MSH3 and Huntington disease: Transcriptional dysregulation is a molecular phenotype that has been well characterized in Huntington's disease post-mortem brains and mouse models.14,50 This is particularly the case for the striatal transcriptome of an allelic series of knock-in mice13 for which a robust disease signature has been established.51 Therefore, we performed RNA-seq on striata from wild-type, zQ175, Msh3−/− and zQ175:Msh3−/− mice to investigate the effect of Msh3 ablation on the striatal transcriptome of zQ175 mice at 6 months of age.