The interkinetic envelope contains INM but lacks ONM proteins. (A) Left: Schematics of INM and ONM protein theoretical localization at the nuclear envelope. Right: Representative images of an ROI centered around chromosomes from oocytes expressing mCherry::H2B and either GFP::EMR-1^Emerin (n = 6), GFP::BAF-1^BAF (n = 20), GFP::LMN-1^LaminB1 (n = 7), SUN-1^SUN1::GFP (n = 17), GFP::ZYG-12 (n = 14), or GFP::SPCS-1^SP12 (n = 18) during interkinesis and interphase. Timings indicated at the bottom left corner of images are from anaphase I onset. Scale bar, 5 μm. (B) Representative time-lapse images centered on chromosomes of oocytes expressing mCherry::H2B (magenta) and GFP::SERP-1.1^RAMP4 (green) (n = 6) during meiosis I and II. Timings indicated at the bottom left corners of images are from anaphase I onset. Scale bar, 5 μm. (C) Representative images of oocytes expressing mCherry::H2B (magenta) and either GFP::ZYG-12, GFP::SPCS-1^SP12 or GFP::SERP-1.1^RAMP4 (green) during interkinesis, with a magnification of the ROI (white dashed box) displayed on the left. (D) Left: Three-dimensional reconstructions centered on chromosomes of a mid-anaphase I (top) and a late interkinesis (bottom) oocyte acquired by SBF-SEM. Chromosomes in magenta, membranes in contact with chromosomes in green, plasma membrane in gray, eggshell in gold, and endoplasmic reticulum in blue. Right: Magnifications of an ROI viewed from two different angles to show the lack of continuity between the interkinetic envelope and the ER. Scale bars, 1 μm for the full view and 0.5 μm for the ROI.