In two new studies, researchers at the UC Davis MIND Institute have clarified how a long-banned group of chemicals, called polychlorinated biphenyls (PCBs) affect genetic activity. The research helps explain how biological systems respond to these exposures, including key differences between males and females.
“PCBs were banned in the 1970s but are still around us,” said Janine LaSalle, professor in the Department of Medical Microbiology and Immunology, MIND Institute faculty member and senior author on both studies. “PCB chemicals are decreasing in the environment, but surprisingly, low exposure levels aren’t always less hazardous. Higher chemical levels can trigger the body to turn on DNA repair and other stress-related pathways. However, lower levels can slip under the body’s radar and have long-term effects.”
LaSalle and colleagues used PCBs as a lens to better understand developmental biology. The first paper investigated why girls seem to respond differently than boys to some environmental and genetic exposures linked to neurodevelopmental conditions. The second dissected the combined role the MECP2 gene and PCBs play in Rett syndrome.
Together, the two studies provide a more detailed picture of how PCBs influence gene expression and how the body responds.