Figure 1.
The matrisome of the forelimb is specialized during murine embryogenesis
Tissue fractionation was combined with LC-MS/MS to analyze the matrisome of embryonic day (E)11.5-E14.5 whole murine embryos and forelimbs (n = 3 biological replicates/time point). Cytosolic (C), nuclear (N), and membrane (M) fractions from whole embryos were combined into one CNM fraction (Figure S1A) and analyzed, along with cytoskeletal (CS) and insoluble (IN) fractions of the whole embryos (E) and forelimbs (F), by LC-MS/MS (Table S1).
(A) The distribution of cellular compartments20,24 in the IN, CS, and CNM fractions, plotted as average of the biological replicates. For all tissues and time points, there was significantly more matrisome, based on the percentage of total raw intensity attributed to ECM proteins, in the IN fractions compared to CS and CNM (p < 0.001, one-way ANOVA).
(B and C) Volcano plots comparing differences in ECM protein composition between (B) E11.5 forelimb and embryo, and (C) E14.5 forelimb and embryo. Gray lines denote >2-fold change and p < 0.05 (two-tailed t-test).
(D) E14.5 WT brains (n = 3) were processed as described for the forelimbs, and revealed there were distinct matrisome compositions in functionally different tissues (Table S1). Gray lines denote >2-fold change and p < 0.05 (two-tailed t-test).
(E) Development-associated Gene Ontology (GO) terms generated by analyzing ECM proteins that were significantly more abundant or exclusively identified in the forelimb and brain, and the corresponding log10-transformed p values.