Multigenerational Effects of Endocrine-Disrupting Molecules

Emilie Rissman, PhD, Professor of Biochemistry & Molecular Genetics, University of Virginia, studies mammalian behavioral genetics. Because many social behaviors are activated only when gonadal steroid hormones are present, the genes for steroid hormone receptors are currently under study in her lab. She has found that androgen receptor is required for normal social affiliative behavior in male mice. In addition, her work shows that several social behaviors are sexually dimorphic, in part, because of differences in sex chromosome genes. Her work in mice is relevant to several sexually dimorphic neurobehavioral diseases including autism spectrum disorder.

• Dr. Rissman, I’m very pleased to be interviewing you because since you are one of the few researchers to explicitly examine multigenerational effects of endocrine disruption as it relates to abnormal behavior and neurodevelopment in offspring. How did you come to examine this question?
• How did gestational BPA exposure differentially affect succeeding generations?
• What epigenetic mechanisms are at play with exposure to EDCs?
• What do we know about hormone and other receptors on and in germ cells? And somatic cells, if there’s a difference.
• What role does the steroid hormone receptor play in epigenetic function?
• Why do hormone-disrupting molecules affect epigenetic activity?
• Some of the scientists I’ve spoken with differentiated between “strong” exposures and weak ones in terms of likelihood of epigenetic impacts. Some strong ones mentioned included steroid hormones and their mimics, cigarette smoke and psychoactive drugs. Comparatively weak ones were thought to include variability in stress and nutrition. Do you agree with this general distinction?
• It seems we forget there’s a long and complicated molecular phase of the human life cycle. For example, those who say BPA or pesticides are safe cite studies on adults, children or fetuses. But isn’t the most vulnerable phase gametes and precursor cells? What do you consider to be important windows of vulnerability?
  While nearly all scientists find endocrine disruption a concern, some say “there’s just not enough evidence yet” to be concerned about ambient exposures. How do you respond to that? What would be “enough” evidence?

Read the full interview on Germline Exposures, by Jill Escher, April 2014