Fig. 2: Telomeric PMsat acts as the primary cohesion site in oocytes.

a P. maniculatus mitotic cells (ovarian granulosa cells) and meiosis II oocytes expressing dCas9-mCherry with gRNA targeting PMsat were fixed and stained for HEC1. For the mitotic cells, PMsat was labeled by Oligopaint. Line scans of the signal intensities of HEC1 and PMsat across the PMsat loci were performed; n = 13 and 46 cells from three and 11 independent experiments were analyzed for mitosis and meiosis II, respectively; lines represent the mean intensities; error bars, SD. b Chromosome spreads using P. maniculatus meiosis I oocytes expressing dCas9-EGFP and meiosis II oocytes expressing dCas9-mCherry together with gRNA targeting PMsat were stained with HEC1 and REC8; n = 14 and 9 cells from three independent experiments were analyzed for meiosis I and II, respectively. Additional examples of REC8 staining in Supplementary Fig. 5b. c P. maniculatus meiosis I oocytes microinjected with mCherry-Trim21 mRNA together with either control IgG antibody or anti-REC8 antibody were matured to meiosis II and fixed and stained for MCAK (a PMsat marker, see Fig. 4c) and HEC1. Chromosomes with a single kinetochore (HEC1) were scored as single chromatids, and the proportion of chromosomes exhibiting sister chromatid separation was quantified; each dot represents an individual experiment; n = 23 and 15 cells from three independent experiments for the IgG and REC8 antibody, respectively; red line, mean. The images are maximum projections showing all the chromosomes (left) and optical sections to show individual chromosomes (right); asterisks denote the chromosomal location of internal PMsat (orange) and telomeric PMsat (yellow) on dual PMsat chromosomes, scale bars, 5 µm. Source data are provided as a Source Data file.