Shh^{tm1(cre/ERT2)Tshim}

Cre recombinase was inserted into the 3' end of the locus. All procedures for generating knock-in animals were performed at inGenious Targeting Laboratory (Stony Brook, NY). An internal ribosome entry site (IRES) preceding the cre coding sequence permitted expression of both Shh and cre proteins from the same mRNA. No disruption of endogenous gene activity was detected. (J:171106)