Faculty Publications

Publication Date



Cell Biology | Molecular Biology


The microRNA miR-7 is perfectly conserved from annelids to humans, and yet some of the genes that it regulates in Drosophila are not regulated in mammals. We have explored the role of lineage restricted targets, using Drosophila , in order to better understand the evolutionary significance of microRNA-target relationships. From studies of two well characterized developmental regulatory networks, we find that miR-7 functions in several interlocking feedback and feedforward loops, and propose that its role in these networks is to buffer them against perturbation. To directly demonstrate this function for miR-7, we subjected the networks to temperature fluctuation and found that miR-7 is essential for the maintenance of regulatory stability under conditions of environmental flux. We suggest that some conserved microRNAs like miR-7 may enter into novel genetic relationships to buffer developmental programs against variation and impart robustness to diverse regulatory networks.

Document Type

Accepted Version


This article is the author-created version that incorporates referee comments. It is the accepted-for-publication version. The content of this version may be identical to the published version (the version of record) save for value-added elements provided by the publisher (e.g., copy editing, layout changes, or branding consistent with the rest of the publication).


This is the author’s version of a work that was accepted for publication in Cell. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Cell, volume 137, issue 2, 2009, pages 273-282 doi:http://dx.doi.org/10.1016/j.cell.2009.01.058

Original Citation

Xin Li, Justin J. Cassidy, Catherine A. Reinke, Stephen Fischboeck, & Richard W. Carthew
A microRNA imparts robustness against environmental fluctuation during development.
Cell, 2009, volume 137, issue 2, pages 273-282



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