An Hsp70 promoter drives expression of the Dmau\mariner\T coding region containing a M1K amino acid substitution (caused by two successive nucleotide substitutions, T173A and G174A).
Heteroallelic combination with Dmau\mariner\Ths.PL causes a lower excision rate than with Dmau\mariner\Ths.PL alone, regulation by dominant negative complementation (DNC).
In the absence of heat shock P{M1K} mutant Dmau\mariner\T reduces the amount of w::Dmau\wpch.tGa mosaicism.
Assayed in D.melanogaster.