传染性法氏囊病病毒超强毒株致弱的分子生物学特征

为了探索传染性法氏囊病病毒（ＩＢＤＶ）超强毒株致弱的分子特征变化，采用ＲＴ－ＰＣＲ技术，从超强毒（ｖｖＩＢＤＶ）及其不同代次细胞传代致弱毒中扩增到编码ＶＰ２蛋白的ｃＤＮＡ高变区基因，并对其序列测定。将ｖｖＩＢＤＶ及其致弱毒株ＶＰ２高变区的氨基酸与其它血清Ⅰ型毒株比较，发现ｖｖＩＢＤＶ与其致弱毒株在ＶＰ２高变区的２２２、２４２、２５３、２５６、２７１、２７９、２８４、２９４、２９９和３００位氨基酸发

Preliminary Research on Molecular Biological Bsasis of the Very Virulent Ctious Burial Disease Virus and its attenuated Strains

To elucidate the virulence of the very virulent strain of IBDV can turn into the low pathogenic strain.The cDNA fragment coding host-protective antigen VP2 were amplified from vvIBDV and its different generation at tenuated strains which were propagated in SPF embryo and CEF.By means of RT-PCR, the nucleotide sequences of variable region of VP2 were determined by Sanger''s DNA sequence method, and the amino acid sequence were deduced.The amino acid sequence of vvIBDV and its attenuated strains were compared.It was shown that vvIBDV and its attenuated strains'' amino acid are different in 222, 242, 253, 256, 271, 279, 284, 294, 299, 300 sites.Because the change of this key amino acids makes hydrophilic regions and heptapeptide region change, vvIBDV was at tenuated into low pathogenicity.