title: Gene conservation among endospore-forming bacteria reveals additional sporulation genes in Bacillus subtilis.
abstract: The capacity to form endospores is unique to certain members of the low-G+C group of Gram-positive bacteria (Firmicutes) and requires signature sporulation genes that are highly conserved across members of distantly related genera, such as Clostridium and Bacillus. Using gene conservation among endospore-forming bacteria, we identified eight previously uncharacterized genes that are enriched among endospore-forming species. The expression of five of these genes was dependent on sporulation-specific transcription factors. Mutants of none of the genes exhibited a conspicuous defect in sporulation, but mutants of two, ylxY and ylyA, were outcompeted by a wild-type strain under sporulation-inducing conditions, but not during growth. In contrast, a ylmC mutant displayed a slight competitive advantage over the wild type specific to sporulation-inducing conditions. The phenotype of a ylyA mutant was ascribed to a defect in spore germination efficiency. This work demonstrates the power of combining phylogenetic profiling with reverse genetics and gene-regulatory studies to identify unrecognized genes that contribute to a conserved developmental process.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
authors.forename: Bjorn A
authors.initials: BA
authors.lastname: Traag
authors.forename: Antonia
authors.initials: A
authors.lastname: Pugliese
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Eisen
authors.forename: Richard
authors.initials: R
authors.lastname: Losick
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development*; D017124:Conserved Sequence; D004725:Endospore-Forming Bacteria / Q000235:genetics* / Q000254:growth & development*; D017353:Gene Deletion; D005798:Genes, Bacterial; D010802:Phylogeny; D017385:Sequence Homology; D013171:Spores, Bacterial / Q000235:genetics* / Q000254:growth & development*