Credits: Day's Edge Productions for Illumina

While whole genome sequencing has driven our understanding of how genes map to biological traits, another technology has developed in parallel, allowing us to selectively edit those traits in practically any organism: CRISPR. Since Jennifer Doudna and Emmanuel Charpentier published their Nobel-winning paper about CRISPR in 2013, this set of “molecular scissors” has become the go-to genome editing tool for genetics researchers all over the world. CRISPR’s uses range from “breaking” genes in single-cell organisms to understand what they do, to creating therapies for devastating genetic illnesses like sickle cell disease, but one of its most radical applications is “heritable genome editing,” the alteration of germ cells to produce traits that an organism will pass to its descendants. While illegal in humans for now, heritable genome editing in other animals offers a fascinating (and somewhat disturbing) set of public health tools. “The Reservoir” follows MIT researcher Kevin Esvelt as he works with the community on Nantucket to fight Lyme disease with genetically altered mice.