Homozygotes usually have two indentations, symmetrically placed on both sides of the anterior edge of the thorax. The expression of indentations varies, sometimes they are unequal in the same fly. Wings are often raised. Heterozygotes usually have one large indentation in the anterior part of the thorax which is more extensive than each of the indentations in homozygotes, but less constant in location and expression.
In heterozygote, most flies show one or two indentations on thorax at front. Homozygote has two smaller, sharper dents. Wings often raised. RK3.
Belgovsky
