Reduced penetrance of head defect phenotype when in trans with Abd-Biab9-tuh-3.
A5-A8 are transformed to A4, females lack genitalia, and there is a weak haploinsufficient transformation of A5-A8. Parasegments 10-13 are transformed to parasegment 9 in embryos.
Heterozygous males have a 7th tergite, there is loss of pigment in the anterior of the 5th tergite, and the 6th sternite has bristles.
Homozygous larvae exhibit transformation of the ventral setal belts of abdominal segments 5, 6, 7 and 8 to segment 3 or 4 identity.
Fails to complement iab-5 and iab-6 alleles.
m- r+ mutant, eliminating function of Abd-B function.