Figure 3.

Phenotypic rescue of the chorion gene amplification defect in k43^fs293. Chorion gene amplification was quantitated by isolating DNA from stage 13 egg chambers, and transferring equal portions to identical slot blots. One membrane was hybridized with an rDNA probe, as indicated, which serves as a nonamplifying control for DNA concentration. The second membrane was hybridized with a chorion probe fragment from the third chromosome chorion gene locus, as indicated. (A) Mutant: y ac w; k43^fs293. (B) Mutant + rescue: the transgenic 7.5-kb HpaI to XbaI rescue fragment in the k43^fs293 background, y ac w; p[yellow+; HX7.5]/+; k43^fs293. (C) Control: flies heterozygous for the recessive k43^fs293 mutation, y ac w; k43^fs293/+. (D) Male DNA: DNA isolated from adult male Drosophila as a nonamplifying control. Amplification was quantitated in this and additional experiments. Amplification in the mutant (A) was ≤7% of control. Amplification in the rescue strain (B) was equal to control.