In addition to genes, the genomes of all organisms contain parasites, called transposable elements, that can selfishly mutate the cell if not controlled. This project seeks to understand the very first steps that cells use to "turn off" genomic parasites. New molecular tools will be generated and delivered to the biological community, together with new data to reveal the "off-switch" mechanism, so that the switch can be targeted, avoided, or used as a research tool. In addition, the project will prepare the next generation of biologists to join the future scientific workforce by mentoring and training researchers at undergraduate, graduate and postdoctoral levels. The project will also expose hundreds of STEM-minority middle school students to research science and the scientific method to facilitate community interaction and empower a more diverse STEM future.
Chromatin modifications, such as DNA methylation, play important roles in genome maintenance and expression by providing heritable epigenetic information that is transmitted across cellular generations. For cells, this mechanism is prudent, as it obviates the need for each cell and generation to determine de novo (for the first time) which regions of the genome should be expressed vs. silenced. However, this mechanism has made it difficult for researchers to determine the rules governing how patterns of chromatin modification are initiated. The goal of this project is to identify these rules. Using Arabidopsis thaliana as a model organism, the research includes developing new molecular tools to study the initial trigger of small RNA production, a step which is essential for directing chromatin modification. Then the new tools will be used to test whether known proteins involved in small RNA metabolism can trigger de novo silencing and to discover new proteins that function at the trigger point. The tools should have broad utility in the field, and the research is expected to deliver transformative insights to unlock the ability to target, avoid, or engineer de novo chromatin modification in plants.
This award was co-funded by two programs in the Biological Sciences Directorate: Genetic Mechanisms in the Division of Molecular and Cellular Biosciences and Plant Genome Research Program in the Division of Integrative Organismal Systems.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
