title: Molecular cloning, characterization and expression analysis of the complement component C6 gene in grass carp.
abstract: The complement system, as a representative of innate immunity, plays a key role in the host defense against infections. C6 is the member of complement components creating the membrane attack complex (MAC). In this study, we cloned and characterized the grass carp complement component C6 (gcC6) gene. Our data showed that gcC6 gene contained a 2724bp open reading frame (ORF), a 237bp 5'-untranslated region (UTR) and a 219bp 3'-UTR. The deduced amino acid sequence of gcC6 showed 77.6% and 58.9% identity to zebrafish C6 and rainbow trout C6, respectively. GcC6 gene was expressed in a wide range of grass carp tissues, and the highest expression level of gcC6 was detected in the spleen and liver. Upon challenge with Aeromonas hydrophila, its expression was significantly up-regulated in muscle, trunk kidney, liver, head kidney, spleen, heart and intestine, whereas it was down-regulated in the brain and skin. The expression level of gcC6 was high at the unfertilized egg stage. It was significantly increased at 1 day post-hatching, but it was decreased at 10 days post-hatching. This result suggested that the complement C6 transcripts in early embryos were of maternal origin.
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yu-Bang
authors.initials: YB
authors.lastname: Shen
authors.forename: Jun-Bin
authors.initials: JB
authors.lastname: Zhang
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Xu
authors.forename: Jia-Le
authors.initials: JL
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D003183:Complement C6 / Q000235:genetics*; D020869:Gene Expression Profiling / Q000662:veterinary; D005796:Genes / Q000235:genetics* / Q000276:immunology; D016366:Open Reading Frames / Q000235:genetics
chemical_list: D003183:Complement C6