Fig. 1: F-actin localizes to pMTOCs in mouse oocytes.

A Time-lapse live confocal microscopy of pMTOCs (Cep192-eGfp, pseudo-magenta) and F-actin (SiR-actin, gray) in prometaphase I mouse oocytes. Fluorescence images were taken every 3 sec. Yellow arrows represent F-actin fibers connecting pMTOCs. Scale bar represents 5 μm (1.5 μm in zoomed images). Time points represent the timing from the start of confocal imaging. B Representative Super-resolution Stimulated Emission Depletion (STED) image of F-actin enrichment at pMTOCs in a metaphase I oocyte. The oocyte was labeled with phalloidin (F-actin, gray), α-tubulin antibody (green) and pricentrin antibody (magenta). DNA was stained with Hoechst (blue). Scale bar represents 10 μm. The right panels show a 3D reconstruction for a pMTOC-associated F-actin. C Quantification of F-actin enrichment at pMTOCs. D Time-lapse live confocal microscopy of an oocyte expressing Cep192-eGfp (pMTOCs, pseudo-green) and stained with SiR-actin (F-actin, gray). Time points represent the timing from NEBD. Yellow arrows represent F-actin enrichment at pMTOCs. The total number of examined oocytes from 3 independent replicates is 24 oocytes. E Schematic diagram depicting the recruitment of F-actin to pMTOCs and the spindle, forming spindle-localized F-actin. Data are represented as means ± SEM. Asterisks represent significant differences, **** p < 0.0001. The total number of analyzed oocytes per each experimental group (from 3 independent replicates) is specified above each graph.