9508630 Wendel A common natural phenomenon in plants is chromosome doubling or polyploidy. More than two-thirds of all plant species are suspected of having passed through one or more rounds of chromosome doubling during their evolutionary history, including many economically important species such as the wheat, potato, cotton, soybean, and sugar cane. Chromosome doubling is highly correlated with hybridization between closely related species. One consequence of polyploidy is that all chromosomes, and hence genes, become duplicated in the new genome, thereby creating "genetic redundancy". It has been hypothesized that this redundancy leads to new gene functions, because one copy of each gene is free to change while the other retains its original function. Alternatively, perhaps one of the duplicated copies is lost through mutation, or perhaps both copies maintain the original function. There is very little known about the extent to which these processes operate in nature or their relative frequency. Dr. Jonathan Wendel of Iowa State University is addressing the question, What happens to duplicated copies of genes in polyploid plants? Using tools of molecular biology and a model system of diploids and polyploids from the cotton genus, Gossypium, duplicated genes will be isolated, sequenced, and compared to each other as well as to copies from their non-polyploid ancestral types. Many different types of genes will be studied from different chromosomes with the aim of discovering general principles that guide the fate of duplicated genes in polyploids. Results from this research will also help guide the choice of nuclear genes used for phylogenetic analysis of closely related species and genera.
