Figure 3.

Totipotent cells distribute in preimplantation embryos up to the four-cell stage. (a,b,d,e) 1CZ, 1C, 2CB, 4CB, or 8CB pseudoblastocysts at 96 hpi were transferred surgically to the uterine horns of pseudopregnant (a,b) or pregnant (d,e) ICR female mice (n = 5 each) at a ratio of 20 (a,d) or 30 (b,e) pseudoblastocysts per mouse. Pregnancy status was determined by C-section at E18.5 (a,b) or after vaginal delivery (d,e). The rate of viable pups (or birth) was determined as the proportion of transferred pseudoblastocysts that gave rise to viable pups (left panels), and the difference in the rates of viable pups among the different types of embryo and its simultaneous 95% CI (a,d) or 95% CI (b,e) are shown in the right panels. The P values in (a) and (d) were determined with the two-sided Fisher’s exact test followed by adjustment with the BH method (FDR = 0.05), and those in (b) and (e) were determined with the two-sided Fisher’s exact test. *P < 0.01, **P < 0.001. n indicates the number of pseudoblastocysts transferred. Embryo transfer was performed on at least three different days for each blastomere stage. (c) Representative images of embryos, their placentas, and debris of absorbed embryos from a single litter derived from 1C or 4CB pseudoblastocysts at E18.5. (f) Representative images of neonatal mice (upper panel) and weaned mice (lower panel) derived from 4CB embryos. (g) Rate of 3-week-old weaned pups in (d) and (e). The P value was determined with the two-sided Fisher’s exact test. n indicates the number of neonatal mice.