An investigation into the metamorphosis of the mutant lethal-translucida of drosophila melanogaster

Summary Development of lethal translucida pupae is under normal conditions predominantly blocked in the early pupal stages. Imaginal differentiation, though almost exclusively restricted to the head and thorax, is exhibited in only 20–30% of the individuals.When ltr pupae are subjected to pure oxygen both the frequency and the intensity of imaginal differentiation is strongly increased. Then 60–70% of the pupae shows metamorphosis of the head and thorax, whereas abdominal differentiations could be observed in about 20%.The minimal time during which the pupae must be kept in oxygen, to give a maximum percentage of metamorphosing individuals in air, is 100–120 hours for differentiations of the head and thorax and about 140 hours for those of the abdomen.These experimental results suggest that part of the incomplete metamorphosis in homozygous ltr pupae is due to an insufficient supply of oxygen.The differentiation of normal eye implants within non-metamorphosed ltr pupae showed that the reaction capacity of the imaginal tissues in the ltr/ltr genotype is also significantly weakened.In the discussion of the results, our data have been related to those of Chen on lowered oxygen consumption in ltr pupae. It seems probable that in those ltr pupae showing metamorphosis of the head and thorax, a better oxygen supply existed already from the time of puparium formation.With 6 text-figures.This work was started in 1949 in the Institute of Zoology and Comparative Anatomy of the University of Zurich.