Genome Divergence Pattern and its Correlation to DNA Repairing Pathway

Progress of sequencing technologies has generated a huge amount of genomic sequences, which provide a great opportunity to address fundamental questions about the genome itself. By investigating the Base Composition across SNPs (BCS) within species, we have discovered a conserved pattern, i.e., modern crops have significantly higher [AT] values than their wild relatives. This consistent pattern across multiple species implies BCS can well capture the overall genome divergence assembled from millions of polymorphisms accumulated through evolution. We hypothesize that genetic component may contribute to the genome divergence. To test this hypothesis, 302 soybean genomes and 635 Arabidopsis genomes were analyzed. The well-characterized solar UV signature motifs are enriched around SNPs in both species. This indicates solar UV radiation is one of the major forces driving the divergence of plant genomes. Genome-wide scan results show that genes involved in UV damaged DNA repairing pathway are overrepresented in regions significantly associated with genome divergence. Research discoveries from this genetic mechanisms study will broadly enrich our understanding of genomics, genetics, and evolution.