Encountering MicroRNAs in Cell Fate Signaling

Abstract
The recent discovery of short regulatory RNAs called microRNAs has expanded our understanding of the regulation of gene expression, yet little is known about the role of microRNAs in developmental signaling pathways. In their Perspective, [Karp and Ambros][1] discuss a new study by [Yoo and Greenwald][2] that finds a microRNA to be a direct target of LIN-12/Notch signaling. This influences cell fate decisions during C. elegans development and may extend to other organisms, because the Notch signaling pathway is highly conserved. [1]: http://www.sciencemag.org/cgi/content/full/310/5752/1288 [2]: http://www.sciencemag.org/cgi/content/full/310/5752/1330