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.
Hybrid females carrying produnspecified and derived from a cross of D.melanogaster females to D.simulans males do not differ in viability from hybrid females carrying a wild-type D.melanogaster prod allele. The sex ratios of progeny from a cross of D.simulans Dsim\Lhrunspecified males to D.melanogaster prod+ or produnspecified/+ females are not significantly different from 0.5 or from each other.