title: cDNA cloning and tissue expression of plasma lysozyme in the eastern oyster, Crassostrea virginica.
abstract: The cDNA sequence of a 17,861 Da lysozyme first purified from plasma of eastern oysters (Crassostrea virginica) was identified and its complete amino acid sequence deduced. The amino acid sequence of the plasma lysozyme, designated cv-lysozyme 1, contained both a unique and a conserved region when compared to the amino acid sequences of other bivalve lysozymes. In situ hybridisation located cv-lysozyme 1 gene expression in mantle and gill cells in standard histological sections. Quantitative real-time RT-PCR detected cv-lysozyme 1 expression in all organs examined and circulating haemocytes. The number of cv-lysozyme 1 mRNA transcripts was particularly high in mantles and labial palps suggesting those organs are the main sites of cv-lysozyme 1 synthesis. Cv-lysozyme 1 enzyme activity measured by lysing Micrococcus lysodeikticus bacteria and expressed in units per gram tissue was highest in mantles, labial palps and gills. Most cv-lysozyme 1 enzyme activity in oysters was found in plasma. Cv-lysozyme 1 main organs of synthesis, its abundance in plasma and its strong antimicrobial properties suggest its main role is in oyster host defences.
authors: Cooperative Aquatic Animal Health Research Program, Department of Veterinary Science, 111 Dalrymple Building, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
authors: Naoki
authors: N
authors: Itoh
authors: QingGang
authors: Q
authors: Xue
authors: Yanli
authors: Y
authors: Li
authors: Richard K
authors: RK
authors: Cooper
authors: Jerome F
authors: JF
authors: La Peyre
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D049896:Crassostrea / Q000201:enzymology*; D005786:Gene Expression Regulation; D006434:Hemocytes / Q000201:enzymology; D017403:In Situ Hybridization / Q000662:veterinary; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D012333:RNA, Messenger; D009113:Muramidase