Fig 1: Spatial-temporal expressions of the macrophage cluster and endothelial cluster in the TMJ disc.a UMAP plot of 9 clusters (refer to Methods for the codes used). The macrophage cluster (MPhs, Cluster 2) is marked in yellow. b Violin plot of C1qa/C1qb/C1qc in the 4 principal cell types. Expression values are nonnormalized. c Representative images of TMJ discs subjected to immunofluorescence staining for C1QA at different stages. Green: C1QA; blue: DAPI. A: anterior band, P: posterior band, white dotted lines: boundary of the discs. N = 6 independent animals with similar results. Scale bar: 50 µm. d Flow cytometry plot of MPhs stained with C1QA antibodies. The dot plots display representative data (left). The quantifications of %C1QA+ cells (mean + /-SD) at different stages are presented (right). N = 3 independent biological samples. The one-way ANOVA with Tukey’s multiple comparison test was used for analysis, *p = 0.0413, **(3d vs. 78-82w) p = 0.0012, **(3w vs. 78-82w) p = 0.0044. Abbreviations: FSC-A: forward scatter area. e UMAP plot of 9 clusters (refer to Methods for the codes used). The endothelial cluster (ECs, Cluster 5) is marked in green. f Violin plot of Pecam1 in the 4 principal cell types. Expression values are nonnormalized. g Representative images of TMJ discs subjected to immunofluorescence staining for PECAM-1 at different stages. Green: PECAM-1; blue: DAPI. A: anterior band, P: posterior band, white dotted lines: boundary of the discs. N = 6 independent animals with similar results. Scale bar: 50 µm. h Flow cytometry plot of ECs stained with PECAM-1 antibodies. The dot plots display representative data (left). The quantifications of % PECAM-1+ cells (mean + /-SD) at different stages are presented (right). N = 3 independent biological samples. The one-way ANOVA with Tukey’s multiple comparison test was used for data analysis, *p = 0.0414, **p = 0.0089. Abbreviations: FSC-A: forward scatter area.