Tg(Pgk1-lacZ)13Vmel

A construct was generated that consisted of two tandemly arrayed selectable marker genes expressed from the mouse Pgk1 promoter. The sequence coding for neomycin phosphotransferase flanked by loxP sites was 5' to the sequence encoding beta-galactosidase (lacZ; followed by the SV40 polyadenylation sequence). To prevent translation of lacZ from dicistronic transcripts, 2 copies of the bovine GH polyA sequence were inserted downstream of neo. Cre-mediated recombination will result in lacZ translation. The construct was electroporated into D3 ES cells. One clone (plnLacZ13) with one copy of the transgene was selected for further analysis and injected into C57BL/6 blastocysts. (J:47007)