从芦花鸡分离的J亚群ALV病毒及其gp85基因演化

Identification and evolution of gp85 gene of ALV-J isolated from Chinese indigenous chicken breed“Luhua”

采用RT-PCR方法直接从芦花鸡肿瘤中进行禽白血病病毒（Avian leucosis virus,ALV）的核酸扩增,经测序证实为ALV。将上述病料接种DF1细胞（C/E）进行盲传,并对其感染细胞上清进行ALV P27抗原检测,结果为阳性,证实获得了一株病毒,命名为SDJN2012。用PCR方法扩增其囊膜蛋白gp85基因并测序,与GenBank中的ALV参考毒株进行核苷酸或氨基酸同源性比较。结果表明：SDJN2012与山东较早发现的J亚群ALV代表株SD0001的核苷酸（氨基酸）同源性最高,达93.4%（92.6%）,与J亚群不同年代的代表株同源性为88.6%～93.3%（88.2%～90.6%）,而与A,C,D,E亚群ALV毒株的同源性仅为19.7%～32.2%（10.2%～32.2%）,进一步确证分离到的病毒为J亚群ALV。对种蛋的跟踪监测证实：ALV蛋清P27抗原阳性率为37.6%,而血清学监测则呈现多样性的变化：鸡群发病前J亚群ALV抗体检测为阴性,发病后阳性率仅为9.35%,而A/B亚群阳性率则由发病前的9.8%,攀升到发病后的75.4%,彰显出ALV病原学、血清学和分子流行病学的复杂性。

Avian leukosis virus（ALV） was isolated from the tumors of Chinese native breed＂Luhua＂chicken,and was confirmed by RT-PCR and DNA sequencing. Then,a virus strain,named SDJN2012,was confirmed by detection of P27 antigen from the virus supernatant via inoculation of DF1 cells（C /E）. The gene of envelope protein gp85 were cloned and sequenced by designing specific primers of gp85 motif from ALV reference strains in GenBank,and the nucleotide and amino acid homologies were compared. The results showed that the SDJN2012 had the highest nucleotide（amino acid） homology 93. 4%（92. 6%） with SD0001 strain,the first viruses of the subtype J strains dis-covered in Shandong. Besides,SDJN2012 shared 88. 6% ～ 93. 3%（88. 2% ～ 90. 6%） nucleotide（ amino acid）homologies with different subtypes of J strains,and 19. 7% ～ 32. 2%（10. 2% ～ 32. 2%） homologies of A,C,D,E subtypes of ALV homolog,which further confirmed that the isolated virus was J subtype ALV. The positive rate of P27 antigen was 37. 6%. The antibodies of ALV J subtype were negative before onset,and were only 9. 35% positive after onset. While,the positive rate of A /B subtype from climbed to 75. 4% after onset from 9. 8%,which indicated the complexity of ALV clinical etiology,serology and molecular epidemiology.