title: Molecular characterization and functional analysis of Toll-like receptor 3 gene in orange-spotted grouper (Epinephelus coioides).
abstract: Toll-like receptor 3 (TLR3) plays an important role in activating innate immune responses during viral infection. In this report, TLR3 (EcTLR3) was characterized and analyzed for the first time in Epinephelus coioides. The full-length EcTLR3 cDNA is predicted to encode a 909 amino acid polypeptide that contains a signal peptide sequence, 18 leucine-rich repeat (LRR) motifs, a transmembrane region and a Toll/interleukin-1 receptor (TIR) domain. Quantitative real-time PCR revealed that the EcTLR3 mRNA was much more abundant in the liver than in other immune organs, and that the expression levels were very low in hemocyte and muscle. During development of the grouper, the levels of EcTLR3 transcripts increased with age, with very low expression levels at the early stages of development. EcTLR3 mRNA levels were examined in the liver at different times after treatment with polyriboinosinic polyribocytidylic acid (Poly I:C), and in nervous necrosis virus (NNV)-infected larval groupers. The results suggested that EcTLR3 plays an important role in a fish's defense against viral infection.
authors.affiliation: Fisheries Research Institute of Fujian, Xiamen 361012, China.
authors.forename: Kebing
authors.initials: K
authors.lastname: Lin
authors.forename: Hui
authors.initials: H
authors.lastname: Ge
authors.forename: Qi
authors.initials: Q
authors.lastname: Lin
authors.forename: Jianshao
authors.initials: J
authors.lastname: Wu
authors.forename: Libin
authors.initials: L
authors.lastname: He
authors.forename: Qiongshan
authors.initials: Q
authors.lastname: Fang
authors.forename: Chen
authors.initials: C
authors.lastname: Zhou
authors.forename: Minqiu
authors.initials: M
authors.lastname: Sun
authors.forename: Zhongchi
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005393:Fish Diseases / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D006434:Hemocytes / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism / Q000821:virology; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000276:immunology*; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000821:virology; D010802:Phylogeny; D012327:RNA Virus Infections / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D017386:Sequence Homology, Amino Acid; D051196:Toll-Like Receptor 3 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D051196:Toll-Like Receptor 3
keywords: Epinephelus coioides; Gene expression; IHNV; Innate immunity; JNK; Jun N-terminal kinase; LRR; NNV; PAMPs; PRRs; Poly I:C; RNA virus; TIR; TLR3; TLRs; Toll-like receptors; Toll/interleukin-1 receptor; VNN; infectious hematopoietic necrosis virus; leucine-rich repeat; nervous necrosis virus; pathogen-associated molecular patterns; pattern recognition receptors; polyriboinosinic polyribocytidylic acid; viral nervous necrosis