Generalized Adjacency in Genetic Networks and the Conservation of Functional Gene Clusters

Given genetic networks derived from two genomes, it may be difficult to decide if their local structures are similar enough in both genomes to infer some ancestral con- figuration or some conserved functional relationships. Current methods all depend on searching for identical substructures. We explore a generalized vertex proximity criterion, and present analytic and probability results for the comparison of random lattice networks. We then apply it to the comparison of the genetic networks of two evolutionarily divergent yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe. We show that the overlapping parts of the networks of the two yeasts share a common structure beyond the shared edges. Detecting the shared generalized adjacency clusters in the genetic networks of the two yeasts show that this analytical construct can be a useful tool in probing conserved network structure across divergent genomes.