Fig. 1

Neuron maturation relevant functional modules in protein-protein interaction (PPI) network. a The network of PPI modules. Nodes represent distinct modules and are scaled to reflect the number of proteins in each. Colors of nodes represent directions of expression changes during neuron maturation: red – higher in mature neurons, blue – higher in immature neurons, and grey – no significant tendency. Nodes are connected if proteins within the respective modules interact with significantly high frequency. Ellipses mark the functional clusters of modules. b Functional and expression properties of the discriminating modules. The tree shows the hierarchical clustering of Gene Ontology (GO) similarity among discriminating modules using GOSemSim. Colors of module labels represent directions of expression changes of the respective modules during neuron maturation. Colors of the column next to module labels show the overlapping WGCNA-based coexpression modules (red – mature-high; blue – immature-high; blank – no significant overlap). Colors of the next two columns show gene expression changes of the respective modules in two brain RNA-seq data (left: He Z, et al. 2014; right: BrainSpan) covering prenatal and early postnatal development stages: red – increase during development, blue – decrease during development. Color darkness indicates whether the change is significant according to Wilcoxon rank sum test. Boxes mark adversarial module pairs. Signature functions, defined as module-specific GO-BP terms annotated to majority of genes in modules are shown next. The rightmost bars show the neuron specificity index (NSI) of each module: orange – positive NSI; green – negative NSI