This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2015. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Danelle Seymour is "Exploring the causes and consequences of rapid transposon evolution in grass genomes" The host institution for the fellowship is the University of California, Irvine and the sponsoring scientist is Dr. Brandon Gaut.
The most economically important crop species, including rice, maize, wheat, and barley are members of the grass family. The genomes of these species are extremely variable in size, and this is largely the result of rapid proliferation of mobile genetic elements, or transposons. While the genomic distribution of transposons in each species has been reported, the evolutionary forces that shape rapid, global changes in their distributions are unknown. This project aims to characterize the evolutionary forces that drive large changes in genome structure in eight grass species and whether such changes also have functional consequences. This project will provide the fellow with an evolutionary perspective important for connecting basic genomics research to plant phenotype, as well as the opportunity to provide long-term mentoring to undergraduates interested in genomics research.
Transposons are insertional mutagens and host genomes have evolved mechanisms to mitigate their spread. Transposon silencing can reduce transcription of flanking endogenous genes, but the duration of these changes is unclear due to the rapid evolution of inserted sequences. Exploring the interplay between these two forces, transposon proliferation and host silencing of transposition, is central to understanding how plant genomes evolve. This research aims to characterize the extent that transposon proliferation impacts the evolution of host genomes and ultimately the host phenotype using a comparative phylogenetic approach focusing on eight grass species. First, a unified framework for transposon identification and annotation in all eight species will be developed which will serve as an important community resource. Next, this resource will be used to characterize the role of transposons in the evolution of gene expression. Using a phylogenetic approach, it is possible to characterize the duration of transposon-induced phenotypic changes, in this case gene expression, and the extent that such changes shape the evolution of gene expression networks in this important plant family.
