Poly-glutamine repeat length comparison between human-rat and human-mouse orthologous proteins. Comparison of the poly-glutamine length between human-rat orthologous proteins (light orange, dark orange) and human-mouse orthologous proteins (light blue, dark blue). Dark orange and dark blue correspond to repeats in genes associated with repeat-expansion disease in humans: SCA1, spinocerebellar ataxia 1 protein, or ataxin1; SCA2, spinocerebellar ataxia 2 protein; SCA7, spinocerebellar ataxia 7 protein; MJD, Machado-Joseph disease protein, or voltage-dependent calcium channel gamma-1 subunit; CACNA1A, spinocerebellar ataxia 6 protein, or calcium channel alpha 1A subunit isoform 1; DRPLA, dentatorubro-pallidoluysian atrophy protein; HD, Huntington's disease protein, or huntingtin; TBP, TATA binding protein or spinocerebellar ataxia 17 protein. In the case of SCA2 the rat orthologous sequence did not contain the human amino-terminal region, wherein the repeat is located. Points below the diagonal line correspond to a repeat length that is more than double in humans versus rodents.