Figure 4.

Eomes is dispensable for reprogramming of murine fibroblasts. (A) Schematic illustration of the Eomes alleles used in (D–G). MEFs carry one functional null allele with a GFP knock-in at the Eomes locus and a second conditional allele, where exons 2–5 are flanked by loxP sites. The tamoxifen (4-OHT)-inducible CreER-recombinase is expressed from the Rosa26 locus and used to induce the complete genetic deletion of Eomes by 4-OHT administration⁸. (B,C) 4-OHT treatment regimen used for timed Eomes ablation during reprogramming. Orange lines indicate tamoxifen treatment intervalls: A: d-3 to d-1 (48 h), B: d5–9 (96 h), C: d10-d14 (96 h). (D) Representative images of Alkaline phosphatase staining of iPSC colonies at different timepoints of 4-OHT treatment as indicated. (E,F) FACS-based quantification of (E) Ssea1 and (F) Oct3/4 positive cells at day 20 of reprogramming following with and without 4-OHT administration. Scale bars in all images: 50 µm. Representative experiments from n = 3 in triplicates are shown.