Periodic Reporting for period 1 - MICRODEV (Microplastics: morphological and genetic developmental effects in a marine invertebrate.)
Période du rapport: 2021-03-01 au 2023-02-28
Fifty trillion microplastic particles are floating in the sea. Although microplastics alter the development of a range of marine invertebrates, the consequences of these developmental effects are likely underestimated, and the effects for ecosystems are unknown. No systematic studies have characterized the range of developmental defects elicited by microplastic contamination on marine invertebrates. Using the sea urchin Paracentrotus lividus as a model, this project aimed at: (1) explore the morphological and genetic consequences of microplastic exposure on development; (2) identify which characteristics of the plastic particles cause the effects; (3) assess if the effects are specific, altering developmental pathways, or a consequence of general toxicity. This multidisciplinary, novel work will transform our understanding of the effects of microplastic contamination on development, including the underlying genetic mechanisms, and their implications for other animals exposed to MP contamination. Plastic waste is a topic of major societal interest, and media coverage around plastics and marine pollution suggests that this project is of great interest to the general public, and is meant to help stakeholders (fishermen/farmers and third sector (NGOs) along with plastic manufacturers) and regulatory bodies avoid damage to stocks and livelihoods.
We have shown that new plastic nurdles are able leach harmful chemicals, in particular heavy metals (Zn) that, at high concentrations, disrupt the development of sea urchin embryos. These chemicals produce transcriptomic changes that involve the disruption of major developmental gene regulatory networks as well as metabolic pathways, and challenge axis formation and cell type specification and differentiation in sea urchin larvae (Paganos et al., 2023).
Continuous exposure of adult P. lividus to high concentrations of PVC leachates, containing high amounts of zinc (1µg/g), for two weeks does not affect their capacity to produce embryos and larvae, and fertilisation of eggs can also happen in these conditions. However, embryos grown in contaminated water have higher levels of arrested development at very early stages (before gastrulation) when they are derived from adults that were in contaminated water. We also found that, in contaminated conditions, adults show reduced immune cell counts and increased oxidative stress. Nevertheless, their production of gametes (but not embryogenesis) appears resilient to contaminated water. However, sublethal effects seen in the adults may lead to transgenerational effects that reduce developmental robustness of the embryos. (Jimenez-Guri et al., 2023).
These results have been disseminated in several conferences and meetings, and have been published in open access journals (https://dx.doi.org/10.1016/j.scitotenv.2022.160901(s’ouvre dans une nouvelle fenêtre) and https://doi.org/10.1016/j.marpolbul.2023.115604(s’ouvre dans une nouvelle fenêtre)). Three more publications are expected to arise from the action.
Continuous exposure of adult P. lividus to high concentrations of PVC leachates, containing high amounts of zinc (1µg/g), for two weeks does not affect their capacity to produce embryos and larvae, and fertilisation of eggs can also happen in these conditions. However, embryos grown in contaminated water have higher levels of arrested development at very early stages (before gastrulation) when they are derived from adults that were in contaminated water. We also found that, in contaminated conditions, adults show reduced immune cell counts and increased oxidative stress. Nevertheless, their production of gametes (but not embryogenesis) appears resilient to contaminated water. However, sublethal effects seen in the adults may lead to transgenerational effects that reduce developmental robustness of the embryos. (Jimenez-Guri et al., 2023).
These results have been disseminated in several conferences and meetings, and have been published in open access journals (https://dx.doi.org/10.1016/j.scitotenv.2022.160901(s’ouvre dans une nouvelle fenêtre) and https://doi.org/10.1016/j.marpolbul.2023.115604(s’ouvre dans une nouvelle fenêtre)). Three more publications are expected to arise from the action.
This project has progressed knowledge beyond the state of the art by systematically describing morphological effects of plastic leachates contamination in developing embryos, and mechanistically describing transcriptomic changes and metabolic consequences. We also further knowledge in the consequences of plastic leachate toxicity in adult sea urchins and show its implication in the increased oxidative stress of their immune cells. Further results on different species from the morphological and transcriptomic point of view are expected from this project. The results have the potential to greatly benefit the EU and beyond and strongly align to the Marine Strategy Framework Directive and the Strategy on Plastics in a Circular Economy Initiative, which deal with marine litter and the negative impacts on marine-related bio-diversity. Plastic waste is a topic of major societal interest, and media coverage around plastics and marine pollution suggests that this project is of great interest to the general public. Beneficiaries include fishermen/farmers and third sector (NGOs) along with and plastic manufacturers and policy makers.