Cluster analysis of differential gene expression in N. oceanica under N deprivation and after NR. A, Expression patterns of differentially expressed genes (P ≤ 0.01) grouped into four clusters (C1–C4). Analysis and normalization were performed using K-means clustering (k = 4) with the Pearson correlation distance metric using MeV (version 4.8.1) software. B, Distribution of differentially expressed genes categorized by function within each cluster.