Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Workshop: Aquaculture
Shrimp culture is one of the most important aquaculture industries in the worldwide. The outbreak of infectious diseases caused significant losses in this industry. For protection of these infectious diseases of shrimp, we have to understand the immune and defense system of shrimp. Hemocytes cells are thought to be important cells for the immune and defense systems of crustacean. However, there is not enough information for understanding crustacean immune and defense mechanisms for development of methods for protection of infectious diseases. An expressed sequence tag analysis was conducted for discovery of immune- and defense-related genes of kuruma shrimp, Penaeus japonicus. Two cDNA libraries were constructed from healthy and white spot syndrome virus (WSSV) infected kuruma shrimp hemocytes. We sequenced 635 clones and 370 clones from healthy and virus infected shrimp cDNA libraries, respectively. Of 635 clones (healthy shrimp), 284 clones (44.7 %) had significant homology to known genes in DNA/protein databases. 174 (47.0%) of 370 clones (virus infected shrimp) were significantly matched with sequences in DNA/protein databases. There were 27 EST for immune- and defense-related genes including prophenoloxidase system, antibacterial peptides and protein, membrane associated proteins, and soluble proteins. The expression patterns of defense and/or immune-related genes of kuruma shrimp hemocytes were characterized by RT-PCR and quantitative real-time fluorescence RT-PCR. The expression patterns and the amount of expressed mRNAs of genes varied in different genes, stimulations and time points. The results of real-time fluorescence RT-PCR indicated that the absolute copy numbers of mRNA can easily be calculated.