This transgene contains a 4 kb XhoI/NheI fragment from the upstream promoter region of Fgf15 and a proximal Fgf15 promoter fragment, extending from nucleotide (nt) -520 to nt -80 (counting the first base of the protein coding sequence as nt +1), driving expression of Cre recombinase specifically in pharyngeal ectoderm and endoderm. (J:102843)