cholerae and V. mimicus genomes, supporting the conclusion that both represent unique species not described before. Moreover, genes conserved among V. cholerae, V. mimicus, and the two new species varied sufficiently to suggest ancient speciation via genetic drift of the ancestral core genomic backbone. Furthermore, results of our analyses suggest Vibrio sp. RC341 to have evolved from

a progenitor of V. cholerae and V. mimicus, whereas Vibrio sp. RC586 is concluded to have evolved from an early V. mimicus clade. Although the ANI of all genomes analyzed in this study demonstrates divergence, putative genomic islands were found to cross species boundaries, often at an higher ANI than the conserved backbone. These data, coupled with phylogenetic analyses, point to lateral transfer MK0683 ic50 of the islands and phages among V. cholerae, V. mimicus, Vibrio sp. RC341, and Vibrio sp. RC586 in the

natural environment. Furthermore, homologous GI insertion loci were present in both new species and in the case of V. cholerae, these insertion loci were not GI-specific. The pool of DNA laterally transferred between and among members of the Vibrionaceae strongly suggests selleck compound that near-neighbors of V. cholerae act as reservoirs of transferable genetic elements and virulence in the environment and that V. cholerae is not alone in propagating these elements therein. Results of this study also demonstrate a widespread allelic variation in these elements and evidence of evolution of mobile genetic elements, including pathogenicity islands, through a multistep mosaic recombination with other elements, including phage. The ability of vibrios to incorporate exogenous DNA at several loci that encode a large combination of GIs, thereby, allows optimization of the genome

for success in a specific niche or wider ecology in the natural environment. Methods Genome sequencing Draft sequences were obtained from a blend of Sanger and 454 sequences and involved paired end Sanger sequencing on 8 kb plasmid libraries to 5× coverage, 20× coverage of PAK5 454 data, and optional paired end Sanger sequencing on 35 kb fosmid libraries to 1-2× coverage (depending on repeat complexity). To finish the genomes, a collection of custom software and targeted eFT-508 datasheet reaction types were used. In addition to targeted sequencing strategies, Solexa data in an untargeted strategy were used to improve low quality regions and to assist gap closure. Repeat resolution was performed using in house custom software [37]. Targeted finishing reactions included transposon bombs [38], primer walks on clones, primer walks on PCR products, and adapter PCR reactions. Gene-finding and annotation were achieved using an automated annotation server [39]. The genomes of these organisms have been deposited in the NCBI Genbank database (accession nos. NZ_ACZT00000000 and NZ_ADBD00000000).