Figure 3. PEZO-1 mutants exhibit severe ovulation defects.

(A–E) Ovulation in wildtype animals. (A, B) Ovulation is initiated by oocyte (yellow dotted circle) entry into the spermatheca, which was labelled by the apical junctional marker DLG-1::GFP (green). (C) Fertilization occurs in the occupied spermatheca (yellow dotted circle). (D, E) After fertilization, the sp-ut valve (red arrows) opened immediately to allow the newly fertilized zygote (yellow dotted circle) to exit the spermatheca and enter the uterus. (A′–E′) Abnormal ovulation was observed in pezo-1 CΔ animals. Control of the spermathecal valves was aberrant (C′–E′) during ovulation and the DLG-1::GFP labelled sp-ut valve (red arrow) never fully opened; the oocyte was crushed as it was expelled (E′). (F–M) Two examples of ovulation defects observed in the pezo-1 C∆ mutants. (F–I) The ovulating oocyte (white dotted circle) was pinched off by the spermathecal distal valve (red arrows in panel [H]). This oocyte never exited into the uterus. (J–M) pezo-1 CΔ oocytes frequently failed to enter the spermatheca and were retained in the oviduct (M). The black arrow above panel (A) shows the direction of embryo travel through the spermatheca from left to right. All four image time series follow this same left to right orientation. The timing of each step is labeled on the bottom right in minutes and seconds. Scale bars are shown in each panel.