Single base change that disrupts the open reading frame and generates a predicted protein lacking the DNA binding domain.
Homozygous embryos have half the number of normal body segments and each is roughly twice the normal width. At embryonic stage 16 none of the three midgut constrictions have formed. At early stages of development interruptions in the visceral mesoderm are observed at many positions along the anterior-posterior axis, as development proceeds interruptions are less frequent. One interruption, coincident with the Antp expression domain, invariably persists.
Pair rule phenotype. Only half the number of denticle belts are present as a result of the deletion of alternate segments.