Differential response to avian leukosis virus infection exhibited by two chicken lines.

Infection of susceptible chickens with avian leukosis virus (ALV) results in the development of bursal lymphomas. These neoplasms develop within the bursa of Fabricius following a latent period of several months. The response exhibited by two previously uncharacterized chicken lines to ALV infection has been examined. The two lines, Hyline SC and FP, responded differently to ALV infection. During a 24-week period following intravenous ALV infection, 27 of 50 SC chickens developed bursal lymphomas. No lymphomas developed in the 36 FP chickens tested. A majority of the SC chickens that developed lymphomas also exhibited widespread metastasis to the liver, spleen, and kidneys. Analysis of cellular DNA from the primary and metastatic tumors demonstrated the clonal nature of these neoplasms and revealed altered c-myc loci, as reported in other studies, suggesting the importance of this locus in the development of these tumors. Further characterization of the ALV infection of SC and FP chickens will provide an opportunity to analyze the mechanism of resistance and to contribute to the understanding of the tumorigenic process.