At 25oC, the survival rates of homozygotes are: adult survival - 3%, eclosion - 12%, pupation 27%. At 18oC, the survival rates of homozygotes are: adult survival - 6%, eclosion - 27%, pupation 59%. Ptp69D19 embryos show motor axon defects; 18% of ISNb axons, 7% of ISN axons, 10% of SNa axons and 3% of SNc axons show defects.