Hprt1^{tm2(Myh6-GAL4)Vmc}

The following sequences were inserted in place of the endogenous promoter, exons 1-2 and 5' end of intron 2, which are lacking in the ES cells used: the mouse Myh6 promoter, the yeast GAL4 gene, human GH poly(A) signal sequence, human HPRT promoter and exon 1, and mouse Hprt intron 1, exon 2 and 5' part of intron 2. In this allele the Myh6 promoter drives the expression of GAL4 and the human HPRT promoter drives the expression of the restored (but now human-mouse hybrid) Hprt gene. (J:330678)