title: Identifying genetic determinants needed to establish a human gut symbiont in its habitat.
abstract: The human gut microbiota is a metabolic organ whose cellular composition is determined by a dynamic process of selection and competition. To identify microbial genes required for establishment of human symbionts in the gut, we developed an approach (insertion sequencing, or INSeq) based on a mutagenic transposon that allows capture of adjacent chromosomal DNA to define its genomic location. We used massively parallel sequencing to monitor the relative abundance of tens of thousands of transposon mutants of a saccharolytic human gut bacterium, Bacteroides thetaiotaomicron, as they established themselves in wild-type and immunodeficient gnotobiotic mice, in the presence or absence of other human gut commensals. In vivo selection transforms this population, revealing functions necessary for survival in the gut: we show how this selection is influenced by community composition and competition for nutrients (vitamin B(12)). INSeq provides a broadly applicable platform to explore microbial adaptation to the gut and other ecosystems.
authors.affiliation: Center for Genome Sciences, Washington University School of Medicine, St. Louis, MO 63108, USA.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Goodman
authors.forename: Nathan P
authors.initials: NP
authors.lastname: McNulty
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.forename: Douglas
authors.initials: D
authors.lastname: Leip
authors.forename: Robi D
authors.initials: RD
authors.lastname: Mitra
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Lozupone
authors.forename: Rob
authors.initials: R
authors.lastname: Knight
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Gordon
mesh_terms: D000818:Animals; D001439:Bacteroides / Q000145:classification / Q000235:genetics* / Q000502:physiology; D041981:Gastrointestinal Tract / Q000382:microbiology* / Q000502:physiology; D005856:Germ-Free Life; D006801:Humans; D051379:Mice; D010802:Phylogeny; D013559:Symbiosis