Dll1^{tm1.1(cre/ERT2)Cle}

Homologous recombination was employed to insert an EGFP-IRES-cre/ERT2 cassette, Frt-flanked neo selection cassette and polyA signal into the ATG codon of exon 1 of Dll1 in ES cells. The neo marker was deleted in vivo by flippase (Flp) expression. GFP expression can be detected by confocal analysis in some mesenchymal cells and blood vessels, and in intestinal epithelial cells at the bottom and higher up in crypts. (J:193937)