EAPSI: Membrane Steroid Hormone Receptor Activity of Fathead Minnow when Exposed to a Contaminants of Emerging Concern Mixture

Wang Lina C, Mankato MN

Investigators

Abstract

In the aquatic ecosystem, fish are exposed throughout life to complex mixtures of chemicals. Some of these chemicals mimic hormones in organisms. These hormone-like chemicals may in turn alter fish behavior, from decreased the vigor of male nest defense to swimming performance in larval fathead minnows (Pimephales promelas). In severe cases of chemical exposure, the entire fish population can collapse. This mixture of chemicals of emerging concern (CECs), are a common source of hormone-like compounds in aquatic ecosystems. Over the past few years, CEC use has increased alongside the growth in human population. Though the effects of single CECs have been explored in fishes, the effects of an entire mixture of CECs has not. The award research will shed light on the pathway chemicals take when present in a complex mixture by cloning and characterizing membrane steroid hormone receptors, including the estrogen receptors, to determine if a molecular difference is related to changes in behavioral endpoints. This research will be conducted in collaboration with Dr. Yoshinao Katsu, a noted expert in endocrine disruption and developmental effects of estrogen-like chemicals, at Hokkaido University in Sapporo, Japan. CECs have been found to affect fecundity, foraging ability, and other apical endpoints. This project will focus on the membrane receptors (i.e. GPR30 and membrane progesterone receptor) activation by an environmentally derived urban CEC mixture in P. promelas. Most membrane steroid hormone receptors are G protein-coupled receptors, thus a second messenger analysis will be conducted to understand the membrane steroid receptors mechanisms and determine if it is linked to CEC-exposure and/or behavioral endpoints. The objectives of this projects are: (1) To clone and characterize membrane steroid hormone receptors in P. promelas; (2) To examine the interaction of the membrane receptor activity with behavioral endpoints under CEC-exposure. This project will support a larger project seeking to characterize and evaluate how environmentally derived CECs mixture from urban sources affect fathead minnow populations in the Laurentian Great Lake Basin. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.