Extended Data Fig. 6: Nuclear enrichment of condensin II subunits in late prophase I.
From: Condensin dysfunction is a reproductive isolating barrier in mice
a, domesticus and hybrid oocytes were fixed at prophase I and stained for SMC2 and SMC4. The graph shows the quantification of SMC2 and SMC4 intensities in the nucleus; each dot in the graph represents a single oocyte (SMC2: n = 26 and 21 oocytes for domesticus and hybrid, respectively; SMC4: n = 24 and 27 oocytes for domesticus and hybrid, respectively). b, domesticus, hybrid and spretus oocytes were fixed at prophase I and stained for NCAPG2 (Bethyl A300-605A). The graph shows the quantification of NCAPG2 intensities in the nucleus, which shows a similar trend with Fig. 3a where a different NCAPG2 antibody (Bioss bs-7721R) was used; each dot in the graph represents a single oocyte (n = 27, 19 and 24 oocytes for domesticus, hybrid and spretus, respectively); unpaired t-test (two-sided) was used for statistical analysis; *P = 0.015. c, Western blot of NCAPG2 using thymus tissues and oocyte samples. As a loading control, stain-free gel image was shown to indicate the total protein amount loaded to each lane. Oocyte collection and western blot were repeated four times to quantify the total NCAPG2 protein level in each genotype. Total NCAPG2 protein levels were equivalent among domesticus, spretus and hybrid oocytes. For gel source data, see Supplementary Fig. 1. d, domesticus, musculus, spretus and spicilegus oocytes were fixed at prophase I and stained for NCAPG2. NCAPG2 intensities in the nucleus were quantified; each dot in the graph represents a single oocyte (n = 18, 24, 21 and 33 oocytes for domesticus, musculus, spretus and spicilegus, respectively); unpaired t-test (two-sided) was used for statistical analysis; ****P < 0.0001. Images are optical slices to show the nucleus. e, Chromosome spreads were performed at metaphase I using domesticus, spicilegus and domesticus × spicilegus hybrid oocytes expressing MajSat and counterstained with DAPI. Centromeric MajSat intensities were quantified in domesticus and spicilegus oocytes (n = 488 and 354 centromeres for domesticus and spicilegus, respectively); unpaired t-test (two-sided) was used for statistical analysis; ****P < 0.0001. Centromere MajSat signal ratios in domesticus × spicilegus hybrid oocytes were calculated as the domesticus centromere divided by the spicilegus centromere signal for each bivalent (n = 183 chromosomes); each dot in the graph represents a single bivalent chromosome. The quantification shows that spicilegus centromeres have less major satellites compared to domesticus ones, consistent with a previous study using dot-plot hybridization58. Images are maximum intensity z projections to show all chromosomes or optical slices to show individual chromosomes; red line, mean; scale bars: 5 µm.
