Runx1^tm3Dow

A floxed stop cassette containing a strong polyA signal was inserted into intron 3, upstream of the murine/human hybrid sequence engineered from human t(8;21) cDNA and used to generate Runx1tm2Dow. While trace levels of an alternatively spliced transcript including the downstream region were detected, no such protein was identified in mutant mice by Western blot analysis. Excision of the floxed polyA signal and the resultant expression of the inserted human sequence was achieved when mice carrying this allele were bred with transgenic mice expressing cre recombinase. (J:77129)