title: Comparative Transcriptome Analysis of Vibrio splendidus JZ6 Reveals the Mechanism of Its Pathogenicity at Low Temperatures.
abstract: Yesso scallop-pathogenic Vibrio splendidus strain JZ6 was found to have the highest virulence at 10°C, while its pathogenicity was significantly reduced with increased temperature and completely incapacitated at 28°C. In the present study, comparative transcriptome analyses of JZ6 and another nonpathogenic V. splendidus strain, TZ19, were conducted at two crucial culture temperatures (10°C and 28°C) in order to determine the possible mechanism of temperature regulation of virulence. Comparisons among four libraries, constructed from JZ6 and TZ19 cultured at 10°C and 28°C (designated JZ6_10, JZ6_28, TZ19_10, and TZ19_28), revealed that 241 genes were possibly related to the increased virulence of JZ6 at 10°C. There were 10 genes, including 2 encoding Flp pilus assembly proteins (FlhG and VS_2437), 6 encoding proteins of the "Vibrio cholerae pathogenic cycle" (ToxS, CqsA, CqsS, RpoS, HapR, and Vsm), and 2 encoding proteins in the Sec-dependent pathway (SecE and FtsY), that were significantly upregulated in JZ6_10 (P < 0.05) compared to those in JZ6_28, TZ19_10, and TZ19_28, which were supposed to be responsible for adhesion, quorum sensing, virulence, and protein secretion of V. splendidus. When cultured at 10°C, JZ6 cells were larger and tended to aggregate more than those cultured at 28°C. The virulence factor (extracellular metalloprotease) was also found to be highly expressed in the extracellular product (ECP) of JZ6 at 10°C, and this ECP exhibited obvious cytotoxicity to oyster primary hemocytes, A549 cells, and L929 cells. These results indicated that low temperatures (10°C) could enhance adhesion, activate the quorum sensing systems, upregulate virulence factor synthesis and secretion, and, lastly, increase the pathogenicity of JZ6.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo, Zhejiang Province, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Dahai
authors.initials: D
authors.lastname: Gao
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, China lshsong@dlou.edu.cn.
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D020869:Gene Expression Profiling; D010125:Ostreidae / Q000382:microbiology*; D012758:Shellfish / Q000382:microbiology; D059467:Transcriptome; D014733:Vibrio / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors