Experiment Testing virus region 4 (VR4) mutant cross-species compatible Adeno Associated Viruses (ccAAVs) in mice. Experiment Condition AAV9-mCherry Assay Description: Relative neuronal transduction levels were quantified by counting the number of transduced neurons, identified based on morphology, for each brain region per 50um sagittal section Tissue Measured: midbrain Cell Type : neuron Measurement Type: Delivery Efficiency Record ID 15000000357 Editor Delivery System Delivery System Subtype Guide Vector AAV9-mCherry; Model Species Mouse Model Name C57BL/6 Sample Sex Male Application Method intravenous Application Site Dosage 5e13 vg/kg Injection Frequency once Injection Rate Injection Volume 200 microliters Days post injection 4 weeks Editor Format AAV vector encoded Antidote Id Antidote Description Measured Values Samples Size: 3   Replicate Result (Delivery Efficiency) Measurement Units: # of cells in 50um Section Mean 149.33  1 166  2 180  3 102

Representative image of AAV9-mCherry delivery in midbrain. Neuronal and astrocytic expression were visualized by immunohistochemical staining.