In the Ambros lab, we are investigating how stress alters the functions of small regulatory RNAs in the worm C. elegans. Physiological stresses, such as starvation or infection, can trigger an “emergency response pathway” that switches on a broad range of genes that help the organism survive. One way cells can coordinate the activity of related sets of genes is via the generation of small regulatory ribonucleic acids (RNAs), called microRNAs. Using an array of cutting-edge techniques in molecular and cell biology, genetics and computation, I will evaluate whether the stress of feeding C. elegans an infectious bacterium, rather than the harmless bacteria it normally eats, changes the worms’ overall production of microRNAs, or whether there are specific microRNAs whose synthesis or turnover are tailored to handle this affront. These findings could point the way toward therapeutic intervention for a variety of conditions that are thought to be precipitated by increased cellular stress, including cancer and aging.