Étudiants-chercheurs étoiles January 2018

Daniel Agudelo and Alexis Duringer

PhD students in Molecular Medicine
Université Laval

Award-winning publication: Marker-free coselection for CRISPR-driven genome editing in human cells

Published in: Nature Methods


The scientific community was quick to adopt the recently developed CRISPR-Cas9 genome editing system. Making it possible to consider the correction of the dysfunctional genes involved in many diseases, the tool has brought new hope to gene therapy. Despite its apparent simplicity, the implementation of the CRISPR system remains an arduous and time-consuming task. The challenge partially lies in the varying efficiency of the many RNA guides that direct the Cas9 enzyme to the targeted DNA sequence. Selecting active RNA guides and identifying and isolating the cells with specific genetic modifications is a long and costly process. Versatile and widely applicable methods to select the genetically modified cells must therefore be developed. Daniel Agudelo, Alexis Duringer and their team have established a method to create ouabain-resistant cells (ouabain is a chemical compound that eliminates cells in 48 hours) that carry the targeted genetic modification. The technique builds on the fact that by simultaneously targeting two different genes (ouabain resistance and the initially targeted genetic modification) and relying on ouabain to sort the cells with the initial modification, the remaining cells have a better chance of containing the second modification. The quick technique helped increase the frequency of the targeted mutation in different cell types and primary human cells by up to 20 times, potentially leading to a major therapeutic impact.