Z Scores of Four-Node Network Motifs, Classified by Stability

<p>Density groups consisting of four, five, and six-edge network motifs contain at least one motif in each stability class. Box and whisker plots indicate a difference in the average Z score between stability classes (I, II, and III correspond to SSS = 1, SSS ≈ 0.4, and SSS < 0.2, respectively). The networks examined here are the transcriptional networks of (A) <i>E. coli,</i> (B) <i>S. cerevisiae,</i> (C) STKE network, (D) <i>D. melanogaster</i> developmental transcriptional network, and (E) <i>C. elegans</i> neuronal network. A box and whisker plot is interpreted as follows: The box indicates the inner quartile range. The median Z score is indicated by a horizontal red line within the box. The whiskers extend to cover the upper and lower quartiles up to a distance of 1.5 times the inner quartile range. Red crosses indicate extreme scores (beyond the whisker length). <i>P</i>-values attached to each plot express the probability that the observed difference in Z scores between stability classes is expected by chance.