A loxP sequence and an Flp-flanked neo was inserted 381 bp upstream of exon 12 and a second loxP sequence was inserted downstream of exon 12. Exon 12 encodes the putative transmembrane segment M3. Crossing with Tg(EIF1A-flp)66Mim removed the neo. Western blot analysis demonstrated that protein expression in cerebellar homogenates from mutants was comparable to that of wild-type. (J:97405)