|Rooney, Alejandro - Alex|
Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2007
Publication Date: 3/17/2007
Citation: Xue, B., Rooney, A.P., Kajikawa, M., Okada, N., Roelofs, W.L. 2007. Novel sex pheromone desaturases in the genomes of corn borers generated through gene duplication and retroposon fusion. Proceedings of the National Academy of Sciences. 104(11):4467-4472. Interpretive Summary: Moth caterpillars pose a food safety concern because aflatoxin- and other mycotoxin-producing fungi grow on agricultural crops especially when damaged by these pests. The use of synthetic sex pheromones (sex attractants) to control moth pests is an appealing alternative to the use of chemical pesticides. However, in order to fully exploit sex pheromones as caterpillar biocontrol agents, we need to understand how many genes are responsible for their production, whether or not all species possess the same genes, and how new or different pheromones are produced. In this study, we show that there are a number of previously unknown pheromone production genes in moths that are "cryptic". The existence of these genes demonstrates that moth pheromone biosynthesis is much more complex than we have appreciated.
Technical Abstract: The biosynthesis of female moth sex pheromone blends is controlled by a number of different enzymes, many of which are encoded by members of multigene families. One such multigene family, the acyl-CoA desaturases, is comprised of certain genes that function as key players in moth sex pheromone biosynthesis. Although much is known regarding the function of some of these genes, very little is known regarding how novel genes have evolved within this family and how this might impact the establishment of new sex pheromone blends within a species. We have discovered that several cryptic Delta 11 and Delta 14 destaurase genes exist in the genomes of the European and Asian corn borers (Ostrinia nubilalis and O. furnacalis, respectively). Furthermore, an entirely novel class of desaturase gene has arisen in Ostrinia lineage and is derived from duplication of the Delta 11 desaturase gene and subsequent fusion with a retroposon. Interestingly, the genes have been maintained over relatively long evolutionary time periods in corn borer genomes, and they have not been recognizably pseudogenized, suggesting that they maintain functional integrity. The existence of cryptic desaturase genes exist in moth genomes indicates that the evolution of moth sex pheromone desaturases in general is much more complex than previously recognized.