Complete genome sequence of Vibrio parahaemolyticus CHN25 and transcriptomic analysis of cold shock proteins of VpaCspA and VpaCspD in the adaptation of low temperature growth

To investigate low-temperature tolerance of the bacterium, three in-frame gene deletion mutants of VpacspA and VpacspD were constructed using homologous recombination method. When compared to the wild type strain, the growth of ?VpacspA mutant was strongly repressed at 10 0C, whereas the deletion of VpacspD gene greatly activated the bacterium growth at the low temperature. Transcriptome data revealed that 12.4% of the expressed genes in V. parahaemolyticus CHN25 was significantly changed in ?VpacspA mutant grown at 10 0C, including those involved in amino acid degradation, ATP-binding cassette (ABC) transporters, secretion systems, sulfur and glycerophospholipid metabolisms, whereas the low temperature elicited 10.0% of the genes from ?VpacspD mutant, such as phosphotransferase system, nitrogen and amino acid metabolisms. Moreover, the major changed metabolic pathways in dual-gene deletion mutant (?VpacspAD) differed radically from those in single-gene mutants. Comparison of transcriptome profiles further revealed a number of differentially expressed genes shared among the three mutants, as well as regulators specifically, coordinately and or antagonistically regulating in the adaptation of V. parahaemolyticus CHN25 to the low-temperature growth. Overall design: mRNA profiles of mid-log phase WT(G), ?VpacspA, ?VpacspD and ?VpacspAD at 10 °C were generated by deep sequencing using Illumina HiSeq 2500