THE PROTOONCOGENE C-MYB IS EXPRESSED IN SPORADIC BOVINE LYMPHOMA, BUTNOT IN ENZOOTIC BOVINE LEUKOSIS

We examined bovine c-myb gene expression in six samples of sporadic bo vine lymphomas (two calf, three thymic and one intermediate) and five of enzootic bovine leukosis. Tumor cells of the sporadic bovine lympho mas were of immature cell lineage (one B lymphoma and five T lymphomas ). The c-myb mRNA was expressed in almost all the sporadic bovine lymp homas (except for one thymic form) including a BoCD8 single positive T lymphoma. On the contrary, c-myb was not expressed in mature B lympho mas of enzootic bovine leukosis. The results suggest that c-myb expres sion is closely associated with tumor cell differentiation of bovine l ymphomas.