Polytene chromosomes normal.
Adults viable.
Homozygous female or hemizygous male flies often show a complete loss of the callus and bristles on the humerus. The prothoracic spiracle is unaffected. The second and third legs are often partially transformed towards the first leg. This transformation is restricted to the anterior compartment, and is particularly noticeable distally, where an extra sex comb appears. The first abdominal segment occasionally shows a partial transformation to a more posterior segment; dorsally, pigment and large bristles appear on the tergite, and ventrally, the sternite acquires bristles characteristic of the second or third abdominal segment. The fourth abdominal segment is often partially transformed to the fifth or sixth abdominal segment in males. Lethal over deficiencies that uncover the locus.
Abd-BUab-1, ph-d1 has lethal phenotype
Abd-BMcp-1, ph-d1 has abdominal segment 3 phenotype
The abdominal transformations are enhanced by Df(3R)P9, and suppressed by Dp(3;3)P5. The leg transformations are suppressed by Dp(3;3)D1, and enhanced by Df(3R)Scr. Dominant enhancer of Pc3. Interacts with esc20. Lethal in combination with Abd-BUab-1. The third abdominal segment is transformed towards segment five or six in males also carrying Abd-BMcp-1. Does not interact with AntpHu.
Gans and Komitopoulou.