Plastic debris contamination is a growing environmental concern in marine habitats. Large plastic objects break-up over time to create micro- and nano- particles, collectively called microplastics (MP), which account for the overwhelming majority of plastic particles in the sea. Little is known about the impacts of MP on wildlife or humans and this presents an important research priority. Several studies have demonstrated that MP can affect sea life negatively. Amongst these, they have been reported affecting development (causing malformations, delayed growth and increased death rates). These developmental effects have never been characterised, and their molecular basis remains unknown. Developmental defects may impact population survival by decreasing the number of individuals, or their fitness, in range of marine organisms. This pioneering project will identify the effects of MP exposure in the development of the sea urchin Paracentrotus lividus, bridging interests for ecology, toxicology, developmental biology and aquaculture. I will characterise the developmental morphological malformations caused by MP and their underlying genetic mechanisms. This Fellowship will provide an excellent opportunity to complement my strong background in genetics and molecular and developmental biology and expertise in ecotoxicology and microplastic pollution with transcriptomic analysis and the deep understanding of this model organism for development and toxicology under the supervision of Dr. Arnone, a world leading expert in the field. This will provide me with a firm skill set and knowledge to further my research career. The knowledge and expertise I will acquire in the Arnone lab, together with being hosted by a supportive and acclaimed institution, and the prestige of the MSCA fellowship, will allow me to open a unique and timely line of research and will be crucial for my transition into an independent European researcher.