Erbb2^{tm8.1(Erbb2)Mul}

Single-cell embryos with one copy of the Erbb2tm8(Erbb2)Mul recombinant allele were microinjected with a plasmid containing Cre recombinase under the control of the chicken actin promoter. The actin promoter is expressed at the two-cell phase in the mouse embryo and results in direct excision of the floxed neo in the germline and places the Erbb2 cDNA insert under the control of the endogenous promoter in all tissues in which it is normally expressed. (J:89255)