Robert Johnston

2012 Regional Award Winner — Post-Doc

Robert Johnston

Current Position:
Assistant Professor of Biology

The Johns Hopkins University (Previously at New York University)

Developmental Biology


A simple look at a pair of identical twins would suggest that much of development is amazingly reproducible. However, one would only have to look into the eyes of these twins to see something remarkable: the different types of cells that detect light are randomly distributed and thus each twin is unique. Stochastic specification is critical for generating a wide range of cell types, from human cone cells that detect colors, to olfactory neurons that sense odors, to B cells required for immune responses. Despite its importance, very little is understood about how this fundamentally different strategy operates.

Studying the fruit fly eye, Dr. Johnston identified the DNA elements that control stochastic expression of a critical regulatory gene. This gene is particularly interesting because it is not only controlled by nearby elements, like most genes, but also cross-regulation between copies of the gene. Dr. Johnston’s research also characterized the network that integrates stochastic inputs to determine gene expression patterns in the color- and motion-detecting cells of the eye. In addition to this research on stochastic mechanisms in the fly, Johnston’s lab studies how the cone cells in the human eye randomly choose their color sensitivity using human retinas grown from stem cells.