No nucleotide change is detected in the protein coding sequence or the introns.
1% of embryos derived from homozygous females have a class I phenotype (they are strongly dorsalised, lacking both ventral denticles and filzkorper), 11% have a class II phenotype (they lack ventral denticles but have filzkorper), 58% have a class III phenotype (they have ventral denticles) and 30% have a class H phenotype (they are phenotypically normal and hatch). 85% of embryos derived from gdp18/Df(1)KA10 females have a class I phenotype, 9% have a class II phenotype and 6% have a class III phenotype.