Abstract:
ObjectiveGene duplication through paralogous gene evolution is an important way of prokaryotic genome evolution, while the characteristics of duplication genes in Vibrio cholerae genome are poorly understood. In this study, we analyzed the number, diversity of duplication genes and difference in duplication genes between two biotypes of toxigenic strains of V. cholerae O1.
MethodsWe selected 300 strains of V. cholerae O1 of two biotypes causing the sixth and seventh pandemics. The numeric distribution and differential duplication genes between two biotypes were analyzed by using blastp and MCL; the diversity of duplication genes and genes of diversity difference were analyzed by measuring the average distance between any two sequences.
ResultsThe results showed that the average number of homologous gene clusters per strain was 242.63, the average number of that was 244.85 for El Tor biotype strains, and 209.74 for classical biotype strains. El Tor biotype had more duplication homologous gene clusters than classical biotype. Thirteen homologous gene clusters with significant different copies numbers between El Tor biotype and classical biotype were screened out; their functions mainly include the anions, amino acids or other substances transport, localization and transmembrane transport. By analyzing the genetic diversity of homologous gene clusters with duplication genes, we found 50 homologous gene clusters with different diversity between the two biotypes, the biological processes they participate in mainly include anions, amino acids or other substances transport, localization and substrate-specific transmembrane transport activity, etc.
ConclusionThe evolution of the duplication genes of V. cholerae has a certain functional tendency; the characterization of it could provide a new point for the understanding of the adaptive evolution of the genome, the diversity of strains and the differential evolution of the genomes of two biotypes.