The transgene was generated by a bacterial recombineering technique to insert a cre/ERT2 expression cassette containing the polyadenylation site (polyA) from the SV40 early region into the exon 1 of the mouse Zic2 gene of a BAC clone RP23-158G6 (CHORI). Two transgenic founder lines were selected and established. Line 1463 shows broader cre activity in the spinal cord with some reporter staining seen in the dorsal root ganglion.