Control of oocyte production, development, and release inDrosophila melanogaster

Abstract

Sterility in the Hairy-wing 49c mutant ofDrosophila melanogaster is due to the failure of mature oocytes to pass from the oviduct into the uterus.Patterns of oocyte accumulation in the ovaries, oviducts and uterus of mutant and wild-type flies indicate that ovulation is initiated first by mating and thereafter by the absence of an oocyte in the uterus. While oocyte production is also stimulated by mating, it is maintained by a low number of oocytes in the ovary.Mating also appears to initiate events which cause mature oocytes to deteriorate if they are not soon oviposited.

Sperm-Storage Defects and Live Birth in Drosophila Females Lacking Spermathecal Secretory Cells

“…This result implies a defect in ejecting eggs from the uterus (oviposition) rather than egg production and release (ovulation). However, those females with stuck eggs did not appear to have a “log jam” of eggs in the oviduct, suggesting either: (1) that inability to eject a fertilized egg signals back to the ovary to halt or slow ovulation [39] , [40] ; or (2) that ovulation is independently slowed by SSC loss.…”

Male contributions to egg production: the role of accessory gland products and sperm inDrosophila melanogaster

“…The oocyte-accumulation pattern is de¢ned by the number and type of vitellogenic oocytes present in the ovary. Vitellogenic oocytes were classi¢ed into three categories (Holzworth et al 1974): (i) stages 8^9, when yolk comprises one-third or less of the oocyte; (ii) stages 10A^12, in which yolk comprises one-half or more of the oocyte; and (iii) stages 13^14, in which dorsal appendages are present. Since no signi¢cant di¡erence in the distribution of oocyte stages between the left and the right ovaries was found (data not shown), data from the left and right ovaries were pooled and analysed as number of oocytes per female.…”

“…In contrast, females during maximum fecundity show a constant distribution of oogenic stages, suggesting that oocytes are produced as fast as mature oocytes leave the ovariole (King & Sang 1959). Though egg deposition a¡ects the production of additional oocytes, mating can stimulate oogenesis in the absence of egg deposition (Holzworth et al 1974).…”