Development Of Diagnostic Method For Three Avian Tumors RE, MD And LL

Avian tumors are caused by several kinds of viruses. The three major avian oncogenic viruses are Marek's disease virus, reticuloendotheliosis virus and Avian Leucosis virus. Lympholytic (Lymphoid Leukosis) leucosis induced by Avian Leukosis virus are similar both macroscopically and microscopically to those caused by MDV and REV. In order to develop a diagnostic method, following experiments have been conducted in this study:â‘ REV and ALV were propagated on CEF;â‘¡To develop the PCR techniques as a diagnostic method for viruses that cause neoplastic diseases or immunodeficiency in chickens;â‘¢39 chickens with clinical signs of neoplastic tumor were examined through histopathology and PCR method;â‘£one-day-old SPF chickens were experimentally inoculated with MDV-Beijing 1 isolate, REV-T and REV-SNV. The results provided the experimental data for further exploring of the occurring and diagnosis the three avian tumor diseases.The CEF remained normal and no cytopathic effect appeared post inoculation of REV and ALV. By means of PCR with the specific primers from the LTR sequence of RE and LL and the 132bpr of MD, each of genes was amplified and electrophoresis was carried out, the gene length MD, RE and LL were 132bp, 291bp and 182bp respectively.The data of PCR were thatâ‘ 18 samples of birds were MDV positive, ratio is 33.3%;â‘¡6 samples were ALV positive, ratio is 2.6 %;â‘¢A total of five chickens were positive both MDV and ALV, the ratio is 12.8%. As to REV, the negative samples of PCR are same results as the antibody detected by ELISA.Throughout histopathology observation, neoplastic cell were in liver, spleen, kidney, proventriculus, bursa of fabricius, cardiac muscle and some tumor cell showed the different phase mitosis.Three flocks of SPF chickens were inoculated with MDV, REV-T and SNV. The PCR result showed that MDV positive samples are 50% and SNV positive are 66.7%. Tumor cell were observed in the REV-T negative chickens tissues such as liver, spleen, kidney, proventriculus, bursa of fabricius, lung and so on. Some cells have mitosis. The neoplastic cell could be observed both in the PCR-positive and negative samples.