Extended Data Fig. 4. Serine synthesis promotes differentiation.

a, Western blot of Phgdh knockdown in WT EpdSCs. shPhgdh2.1 and shPhgdh2.2 represent independent transductions with same shRNA and in subsequent experiments, shPhgdh2.2 is referred to as shPhgdh2. Experiment was performed twice with similar results. shRNA sequences can be found in Supplementary Table 5. b, 48 hour population doublings of shPhgdh WT cells (n=3 biologically independent samples). Data are mean ±SEM. c, Intracellular serine pools upon Ser/Gly starvation (n=3 biologically independent samples). Data are mean ±SEM. d, Involucrin immunofluorescence in shPhgdh lines cultured with DMSO or DM-αKG following 24 hours of Ser/Gly starvation (n=3 independent experiments). Data are mean ±SEM. e-f, Representative immunofluorescence (e) and quantification (f) of Involucrin in indicated conditions (n=3 independent experiments). Data are mean ±SEM. Statistical significance was determined using a two-way ANOVA with Sidak’s multiple comparison test in panels b and f, Tukey’s multiple comparison test in panel d, and an ordinary one-way ANOVA with Dunnett’s multiple comparison test in panel c. Scanned images of unprocessed blots are shown in Source Data Extended Fig. 4. Numerical data are provided in Statistics Source Data Extended Fig. 4.