Non‐invasive, Repeated Measurement of Estrogen Levels within Subjects in Prairie Voles

Abstract

Prairie voles are a good model for the studying the formation of social bonds; in particular, the formation of monogamous pair bonds. Previous studies in our lab have shown that successful pair bond formation hinges on pregnancy onset within a short time after mating. Female prairie voles only enter estrous when exposed to a potential mate. A surge in estrogen levels induces behavioral estrous and progressive increases in estrogen are seen throughout the course of pregnancy. Measurements of estrogen are generally taken from blood plasma, but collection methods are highly invasive or require the termination of subjects. To better measure estrogen levels in female prairie voles over a time course, a non‐invasive means of collecting samples is needed.We measured estrogen levels in fecal samples collected from female prairie voles over the course of pairing, mating, and pregnancy. Estrogen was extracted from fecal pellets using an organic solvent and ELISAs were run to measure changes in 17b‐estradiol concentrations. Animals that became pregnant showed progressively increasing levels of fecal estrogen over the course of mating and pregnancy, while animals that did not achieve pregnancy showed distinctly less fecal estrogen over the same time course. Our results suggest that measurement of fecal estrogen provides an alternative to more invasive means of measuring changes in sex hormones across time within subjects.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.