title: Characterization and expression of Megalobrama amblycephala toll-like receptor 22 involved in the response to Aeromonas hydrophila.
abstract: The toll-like receptors (TLR) tlr22 was identified and characterized for the first time in one of the economically most important freshwater fish species in China, Megalobrama amblycephala. The full-length cDNA (4039 bp) of M. amblycephala tlr22 contains an open reading frame of 2706 bp, encoding a 901 amino-acid long polypeptide. The putative polypeptide contains 16 leucine-rich repeat (LRR) motifs, an LRR C-terminal, a transmembrane region and a cytoplasmic toll-interleukin-1 receptor (TIR) domain. Phylogenetic analyses revealed that M. amblycephala Tlr22 shared the closest relationship with a grass carp ortholog. tlr22 was constitutively expressed in nine tissues and during 10 developmental stages studied, albeit with varying expression levels. Along with many pathological changes observed after Aeromonas hydrophila bacterium infection, tlr22 and myd88 mRNA were significantly upregulated in blood, head kidney, spleen and intestine, indicating that tlr22 is involved in the immune response. These results provide an insight into tlr22 regulation mechanisms in the innate immune response to bacterial infection.
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: R F
authors.initials: RF
authors.lastname: Lai
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: I
authors.initials: I
authors.lastname: Jakovlić
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: J
authors.initials: J
authors.lastname: Wei
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: F B
authors.initials: FB
authors.lastname: Zhan
authors.affiliation: Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde, 41500, China.
authors.forename: P H
authors.initials: PH
authors.lastname: Yang
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, Reproduction of Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.|Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: W M
authors.initials: WM
authors.lastname: Wang
mesh_terms: D016980:Aeromonas hydrophila / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps / Q000235:genetics; D002681:China; D003001:Cloning, Molecular; D003530:Cyprinidae / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D005393:Fish Diseases / Q000276:immunology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D060226:Head Kidney / Q000378:metabolism; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D008297:Male; D008969:Molecular Sequence Data; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D053594:Myeloid Differentiation Factor 88; D012333:RNA, Messenger; D051193:Toll-Like Receptors
keywords:  tlr22; head kidney; immune response; intestine; myd88; spleen