Studies On The Pathogenic Characteristics Of Layer Chicken And Chinese Local Breed Infected With Avian Leukosis Virus Subgroup J

To study the pathogenic characteristics of layer chicken and Chinese local breed infected with ALV-J, offer accurate method for differential diagnosis, cut down economy missing. Using diagnosis assays of histopathology, immunohistochemistry, molecular biology, we describe the new pathogenic characteristics of ALV-J according to several new cases, and discuss all kinds of agents initially.The histopathology of immune organs and some visceral organs results showed that ALV-J mainly madehyperplasia of eosinocytes proliferate. Even some bone marrow was substituted by these cells. This lesion was related to apoptosis of lymphocytes besides lesions of bone marrow. Myelocytes proliferated in some visceral organs.The viral glucoprotein SU was detected to show distribution of ALV-J in the immune organs by immunohistochemistry. The results showed that ALV-J was found in all immune organs. The stain of bone marrow was moderate, but not all myelocytes were positive. The positive cells were follicular reticular cells in bursa, medulla epithelial cells, plasma cells and myelocytes in thymus, medullary sinus endothelial cells, reticular cells and some myelocytes in spleen. This distribution showed the infection period of ALV-J.Using molecular biology assays, a pair of primers (P1 /P2) was designed according to the sequence of ALV-J gp85 gene. DNAs were extracted from the liver. About 0.9kbp fragment was amplified by PCR. On the basis of the result of PCR, it was diagnosed as ALV-J.This study showed that mumerous myelocytes and reticulum cells were found in the tumor or other tissues of affected chickens by histological examination. So we diagnosed co-infection of ALV-J and REV by gross lesion, histopathology and immunohistochemistry (IHC) technique, this was first found in layer chicken. Another case was that Chinese local chickens infected ALV-J. Affected chickens showed wasting, weight loss, anemia, occasional paralysis, and abnormal feathering. Histological examination, granulated myelocytes proliferated in almost all tissues, and IHC detection, viral specific antigen expression in various tissues. The two cases indicated that ALV-J host range had been extension. ALV-J only caused myelocyte tumor of meat type broiler chickens previous, but now, it can caused tumor of layer chicken and Chinese local chicken. We must pay close attention to blocking ALV-J expending to other host.