Weak segmentation phenotype. The Malpighian tubule phenotype is variable in homozygous embryos. In most embryos there are short thickened buds rather than long tubules and there are often more than four buds. In about 30% of embryos the posterior tubules are elongated. The distribution of nuclei in the tubules in most cases is similar to the gut (no zigzag pattern), nests of nuclei are found in the region of origin of the tubules between the posterior midgut and hindgut. The ureter is almost completely deleted.

Weak allele. Segments T2, T3, A1, A2, A3 and sometimes A4 are deleted.