Figure 1.

Generation of SRGAP2C TG monkeys and longitudinal brain imaging tracking. (A) Image of the TG monkey TG05 in early infancy. (B) Schematic illustration of the generation of TG monkeys, with plasmids (I–III): I, pLv-FhSyn-SRGAP2C-2A-EGFP; II, PMD2.G; III, PsPAX2. Upper panel, structure of the lentiviral vector with an inserted SRGAP2C gene copy next to the EGFP gene copy. EGFP, enhanced green fluorescence protein; LTR, long terminal repeat. (C) Validation of SRGAP2C copy number in the TG monkeys: left panel, variation in copy number among the TG monkeys; right panel, random distribution of the integrated SRGAP2C gene copies across chromosomes. (D) Timeline for longitudinal MRI data collection. (E) Brain volume changes: left, total brain volume; right, total WM volume, with age represented on a logarithmically scaled horizontal axis. (F) Volume changes of occipital lobe: left, gray matter volume; right, WM volume. (G) Overview of WM maturation patterns illustrated schematically. The pie chart displays the proportions of tracts with different maturation patterns. (H) Uncinate fasciculus depicted as a representative tract with size (embedded figure), but no FA, changes; left, left-hemisphere; right, right-hemisphere. (I) Superior temporal lobe WM illustrated as a representative tract with FA, but no size (embedded figure) changes. (J) Inferior temporal lobe WM depicted as a representative tract with both size (embedded figure) and FA differences. In (E–J), gray and white backgrounds correspond to T1-based size and FA-value, respectively. Group effect significance assessed via linear mixed model (LMM), with P < 0.05 considered significant.