Klf4 maintains epidermal stem cell proliferation by repression of p53 expression.
(A) BrdU and p63 labeling were performed on embryos injected with klf4 5mmMO2 (control) (a-e), combined klf4 MO1/klf4 MO2 (f), p53 MO (g), combined cdkn1a MO/ klf4 MO1/klf4 MO2 (h), combined p53 MO/klf4 MO1/klf4 MO2 (i), combined klf4-7mm mRNA/klf4 MO1/klf4 MO2 (j), or combined klf4ΔC-7mm mRNA/klf4 MO1/klf4 MO2 (k). Nuclei are counterstained with Hoechst 33342 (c). Both p63+ and p63+BrdU+ cell number were enumerated in the circled areas. Examples of p63 and BrdU colocalized cells (asterisk) are shown. The percentage of p63+BrdU+ cells in embryos after indicated treatments was quantified (l). (B) p53 expression in embryos injected with combined klf4 MO1/klf4 MO2, combined klf4-7mm mRNA/klf4 MO1/klf4 MO2, or combined klf4ΔC-7mm mRNA/klf4 MO1/klf4 MO2 was measured by RT-qPCR. (C) cdkn1a/p21 expression in embryos after indicated treatments was measured by RT-qPCR. Statistical significance was determined by Student’s t-test. *p < 0.05; **p < 0.01; ***p < 0.001. Scale bar, 50 μm. Error bars indicate standard error.