Convergent Evolution of Biochemical Innovations in Polychaetes: Characterizing the Molecular Basis of Bioluminescence and Venom Production

The convergent evolution of phenotypic traits is a widespread phenomenon across the tree of life and is explained as the outcome of different taxa facing similar selective forces or environmental conditions. A longstanding question in evolutionary biology is whether the evolution of convergent phenotypes in unrelated lineages is driven by similar or different molecular processes. The research presented here investigates this question by characterizing the molecular basis of two biochemical innovations, bioluminescence and venom production, that have evolved independently in different lineages of polychaetes worms (Annelida). We use an integrative approach, combining next-generation sequencing, phylogenetics and computational tools to evaluate whether these two convergent traits are the result of similar genetic and molecular mechanisms in different lineages. We have generated a great amount of genomic resources that allowed us to investigate bioluminescence and identify candidate genes responsible for light production in three species of Syllidae (Chapters 2 and 3) and Polynoidae (Chapter 4), as well as a wide diversity of putative toxins in the transcriptomes of three Amphinomidae species (Chapter 5) and four Polynoidae species (Chapter 6). Our results provide a more comprehensive scenario to understand the molecular basis, gene expression patterns and evolution of bioluminescence and venom production in polychaetes, and suggest that convergent traits are generally the result of similar molecular mechanisms in unrelated lineages