A knockout-first allele was created using the Ano5 vector. The following elements were inserted into the locus: an FRT site, an exogenous intron, an IRES, the lacZ reporter gene, SV40 polyA features, a loxP site, a neomycin resistance gene cassette, a second FRT site and a second loxP site into intron 8. A third loxP site was inserted into intron 9. RT-PCR confirmed the loss of transcription from exon 9 onwards. qRT-PCR showed overall reduction of 80% in transcription from this allele. Western blots confirmed the lack of protein expression from this allele. (J:235810)