Huntingtin (HTT) is a disease-associated gene widely expressed in various tissues and organs, including the central nervous system, and is essential for normal development. The coding region of the HTT gene contains a polymorphic trinucleotide (cytosine-adenine-guanine, CAG) repeat sequence near its 5' end, which forms a polyglutamine (polyQ) tract during translation. Huntington's disease is a neurodegenerative disorder characterized by the loss of striatal neurons, caused by the aberrant expression of the CAG repeat sequence in the HTT gene. When the CAG repeat is expanded beyond 35 copies, it leads to abnormal polyQ expansion, resulting in incorrect folding of HTT protein fragments, dysregulation of protein-protein interactions, and accumulation in the cell nucleus and neuronal terminals, ultimately affecting neural signaling, intracellular protein transport, and mitochondrial function ^[1]. Currently, there are no effective drugs or methods to prevent or treat Huntington's disease, and there is a great need for further research into its mechanisms and the development of therapeutic approaches ^[2].

This strain is an hHTT Q150 knock-in mouse model generated by gene editing technology, in which a mutated human HTT gene sequence carrying 150 CAG repeats is inserted into the mouse genome. Literature reports have shown that these mice exhibit pathological features and functional impairments characteristic of Huntington's disease, and are suitable for developing and screening therapeutic drugs for Huntington's disease and safety evaluation ^[3]. The heterozygous FVB-hHTT Q150 KI mice are viable and fertile.