Ultra-structural changes in the thymus of chickens experimentally infected with chicken infectious anemia virus

The present investigation was undertaken to studythe ultra-structural changes in thymus following chicken infectious anemia virus (CIAV) infectionin chicks. Some thymocytes with electron-dense rings in their nuclei and few thymocytes showing chromatin aggregation were noticed in the cortex region with scarcity of the cells on 7 days post infection (DPI). At day 14, the cortex was severely depleted of thymocytes with some thymocytes showing apoptotic nuclei and some with broken nuclear fragments. The aggregations of virus-like particles surrounded by membrane like structures were also observed in the cortex region. The cortex started repopulating with thymocytes whereas some cells with apoptotic bodies were detected on day 21, whereas on day 28 the cortex area of infected group became comparable to the cortex of the control chickens after repopulation of cells. Findings of the study indicate that CIAV causes apoptotic death of the thymocytes following experimental infection.