Study On Microsatellite Instability Of Marek’s Tumor And Spf Chicken Inoculated With Hvt Live Vaccine

Marek’s disease is a common neoplastic disease. Nowadays there have been no reports on early diagnosis of the tumor and the reports on microsatellite instability of host genome of MDV-infected chicken are still rare except our laboratory. A experiment is conducted to find whether there is change of MSI and LOH in host genome after infected by low virulent strain of MDV.40SPF chickens were raised and inoculated with HVT low virulent strain of MDV. The conditions about microsatellite instability of these chicken’s genome were detected, and the regularity of microsatellite instability were studied. The results would provide important information for early diagnosis and anti-disease breeding of Marek’s disease.Test1:The clinical examination pathologic diagnosis and molecular biology diagnosis for some cases from some farm in Anhui Province were carried out in this experiment; Test2:the reasearch on microsatellite instability of the cases was studied through45advanced microsatellite sites by PCR、PAGE and silver staining; Test3:40SPF chickens were raised and inoculated with low virulent strain (herpesvirus of turkey live vaccine of Marek’s disease) on10days old, and the heart blood were collected and lymphocyte were separated after two weeks, which were done regularly afterward. At the same time, normal tissues were also collected as control, and DNA extracted from cytes.45microsatellite sites were selected based on our previous experiments and genome microsatellite instability was detected by PCR、PAGE and silver staining.The results:1) the disease broken out in this farm was Marek’s disease via a series of diagnosis, which belonged to serotype Ⅰ;2) among45advanced microsatellite sites, microsatellite instability happened in39microsatellite sites, it also could be found that there were coincidence of75.6%on the change of microsatellite instability between tumor issue and lymphocyte;3) the changes on microsatellite instability happened in44microsatellite sites of SPF chicken after inoculated with low virulent vaccine, which mainly appeared in these samples collected in the previous three or four times; microsatellite instability was not detected in the samples of the fifth time collected from chickens which took on microsatellite instability.The experiment investigated microsatellite instability the first time after the chickens were inoculated with live vaccine and it was found that microsatellite instability appeared in protophase and returned to normal condition in anaphase, and the phenomenon maybe was a result from synthetic actions among restoration system itself, immunological reaction、 neutralization reaction and so on. It suggested a new point for early diagnosis and detection for Marek’s disease quickly and effectually by microsatellite technology based on PCR、 electrophoresis and silver staining. Meanwhile the condition that the changes of microsatellite instability appeared after inoculating low virulent strain and then disappeared after the antibody emerged could provide an assistant method to detect the quality of vaccine.