Transcription analysis of gene expression island VcB V. cholerae by method of full-genomic sequencing

Abstract

The aim of the study was to analyze the expression of V. cholerae genes that are part of the VcB island by means of full-genomic sequencing of the transcriptome. The VcB island is localized on the second chromosome in all toxigenic vibrios studied and is absent in the atoxigenic apiliated strains. Two strains of V. cholerae O1 ctxA+ tcpA+ and one strain V. cholerae O1 ctxA- tcpA- were studied. The pool of total RNA vibrios was isolated by a technique based on differential precipitation in the presence of lithium ions. In the total pool of sequenced RNA, RNA encoded in the order of 3 500 by known cholera vibrio genes was identified. In a pool of total RNA from two ctx + tcpA + strains RNA transcripts were found for the five genes included in the VcB island, excluding the VCA0282 gene, previously identified as the ISVch5-transposase. In the the pool of total RNA from the ctx- tcpA- strain no transcripts of the two genes previously described as VCA0282-transposase and VCA0283 were detected. A possible explanation may be the existence of copies of these genes in other parts of the genome of the ctxA- tcpA-V. cholerae.