Mbnl1^tm1Sws

A loxP-flanked neomycin selection cassette replaced exon 3 and flanking sequence. The neomycin cassette was removed by transient Cre expression in ES cells prior to the production of chimeric mice. RT-PCR analysis demonstrated that no transcripts with sequences from exon 3 were present, but other splice isoforms expressed from this gene were detectable. Immunoblot analysis further confirmed the absence of protein isoforms containing sequences encoded by exon 3. (J:86903)