Htt^tm1Mfc

A fragment extending from 18 bp upstream of the polyglutamine stretch in exon 1 to 100 bp into intron 1 was replaced with human HD sequence containing 140 CAG repeats. A floxed neo cassette was retained 1.3 kb upstream of exon 1. Western blot analysis of homozygous mutant cerebellum and forebrain tissues identified protein corresponding with the mouse/human hybrid protein. Similar levels of mutant and endogenous protein were observed. The repeat number is not stable and may expand or contract. (J:85298)