Screening Of Virus-induced Genes And Characterization Of Pigment Epithelium-derived Factor In Japanese Flounder, Paralichthys Olivaceus

Japanese flounder (Paralichthys olivaceus) is one of important marine aquaculture fishes, and has been formed a large-scale economic benefit in China. However, the increasing cultivating density causes frequent breakout of virus disease in flounder, which has leaded to tremendous economic losses. In order to provide theoretic basis on defending viral diseases in flounder, it is significant and urgent to further study the molecular mechanism underlying flounder antiviral immune responses.In this study, a subtractive cDNA library was successfully constructed with mRNAs made from Japanese flounder embryonic cells (FEC) treated with UV-inactivated grass carp hemorrhage virus (GCHV) and control cells using suppression subtractive hybridization (SSH). PCR and dot blotting obtained a total of 148 ESTs through screening of subtractive cDNA library. Sequencing and bioinformative analyses reveal that the genes represented by these ESTs can be divided into seven groups, including cell division, cell signaling/cell communication, cell structure/motility, cell/organism defense, gene/protein expression and metabolism and so on.Among 148 ESTs, three are homologous to mammalian pigment epithelium-derived factor (PEDF) genes, indicating that they represent a flounder PEDF homolog (named Paralichthys olivaceus PEDF, PoPEDF). PEDF is a...