Emergent Topological and Statistical Properties of Gene Regulatory Grids

January 6, 2016
Network grid image

Gene regulatory grids (GRGs) are static representations of gene regulatory networks (GRNs) encompassing all possible regulator-target gene interactions thereby providing a system-wide view of transcriptional gene regulation. To understand the architectural organization of GRGs, we investigate their emergent topological and statistical properties in the following model organisms: Caenorhabditis elegans, Drosophila melanogaster, mus musculus and Saccharomyces cerevisiae. We then determine how the properties vary as a function of grid size within and across species, with an aim of describing the expected GRGs for non-model organisms. For each GRG of the aforementioned species, we investigate: (a) node degree distribution as a proxy for determining grid scale-free property; (b) average clustering coefficient and path length as determinants of small-world property; and (c) presence of network motifs and hubs. Preliminary results indicate that GRGs are scale-free and their connectivity can be used in estimating the number of all interactions in a fully-connected grid.