Further characterization of female sterile (1) 1304 mutant of Drosophila melanogaster

The Drosophila melanogastor mutant fs(1) 1304 (1‐19 ± 2) has been characterized using various experimental approaches. The mutant ap4 (2‐55.2), used as a control in some of the experiments reported in this paper, has also been examined more carefully. Electrophoresis of ovarian extracts from the mutants on polyacrylamide gels yield results suggesting that vitellogenesis is completely inhibited in ap4/ap4 females, while it proceeds at an abnormally slow rate in fs/fs females. Both mutants accumulate hemolymph proteins in amounts in excess of those found in the hemolymph of wild type females, suggesting that uptake of proteins from the hemolymph is affected by both the mutant genes. Qualitative differences in the banding patterns obtained from the hemolymph of wild type and ap4 female suggest that homozygous ap4 females may also be defective in the synthesis or processing of yolk proteins. Three of the protein bands observed in our electropherograms are suspected to represent yolk proteins, and an additional band is thought to represent an aggregate of the three yolk proteins. Neither juvenile hormone nor ecdysone treatment enhance vitellogenesis in fs(1)1304, although ap4 females produce yolky oocytes after JH treatment, in agreement with previously reported results. Ovarian transplantation studies suggest that fs(1)1304 behaves autonomously. Previous studies have shown that ap4 females behave non‐autonomously.