Robert J. Johnston, Ph.D.

Research

My research explores the development of the cells responsible for color vision. Many aspects of development are precisely regimented, with specific sets of genes activated like clockwork to dictate the fate of a cell, including which proteins it will make. But some systems are less meticulous. We found that, in the fly retina, the scattershot distribution of cells that produce different visual pigments is governed by the random activation of a single gene: when the gene is on, one pigment is produced; when it is off, the other is made. My laboratory will determine how each of the two copies of this gene in a retinal cell “decides” whether to switch on or off, and how it communicates this decision to its partner so that both can “agree”—work we plan to extend to the selection of visual pigments in human retinal cells. These findings will deepen our understanding of how random processes contribute to complex networks of gene regulation and how this type of regulation may go awry during ocular disease.