DNA replication is delayed in Vas-SCF zygotes.

<p>(A) Three different patterns of EdU staining in Vas-SCF zygotes during S-phase. Each set of four images represents the same zygote at different focal planes to view the paternal (right) and maternal (left) pronuclei. (Aa-d) In most cases during early S-phase, EdU staining was only visible in the maternal pronucleus. (Ae-h) EdU staining was much more intense in the maternal pronucleus, but was it was also visible in the paternal. (Ai-l) Edu staining was visible at equal intensity in both pronuclei. All images are shown at the same magnification, bar = 20 µm. (B) Zygotes with any EdU staining in the paternal pronucleus, whether it was much less or equal to that of the maternal pronucleus, were scored as positive. (C) Only zygotes that had paternal pronuclei with EdU staining intensities equal to that of the maternal pronuclei in the same zygote were scored only as positive. Error bars represent standard deviations, and points on the graphs for which the error bars are not visible had standard deviation values below the size that is covered by the point drawn to indicate the value. For at 50 Vas-SCF zygotes were scored for each time point, and 30 Vas-Ctrl zygotes were scored. In all zygotes at 8 hrs and beyond, maternal pronuclei had strong EdU staining. All images are shown at the same magnification, bar = 20 µm.