马传染性贫血病毒弱毒株感染驴胎皮肤细胞(FDD)的前病毒DNA整合动态

INTEGRATION DYNAMICS OF PROVIRAL DNA IN FETAL DONKEY DERMAL CELL INFECTED BY ATTENUATED STRAIN OF EQUINE INFECTIOUS ANEMIA VIRUS

马传染性贫血病毒（Ｅｑｕｉｎｅｉｎｆｅｃｔｉｏｕｓａｎｅｍｉａｖｉｒｕｓ，ＥＩＡＶ）弱毒株，经驴胎皮肤（Ｆｅｔａｌｄｏｎｋｅｙｄｅｒｍａｌ，ＦＤＤ）细胞培养、斑点杂交及ＰＣＲ检测，在感染后２－１０天的细胞染色体中均检出前病毒ＤＮＡ，证明ＥＩＡＶ弱毒株对感染细胞具有整合作用。在感染后第６天，整合的前病毒的量达到高峰，其含量与病毒的致细胞病变作用（ＣＰＥ）相对应。前病毒的存在形式为整合形式，未检出非整合形式的前病毒，在健康的ＦＤＤ细胞中未检出前病毒，说明ＥＩＡＶ属于外源性病毒。ＥＩＡＶ弱毒株基因组两端的ＬＴＲ序列之中各存在一个限制酶ＭｌｕⅠ位点，这与美国强毒株相同，但弱毒株基因组的３端ＭｌｕⅠ位点上游２ｋｂ位置可能存在另一个ＭｌｕⅠ位点。

The attenuated strain of equine infectious anemia virus (EIAV) was propagated in fetal donkey dermal(FDD) cells.By dot-hybridization and PCR detection,proviral DNA was detected in the chromosomes of the cells infected by EIAV on day 2-10 postinoculation,indicating that the provirus of EIAV attenuated strain had integrated into the infected cell genome.The quantity of integrated proviral DNA reached to the highest level on day 6 postinoculation,and was correlated with the cytopathic effect of the virus.Unintergrated provirus was not detectable.No provirus was detectable in normal FDD cells,indicating that EIAV is not endogenous to the cell genome.There is probably an additional MluⅠ site at 2kb upstream from the 3’ end MluⅠ site of EIAV attenuated strain genome.