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Expression of Immune-Related Genes in the Pacific White Shrimp, Litopenaeus vannamei and Their odulation by beta-glucan via Oral Administration

by Wang, Yu-Chi

Abstract (Summary)
The present study investigated the expression profiles of nine genes involved in immune defense of the Pacific white shrimp Litopenaeus vannamei and their responses to oral administration of beta-1,3-glucan. The nine immune related genes were beta-glucan binding protein-high density lipoprotein (BGBP-HDL), lipopolysaccharide/beta-glucan binding protein (LGBP), hemocyanin, prophenoloxidase (proPO), transglutaminase (TGase), penaeidin-3 (PEN-3), crustin, cytosolic manganese superoxide dismutase (cMnSOD), and lysozyme. A series of experiments were carried out in the study including: (1) cDNA cloning and characterization of proPO and LGBP; (2) tissue mRNA expressions of the nine genes in adult shrimp; (3) expression and localization of the nine genes during larval and postlarval ontogenic development; (4) the effects of dietary beta-1,3-glucan on the expression of the nine genes. The cDNA cloning study showed that the proPO cDNA contains an open reading frame of 2061 bp and encodes a 686 amino-acid peptide. The protein sequence of the proPO has a similarity of 85% with those of Penaeus monodon and P. semisulcatus and has an identity of between 58 and 77% with other crustaceans. Northern blot analysis revealed that proPO was constitutively expressed mainly in hemocytes. Its transcripts were observed in hemocytes and many other tissues when detected with RT-PCR. The results of in situ hybridizations showed that the hemocytes that infiltrated in tissues were responsible for the positive signals. The LGBP cDNA contains an open reading frame of 1104 bp and encodes a 367 amino-acid protein with a 17 a. a. signal peptide. The protein sequence of the LGBP has a similarity of 97% with LGBP of L. stylirostris, >90% identity with BGBP of P. monodon and LGBP of Fenneropenaeus chinensis and has an identity of between 63 and 86% with other crustaceans. Northern blot analysis revealed that LGBP was constitutively expressed mainly in hepatopancreas. The results of in situ hybridizations showed that the hepatopancreatic F cells might be the major cell type for LGBP production. Using the complete cDNAs of proPO and LGBP and partial fragments of the other seven genes, their tissue expressions were analyzed by conventional RT-PCR, quantitative real time PCR (qPCR) and in situ hybridization. The results demonstrated that BGBP-HDL, LGBP and hemocyanin were mainly expressed in the hepatopancreas and their expressions levels were about 10 to 30% those of
Bibliographical Information:

Advisor:Cheng-Fang Chang; Ching-Ming Kuo; Jiann-Chu Chen; Houng-Yung Chen; Yen-Ling Song; Winton Cheng

School:National Sun Yat-Sen University

School Location:China - Taiwan

Source Type:Master's Thesis

Keywords:immune litopenaeus vannamei gene expression in situ hybridization beta glucan ontogenesis quantitative real time polymerase chain reaction qpcr

ISBN:

Date of Publication:07/04/2007

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