Fig. 4
(A-D) At 15 minutes post fertilization, Coomassie Blue staining shows a single hole, the micropyle, in the chorion above the animal pole of wild type eggs (A, n = 92), but not in taz-/- eggs (B, n = 131). Upon activation, a cytoplasmic extension towards the micropyle is observed in wild type eggs (C, n = 162). By contrast, no cytoplasmic projection is observed in taz-/- eggs (D, n = 142). Insets in A and C are magnified images of the area within the pink circle. (E-F’) Two DAPI-stained pronuclei and one Actin-rich polar body are observed in a fertilized wild type eggs at 10 minutes post fertilization (E, E’, n = 61/63), whereas activated taz-/- eggs show one pronucleus and one polar body (F, F’, n = 47/47), suggesting that taz-/- egg is not fertilized, and the second polar body is extruded. White boxes in E to F denote regions magnified in E’ to F’. Red arrow, polar body; light blue arrow, pronucleus; AP, animal pole; VP, vegetal pole. Scale bar, 0.5 mm in A-B, 0.25 mm in C-D, 50 μm in insets in A and C, 100 μm in E-F and 20 μm in E’-F’.