title: Gene gain and gene loss in streptococcus: is it driven by habitat?
abstract: Bacterial genomes can evolve either by gene gain, gene loss, mutating existing genes, and/or by duplication of existing genes. Recent studies have clearly demonstrated that the acquisition of new genes by lateral gene transfer (LGT) is a predominant force in bacterial evolution. To better understand the significance of LGT, we employed a comparative genomics approach to model species-specific and intraspecies gene insertions/deletions (ins/del among 12 sequenced streptococcal genomes using a maximum likelihood method. This study indicates that the rate of gene ins/del is higher on the external branches and varies dramatically for each species. We have analyzed here some of the experimentally characterized species-specific genes that have been acquired by LGT and conclude that at least a portion of these genes have a role in adaptation.
authors.affiliation: Department of Biology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Pradeep Reddy
authors.initials: PR
authors.lastname: Marri
authors.forename: Weilong
authors.initials: W
authors.lastname: Hao
authors.forename: G Brian
authors.initials: GB
authors.lastname: Golding
mesh_terms: D000220:Adaptation, Biological; D017753:Ecosystem; D019143:Evolution, Molecular; D020440:Gene Duplication; D022761:Gene Transfer, Horizontal / Q000502:physiology; D005798:Genes, Bacterial / Q000502:physiology; D016680:Genome, Bacterial; D019656:Loss of Heterozygosity / Q000502:physiology*; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D010802:Phylogeny; D011487:Protein Conformation; D013045:Species Specificity; D013291:Streptococcus / Q000145:classification / Q000235:genetics*; D013292:Streptococcus agalactiae / Q000235:genetics; D013295:Streptococcus mutans / Q000235:genetics; D013296:Streptococcus pneumoniae / Q000235:genetics; D013297:Streptococcus pyogenes / Q000235:genetics; D048249:Streptococcus thermophilus / Q000235:genetics