To establish a cellular imaging system for HD and evaluate the effects of PolyQ expansion on Htt protein dynamics, we fused disease-inducing Huntingtin protein exon 1 fragment (mHtt-94Q) (Rubinsztein, 2002; Yamamoto et al., 2000) and its wild-type counterpart (Htt-25Q) (Krobitsch and Lindquist, 2000) to a monomeric photo-switchable protein (mEOS3.2 (Zhang et al., 2012); w/o nuclear localization signal - NLS). This evidence concerns the gene HTT and Huntington disease.