Complete genome of Micrococcus luteus V017 and its transcriptomic response to gamma ray radiation

Abstract:

[Background] Radioresistant microorganisms are important type of extreme microbial resources, which are of great significance for studying radiation-resistance mechanism and environmental protection. [Objective] To analyze the genetic background of Micrococcus luteus V017 and the transcriptome response to radiation through genome and transcriptome. [Methods] The full genome of strain V017 was sequenced and its unique gene sequence was revealed by comparative genome analysis. Further, transcriptome response of strain V017 to gamma ray radiation was performed, and then followed by functional analysis of their differentially expressed genes. [Results] The whole genome of V017 was obtained through de novo assembly. The genome size was 2 527 399 bp with GC content of 72.9%. Comparative genome analysis revealed many mobile element sequences unique in V017 genome, which may be helpful for it to adapt to the extreme irradiation environment. Transcriptome analysis showed that the basic metabolic pathways such as fatty acid and tryptophan metabolic pathways were significantly down-regulated. By contrary, expression level of the DNA damage repair pathways was significantly up-regulated. Especially, homologous recombination repair may play a major role in response to irradiation. [Conclusion] The genomic and transcriptome data analysis implied that the specific mobile sequences of strain V017 may help to adapt to the radiation environment through modulation of DNA rearrangement. Alternation of DNA damage repair and basic metabolic pathways in response to radiation stress may be an important reason for the moderate radiation resistance of strain V017. These studies laid the foundation for further understanding the adaptation and resistance mechanisms of radioresistant microorganisms, as well as the utilization of its microbial resources.