Non-H-2-linked genetic control of resistance to BALB/c fibrosarcoma Meth-A

The genetic control of hybrid resistance to BALB/c fibrosarcoma Meth-A was investigated. A Meth-A tumour grew slower in (BALB/c x C57BL/6)F1 and reciprocal hybrid mice than in syngeneic BALB/c mice and was also found to grow slower in females than in males. Significant F1 resistance was demonstrated after both subcutaneous and intraperitoneal injection of tumour cells. However, (BALB/c x DBA/2)F1 mice did not show any significant resistance to Meth-A. In H-2 linkage studies of [BALB/c x (BALB/c x C57BL/6)] backcross mice, no statistically significant differences in the resistance of H-2 heterozygotes and homozygotes to Meth-A were observed. These results indicated that F1 hybrid resistance to Meth-A was controlled by non-H-2-linked resistance factor(s). No linkage was observed between resistance to Meth-A and coat colour c- and b-loci.