Phox2b^{tm1(Phox2a)Mist}

Targeting took place in PC3 ES cells homozygous for Tg(Prm-cre)70Og, a cre transgene that expresseses Cre recombinase only in halpoid spermatids under control of the male-germline specific protamine promoter. The Phox2a coding sequence was inserted upstream of exon 1 along with an IRES-GFP and a floxed neo cassette, which was removed by cre-mediated recombination upon passage through the male germline. In situ hybridization and immunohistochemistry confirm the altered expression pattern of the knocked in coding region and absence of endogenous target gene expression. For unknown reasons the EGFP reporter was nonfunctional. (J:126634)