Mutant embryos do not hatch at all at 23[o]C and higher temperatures, but show a normal hatch rate of approximately 90% at lower temperatures. Mutant larvae shifted to the restrictive temperature of 29[o]C fail to pupate, become necrotic and die. Mutant pupae shifted to 29[o]C fail to eclose. Mutant male adults are viable at 21[o]C, but die after approximately 3 days at 29[o]C. Mutant adult females survive for a week at 29[o]C, but lay fewer and fewer small eggs that do not develop or hatch. Many egg chambers from mutant females shifted to 29[o]C for 3 days show a severe defect in oogenesis after stage 7, when the egg chambers appear to undergo apoptosis.

Nuclear ultrastructure is normal in mutant embryos after 30 minutes at the restrictive temperature of 33[o]C.