title: Complement C3 gene: Expression characterization and innate immune response in razor clam Sinonovacula constricta.
abstract: Complement component 3 (C3) is central to the complement system, playing an important role in immune defense, immune regulation and immune pathology. Several C3 genes have been characterized in invertebrates but very few in shellfish. The C3 gene was identified from the razor clam Sinonovacula constricta, referred to here as Sc-C3. It was found to be highly homologous with the C3 gene of Ruditapes decussatus. All eight model motifs of the C3 gene were found to be included in the thiolester bond and the C345C region. Sc-C3 was widely expressed in all healthy tissues with expression being highest in hemolymph. A significant difference in expression was revealed at the umbo larvae development stage. The expression of Sc-C3 was highly regulated in the hemolymph and liver, with a distinct response pattern being noted after a challenge with Micrococcus lysodeikticus and Vibrio parahemolyticus. It is therefore suggested that a complicated and unique response pathway may be present in S. constricta. Further, serum of S. constricta containing Sc-C3 was extracted. This was activated by LPS or bacterium for verification for function. The more obvious immune function of Sc-C3 was described as an effective membrane rupture in hemocyte cells of rabbit, V. parahemolyticus and Vibrio anguillarum. Thus, Sc-C3 plays an essential role in the immune defense of S. constricta.
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources and College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Maoxiao
authors.initials: M
authors.lastname: Peng
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources and College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Donghong
authors.initials: D
authors.lastname: Niu
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources and College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources and College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources and College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China. Electronic address: jlli2009@126.com.
authors.forename: Jiale
authors.initials: J
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D049872:Bivalvia / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D003001:Cloning, Molecular; D003176:Complement C3 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D007113:Immunity, Innate / Q000235:genetics; D008837:Micrococcus / Q000502:physiology; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014733:Vibrio / Q000502:physiology
chemical_list: D003176:Complement C3; D018076:DNA, Complementary; D012333:RNA, Messenger
keywords: Complement C3; Innate immunity; Sinonovacula constricta