Lethal effects of low and "null" activity alleles of 6-phosphogluconate dehydrogenase in Drosophila melanogaster

EMS-induced "null" and low activity alleles for 6-phosphogluconate dehydrogenase were characterized with respect to enzymatic activity, relative viability, fertility, and the effective lethal phase. It was determined that flies hemizygous and homozygous for the low activity allele, Pgd minus, possessed a depressed development rate, diminished viability, and loss of female female fertility. Heterozygotes for Pgd minus and a deficiency for Pgd+ were lethal. The "null" activity allele demonstrated a lethal phenotype in both the hemizygous and homozygous condition. The effective lethal phase for the "null" allele occurs during late embryonic development (20-22 hr).