Fig. 4: Development of maternal Piwil3^−/− embryos is delayed.

a The composition of small RNA categories according to their length distribution during oocyte and embryo development in WT or Piwil3^−/− golden hamsters. Early-stage oocytes were collected from ovaries, and MII oocytes were collected by spontaneous ovulation. The embryos were collected from the oviducts of WT and Piwil3^−/− female hamsters mated with WT male hamsters. The small RNA counts were normalized to the exogenous spike-in. b Line charts showing the expression pattern of piRNAs in Piwil3^−/− embryos compared to WT. Data in (a–b) are the average values of the biological replicates at each time point: n = 3 (GV), n = 4 (MII), n = 5 (11 h.p.e.a.), n = 4 (34 h.p.e.a.), or n = 2 (54 h.p.e.a.) for WT; n = 3 (GV), n = 4 (MII), n = 5 (11 h.p.e.a.), n = 3 (34 h.p.e.a.), or n = 2 (54 h.p.e.a.) for Piwil3 mutants. Piwil3^−/−, Piwil3^−/− oocytes or maternal Piwil3^−/− embryos. c Representative images showing the delayed development of maternal Piwil3^−/− embryos at 18 h.p.e.a. Scale bar, 100 µm. d Histogram showing embryogenesis ratio of WT and maternal Piwil3^−/− embryos 18 h.p.e.a. PN0, shortly after the fertilization but before entering the pronuclear stage. Source data are provided as a Source Data file.