Fig. 5: The transcriptome of oligodendrocytes lies on a spiral trajectory flanked by ENPP6/MUSK gradient and marked by the succession of transcription factors.

a 2D UMAP plot of oligodendrocytes (OLI) colored by Level 2 subclustering (top) and transcriptomic distance in pseudotime (bottom, starting at OLI1, denoted by ①). b Two viewing angles of a 3D UMAP plot of OLI subclusters and corresponding expression of selected genes. c The expression of MUSK is detected in OLIG2⁺ cells in adult marmoset brain by combined immunofluorescence staining and fluorescent in situ hybridization (Hybridization chain reaction v3.0). d Heatmap showing the expression of transcription factors (TF) across pseudotime. Nuclei were grouped into 125 bins (columns, steps 1–125). The jitter plot above the heatmap is colored by OLI subcluster for visual reference. Three major branches of genes were annotated (❶, ❷, and ❸). The expression of 63 TF could be grouped into three sets (Set 1: steps 0–60, present in OLI1–2, with Branch 1^high and Branch 3^low; Set 2: steps 60–80, present in OLI3, with Branch 2^high; Set 3: steps 80–125, present in OLI4–6, with Branch 1^low and Branch 3^high). e Box plots showing the distribution of OLI subclusters across pseudotime with median annotated; n = 11,977 (OLI1), 15,451 (OLI2), 18,623 (OLI3), 45,475 (OLI4), 30,691 (OLI5), 6,493 (OLI6) nuclei analyzed. The lower and upper hinges of the box plot correspond to the 25^th and 75^th percentiles, whiskers extend from the hinges to maxima or minima at most 1.5 times inter-quartile range. f The expression of TF with linearly decreasing (TRPS1) and increasing (CREB5) expression. g The expression of TF with levels that peak at various pseudotime points. The center of the error bands was defined by a locally estimated scatter plot smoothing (LOESS) curve fit for each expression pattern; the flanking gray bands indicate 95% confidence intervals.