Cop（Caspase recruitment domain only protein

COP） gene which contains apoptotic domain of Rana grylio virus（RGV COP） was cloned

sequenced and expressed in E.coli and Epithelioma papulosum cyprini（EPC） cells.From the results of sequence analysis

the cop gene is 288 bp long and encodes a protein of 95 aa with a predicted molecular mass of 10.4×103.Alignment of the deduced amino acid sequence of RGV COP with Homo sapiens caspase-1 dominant-negative inhibitor pseudo-ICE isoform 2（Human COP） and other six iridovirus showed that they had the homology degree of 33% to 94%.The recombinant prokaryotic and eukaryotic expression plasmid containing this fragment was constructed.The former expressed in E.coli.BL21 and an expected 14×103 fusion protein was isolated by SDS-PAGE.EPC cells transfected with the later plasmid were stained with DAPI and observed under a Leica DM IRB fluorescence microscope.Green fluorescence was observed in whole cell.It’s first report of this gene in iridovirus.