Figure 3.

The matrisome continued to change during postnatal musculoskeletal growth

(A, left) Heatmap of row z-scores and (A, center) corresponding combined LFQ intensities for ECM proteins identified in the E14.5, P3, and P35 forelimbs (Table S2). White boxes signify proteins not identified in n ≥ 2 biological replicates. (A, right) The distribution of individual ECM identified by proteomic studies of isolated tissues, including muscle (M), myotendinous junction (J), tendon (T), enthesis (E), cartilage (C), and bone (B).^{39,40,41,42,43,44}

(B) Top 10 abundant ECM proteins in E14.5, P3, and P35 forelimbs show differences in matrisome composition as a function of development.

(C) Volcano plot comparing ECM proteins identified at E14.5 and P35. Gray lines denote >2-fold change and p < 0.05 (two-tailed t-test).

(D) Nascent matrisome from P35-P36 forelimbs identified by BONCAT. ECM proteins were ranked by abundance at 6-hpi; PRELP was only identified 24-hpi. Values are the average raw intensity for n = 3. Matrisome components that were exclusive to adolescence, compared to embryonic forelimbs (Figure 2D), are marked with ^#.

(E and F) Comparison of the relative percentage of matrisome intensity between unenriched and enriched samples. Points are the average of n = 3 biological replicates. Labels on the left indicate ECM proteins of interest that were only identified in unenriched samples. Lines connect proteins identified in both unenriched and enriched samples (labeled on the right). Darker, bolded lines highlight ECM proteins of interest and ∗ indicates a significant change in intensity percentage between unenriched and enriched sample (two-tailed t-test, p < 0.05).