Esrrb^tm1.1Nat

A targeting vector was designed to place a loxp site 184 bp upstream, as well as a loxP site 123 bp downstream of exon 2 of the targeted gene. An FRT-flanked PGK-neo cassette was also placed just downstream of the 3' loxP site. Correctly targeted ES cells were injected into C57BL/6 blastocysts and chimeric males were bred to C57BL/6 (to generate Nr3b2CKO+neo mice). The neomycin selection cassette was excised by crossing to mice constitutively expressing the Flp recombinase (unspecified genetic background, see Stock No. 003800), generating this Nr3b2CKO allele with a single FRT site remaining. (J:124941)