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The Dynamic Genome: Introducing Evolution to Undergraduates
Summary: Sue Wessler's research group focuses on identifying plant transposable elements and determining how they contribute to gene and genome evolution. For her HHMI project, she is designing a facility, modeled after her research laboratory, where undergraduates and high school teachers will learn to use both computational and wet bench experimental approaches to characterize transposable elements in genomic DNA databases.
Project Summary
The goal of our project is to motivate students to learn how evolution works by involving them as active participants in a laboratory course focused on the dynamic component of genomes. Our model for this course is our research laboratory, where undergraduate and graduate students and postdoctoral associates use a combination of computational and wet bench experimental approaches to “look under the hood” and see what genomes are made of and how they evolve. Our project will replicate aspects of the research laboratory in order to create a “portal” where students quickly learn how to access the huge databases of biological information to address relatively simple and straightforward questions.
The course will focus on transposable elements, which are both simple and extraordinarily abundant, comprising a staggering 50 percent of the human genome and over 90 percent of some plant genomes. However, while transposable elements are the vast majority of the output of DNA sequencing projects, most research laboratories largely ignore them. As such, one outcome of this course is that students will experience the excitement of scientific discovery, as they will be the first to analyze significant portions of a newly sequenced genome. By helping to determine the transposable element content of a genome, students will learn that the genome is more than an instruction manual for making an organism; it is also an historical record of how species evolve.
Assisting in teaching the course will be undergraduate apprentices from the University of Georgia's Center for Undergraduate Research Opportunities as well as graduate assistants and a postdoctoral teaching fellow, all of whom will first be trained in the laboratory. We will also use the laboratory facility to conduct summer workshops for local high school teachers and their students. In addition, we have established a collaboration with the innovative High Tech High in Los Angeles, which focuses on participatory science education for groups of students who are underrepresented in the sciences.
Research Summary
Our research concerns the interaction between transposable elements and plant genes. Our laboratory was the first to demonstrate that elements could function as introns, that miniature inverted-repeat transposable elements (MITEs) predominate in normal genes, and that plant retrotransposons are the major cause of spontaneous insertion mutations. Most important to our HHMI project, we have pioneered the use of the genome-wide approaches (both bioinformatic and wet bench) in transposable element discovery and analysis. This change in focus from genetic to genomic approaches led to our decision to switch from maize with its genetic strengths to its grass relative, rice, with its genomic advantages. The decision to switch organisms was rewarded with the surprising finding that transposable elements routinely capture and rearrange gene fragments (Pack-MULEs) and the discovery of the first active MITE (mPing). Particularly exciting is our recent discovery of rice strains where the mPing MITE has amplified from 50 copies to over 1200 copies within the past 50 years. Remarkably, most of the new insertions are in or near rice genes, providing a wonderful opportunity to look at the earliest stages in transposon-mediated gene diversification.
Last updated September 2006
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