Fig. 2. Defective ovulation in par-3(RNAi) worms. Images from time-lapse Nomarski video microscopic observations of meiotic maturation and ovulation in the wild type (left) and a first ovulation in par-3(RNAi) (right). Real time (minutes:seconds) is indicated in the top left corner, with the zero time point corresponding to the time that nuclear envelope break down (NEBD) was observed (black arrows). An oocyte (o), the oocyte nuclear envelope (ne), the sheath (sh) and the spermatheca (sp) are indicated. The oocyte enters the spermatheca in the wild type at 0:45 and is transferred to the uterus at 1:10. However, in par-3(RNAi) worms, the oocyte remains in the proximal gonad even 4:28 after the NEBD. The contraction of sheath cells and distal extension of the spermatheca was observed in both worms (arrowheads). Scale bar: 10 µm.