Distinct populations of embryonic epithelial progenitors generate Lgr5+ intestinal stem cells

To follow the changes in the transcriptional programs accompanying the specification of the embryonic Lgr5+ cells we sequenced whole transcriptomes of embryonic intestinal epithelium progenitors (at E13.5 and E15.5). EpCAM positive embryonic gut epithelium was isolated from dissected small intestines using fluorescence activated cell sorting (FACS). Lgr5+ progenitors were purified on the basis of GFP fluorescence from Lgr5GFP-Cre-ERT mice (Barker et al. 2007). Double positive embryonic progenitors were isolated by FACS based on GFP and tdTomato fluorescence. Intestinal epithelial cells from two embryonic stages (E13.5 and E15.5) were used. For embryonic stages biological triplicates were analysed.