APPARENT CYTOPLASMIC STERILITY IN DROSOPHILA PAULISTORUM

Abstract

When crossed, the Mesitas and Santa Marta strains, both belonging to the Transitional race of Drosophlla paulistorum, produce fertile female and some sterile male hybrids. A genetic analysis suggests that the sterility in this case is caused, chiefly if not exclusively, by interaction of the Y chromosome of one strain, with the cytoplasm of the other strain. If the Y and the cytoplasm come from the same strain, the male is fertile, while if their sources are different, the male is usually sterile.