S18: Twenty new actinomycete genome sequences: Early insights into genome organization and natural product biosynthesis

We have generated high quality draft sequences of twenty new actinomycete genomes.  Analyses of these genomes demonstrate that: (1) The auxiliary genomes of Streptomyces spp. are exceptionally large.  (2) Streptomyces genomes are sectored, with core genes closer to the center of the linear chromosome and genes unique to each strain closer to the chromosome ends.  (3) Biosynthetic gene clusters for natural products are overrepresented within the auxiliary genome.  I will discuss preliminary analyses suggesting that the auxiliary genomes of Streptomyces spp. are unusually dynamic, experiencing relatively high rates of gene gain/loss and harboring many genes that show signatures of horizontal gene transfer.