FURTHER OBSERVATIONS ON lgMI(LID-GAP MILLER) AND OTHER OPEN-EYE MUTANTS IN THE HOUSE MOUSE

Abstract
The results of investigations on a number of open eye mutants in the mouse are as follows the penetrance and severity of expression of the lgMl mutant increased with selection; the therapeutic effect of cortisone on the lgMl mutant is specific for the litter and generation treated; the high neonatal mortality observed in the original experiments was caused by a failure of milk let down in the treated dams; and 2 other open eye mutants are allelic or identical to the lg and lgMl mutants. However, none of the other open eye mutants, including the lg, lgSt and the Stein mutant were found to respond to cortisone treatment. Therefore, while the lg, lgMl, lgSt and Stein mutants were found to be allelic or identical by the complementarity tests, they differ in their physiological response to cortisone.