Fig. 5.

Six clusters were defined using a k-means clustering algorithm. Genes in the early response cluster (n = 88) were upregulated primarily at 4 hours. Expression of genes in the matrix-formation (up) clusters peaked between 12 and 16 days, and this cluster was subdivided into three magnitudes: high (n = 23), medium (n = 182), and low (n = 308). Expression of genes in the matrix-formation (down) clusters peaked at 16 days, and this cluster was subdivided into two magnitudes: high (n = 124) and low (n = 326).