Fig. 1.

Pharmacological inhibition of p110β leads to a decrease in self-renewal of murine ESCs. (A) Murine ESCs (mESCs), cultured in the presence of LIF and serum, were treated for 4 days with LY294002 or TGX-221 at the doses shown or with vehicle alone (DMSO). Self-renewal was assessed by staining for alkaline-phosphatase activity and representative colonies are shown. Scale bars: 100 μm. (B) The average percentage of alkaline-phosphatase-positive, self-renewing colonies in each condition are shown with s.e.m. (n=4). ANOVA and Dunnett's post-hoc test were applied; ^***P<0.001. (C) Cells were treated with TGX-221 for 30 minutes prior to stimulation with 10³ U/ml LIF for 10 minutes. Cell lysates were resolved by SDS-PAGE and immunoblotting carried out using the antibodies indicated to detect PI3K downstream signalling. (D) Cells were cultured for 4 days in the presence or absence of LIF or in the presence of LIF and 100 nM TGX-221 and immunoblotting carried out as above.