In Vitro Growth of Thymic Tumor Cell Lines from Xenopus

A spontaneous lymphoid thymus tumor was discovered in a male Xenopus of the MHCff genotype. The tumor cell can be transplanted in histocompatible larval ff hosts, but notin ff adults unless irradiated (3000 rad). The tumor is rejected by allogeneic hosts. Thetumor cells express neither markers of the B-cell lineage nor MHC encoded molecules;they express only markers of the T-cell lineage. Its lymphoid population is clonal asrevealed by the existence of a stable rearrangement pattern of the immunoglobulingenes. Cell lines growing continuously in vitro have been derived from the tumor.