Alumni Spotlight: Sensing
Liman '85 studies missing genetic link in humans
is a leading researcher in the field of pheromones.
Taped to the door of Emily Liman '85's laboratory at the University
of Southern California is a New Yorker cartoon depicting a couple
at a cocktail party. The underlying caption reads: "There's
no, no in your eyes, but yes, yes in your pheromones."
Ironically, Liman's research as a molecular biologist suggests
that the organ dedicated to sensing pheromones in many mammals
the vomeronasal organ (VNO) is, like the appendix, nonfunctioning
in humans. Her papers on the topic have made headlines in scientific
and pop-culture publications alike, from Wired magazine to the Boston
Pheromones are a chemical substance produced by humans and animals
that serve as a stimulus to other individuals of the same species.
They are responsible for regulating the mating patterns in a host
of animals, from mice to bees to moths. It's not that humans don't
emit pheromones, says Liman. Rather, our VNO, located in the nasal
passage, lacks the necessary gene to communicate these signals to
Prior to joining the USC faculty in 1999, Liman served as a post
doc at Massachusetts General Hospital and was the first to pinpoint
the TRP2 molecule as an important player in transmitting pheromone
signals in mice. She also found that humans lack this gene, rendering
the VNO inoperative.
When and why did we lose the ability to sense pheromones using
Together with a colleague at USC, Liman is currently exploring
this very question. For her latest study, funded by the National
Institutes of Health, Liman is focusing on the DNA of primate species.
Her findings suggest that the loss of pheromone detection may coincide
with an increased dependence on vision.
Liman has always been drawn to the field of sensory perception,
a topic that first inspired her to study biology at Princeton. "There
is a direct link between the sensory system and our behavior and
experience," she says. As an undergraduate, Liman devoted her
independent research to the study of animal behavior. For her senior
thesis, she devised a series of experiments to determine the methods
by which squirrels are able to relocate the nuts they've hidden.
Liman delved into the field of molecular biology while earning
her Ph.D. at Harvard University. Although she had originally intended
to study vision, she became interested in electrophysiolgy
the study of electrical impulses within cells. Her doctoral work
focused on ion channels, the pathways by which chemicals are transformed
into electrical impulses.
After earning her doctorate in 1992, she saw the opportunity to
make an impact in the field of olfaction and joined the lab of leading
Harvard neurobiologist Linda Buck as a postdoctoral fellow. At that
time, Buck had just made a major discovery by identifying 1,000
unique receptor molecules that detect odors and, in various combinations,
transmit different smells to the brain. Liman was charged with finding
a similar system for pheromone detection.
By Tamar Laddy '94
Tamar Laddy is a film student at the University of Southern