1型鸭甲肝病毒LY0801株VP1基因在鸭胚传代中的变异规律研究

GENETIC VARIATION OF VP1 GENE OF DUCK HEPATITIS A VIRUS TYPE 1 LY0801 STRAIN DURING REPEATED PASSAGES IN DUCK EMBRYOS

为了解1型鸭甲肝病毒（Duck hepatitis A virus type 1）VP1基因在鸭胚传代中的变异规律,本研究将LY0801株DHAV-1在鸭胚体内传代至30代,分别对1~5、10、15、20、25、30代病毒进行VP1基因的克隆测序。各代次病毒分别以108copies/胚接种9日龄健康鸭胚,测定各组鸭胚的平均死亡时间和病毒在鸭胚尿囊液中的增殖拷贝数。结果表明：DHAV-1在鸭胚传代过程中,不同代次之间出现12个氨基酸的反复变异和同步变异,分别为R43M（K）、T48A、T101S、L169F、T180I、S181L、R183Q、E184A（K）、G187D、D193N、M213R、H219Y;在传代过程中,病毒致死鸭胚的时间逐渐延迟,但病毒在鸭胚内的增殖拷贝数未呈现稳定增长的趋势。

To survey the genetic variation of VP 1 gene of Duck hepatitis A virus type I （DHAV-I）, DHAV- 1 LY0801 isolate was carried 30 serial passages in duck embryos. The VP1 gene of the first to fifth, tenth, fifteenth, twentieth, twenty-fifth and thirtieth passages was amplified and sequenced respectively. With the dose of 108 COllies per embryo, each ten 9-day-old healthy duck embryos were inoculated with different passages of virus, and the mean death time of each group and the vial copies in duck embryo allantoic fluid were detected. The results showed that there were 12 amino acid mutation sites in VP1 gene in different passages, which were R43M（K）, T48A, T101S, L169F, T180I, S181L, R183Q, E184A（K）, G187D, D193N, M213R and H219Y. The 12 amino acid mutations appeared in different passages simultaneously and repeated the mutations in the first 30 passages. In the passaging process, the mean death time of duck embryos was increasing with increasing passage times, but the virus proliferation in duck embryos did not show a steady growth trend.