Fig. 2: Forelimb ECM composition was partially disrupted by the absence of muscle.

A Left: log₁₀(combined LFQ intensity value) heat map of matrisome components manually grouped via ECM protein classification. Combined LFQ intensity values for different fractions were generated following²⁵ and proteins identified in n ≥ 2 biological replicates were included. White boxes signify zero intensity values. Right: C1 Fluidigm single-cell RNA-sequencing (scRNA-seq) data of the matrisome identified in E10-E15.5 limbs generated by He et al., as previously reported in ref. ²⁵. Color indicates log₂(average expression +1) and circle size represents percentage of cells expressing that specific transcript. Cell types: 1 mesenchymal; 2 muscle 1; 3 muscle 2; 4 muscle 3; 5 chondrocyte; 6 perichondrial; 7 neural crest; 8 endothelial; 9 erythro-myeloid progenitors; 10 macrophage; 11 epithelial. Heat map and scRNA-seq data of affiliated proteins can be found in Fig S2. B Pax3^Cre/Cre forelimb lacked limb musculature (MY32, myosin; magenta) at E13.5. The shoulder girdle begins below the line. Magnification 10×. Scale bar = 200 μm. C Two-way ANOVA revealed there were no significant differences in matrisome composition between genotypes at E13.5 (p > 0.05, Supplementary Data 1). D Volcano plot comparison of log₂(LFQ) values for Pax3^Cre/Cre and WT E13.5 forelimbs, significance based on p < 0.05. E Matrisome components exclusively identified in either WT or Pax3^Cre/Cre embryos for all tissue fractions. F Select GO terms identified as significant when comparing ECM components that were exclusive to or enriched in Pax3^Cre/Cre or WT E13.5 forelimbs. N = 3 independent biological replicates were analyzed.