Histocompatibility difference between C3HfeB/HeN and C3H/HeN mice: tumour induced in C3HfeB/HeN mice expresses C3H/HeN-associated alloantigen.

A transplacentally induced lung tumour of C3HfeB/HeN mouse origin expresses, as a tumour-associated antigen, a normal tissue component of strain A mice. The genetic locus coding for this alloantigen has been shown to be linked to the H-2 major histocompatibility complex. In the present study we demonstrate that this antigen is also expressed on normal tissues of C3H/HeN mice. Skin grafts exchanged between C3HfeB/HeN and C3H/HeN mice are reciprocally rejected at approximately 3 weeks after grafting. C3HfeB/HeN mice were derived from C3H/HeN mice in 1945. These strains have apparently deviated since then in their genetic regulation of the expression of the MHC-linked genetic locus. The finding of the C3H/HeN-associated antigen on a C3HfeB/HeN mouse-derived lung tumour indicates that this deviation is reversible.