aub^ΔP-3a/+ abolishes repression of P-element excision by the P cytotype. This disruption appears to involve a maternal effect, as cytotype-mediated repression of P-element excisions does not occur in offspring whose mothers were heterozygous for aub^ΔP-3a, even when the offspring do not inherit the aub^ΔP-3a mutation themselves. Paternally inherited aub^ΔP-3a has no effect on th cytotype system of P-element repression. The aub^ΔP-3a mutation only impairs cytotype regulation in the short term as once the mutation has been removed from a line, P-cytotype is quickly reestablished.