Efficient FLP recombination in mouse ES cells and oocytes

Abstract

We report an improved vector, pCAGGS-FLPe, for transient expression of the enhanced FLP recombinase in mouse ES cells and oocytes. In standard transfection experiments, about 6% of total ES colonies showed FLP recombination, albeit with mosaicism within each colony. After microinjection of pCAGGS-FLPe into oocytes, about one-third of heterozygotic mice born showed complete FLP recombination. Thus pCAGGS-FLPe presents two practical options for removal of FRT cassettes in mice. © 2001 Wiley-Liss, Inc.