Vibrio chromosomes share common history
1 Dept. of Civil and Environmental Engineering, 15 Vassar Street, Cambridge MA 02139, USA
2 Infectious Diseases, Childrens' Hospital Boston, 200 Longwood Ave., Boston MA 02115, USA
3 Microbial Sequencing Center, The Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge MA 02142, USA
BMC Microbiology 2010, 10:137 doi:10.1186/1471-2180-10-137Published: 10 May 2010
While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation.
Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II) were identified from 19 sequenced Vibrionales genomes and their phylogenetic comparison suggests consistent phylogenies for each chromosome. Additionally, study of the gene organization and phylogeny of the respective origins of replication confirmed the shared history.
Thus, while elements within the chromosomes may have experienced significant genetic mobility, the backbones share a common history. This allows conclusions based on multilocus sequence analysis (MLSA) for one chromosome to be applied equally to both chromosomes.