Pgr^tm1Omc

To eliminate translation of isoform A, without abrogating the translation of isoform B, the translational start site at codon 166, which is specific to isoform A, was modified to encode alanine. For selection, a silent mutation was introduced resulting in the generation of a novel NheI restriction site and a floxed neomycin selection cassette was inserted into intron 2. Recombinant ES cells were transfected with plasmids expressing cre recombinase, resulting in the excision of the neomycin cassette. Immunoblot analysis of uterine extracts from estrogen treated homozygous mutant mice showed an absence of isoform A. Isoform B protein levels were unaffected. (J:77661)