Polr3a^tm1Bebr

A lox2272 site was inserted in forward orientation into intron 14, approximately 100 bp upstream of the exon 15 splice acceptor. A FRT-flanked neomycin cassette was inserted into intron 15, approximately 150 bp downstream of the splice donor. The neo cassette was followed by a loxP site in forward orientation. The mutant exon 15 containing a G to A change at position 2015, resulting in a glycine to glutamate mutation at amino acid 672, was inserted in reverse orientation 5' to the loxP site. The inverted exon was followed by a FLEX switch consisting of lox2272 and loxP in reverse orientation. (J:250577)