CLONING, EXPRESSION AND PRELIMINARY ANTIGENICITY ANALYSIS OF STRUCTURAL PROTEINS OF A KOI HERPESVIRUS ISOLATE FROM KOI, CYPRINUS CARPIO IN TAIWAN

摘要

The aim of this study was to clone and express the ORF72 and ORF92 genes of koi herpesvirus (KHV) in a prokaryotic system and to examine the antigenicity of recombinant proteins. Phylogenetic analysis revealed that both ORF72 and ORF92 had 100% homology with KHV-J, and 99% homology with those from KHV-U and KHV-I in nucleotides. This suggests that the KHV isolate in Taiwan is more closely related to the Japanese strain (Asian genotype). In the antigenicity analysis, the crude recombinant ORF72 and ORF92 capsid proteins reacted with the positive sera of the survival fish after a KHV outbreak, indicating that these recombinant capsid proteins might mimic antigens of the wild type KHV to induce an immunological response in the infected host. Our results demonstrated potential for general applicability to serological tests and vaccine development.