Differential profile of genes expressed in hemocytes of White Spot Syndrome Virus-resistant shrimp (Penaeus japonicus) by combining suppression subtractive hybridization and differential hybridization.

White Spot Syndrome Virus (WSSV) is the major viral pathogen of culture shrimp. Although remarkable progress has been made in characterizing the WSSV genome, information concerning the antiviral process of host is still limited. To identify the genes differentially expressed along with their expression profile in the hemocytes of the virus-resistant shrimp, suppression subtractive hybridization (SSH) and differential hybridization (DH) were employed. Relying on the sequences identified in the subtractive cDNA library, 30 genes were characterized to be involved in the antiviral process as defense-relevant, among them, 22 are found for the first time in penaeid shrimp. The most interesting finding is that the interferon-like protein (IntlP) and (2'-5') oligo(A) synthetase-like protein (data not shown) known as the antiviral factors showed increased expression in virus-resistant shrimp and the non-specific antiviral activity of IntlP protein was verified by cytotoxicity experiment. A number of proteins with certain similarities to the components of the complement and cytokines system in vertebrates were also found in the subtracted library. The high expression of redox-related factors (NADH dehydrogenase, glutathione peroxidase and transcription factor AP-1 precursor), plasma defensive protein (C-type lectin and laminin-like protein) and translationally controlled tumor protein (TCTP) in the virus-resistant shrimp suggested that they are essential components participating in the antiviral process. Our work provides a wide array of genes differentially expressed in the virus-resistant shrimp, and a framework for further studies aimed at antiviral mechanism in shrimp.