title: Complete genome sequences of rat and mouse segmented filamentous bacteria, a potent inducer of th17 cell differentiation.
abstract: Segmented filamentous bacteria (SFB) are noncultivable commensals inhabiting the gut of various vertebrate species and have been shown to induce Th17 cells in mice. We present the complete genome sequences of both rat and mouse SFB isolated from SFB-monocolonized hosts. The rat and mouse SFB genomes each harbor a single circular chromosome of 1.52 and 1.59 Mb encoding 1346 and 1420 protein-coding genes, respectively. The overall nucleotide identity between the two genomes is 86%, and the substitution rate was estimated to be similar to that of the free-living E. coli. SFB genomes encode typical genes for anaerobic fermentation and spore and flagella formation, but lack most of the amino acid biosynthesis enzymes, reminiscent of pathogenic Clostridia, exhibiting large dependency on the host. However, SFB lack most of the clostridial virulence-related genes. Comparative analysis with clostridial genomes suggested possible mechanisms for host responses and specific adaptations in the intestine.
authors.affiliation: Laboratory for MetaSystems Research, Quantitative Biology Center, RIKEN, Yokohama, Kanagawa, Japan.
authors.forename: Tulika
authors.initials: T
authors.lastname: Prakash
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Oshima
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Morita
authors.forename: Shinji
authors.initials: S
authors.lastname: Fukuda
authors.forename: Akemi
authors.initials: A
authors.lastname: Imaoka
authors.forename: Naveen
authors.initials: N
authors.lastname: Kumar
authors.forename: Vineet K
authors.initials: VK
authors.lastname: Sharma
authors.forename: Seok-Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Mahoko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Naruya
authors.initials: N
authors.lastname: Saitou
authors.forename: Todd D
authors.initials: TD
authors.lastname: Taylor
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohno
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Umesaki
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D016680:Genome, Bacterial; D007422:Intestines / Q000276:immunology / Q000382:microbiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010802:Phylogeny; D051381:Rats; D011916:Rats, Inbred F344; D058504:Th17 Cells / Q000166:cytology* / Q000276:immunology / Q000382:microbiology