This strain represents a SCA3 disease model generated through transgenic technology, expressing a human ATXN3 gene carrying approximately 85 CAG repeats (Q). The number of CAG repeats (Q) in the human ATXN3 gene in this model is associated with the more severe forms of SCA3. Preliminary research data indicate that 2-month-old TG-hATXN3 (85Q) mice exhibit a significant increase in stride width and a shortened latency to fall in the rotarod test, suggesting impairments in motor coordination and activity. Therefore, this strain can be utilized for research on the ubiquitin-proteasome system and the pathogenic mechanisms of SCA3, as well as for the screening, development, and evaluation of targeted therapeutic drugs.