In the both the absence and presence of heat shock, flies carrying eIF-2αHD.hs develop more slowly than control siblings. The most pronounced delay in development occurs when heat shock is administered early in larval development. There is a strong maternal effect; a single heat shock administered to embryos, first, second or third instar larvae prolongs the development of animals carrying eIF-2αHD.hs by as much as an extra day when eIF-2αHD.hs is maternally inherited compared to when it is paternally inherited. Adult flies weigh significantly less than their control siblings. Development is arrested by repeated expression of eIF-2αHD.hs using heat shock for 2 hours every day during development. Most animals are arrested at the second larval instar stage, although a few animals survive to the third larval instar or pupal stage. No animals survive to adulthood.
