ALV-J Hens Clinical, Pathological Observation And Virus Isolation And Identification Of Infectious Clone Of Virus

To understand the pathogenesis and disease diversity of the avian leukosis better,we selected28240-day-old laying hens that could not laying properly from a flock of commercial Hy-line brown layers which attacked by tumor/hemangioma induced by ALV-J and observed continuously in laboratory for50days.7of which died at249～265day-old,1appeared toes hemangioma,6appeared liver and spleen enlargement,vascular tumors or tumor nodules in the necropsy.The remaining21sacrificed in300-day-old,4of which emerged toes hemangioma,there are different visceral lesions such as liver and spleen enlargement,diffuse white nodules or fibrosarcoma tumors,bone sclerosis expect other4in the necropsy. Histopathological observation of liver seen a lot of bones, etc. myeloid cells and lymphocyte infiltration, is typical of myeloid cell tumor lesions.By inoculation blood samples in DF-1cell culture,21exogenous ALV were isolated.Were named SDAU10C1-SDAU10C21. gp85amplification cloning and sequencing of seven isolates, indicating that the isolates and reference strains of subgroup J gp85nucleotide sequence homology of the highest in the86.9-95.5%,50.6-53.3%homology and AE subgroup ALV. On SDAU10C1whole genome amplification cloned and sequenced the gag, pol, gp37gene and LTR for comparison and found that isolates the gag and pol gene subsets strains with reference strains and other subsets borne in more than95%, in fact, these two genes are very conserved between the various subsets. gp37gene encoding the amino acid sequence homology comparison, in about60%of the reference strains of homology with other subsets, in fact, no clear distinction gp37homology with subsets correlation.Animal experiments show that the virus is acute oncogenic virus can lead to a variety of different strains and different day-old chicken tumorigenesis in a very short period of time. Therefore inferred that the strain must integrate a certain proto-oncogenes, resulting in abnormal expression of proto-oncogenes and tumor occurs so rapidly. To this end, the design of the dozens of pairs of amplification primers for different proto-oncogene J subsets of avian leukemia virus chimeric molecules to the gag gene and the fps gene chimera molecule, and further amplified by the helper virus and defective virus wholly genome. In order to better study the virus pathogenicity and tumorigenicity. Helper virus and virus infectious clone. The gene sequences divided into three successively inserted into a plasmid vector, PUC19/18. And transfected into CEF cells, detected by IFA, can see typical infected cells, deeply stained cytoplasm, nucleus fluorescence, but no phenomenon of cell transformation and failed to produce a new virus.Pathogenicity testing no tumorigenesis.