Hprt1^{tm1(Nppa-lacZ)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: in antisense direction: the 638/+70 bp rat Nppa regulatory region sequence, containing the promoter and silencer and enhancer sequences, a beta-globin/IgG chimeric intron, nls sequence, the lacZ beta-galactosidase gene and bovine GH poly(A) signal sequence; in sense direction: human HPRT promoter and exon 1, and mouse Hprt intron 1, exon 2 and 5' part of intron 2. In this allele the rat Nppa regulatory region drives the expression of lacZ and the human HPRT promoter drives the expression of the restored (but now human-mouse hybrid) Hprt gene. (J:278530)