Deficiency heterozygotes eclose only rarely (<5%). In addition to 100% penetrant defects in leg, wing and thorax, rough patches in the eye appear at low frequency. Anterior crossvein is displaced posteriorly. Imaginal discs of dsM213/dsM213 or dsM213/ds33k are within the size range of normal discs, showing no tendency to overgrowth.
Strong allele.