Functional genomic studies on an immune-and antiviral-related gene of MyD88 in orange-spotted grouper,Epinephelus coioides  

作　　者：YAN Yang CUI HuaChun WEI JingGuang HUANG YouHua HUANG XiaoHong QIN QiWei 

机构地区：[1]Key Laboratory of Marine Bio-resources Sustainable Utilization,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China [2]State Key Laboratory of Biocontrol School of Life Sciences,Sun Yat-sen University,Guangzhou 510275,China

出　　处：《Chinese Science Bulletin》2012年第25期3277-3287,共11页

基　　金：supported by the National Basic Research Program of China (2012CB114402);the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-BR-08 and KZCX2- EW-Q213);the National Natural Science Foundation of China (30725027 and 30930070)

摘　　要：Myeloid differentiation factor 88(MyD88) is a universal adaptor protein involved in Toll-like receptors and in interleukin-1 receptor-induced nuclear factor-kappaB(NF-κB) activation.In this study,a new MyD88 gene(designated as Og-MyD88) was cloned from orange-spotted grouper,Epinephelus coioides,based on the expressed sequence tag(EST) obtained following Roche 454 GS-FLX sequencing.The full-length Og-MyD88 cDNA is composed of 1682 bp and encodes a deduced polypeptide of 289 amino acids with 86% homology to MyD88 of Siniperca chuatsi.The deduced amino acid sequence of Og-MyD88 contains a typical death domain at the amino terminus and a conserved Toll/IL-1R(TIR) domain at the carboxyl terminus,as well as three highly conserved motifs(Box1,Box2 and Box3) within the C-terminal TIR domain.In healthy fish,Og-MyD88 was found to be strongly expressed in immune-related tissues,including the spleen,head kidney,kidney,liver,skin and intestine,with lower expression in heart,stomach,brain and muscle.Transcripts of Og-MyD88 were found to be markedly up-regulated in fish spleen after challenge with Singapore grouper iridovirus(SGIV),a highly lethal viral pathogen to grouper fish.Furthermore,the full length Og-MyD88 and its N-terminal death domain were capable of inducing NF-κB activity in HEK-293 cells.Overexpressed Og-MyD88 showed the ability to inhibit replication of SGIV in grouper spleen(GS) cells.These results suggest that Og-MyD88 is involved in the grouper immune response to invasion of viral pathogens and may share similar functions to those observed in higher vertebrates.Myeloid differentiation factor 88 （MyD88） is a universal adaptor protein involved in Toll-like receptors and in interleukin-1 receptor-induced nuclear factor-kappaB （NF-KB） activation. In this study, a new MyD88 gene （designated as Og-MyD88） was cloned from orange-spotted grouper, Epinephelus coioides, based on the expressed sequence tag （EST） obtained following Roche 454 GS-FLXTM sequencing. The full-length Og-MyD88 cDNA is composed of 1682 bp and encodes a deduced polypeptide of 289 amino acids with 86% homology to MyD88 of Siniperca chuatsi. The deduced amino acid sequence of Og-MyD88 contains a typical death domain at the amino terminus and a conserved Toll/IL-1R （TIR） domain at the carboxyl terminus, as well as three highly conserved motifs （Boxl, Box2 and Box3） within the C-terminal TIR domain. In healthy fish, Og-MyD88 was found to be strongly expressed in immune-related tissues, including the spleen, head kidney, kidney, liver, skin and intestine, with lower expression in heart, stomach, brain and muscle. Transcripts of Og-MyD88 were found to be markedly up-regulated in fish spleen after challenge with Singapore grouper iridovirus （SGIV）, a highly lethal viral pathogen to grouper fish. Furthermore, the full length Og-MyD88 and its N-terminal death domain were capable of inducing NF-KB activity in HEK-293 cells. Overexpressed Og-MyD88 showed the ability to inhibit replication of SGIV in grouper spleen （GS） cells. These results suggest that Og-MyD88 is involved in the grouper immune response to invasion of viral pathogens and may share similar functions to those observed in higher vertebrates.

关 键 词：抗病毒相关基因 功能基因组学 石斑鱼 免疫相关 Toll样受体 核因子-κB 氨基酸序列 死亡结构域 

分 类 号：S943[农业科学—水产养殖]