Abstract
The sex-linked maternally influenced lethal gene, sonless (snl), in D. melanogaster was shown to affect the survival of daughters as well as sons of snl/snl mothers but to a lesser degree. Interaction studies of sonless with the sex altering mutants transformer (tra) and doublesex (dsx) revealed that any alteration toward increased masculinity of progeny from snl/snl females reduced their zygotic viability, independent of snl dosage or Y chromosome presence or absence. Possible implications of these results are discussed and the original gene action hypothesis for snl is extended to incorporate these new findings.-Sonless is non-allelic but closely linked to rudimentary (r) and fused (fu), two mutants with similar sex-ratio patterns.
