Figure 5. Time-course analysis reveals a generic response to wounding.

(A) Expression of wound-induced genes at different planarian injuries. A core set of 128 wound-induced genes is plotted in different extended time courses. Worm illustrations show the injury site and isolated tissue location (red block line). Top panel: the expression of different wound-induced clusters from 0 to 24 hpi (lines are loess fit of wound-induced gene expression in each cluster; the same genes were used in all panels). Bottom panel: The expression of the wound-induced genes from 0 to 120 hpi is shown according to fitting of individual genes to a constrained impulse model (Chechik and Koller, 2009) (shown is row z-score; blue-to-red, low-to-high expression, respectively). Right-most column: Conservation of the wound response in anteriorly regenerating G. dorotocephala. Gene order follows orthology assignment between G. dorotocephala and S. mediterranea (Methods; white lines represent genes with no ortholog assigned). (B) WISH analysis of wound-induced genes. Shown are representative animals 4 or 12 hours following incision (scale = 100 μm; ** denote genes for which WISH analysis of incision was previously published). (C) Analysis of onset and offset times in different wound-induced genes clusters and injuries, as computed using the impulse model (ks-test). (D) Expression of representative genes from the early (egr-l 1), late (runt-1), and sustained (inhibin-1) clusters (0-120 hpi) is shown in time course data. Gene expression data points (black dots) are plotted with the impulse fit function (gray line). Onset and offset times, blue and red dashed lines, respectively. (E) WISH validation of onset and decay times for the genes shown in panel D. Gene expression is shown for the three types of injuries tested (anterior, posterior, and incision). Scale = 100 μm. See also Figure S4.