The Strategies Of a Successful Transposable Element

Despite the widespread prevalence of transposable elements (TEs) in the genomes of higher eukaryotes, what is virtually unknown is how they are able to amplify to high copy numbers without being silenced and without killing their host.  In this seminar I will discuss our recent studies on MITEs (miniature inverted repeat transposable elements), a type of class 2 element that was discovered in my laboratory 20 years ago as the most prevalent TE associated with plant genes.  To understand how MITEs can attain high copy numbers, we succeeded in identifying a MITE, mPing, in the midst of rapid amplification throughout the genomes of several related rice strains. High throughput sequencing technologies has been employed to determine mPing’s strategies for success and to understand how mPing impacts host transcription and generates phenotypic diversity.

What is also unknown about high copy number TEs is how they originate and how they are ultimately detected by the host and silenced.  To understand how mPing was born and how it may die, we have exploited transposition assays in yeast and Arabidopsis thaliana to identify possible sources of transposase in the rice genome that can catalyze mPing movement.  From these surprising findings we have devised a scenario for the complete life cycle of mPing.