FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.
Su(Ste)unspecified males show elevated levels of second-chromosome and XY nondisjunction. These males are sick and not fully fertile. As with wild-type cells, the Y chromosome moves to the opposite pole from a pair of nondisjoined second chromosomes nearly 100% of the time in Su(Ste)unspecified cells.
Su(Ste)unspecified/Df(1)X-1 males show elevated levels of XY nondisjunction, which is equal to the sum of the effects of the Su(Ste)unspecified and Df(1)X-1 mutations. Unlike wild-type and Su(Ste)unspecified single mutant cells, the Y chromosome does not always move to the opposite pole from a pair of nondisjoined second chromosomes in Su(Ste)unspecified/Df(1)X-1 males.