Figure 2. BOULE upregulated 3′-UTR of CDC25A in hESCs.

(a) Immunofluorescent staining of BOULE, VASA and DAPI (nuclei) in 12, 16 and 20 W human fetal ovaries. Bar, 10 μm. (b) Distribution and location of BOULE-positive cells in cortex of human fetal ovaries. Percentages of BOULE-positive and VASA-positive cells in the 12, 16 and 20 W human fetal ovaries were counted as described in Supplementary Fig. 3. Areas of ovarian cortex were divided into outer (OUT), middle (MID) and inner (IN) sections. n=4 different fields were counted in each section as shown in Supplementary Fig. 3. Each area contained 50–117 VASA-positive germ cells. (c) 3′-UTR Luciferase reporter assays of CDC25A or CDC25B in 293FT or H9 hESCs. Cells were transfected with empty vectors (NC) or BOULE-overexpressing vectors (oeBOULE). n=3 (biological replicates from ∼25,000 cells), three independent experiments conducted, error bar is s.d., asterisks indicate statistical significance (P<0.05, Student's t-test) between the two samples. (d) FACS analysis of CDC25A promoter-eGFP-3′-UTR reporter assays in hESCs. CDC25A reporter was integrated into hESCs followed by transduction of empty vector (Ctrl vector) or BOULE-overexpressing vector(oeBOULE), representative FACS results were shown, 50,000 cells of control cells without reporter (left plot) and 100,000 cells of cells carrying CDC25A 3′-UTR reporter (middle and right plots) were analysed. Three independent experiments were conducted.