title: Molecular cloning and expression of toll-like receptor 4 (tlr4) in the blunt snout bream (Megalobrama amblycephala).
abstract: Toll-like receptors (TLRs) play a pivotal role in teleost innate immune system. In this study, Megalobrama amblycephala (ma) tlr4 gene was cloned, its putative polypeptide product characterized, and expression analysed. Matlr4 cDNA is 2862 bp long, with an open reading frame of 2364 bp encoding 787 amino acids. MaTlr4 is a typical TLR protein, including the extracellular part with nine leucine-rich repeat motifs, a transmembrane region and a cytoplasmic Toll/interleukin-1 receptor domain. MaTlr4 has the highest level of identity (94%) and similarity (97%) with the grass carp Tlr4.2 homolog. This was also corroborated by the phylogenetic analysis, which placed MaTlr4 in a cluster with other cyprinid homologs. Matlr4 mRNA was ubiquitously expressed in all examined tissues and during all sampled developmental stages. The observed peak in matlr4 mRNA expression during gastrula and somite stages is in good agreement with its proposed role in the development of the neural system. Temporal expression patterns of matlr4 and maMyD88 mRNAs and proteins were analyzed in liver, spleen, head kidney, trunk kidney and intestine after Aeromonas hydrophila infection. And mRNA expression varied between different time-points. Both MaTlr4 and MaMyD88 protein expressions at 12 hpi were significantly enhanced in head kidney and intestine. These results indicate that matlr4 is involved in the immune response in M. amblycephala, and that it is indeed a functional homologue of tlr4s described in other animal species.
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: lairuifang@webmail.hzau.edu.cn.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Lai
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: lifegood1986@126.com.
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: ivanjakovlic@yahoo.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Jakovlić
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: 1203248258@qq.com.
authors.forename: Fanbin
authors.initials: F
authors.lastname: Zhan
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: 1161104243@qq.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Wei
authors.affiliation: Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde, 41500, China. Electronic address: yph098@163.com.
authors.forename: Pinhong
authors.initials: P
authors.lastname: Yang
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: wangwm@mail.hzau.edu.cn.
authors.forename: Weimin
authors.initials: W
authors.lastname: Wang
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003530:Cyprinidae / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D005260:Female; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000276:immunology* / Q000382:microbiology; D060226:Head Kidney / Q000276:immunology; D007113:Immunity, Innate / Q000276:immunology*; D007422:Intestines / Q000276:immunology; D008297:Male; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis; D016415:Sequence Alignment; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D053594:Myeloid Differentiation Factor 88; D012333:RNA, Messenger; D051197:Toll-Like Receptor 4
keywords: Aeromonas hydrophila; Fish; Immunity; Megalobrama amblycephala; MyD88; tlr4