title: Transcriptomic analysis of oyster Crassostrea gigas larvae illustrates the response patterns regulated by catecholaminergic system upon acute heat and bacterial stress.
abstract: Bacterial infection and heat stress, as two major environmental threats of marine molluscs, could affect larval development and dramatically promote mortality of oysters. In the present study, next-generation sequencing, together with determinations of mRNA expression and measurements of enzyme activities, were employed to understand the response patterns of oyster larvae under acute heat and bacterial stress. After RNA-seq, a total of 9472 differentially expressed genes including 4895 significantly up-regulated ones and 4577 significantly down-regulated ones were obtained from 12 transcriptome libraries. GO overrepresentation analysis of the up-regulated genes revealed that the neuroendocrine immunomodulation pathway was activated after acute heat and bacterial stimulation, in which the catecholaminergic regulation played an important role. GO overrepresentation analysis of the down-regulated genes suggested that the immune capacity of Crassostrea gigas larvae was suppressed under stress, which was further validated since superoxide dismutase (SOD) and phenoloxidase (PO) activities in the total protein extract of larvae decreased dramatically after stress. Moreover, the shell formation of trochophore was inhibited and severe mortality was caused after acute heat and bacterial stress. These results collectively indicated that acute heat and bacterial stress could significantly inhibit larval development and suppress immune response of oyster C. gigas larvae. And the neuroendocrine immunomodulation, especially the catecholaminergic regulation, played an indispensable role in the stress response of molluscan larvae.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Functional Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhaoqun
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China. Electronic address: wanglingling@dlou.edu.cn.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
authors.forename: Miren
authors.initials: M
authors.lastname: Dong
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Functional Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Weilin
authors.initials: W
authors.lastname: Wang
authors.affiliation: Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Song
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Mengqiang
authors.initials: M
authors.lastname: Wang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Functional Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D049896:Crassostrea / Q000502:physiology*; D020869:Gene Expression Profiling; D006358:Hot Temperature; D015213:Neuroimmunomodulation / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D059467:Transcriptome
chemical_list: D002395:Catecholamines
keywords: Acute heat and bacterial stress; Catecholaminergic system; Crassostrea gigas larvae; Immunomodulation; Transcriptomic analysis