New Approach Provides Unprecedented Control of Genome Editing in Flies; Promises Insight into Human Development, Disease

In an era of widespread genetic sequencing, the ability to edit and alter an organism's DNA is a powerful way to explore the information within and how it guides biological function. A paper from the University of Wisconsin–Madison (UW-Madison) published as an open-access article in the August 2013 issue of the journal GENETICS takes genome editing to a new level in fruit flies, demonstrating a remarkable level of fine control and, importantly, the transmission of those engineered genetic changes through generations. Both features are key for driving the utility and spread of an approach that promises to give researchers new insights into the basic workings of biological systems, including embryonic development, nervous system function, and the understanding of human disease. "Genome engineering allows you to change gene function in a very targeted way, so you can probe function at a level of detail" that wasn't previously possible, says Dr. Melissa Harrison, an assistant professor of biomolecular chemistry in the UW–Madison School of Medicine and Public Health and one of the three senior authors of the new study. Disrupting individual genes has long been used as a way to study their roles in biological function and disease. The new approach, based on molecules that drive a type of bacterial immune response, provides a technical advance that allows scientists to readily engineer genetic sequences in very detailed ways, including adding or removing short bits of DNA in chosen locations, introducing specific mutations, adding trackable tags, or changing the sequences that regulate when or where a gene is active. The approach used in the new study, called the CRISPR RNA/Cas9 system, has developed unusually quickly.