Molecular Cloning and Sequence Analysis of J-chain in the Reptile El ap he Taeniura

The plasma cell produces the J-chain ,which is a 15-kDa glycoprotein that covalently associates by disulfide linkages with polymeric IgA and IgM .Through the linkage between J -chain and the caudal cysteines of Ig ,the polymerization process could startover .This study cloned the J-chain gene in Elaphe taeniura (hereinafter referred to as snake ) and analyzed the expression levels of it in different tissues .In line with other species ,the cysteine residues used to form disulfide linkages are highly conserved in the snake J-chain gene;Quantitative real-time PCR showed that the J-chain gene was highly expressed in the spleen and intestine ,which is in accordance with other immunoglobulin genes .The cloning of the snake J-chain gene laid a good foundation for researching the polymeric immunoglobulins in snakes .