An Hras1-IRES-EGFP cDNA cassette was cloned into a vector containing the CAGGs promoter followed by a loxP-flanked Beta-geo cassette. The transgenic vector was introduced into E14.1 ES cells. Transgene expressing ES cells were selected and injected into C57BL/6 blastocysts that were transplanted into MCH:ICR female mice. No line numbers for founders were specified. (J:159024)