Molecular cloning and characterization of grouper (Epinephelus coioides) immunoglobulin D gene

• Main Authors: Ying-Yi Lai, 賴盈伊
• Other Authors: Cheng-Hui Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/78305582081505659746

碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 95 === The immunoglobulin(Ig)is the defensive protein of the vertebrate to against the outside pathogens, distributed in the blood and immune organs mainly. The fish immunoglobulin cDNA has been found within decades. Two types of Ig heavy chains, IgM and IgD, are present in teleost. The structure and function of fish IgM is similar to mammal IgM. But the biological function of IgD is still unknown. The aim of this thesis is to clone and characterize IgD heavy chain cDNA of Epinephelus coioides. The cDNA of IgD heavy chain consists of 4119 base pairs encoding 1372 amino acid. The structure of IgD heavy chain contains a variable region(VH), the first constant region of IgM heavy chain(CH 1 of μ), 10 domains(CH 1-7 of δ)and transmembrane domain(TM domain of δ). The region between sixth and seventh domain is only found in Epinephelus coioides. IgD heavy chain has repeated sequence in CH 2, CH 3, and CH 4(CH 2-1, CH 3-1, CH4-1, CH 2-2, CH 3-2, and CH 4-2). The IgD heavy chain cDNA of Epinephelus coioides is 70% identical to that of Japanese flounder. The similarity of amino acid is 52%. The IgD gene was mainly expressed in kidney and spleen and also expressed in other tissues. The expression of IgD heavy chain begin from third day after the fertilization.