No more than 26% of XX dsx^T/dsx¹ mutant pseudomales produce gonads with the most severe group 1 pseudotestes phenotype. The remaining pseudomales have a less severe phenotype, with viable germ cells. otu¹⁰ and Df(1)otu-PΔ1 cause an increase in severity of this phenotype: over 70% of the resulting gonads were of group 1.

Only affects XX flies: the terminalia of XX heterozygous flies carry abnormal male and female elements, with the female genitalia anterior to the male genitalia. The male genitalia are well developed, but the penis apparatus is reduced, the hypandrium is mostly absent and many bristles are abnormal. The female vaginal plate is always present, but is reduced in size with abnormal bristles. There is often a mass of yellow, chitinised material between the vaginal plates, which is a secondary rudimentary penis apparatus. The anal plates have a sexually intermediate shape, and a bristle pattern which is a mosaic of male, female and intermediate bristles. The basitarsus of the foreleg carries a sex comb whose position and shape are intermediate between male and female. XX hemizygotes are sterile pseudomales.