Mutant larvae show an extreme delay in growth and die before attaining wild-type size. At 25oC, the L1 stage lasts 2 days (instead of 1 day in wild-type animals), the L2 stage lasts at least 6 days (instead of 1 day in wild-type animals) and the L3 stage lasts at least 7 days (instead of 2 days in wild-type animals). Small adults occasionally eclose about 10 days later than wild-type flies, but they do not survive. Mutant larvae appear to have numerous mitochondria in the anterior midgut cells, but these mitochondria appear to be respiration-defective (as assayed by dye labelling). Gut pH is normal in mutant larvae. The mutant larvae are not deficient in the digestion of yeast cells and can absorb nutrients through their gut.
Larval growth reduced. 100% survive until 8 days after hatching. 50% survive until 11 days after hatching. 8% survive until 13 days after hatching. DNA replication continues. Mutant phenotype is not cell autonomous. Flies that escape lethality are small. In mutant larval brains, cell proliferation is impaired as compared to other tissues and compared to wild type. Mutant clones induced at 24, 36 and 42 hours after hatching grew to a size similar to wild type. No defects are observed in mosaic adults. Mutant clones in the eye survive well, suggesting non-autonomy of mutant phenotype.