title: Cloning and molecular characterization of complement component 1 inhibitor (C1INH) and complement component 8β (C8β) in Nile tilapia (Oreochromis niloticus).
abstract: Nile tilapia (Oreochromis niloticus), one of the most important groups of food fishes in the world, has frequently suffered from serious challenge from pathogens in recent years. Immune responses of Nile tilapia should be understood to protect the aquaculture industry of this fish. The complement system has an important function in recognizing bacteria, opsonizing these pathogens by phagocytes, or killing them by direct lysis. In this study, two Nile tilapia complement component genes, complement component 1 inhibitor (C1INH) and complement component 8β subunit (C8β), were cloned and their expression characteristics were analyzed. C1INH cDNA was found containing a 1791 bp open reading frame (ORF) encoding a putative protein with 597 amino acids, a 101 bp 5'-untranslated region (UTR) and a 236 bp 3'-UTR. The predicted protein structure for this gene consisted of two Ig-like domains and glycosyl hydrolase family-9 active site signature 2. The C8β cDNA consisted of a 1761 bp ORF encoding 587 amino acids, a 15 bp 5'-UTR and a 170 bp 3'-UTR. The predicted protein of C8β contained three motifs, thrombospondin type-1 repeat, membrane attack complex/perforin domain, and LDL-receptor class A. Expression analysis revealed that these two complement genes were highly expressed in the liver, however, were weakly expressed in the gill, heart, brain, kidney, intestine, spleen and dorsal muscle tissues. The present study provided insights into the complement system and immune functions of Nile tilapia.
authors.affiliation: Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Anyuan
authors.initials: A
authors.lastname: He
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Shoujie
authors.initials: S
authors.lastname: Tang
authors.forename: Chenghui
authors.initials: C
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023681:Cichlids / Q000378:metabolism*; D003001:Cloning, Molecular; D003174:Complement C1 Inactivator Proteins / Q000235:genetics / Q000378:metabolism*; D003185:Complement C8 / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013045:Species Specificity
chemical_list: D003174:Complement C1 Inactivator Proteins; D003185:Complement C8; D018076:DNA, Complementary
keywords: C1INH; C8β; Complement components; Tilapia