fsd^KG02393 homozygotes are viable, but exhibit a temperature-dependent hatching defect. Although the hatching rates of embryos from wild-type and fsd^KG02393 flies are comparable at 25[o]C, embryos from mutant flies exhibit a significantly reduced hatching rate at 18[o]C. At 29[o]C, embryos from fsd^KG02393 females exhibit a hatching rate of 0%. These embryos exhibit variable A-P patterning defects including missing/fused denticle bands. This hatching defect at 29[o]C is strictly associated with the maternal mutant genotype and, furthermore, mutant flies at non-optimal temperatures (18[o]C) do not exhibit a significant reduction in survival rates from larvae to pupae or from pupae to adults.

At 25[o]C, fsd^KG02393 embryos exhibit a posterior shift of the cephalic furrow position compared to wild-type.