Abstract
An expressed sequence tag analysis (EST) was conducted for discovery of immune- and defense-related genes of Japanese flounder, Paralychthys olivaceus and kuruma shrimp, Penaeus japonicus. Eight cDNA libraries were constructed from liver, spleen, skin, kidney, and leukocytes of Japanese flounder. We also constructed two cDNA libraries from healthy and white spot syndrome virus (WSSV)-infected kuruma shrimp hemocytes. We sequenced more than 2, 800 clones and 1, 000 clones of Japanese flounder cDNA libraries and kuruma shrimp cDNA libraries, respectively. We found many putative biodefence and immune response related genes from Japanese flounder, such as cytokines (interleukin 1 β, tumor necrosis factor, chemokines, etc), cytokine receptors (TNFR 1 and 2, IL 1 R, IL 6 R, chemokine receptors, toll like receptors, etc), cell surface molecules (T cell receptors, IgM, IgD, CD 3, CD 8, etc), transcription factors (IRFs, CEBP, Stat 3, etc), complement component (C 3, C 8, C 9), antimicrobial proteins (lysozymes, transferrin, Mx), proteases and protease inhibitors. There were several kuruma shrimp ESTs for immune- and defense-related genes including the prophenoloxidase system, antimicrobial peptides and an antimicrobial protein, membrane-associated proteins, and soluble proteins. The immune- and defense-related cDNAs that are discovered by EST analysis could be useful tools for studying the immune- and defense-response in fish and shrimp.
