Evidence of a functional role for vertebrate steroids has been demonstrated in a number of invertebrate species, including molluscs. This knowledge has generated interest into the possibility of invertebrate endocrine disruption due to exposure to both exogenous steroid hormones and xenobiotics which can mimic the action of these compounds. Exposure to the natural vertebrate estrogen, 17β-estradiol (E2), for example, has been shown to induce accelerated gamete development in multiple mollusc species. Little information exists, however, for freshwater mussels, a group of exceptional conservation interest.
Here, Daniel Sovic, Raoman Lanno, Dr. Kody Kuehnl, and G. Thomas Watters report the findings of two field studies on gametogenesis (Elliptio complanata, Pleurobema clava) as they relate to seasonal estrogenicity of extracts from Polar Organic Compound Integrative Samplers (POCIS) as determined using the Yeast Estrogen Screen (YES) assay. In order to investigate effects of E2 exposure on gamete maturation and viability in freshwater mussels, Elliptio insulsa were dosed at one of three exposure levels. Effects on ova and sperm development were determined on biopsies collected 10 days and 6 months post-exposure and biopsy-generated data were compared with histological sections of vicera collected immediately following final biopsy collection. Comparisons of data collected via biopsy and traditional histological techniques provided data to evaluate the potential for utilizing non-lethal biopsy sampling to assess Unionid gametogenesis.https://fuse.franklin.edu/forum-2013/1022/thumbnail.jp