Heteroallelic combination with Dmau\mariner\T^hs.PL causes a lower excision rate than with Dmau\mariner\T^hs.PL alone, regulation by dominant negative complementation (DNC).

In the absence of heat shock P{E297K} mutant Dmau\mariner\T reduces the amount of w::Dmau\w^pch.tGa mosaicism. P{E297K}/P{hsp70:Mos1} allows an increase in w::Dmau\w^pch.tGa mosaicism over the effect of P{E297K} alone but a reduction in mosaicism compared to a single copy of P{hsp70:Mos1} : negative complementation. In the absence of heat shock P{E297K} exhibits negative complementation when heterozygous with P{hsp70:Mos1} with respect to the extent of Dmau\mariner element excision from w::Dmau\w^pch.tGa in the germline.