PROPATHIN · PROtist PATHobiome-INvertebrate interactions: a multi-approach to understand marine diseases of commercial bivalves

Marine disease outbreaks can devastate populations, alter community structure and affect ecosystem health, which results in biodiversity loses and economic impacts on ecosystem services. Bivalves, which mediate ecosystem processes and functions and provide ecosystem services (e.g. food), harbour a wide variety of protists in their microbiome, including parasites and pathogens. Protist species produce important economic losses on the world’s leading shellfish industries due to parasitic disease outbreaks in bivalve hosts and the transmission of pathogens affecting human health. Although the economic implications of these outbreaks in shellfish aquaculture are significant, very little is known regarding their biology and ecology. In this context, PROPATHIN project is designed to advance our knowledge on marine and food-borne diseases caused by microbial eukaryotes (protists) associated to commercial bivalves, through the multidisciplinary study of protist-bivalve interactions at molecular, cellular and community level. I will employ recently developed molecular (metabarcoding) and ‘omic techniques (single-cell genomics and transcriptomics) coupled with traditional cell biology methods for diagnose of infectious organisms in multicellular hosts. I will assess the diversity, composition and dynamics of oysters and mussels pathobiome in the Ebro Delta aquaculture setting during a year cycle. Environmental parameters will be used to assess the dynamics of such hazardous protists related to seasonal changes. Further, we will sequence the genome and transcriptome of a protist parasite (including different life-cycle stages), from which very little information exists, revealing the genes involved in the infection of bivalve hosts. Overall, PROPATHIN will help us disentangle the nature and dynamics of such host-parasite relationships, crucial to prevent and mitigate their negative economic and societal impacts.