Hprt1^{tm1(ACTB-Bcl2)Sakb}

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 human beta actin promoter, a mouse Bcl2 cDNA, PGK poly(A) signal sequence, human HPRT promoter and exon1, and mouse Hprt intron 1, exon 2 and part of intron 2. In this allele the human ACTB promoter drives the expression of murine Bcl2 and the human HPRT promoter drives the expression of the restored (but now human-mouse hybrid) Hprt gene. (J:34887)