mgeA1/mgeB10, mgeA1/Df(3L)449 and mgeA1/Df(3L)GN19 animals proceed through embryogenesis and hatch on schedule. However, the larvae do not grow but remain as first instars for 5-9 days (the normal first instar period is 24 hours). No gross morphological defects are seen, but mutant larvae appear to move more slowly than wild type.
Homozygotes are embryonic lethal, presumably due to an unrelated second-site mutation on the chromosome.