Figure 3

Largest island in the gene regulatory network of drosophila melanogaster. Gene Network constructed from top 200,000 gene pairs (Costello et al. 2009). Panel A: Nodes are color coded (white-to-red) according with their MCode scores (Bader and Hogue 2003) for clustering. Red nodes are genes tightly clustered. It can be seen that there is strong clustering between nearly all genes. However, no definite structural features are evident. Panel B: Same gene network as in panel A but with node-coloring and sizing determined dy connectivity degree: Big red nodes are highly connected genes whereas small green ones are lowly connected genes. Panels C and D present zoomed-in renderings of the boxes in panels A and B respectively. As in panel A, panel C does not permit to observe network structure. Panel D, in the other hand, shows the presence of some hyper-connected genes (or hubs, here in red) that are densely linked to highly connected nodes (dark orange) passing through less connected ones (light orange) until reaching barely connected genes (yellow and finally green) suggesting some kind of hierarchical structure in the network wiring.