NSF Postdoctoral Fellowship in Biology FY 2020

Kramer, Marianne C, Saint Louis MO

Investigators

Abstract

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2022. 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 Dr. MARIANNE KRAMER is "USING ‘ALL-IN-ONE’ RNA-SEQUENCING TO DISCOVER THE TRIGGERS OF RNA INTERFERENCE" The host institution for the fellowship is the DONALD DANFORTH PLANT SCIENCE CENTER and the sponsoring scientist is Dr. R. KEITH SLOTKIN. Plants are very efficient at identifying and destroying non-self genetic material to defend the host from viral infection and prevent DNA mutations and rearrangements caused by mobile pieces of DNA called transposable elements. These mechanisms are also used to identify and shut down expression from foreign fragments of DNA that are purposefully inserted into the plant genome called transgenes. The field of transposable element and transgene repression is called ‘silencing’, and how this process is first triggered and can discriminate these regions from normal genes is unclear. This project will investigate how the molecular process of silencing is first triggered. Over the course of the project, the Fellow will engage in community outreach to expose STEM minority students to the scientific method through the NSF funded program Mutant Millets and will also work with experienced educators to teach and prepare underrepresented upper-level high school students in the city of St. Louis for entry-level positions in AgTech through a joint partnership between the Danforth Center and St. Louis Community College. The process of transposable element and transgene silencing in plants is a feed-forward cycle that involves DNA methylation, histone modification, and small interfering RNAs. However, the initiation of this feed-forward cycle is mechanistically very different from the cycle itself and is dependent on the production and quality control processing of RNAs. The RNAs that trigger the silencing process have been termed ‘aberrant RNAs’ because there must be something wrong with them or something that differentiates them from genic RNAs. Besides hairpin RNA transcripts that researchers have previously created to purposely trigger silencing, as a field we do not understand what a typical aberrant RNA looks like, or how these RNAs are differentiated from genic RNAs, since these RNAs may only be generated for a brief moment to kick off the cycle of silencing. This project will identify the imperfect ‘aberrant’ RNAs that trigger silencing. Data generated from this project will be shared in open-sourced, peer-reviewed publications and presented at scientific conferences. Transcriptomic data produced in this project will be publicly available on NCBI Gene Expression Omnibus (GEO), plant materials will be stored at the Arabidopsis Biological Resource Center (ABRC), and methods will be published in a peer-reviewed journal and code will be uploaded to GitHub. 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.