title: Molecular Analysis of Atypical Family 18 Chitinase from Fujian Oyster Crassostrea angulata and Its Physiological Role in the Digestive System.
abstract: Chitinolytic enzymes have an important physiological significance in immune and digestive systems in plants and animals, but chitinase has not been identified as having a role in the digestive system in molluscan. In our study, a novel chitinase homologue, named Ca-Chit, has been cloned and characterized as the oyster Crassostrea angulate. The 3998bp full-length cDNA of Ca-Chit consisted of 23bp 5-UTR, 3288 ORF and 688bp 3-UTR. The deduced amino acids sequence shares homologue with the chitinase of family 18. The molecular weight of the protein was predicted to be 119.389 kDa, with a pI of 6.74. The Ca-Chit protein was a modular enzyme composed of a glycosyl hydrolase family 18 domain, threonine-rich region profile and a putative membrane anchor domain. Gene expression profiles monitored by quantitative RT-PCR in different adult tissues showed that the mRNA of Ca-Chit expressed markedly higher visceral mass than any other tissues. The results of the whole mount in-situ hybridization displayed that Ca-Chit starts to express the visceral mass of D-veliger larvae and then the digestive gland forms a crystalline structure during larval development. Furthermore, the adult oysters challenged by starvation indicated that the Ca-Chit expression would be regulated by feed. All the observations made suggest that Ca-Chit plays an important role in the digestive system of the oyster, Crassostrea angulate.
authors.affiliation: Xiamen Medical College, Xiamen, 361008, PR China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, PR China; College of Ocean and Earth Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Bingye
authors.initials: B
authors.lastname: Yang
authors.affiliation: College of Life Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: College of Life Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, PR China; College of Ocean and Earth Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Pu
authors.affiliation: College of Ocean and Earth Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: You
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, PR China; College of Ocean and Earth Science, Xiamen University, Xiamen, 361005, PR China.
authors.forename: Caihuan
authors.initials: C
authors.lastname: Ke
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002688:Chitinases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D049896:Crassostrea / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004064:Digestive System / Q000201:enzymology* / Q000378:metabolism; D004435:Eating; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007814:Larva / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013217:Starvation
chemical_list: D018076:DNA, Complementary; D002688:Chitinases