Motor End-Plate Disease is Expressed in Congenitally Athymic Mice

To test a possible interaction between a neuromuscular disease and thymus function in the mouse, the homozygous condition medmed for motor end-plate disease (MED) was combined with that for the nude gene (nunu). Five nude MED animals (expectation 11 animals) were observed among 181 F2 progeny. Their weight was severely reduced already at 9 to 10 postnatal days, and they died earlier than their nonnude MED littermates. Thus a thymogenic etiology of the MED phenotype is excluded.