title: Characterization, promoter analysis and expression of the interleukin-6 gene in blunt snout bream, Megalobrama amblycephala.
abstract: Interleukin-6 (IL-6) is one of the most important multifunctional cytokines, playing essential roles in mediating the innate and adaptive immune responses. In this study, il-6 gene and its promoter from blunt snout bream, Megalobrama amblycephala, were characterized, and its expression at the transcript level in healthy fish and after bacterial infection was determined by quantitative real-time PCR. The results showed that the M. amblycephala il-6 (Mamil-6) cDNA had an ORF of 699 bp, encoding 232 amino acids, and contained 9 instable motifs in the 3' UTR. The deduced MamIL-6 possessed a 24-amino acid signal peptide and was located in the cytoplasm. Although sequence alignment and phylogenetic analysis revealed that IL-6 is poorly conserved in vertebrates, the protein and genomic structure of il-6 gene was well conserved. Analysis of the Mamil-6 promoter revealed the presence of a conserved TATA box and six major cis-regulatory elements, including C/EBPβ (NF-IL6), AP-1, CRE, GRE, GATA and NF-κB binding sites. In healthy fish, Mamil-6 was the most abundant in the spleen. After Aeromonas hydrophila infection, Mamil-6 was significantly up-regulated in all 6 immune-related tissues examined, suggesting that Mamil-6 plays an important role in the blunt snout bream immune system.
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Fu
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Zhujin
authors.initials: Z
authors.lastname: Ding
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Fan
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Huanling
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Fengjuan
authors.initials: F
authors.lastname: Zhou
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Cui
authors.affiliation: Animal Husbandry and Fisheries Research Center of Haid Group Co., Ltd, Guangzhou, 511400, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Boxiang
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Wang
authors.affiliation: College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. liuhong59@mail.hzau.edu.cn.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China. liuhong59@mail.hzau.edu.cn.|College of Life Sciences, Hunan University of Arts and Science, Changde, 415006, Hunan, China. liuhong59@mail.hzau.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
mesh_terms: D016980:Aeromonas hydrophila; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003530:Cyprinidae / Q000235:genetics* / Q000276:immunology; D018076:DNA, Complementary / Q000235:genetics; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology; D029941:Fish Proteins / Q000235:genetics* / Q000276:immunology; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology; D015850:Interleukin-6 / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D015850:Interleukin-6
keywords: Aeromonas hydrophila; Interleukin-6; Megalobrama amblycephala; Promoter; Sequence analysis; Transcript level