MURINE LEUKAEMIA VIRUS EXPRESSION IN THE AKR FOLLOWING THYMECTOMY

Summary.-Thymectomy effectively prevents the development of spontaneous lymphoma in the AKR but how this effect is achieved remains to be determined. One possible mechanism, namely suppression of genomic expression of the onco-genic murine leukaemia virus now seems unlikely since levels of the group specific MuLV antigen were in comparison with their sham operated controls unaltered in both neonatally and adult thymectomized AKR. ALTHOUGH quite clearly involved, the exact role of the thymus in the develop-ment of the lymphoma which charac-terizes the AKR (Furth, Seibold and Rath-bone, 1933) still remains to be deter-mined (Miller, 1961). One possible effect of thymectomy may be to suppress the titres of murine leukaemia virus group specific antigens and this has been exam-ined here in both neonatally and adult thymectomized AKR. MATERIALS AND METHODS Mice.-The derivation of the AKR/CRC used here has been described previousl