The temporal stability of the Drosophila oocyte.

Individual female Drosophila melanogaster were maintained without yeast for up to 18 days. Some of the females did not lay any eggs during this holding period. The females produce mature oocytes (stage 14) by day 3 and from day 5 onward the females each held about 60 mature oocytes. The nulliparous females were mated and its was shown that the first egg produced by females held up to 18 days before mating could be viable and develop into a normal, fertile adult. On day 2 each female contained about 500 oocytes in post-oogonial stages of oogenesis. The first 500 fertilized eggs were collected from females that had been held nulliparous for 7-10 days before mating. No period of significantly reduced viability was found. It is concluded that the developmental program of Drosophila eggs can be interrupted between oogenesis and fertilization for at least 15 days without loss of the ability to produce normal, fertile adult progeny.