Figure 4. Evidence that N/C ratio is developmentally regulated in mouse.

(A) Analysis of nucleus size in binucleated embryos. Experimental plan is shown to the left, and an example of a binucleated embryo in the centre panel. Data to the right compares nucleus size in binucleated embryos with normal 4-cell controls. 40 control and binucleated embryos each were examined over 2 days. (B) Analysis of nucleus size in ‘double-sized’ blastomeres. Note that the resulting 8-cell-stage nuclei in ’double sized’ blastomeres (n = 42) have nuclei the same size as control 8-cell embryos (n = 56), which are substantially smaller than control 4-cell embryos (n = 40). Data collected over 3 replicates. Different letters indicate P < 0.01 ANOVA (actual values stated in the main text).