Predicting Stressors of Ovary Development Perturbation in Wild Largemouth bass


The increasing amount of pollutants released within the marine environment is a problem that, year after year, is going to augment the negative effects on marine organism. In recent years the decrease in fish populations has been attributed to the potential impact of compounds on ovarian development. In addition, the consumption of fish may have downstream impacts on other species and also the human population. Understanding the molecular events occurring during ovarian development and the effects of pollutants on these molecular events could help in preventing adverse outcomes in both fish and predator species. The advances in ‘omics’ technologies have provided us with a powerful toolset which is able to measure a vast amount of genes within an organism and is central to our approach to understanding ovarian development. We focus our efforts on the Largemouth bass (LMB) (Mycropterus salmoides) which is widely distributed along the USA east coast. They have an important economic value due to their popularity as a sport fish but they are also ecologically relevant due to their trophic position in their freshwater environment as apex predators. Because of the importance of reproductive capacity for species survival, we decided to focus on developing computational models of ovary development and used these to identify chemicals, which can potentially affect reproduction. These represent candidate high-risk pollutants that will be subject of an extensive validation in more conventional biological assays.


The increasing amount of pollutants released in the environment is a major issue for the development of a sustainable economy. The impact of a growing number of men made pollutants affect freshwater and marine environments with profound impact on species of economic importance, making maintaining the integrity of the ecosystem vital for securing a constant food supply (FAFANDEL 2008, Whitehead 2013). Moreover, since most of the species of fish are present in human diet and due to the human position along the trophic chain as apex predators, we are going to be directly impaired.
In recent years the decrease in fish populations has been associated to the potential impact of compounds on reproduction caused by the activity of endocrine disruptors, a very powerful class of pollutants (Kraugerud 2012, Aoki 2011). However, other mechanisms of action are of equal concern as well as the effect of non-specific basal toxicity due to chemical lipophilicity. Therefore, understanding the molecular events underlying the effects of pollutants on key sentinel species may allow us to better explain the mechanism of action of the different chemical classes giving us the tools to regulate their production and release and, at the same time, improve our ability to manufacture safe products. Ultimately, the development of effective biomarkers will help to maintain environmental biodiversity and human wellbeing.
Biomarkers, defined as molecular readouts that can predict toxicity effects, are therefore a powerful tool (Liang 2014). In addition to be potential indicators of a compound mode of action (e.g. vitellogenin is a marker of endocrine disruption), these are useful to identifying if an exposure has occurred at all, they can suggest the route of exposure, and ultimately be predictive of toxicity outcome. Identifying biomarkers is not trivial. In thi