鸡新城疫病毒(青岛株)分离鉴定及HN基因的 克隆、序列分析与同源性比较

Isolation and Identification og NDV Strain Qingdao ami NDV HN Gene in Homology Comparison with NDV Shains Offshore

The study of biologicul character revealed that the mean death time(MDT) of chicken embryos was 57.9h and introcerebral pathogenicity index (ICPI) in 1- day-old chicken was 1.65 and intravenous pathogenicity (IVPI) in 6-week-old chicken was 2.75. The genomic RNA of the NDV strain Qingdao was extracted. The HN gene of the virus has been amplified from viral genomic RNA by RT- PCR. Then it was cleaved with BamH I and Xba I , and directly cloned into vector pBlueseript Il KS(-). By the sequence analysis, the HN gene amplified by RT-PCR was 1792bp long as expected. It included the complete encoding region of HN gene of NDV strain Qingdao. The nuclectide sequence of this HN gene encoding rngion was 1713bp and encoded a protein 571 amino acids. For the amino acid sequence, there are 6 glycosylation site and 13 cysteine resides. Compared with the published 9 NDV straius, the homology of the nuclectide sequence is 88.4%～92.9%, the homology of the deduced amino acid sequence is 90.0%～94.2%. Phylogenetic tree showed the more relationship between the NDV strain Qingdao and Italien strain. The result showed the NDV strain Qingdso was virulent.