Identification and BiochemicaI Characteristics of a NeW Psittacine Virus in China

A strain of new virus was isolated from fledgling budgerigars by authors in 1995 Cytopathic effect became visible after the isolate was passaged 4 generations on budgerigar embryo fibroblast and 5 generations on Chicken embryo fibroblast．The SDS-PAGE proved that viral capsidxgas composed of eight polypeptides with molecular w |gbt from 60 000 tO 14 500 D．The protein WBtS rich in Asp，Glu and Leu，but comparatively poorer in Arg and M et．The ratio of acidicamino acid to basic amino acid WBS l：2．5 l T nudeic acid Was dsDNA and exi~ed as supercoiled circular．relaxed ciseulatand Iinear molecules G 十C of viral DNA was 45％ The molecu 1ar weight oE DNA WBtS 3．3 106D restriction endonuclease analysis According to standards of virus classification．it is proved that the isolate was budgerigar fledgling disease virus which had placed into the Polyomavirus genus of Papovaviridae．