Sexually Dimorphic Gene Expression in the Dorsal Root Ganglia

Ginika Agbim, Dr. Gina Story, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO

Many of us may have experienced during our daily life a curious difference between males and females in terms of how they respond to the temperature of their environment be it at work, traveling in an airplane or car, etc. Generally, women prefer warmer temperatures compared to men and are more sensitive to cold. This is known as sexual dimorphism. One of the questions I attempted to answer in the Story lab this summer is: what is the biological basis for these differences? Can genetics account for these differences? Or are they purely psychological, sociological or cultural?

The sense of “touch” and temperature are initiated by sensory neurons of the dorsal root ganglia (DRG), located in pairs at all levels of the spinal cord. These neurons are tuned to detect somatic stimuli such as heat, cold, chemical irritants and pressure. They then relay these incoming signals to the spinal cord and brain. I asked whether gene expression in this tissue differs between male and female mice—the model organism studied in the Story lab. To answer this question I performed a genome wide screen using microarray or “gene chip” technology.

I found several families of genes of interest that are differentially expressed in male vs. female mice. Some of these genes are well-characterized, while others have no known function in sensory transduction by DRG neurons. These “hits” lay the foundation for the Story lab to follow up in the future identification of novel, sexually dimorphic gene expression in the DRG