A comparison of protein synthesis in imaginal wing discs of wild-type and vestigial of Drosophila melanogaster

Abstract

In vitro incorporation of labelled amino acids into TCA insoluble protein in the imaginal wing discs of vg mutant and wild-type Drosophila melanogaster is compared and correlated with the extent of cellular degeneration during development. (1) With 96–100-hr-old larvae, wing discs isolated from vg mutant incorporate radiolabelled amino acids at a higher rate than wild-type discs, although cellular degeneration is more extensive in vg discs than wild-type discs. This may reflect the larger size of the vg discs since they have more protein than the wild-type discs. (2) The vg discs of 105–110-hr-old larvae have a lower rate of incorporation than the wild-type disc, although both types of discs have the same protein content. This may be due to the presence of more degenerating cells in the vg discs. (3) The rate of incorporation in vg discs of 115–118-hr-old larvae is lower than that of wild-type discs; the vg discs have less protein but more degenerative cells than the wild-type discs. The rates of protein degradation are similar in both discs. Electrophoretic comparison reveals a general reduction in protein synthesis in vg discs as compared with wild-type discs.