P{I-element\gag.RZI} decreases the intensity of the female sterile phenotype that is normally seen in the female progeny of a cross of inducer (I) males with reactive (R) females. There is a correlation between the copy number of P{I-element\gag.RZI} and the decrease in the sterility level. In addition to this zygotic repressive effect, the P{I-element\gag.RZI} transgene also induces maternal and paternal repressive effects when introduced into flies. After introducing the transgene into reactive (R) females, then allowing maternal transmission of the transgenes over several generations, followed by crossing with inducer (I) males, transgenic females show a full reversion of the sterility phenotype as early as the first day of egg laying. This maternal effect is a quantitative effector that accumulates over generations. Zygotic and maternal effects increase with the number of P{I-element\gag.RZI} copies. P{I-element\gag.8S} shows a maternal repressive effect on the degree of female sterility seen as a result a cross of inducer (I) males with reactive (R) females. The maternal repressive effect increases with the copy number of the transgene. P{I-element\gag.8S} does not show a zygotic or paternal repressive effect on the degree of female sterility seen as a result a cross of inducer (I) males with reactive (R) females.