Joint Science Department Seminar


"The role of mobile genetic elements in the experimental evolution of gene regulation in E. coli"
Daniel Stoebel (Pomona '00), Assistant Professor of Biology
Harvey Mudd College
From: 11:00 AM To: 12:00 PM
Thursday, Mar 10, 2011
Keck Science Center, Burns Lecture Hall
Bacteria are able to thrive in the face of variable environments by altering their patterns of transcription. The global regulatory networks that manage these responses vary between strains and species, but we know little about how evolution alters global transcription patterns. I used experimental evolution with E. coli in the laboratory to explore how global regulatory networks can adapt to environmental and genetic perturbations. Global patterns of transcription showed highly parallel patterns of evolution that were driven by the same mutation occuring in independent evolution experiments. This mutation was the insertion of a mobile genetic element (IS10) into a promoter which rewired the regulatory factors required for transcription from that promoter. Strains without this element did not evolve changed regulation of corresponding operon, even though in other circumstances mutations changing regulation can occur. We conclude that mobile genetic elements can play an important role in the evolution of gene regulatory networks not because they create unique phenotypes, but because they elevate the rate of production of some kinds of mutations.
Seminar Registered by: Velda Yount


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