SUMO2 and retinal degeneration: To determine whether our previous findings could be transposed to an in vivo pathological context, we next investigated ATXN7 and SUMO2/3 colocalization in Atxn7100Q/5Q mice, a polyQ-ATXN7 knock-in mouse line that develops retinal degeneration, weight loss, kyphosis, ataxia, ptosis, tremor and gradual loss of mobility (Chen et al., 2012).