Fig. 10. Network motifs and themes in the integrated S. cerevisiae network. Edges denote transcriptional regulation (R), protein interaction (P), sequence homology (H), correlated expression (X) or synthetic lethal interactions (S). (a) Motifs corresponding to the `feed-forward' theme are based on transcriptional feed-forward loops; (b) motifs in the `co-pointing' theme consist of interacting transcription factors that regulate the same target gene; (c) motifs corresponding to the `regulonic complex' theme include co-regulation of members of a protein complex; (d) motifs in the `protein complex' theme represent interacting and coexpressed protein cliques. For a given motif, N_real is the number of corresponding subgraphs in the real network, and N_rand is the number of corresponding subgraphs in a randomized network. Figure reproduced with permission from BioMed Central (Zhang et al., 2005).