부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/S0723-2020(97)80010-0 Byline: Akemi Imaoka, Yasushi Okada, Satoshi Matsumoto, Hiromi Setoyama, Yoshinori Umesaki Keywords: Segmented filamentous bacteria; 16S ribosomal DNA sequence; crab-eating monkey; Fischer 344 rat; host animals Abbreviations: SFB, Segmented filamentous bacteria; F344, Fischer 344; GF, germ-free Abstract: Segmented filamentous bacteria (SFB) have been found in the alimentary tracts of a wide range of animals, where they activate the mucosal immune system. We determined the 16S rDNA sequences of SFBs derived from crab-eating monkey and Fischer 344 (F344) rat, in addition to of that from BALB/c mice (Umesaki et al, 1995), and compared these sequences with those of SE (Swiss) mice, WU rats and chickens reported by Snel et al. (1994, 1995), with special reference to inter-species and within-species differences of the host animals. SFBs isolated from six different hosts mentioned above exhibited levels of 16S rDNA sequence homology of more than 97%. There was only slight divergence in the 16S rDNA sequence between BALB/c and SE mice, and F344 and WU rats, 0.1 and 0.4%, respectively. However, there was some inter-species divergence, except between monkey and rats, suggesting that SFB isolated from different species of animals belong to different species, as proposed by Snel et al. (1995). The phylogenetic tree of SFB 16S rDNA derived from these six kinds of animals, including crab-eating monkey, does not necessarily suggest the coevolution of SFB and their host animals. Author Affiliation: Yakult Central Institute for Microbiological Research, Kunitachi, Tokyo, Japan Article History: Received 2 January 1997