Comparative Phylogenomic Synteny Network Analysis of Mammalian and Angiosperm Genomes

Abstract

BackgroundSynteny analysis is a valuable approach for understanding eukaryotic gene and genome evolution, but still relies largely on pairwise or reference-based comparisons. Network approaches can be utilized to expand large-scale phylogenomic microsynteny studies. There is now a wealth of completed mammalian (animal) and angiosperm (plant) genomes, two very important lineages that have evolved and radiated over the last ~170 million years. Genomic organization and conservation differs greatly between these two groups; however, a systematic and comparative characterization of synteny between the two lineages using the same approaches and metrics has not been undertaken.\n\nResultsWe have built complete microsynteny networks for 87 mammalian and 107 angiosperm genomes, which contain 1,464,753 nodes (genes) and 49,426,268 edges (syntenic connections between genes) for mammals, and 2,234,461 nodes and 46,938,272 edges for angiosperms, respectively. Exploiting network statistics, we present the functional characteristics of extremely conserved and diversified gene families. We summarize the features of all syntenic gene clusters and present lineage-wide phylogenetic profiling, revealing intriguing sub-clade lineage-specific clusters. We depict several representative clusters of important developmental genes in humans, such as CENPJ, p53 and NFE2. Finally, we present the complete homeobox gene family networks for both mammals (including Hox and ParaHox gene clusters) and angiosperms.\n\nConclusionsOur results illustrate and quantify overall synteny conservation and diversification properties of all annotated genes for mammals and angiosperms and show that plant genomes are in general more dynamic.