Uterine and cytoplasmic effects on pup eyelid opening in two inbred strains of mice.

Age at Eyelid Opening (AEO) differs in two inbred strains of laboratory mice: NZB and CBA/H. Ovarian transplantation and fostering methods were employed to test for variation of genotypic expression in different environments. (1) A global maternal effect was demonstrated for AEO in parental and F1 pups. (2) AEO of H and N pups is not affected by the parental vs. F1 modification of post-natal maternal environment. (3) The genotype of the mother, via uterine environment, interacts with pup genotype: only the CBA/H strain reacts to the parental vs. F1 modification in uterine environment. (4) A cytoplasmic effect for AEO was successfully replicated. Additional analyses demonstrate that AEO is not cytoplasmically inherited but rather modulated by the cytoplasmic environment.