Vsx1^tm2Bhr

Targeting took place in ES cells carrying a cre transgene Tg(Prm-cre)70Og, which expresses Cre recombinase under control of the male-germline specific protamine promoter. An IRES-lacZpA cassette and a neo cassette replaced exons encoding a portion of the homeobox domain. Cre-mediated excision removed the neo cassette upon transmission from male chimeras. X-gal staining confirmed beta-galactosidase activity in heterozygotes. (J:89292)