Mobilisation of the progenitor insertion. 59bp of 5' P{EP} sequence are present at the transcriptional start site, along with a 4bp duplication of coding sequences. The mutation results in a frameshift.
Mt299 mutant flies exhibit melanotic spots when kept under crowded growth conditions.
Homozygous flies have no gross abnormalities.
Mt2149 does not dominantly suppress variegation of the w gene caused by In(1)wm4 or P{RS3}panCB-5204-3.
Mt2149 dominantly suppresses variegation of the w gene caused by P{RS5}5-HA-1902, P{RS5}5-HA-1992, P{RS5}5-HA-1925 and T(2;3)V21-P{lacW}92E.x3.