Figure 4.

Geminin Antagonizes Brg1 to Inhibit Repression of Oct4, Sox2, and Nanog in B6/Blu-1 ES Cells

(A) Codepletion of geminin and Brg1 abolishes the upregulation of trophectoderm markers (in green) observed in geminin-depleted ES cells, but not nuclear enlargement (total DNA, red). Geminin and Brg1 codepletion also blocks the loss of Oct4, Sox2, and Nanog (in white) seen in geminin-depleted ES cells. Scale bars represent 20 μm.

(B) Bar chart shows that codepletion of geminin and Brg1 rescues the loss of Oct4, Sox2, and Nanog induced by depletion of geminin alone, particularly in enlarged nuclei.

(C) Codepletion of geminin and Brg1 rescues loss of Sox2 and Nanog in geminin-depleted ES cells. Error bars indicate standard error of the mean using four housekeeping genes for normalization.

(D) Model of how geminin maintains genomic stability and the pluripotent state in ES cells. Suppressed APC/C^Cdh1 activity, possibly mediated by Emi1, stabilizes geminin in ES cells to prevent overreplication of DNA and inhibit repression of the core pluripotency factors Oct4, Sox2, and Nanog by antagonizing the chromatin-remodeling protein Brg1.

For additional related data, see Figure S4.