Fig. 3: Size regulation of diploid–aneuploid epiblasts during peri-implantation development.

Embryos were treated with reversine (or DMSO) at the four- to eight-cell stage transition. a Eight-cell diploid–aneuploid and diploid–diploid chimeras were generated at the eight-cell stage. Immunosurgery was performed at the late blastocyst stage to isolate the ICM from the TE. The ICMs were embedded in Matrigel and cultured in IVC medium for 72 h. n = 19 diploid–aneuploid; n = 1900 EPI cells and n = 21 diploid–diploid chimeras; n = 2636 EPI cells. Student’s t test. b Sixteen-cell diploid–aneuploid and diploid–diploid chimeras were generated at the eight-cell stage. Immunosurgery was performed on the double size chimeras and ICMs were cultured in IVC medium for 72 h as above. Diploid–diploid n = 26 chimeras; n = 1772 EPI cells and diploid–aneuploid n = 30 chimeras; n = 1961 EPI cells. Mann–Whitney test. c Eight-cell diploid–aneuploid and diploid–diploid chimeras were transferred to pseudo-pregnant mothers and recovered 12 h after implantation and then in vitro cultured for 36 h. n = 4 diploid–aneuploid; n = 604 EPI cells and n = 6 diploid–diploid chimeras; n = 737 EPI cells. Mann–Whitney test. For graphs a–c, relative number of cells in the EPI were analysed for both types of chimeras (relative to the average of diploid–diploid chimeras) at the end of the peri-implantation culture to investigate the level of size regulation of diploid–aneuploids with respect to diploid–diploids. ns = not significantly different. d Eight-cell diploid (red)–aneuploid and diploid (red)–diploid chimeras were generated. Immunosurgery was performed and ICMs were cultured as above for 48 h. The percentage of the number of pH3-positive red fluorescent EPI cells of the total red fluorescent EPI cells was analysed for each chimera, for both diploid–diploid and diploid–aneuploid ICMs. n = 21 diploid–aneuploid; n = 546 red EPI cells and n = 13 diploid–diploid chimeras; n = 217 red EPI cells. Scale bars, 20 μm. Squares indicate magnified regions. Scale bars, 10 μm. Student’s t test and **p = 0.0084. For all the graphs, all data are mean ± s.e.m. Source data are provided as a Source Data file.