Cell surfaces and embryos: expression of the F9 teratocarcinoma antigen in T-region lethal, other lethal, and normal pre-implantation mouse embryos.

F9 teratocarcinoma antigen is expressed normally on embryos which are homozygous recessive for each of 4 mutations lethal in early development, including t12. Homozygosity for two post-implantation T-region developmental lethal genes, tw5 and T0r1, may alter F9 antigen expression but the results were not definitive. In addition, the time of appearance of the antigen may be affected by some of the genotypes.