with a gallbladder and a diffuse pancreas were evident. These findings may indicate that the lesser bamboo rat is a caecal fermenter capable of feeding on highly abrasive plant material. Fermentation may take place via a mucus-trap colonic separation mechanism without coprophagy. The digestive system of the lesser bamboo rat is somewhat different from that of spalacid relatives.
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Affiliation(s)
| | - Depicha Jindatip
- Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Thanakul Wannaprasert
- Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
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Duque-Correa MJ, Codron D, Meloro C, McGrosky A, Schiffmann C, Edwards MS, Clauss M. Mammalian intestinal allometry, phylogeny, trophic level and climate. Proc Biol Sci 2021; 288:20202888. [PMID: 33563126 DOI: 10.1098/rspb.2020.2888] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
An often-stated ecomorphological assumption that has the status of 'textbook knowledge' is that the dimensions of the digestive tract correlate with diet, where herbivores-consuming diets of lower digestibility-have longer intestinal tracts than faunivores-consuming diets of higher digestibility. However, statistical approaches have so far failed to demonstrate this link. Here, we collated data on the length of intestinal sections and body mass of 519 mammal species, and test for various relationships with trophic, climatic and other biological characteristics. All models showed a strong phylogenetic signal. Scaling relationships with body mass showed positive allometry at exponents greater than 0.33, except for the caecum, which is particularly large in smaller species. Body mass was more tightly linked to small intestine than to large intestine length. Adding a diet proxy to the relationships increased model fit for all intestinal sections, except for the small intestine when accounting for phylogeny. Thus, the diet has a main effect on the components of the large intestine, with longer measures in herbivores. Additionally, measures of habitat aridity had a positive relationship with large intestine length. The small intestine was longer in species from colder habitats at higher latitudes, possibly facilitating the processing of peak intake rates during the growing season. This study corroborates intuitive expectations on digestive tract anatomy, while the dependence of significant results on large sample sizes and inclusion of specific taxonomic groups indicates that the relationships cannot be considered fixed biological laws.
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Affiliation(s)
- María J Duque-Correa
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Daryl Codron
- Department of Zoology and Entomology, University of the Free State, PO Box 339, 9300 Bloemfontein, South Africa
| | - Carlo Meloro
- Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moores University, Liverpool, UK
| | - Amanda McGrosky
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - Christian Schiffmann
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Mark S Edwards
- California Polytechnic State University, San Luis Obispo, CA, USA
| | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
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Chuluunbaatar T, Ichii O, Nakamura T, Irie T, Namba T, Islam MR, Otani Y, Masum MA, Okamatsu-Ogura Y, Elewa YHA, Kon Y. Unique Running Pattern and Mucosal Morphology Found in the Colon of Cotton Rats. Front Physiol 2020; 11:587214. [PMID: 33192600 PMCID: PMC7649294 DOI: 10.3389/fphys.2020.587214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 10/05/2020] [Indexed: 12/31/2022] Open
Abstract
Cotton rats are one of the experimental rodents used for testing different infectious and non-infectious diseases, including gastrointestinal tract pathology. However, their intestinal morphological characteristics are still poorly understood. Here, we clarified the anatomical and histological characteristics of the cecum and ascending colon (AC) of young (1–3-month old), adult (4–6-month old), and old (10–12-month old) cotton rats. The large intestine (LI) in cotton rats is composed of the cecum, AC, transverse and descending colons, and rectum, and is similar to that of other mammals. The AC begins with a double or triple spiral loop-like flexure (SLLF) and ends with a coupled horseshoe-like flexure (HSLF). A single longitudinal mucosal fold (SLMF) was found at the beginning of the AC along the mesentery line and developed with age. Furthermore, the SLMF contained several lymphatic nodules (LNs), indicating their role in digestive and immunological functions. Small and large protuberant LNs were found in the cecum and SLLF, respectively, whereas thin and flat LNs were observed in the HSLF and transverse colon, respectively. Regarding sex-related differences, adult females had a significantly longer AC with a higher number of SLLFs compared to males. The SLMF length and LN number were also longer and higher, respectively, in adult females compared to adult males. These are crucial findings, indicating the presence of sex-related differences in the morphology of the LI in cotton rats, and ours is the first study to discover a sex difference in the mammalian LI lining. Our study clarified the unique morphology of the LI in cotton rats, which could serve as the principal model for elucidating species-specific digestive tract functions and gastrointestinal disorders.
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Affiliation(s)
- Tsolmon Chuluunbaatar
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Basic Science of Veterinary Medicine, School of Veterinary Medicine, Mongolian University of Life Science, Ulaanbaatar, Mongolia
| | - Osamu Ichii
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Laboratory of Agrobiomedical Science, Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Teppei Nakamura
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Biological Safety Research, Chitose Laboratory, Japan Food Research Laboratories, Chitose, Japan
| | - Takao Irie
- Medical Zoology Group, Department of Infectious Diseases, Hokkaido Institute of Public Health, Sapporo, Japan.,Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Takashi Namba
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Md Rashedul Islam
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Surgery and Theriogenology, Faculty of Animal Science and Veterinary Medicine, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Yuki Otani
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Md Abdul Masum
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Anatomy, Histology and Physiology, Faculty of Animal Science and Veterinary Medicine, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Yuko Okamatsu-Ogura
- Laboratory of Biochemistry, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yaser Hosny Ali Elewa
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Histology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Yasuhiro Kon
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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