title: An Integrative Genomic Island Affects the Adaptations of the Piezophilic Hyperthermophilic ArchaeonPyrococcus yayanosiito High Temperature and High Hydrostatic Pressure.
abstract: Deep-sea hydrothermal vent environments are characterized by high hydrostatic pressure and sharp temperature and chemical gradients. Horizontal gene transfer is thought to play an important role in the microbial adaptation to such an extreme environment. In this study, a 21.4-kb DNA fragment was identified as a genomic island, designated PYG1, in the genomic sequence of the piezophilic hyperthermophilePyrococcus yayanosii. According to the sequence alignment and functional annotation, the genes in PYG1 could tentatively be divided into five modules, with functions related to mobility, DNA repair, metabolic processes and the toxin-antitoxin system. Integrase can mediate the site-specific integration and excision of PYG1 in the chromosome ofP. yayanosiiA1. Gene replacement of PYG1 with aSimRcassette was successful. The growth of the mutant strain ΔPYG1 was compared with its parent strainP. yayanosiiA2 under various stress conditions, including different pH, salinity, temperature, and hydrostatic pressure. The ΔPYG1 mutant strain showed reduced growth when grown at 100°C, while the biomass of ΔPYG1 increased significantly when cultured at 80 MPa. Differential expression of the genes in module III of PYG1 was observed under different temperature and pressure conditions. This study demonstrates the first example of an archaeal integrative genomic island that could affect the adaptation of the hyperthermophilic piezophileP. yayanosiito high temperature and high hydrostatic pressure.
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China; Institute of Oceanology, Shanghai Jiao Tong UniversityShanghai, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Oceanology, Shanghai Jiao Tong UniversityShanghai, China; Deep-Sea Cellular Microbiology, Department of Deep-Sea Science, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of SciencesSanya, China.
authors.forename: Xuegong
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China; Institute of Oceanology, Shanghai Jiao Tong UniversityShanghai, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China; Institute of Oceanology, Shanghai Jiao Tong UniversityShanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
keywords: Pyrococcus; adaptation; deep-sea; genomic island; integrative element; piezophilic hyperthermophile