PUF-11::GFP and PUF-3::GFP are degraded during the OET. (a–f) PUF-11::GFP (a), PUF-3::GFP (d and g), and mSCARLET::LIN-41 (b and e) fluorescence in C. elegans germlines (solid outlines) and early embryos (dashed outlines). The arrow in (a) and (d) indicates the distal mitotic region of each germline. Merged images of (a) and (b) and (d) and (e) are shown in (c) and (f), respectively. (g–j) Images of itIs37[pie-1p::mcherry::histoneH2B::pie-1 3′UTR, unc-119(+)] puf-3(tn1820[puf-3::gfp::3xflag]) oocytes and embryos reveal that PUF-3::GFP (g) is strongly reduced in a meiosis I stage embryo (MI) relative to the −1 oocyte. Chromosomes are marked with mCHERRY: HISTONE (h), and the oocyte-derived chromosomes in this MI embryo appear to be aligning on the metaphase plate. PUF-3::GFP is at background levels in the adjacent postmeiotic 1-cell embryo (pn); this embryo has 2 polar bodies and maternal and paternal pronuclei at opposite ends of the embryo. Merged and DIC images of the same oocytes and embryos are shown in (i) and (j), respectively. The fluorescent images in this series (g–i) are 3D projections of a Z-stack. The DIC image (j) shows a single focal plane. Embryos with slightly higher levels of GFP and mSCARLET relative to older embryos are outlined in green and magenta, respectively (d, e, and g–j). Scale bars: 100 µm (a–f) and 50 µm (g–j). (k) PUF-3::GFP levels decrease after meiotic resumption. Mean GFP fluorescence was measured in images of itIs37[pie-1p::mcherry::histoneH2B::pie-1 3′UTR] puf-3(tn1820) oocytes and embryos and background corrected. Fluorescence intensity is expressed relative to the amount of GFP fluorescence in the oldest oocyte with an intact nucleus; this is the −2 oocyte if the −1 oocyte has initiated nuclear envelope breakdown (NEBD) or is starting to move into the spermatheca (early ovulation stage). Embryonic meiotic stage (e.g. metaphase I, telophase I, and metaphase II) was classified based on the arrangement and organization of maternal chromosomes.