Gt(ROSA)26Sor^{tm6(cre/ESR1)Arte}

A fusion protein consisting of cre recombinase and the mutated ligand binding domain of the human estrogen receptor (ERT2) was inserted into intron 1. The estrogen receptor contains 3 mutations (G400V, M543A, L544A) that increase sensitivity to tamoxifen. Following oral administration of tamoxifen recombination efficiency varies from up to 50% to almost 100% depending on the target allele and tissue. Recombination was lowest in the brain. (J:126518)