Uncovering opsin diversity among bivalve mollusks: molecular evolution and roles associated with visual systems

• Grant number: 22/14347-1
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: May 10, 2023
• End date: October 09, 2023
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: José Eduardo Amoroso Rodriguez Marian
• Grantee: Jorge Alves Audino
• Supervisor: Jeanne Marie Serb
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Iowa State University, United States
• Associated to the scholarship: 19/18834-1 - Diversity and evolution of Bivalve sensory systems: a unifying approach based on comparative transcriptomics and integrative microscopy, BP.PD

Abstract

Eyes provide a tractable system to study how molecular and morphological traits can jointly result in new functions. For instance, visual adaptations frequently result from combinations of opsin-based photopigments and optical components. However, our understanding is limited by eye anatomy and opsin expression data which are missing for many invertebrate visual systems. Bivalve mollusks display a remarkable diversity of photoreceptor organs, including five main types, ranging from simple pigmented cups to complex mirror eyes. While eyes have independently evolved in the group with many subsequent losses, opsin evolution remains largely unexplored in bivalves. In this context, the present research proposal aims to generate transcriptomic data from eyes and mantle tissue for ten species of pteriomorphian bivalves, sampling from all five orders. Candidate opsins will be retrieved and classified based on modern standard procedures, including protein database comparisons and phylogenetic membership. Additional comparative analyses will be conducted to estimate likely functional sites, infer the molecular evolution of bivalve opsins, and investigate their association with different photoreceptor organs. Protein expression in vitro will be tested with selected opsins to determine their spectral sensitivity using spectrophotometry. Overall, the collaboration with the Serb Lab should provide the foundation to investigate opsin evolution and diversity among bivalves. These novel results will allow us to explore eye diversity from a functional perspective and test evolutionary hypotheses across different biological levels, i.e., from molecules to anatomy. (AU)