Convergent evolution of barnacles and molluscs sheds lights in origin and diversification of calcareous shell and sessile lifestyle
Yuan, Jianbo (2022), Convergent evolution of barnacles and molluscs sheds lights in origin and diversification of calcareous shell and sessile lifestyle, Dryad, Dataset, https://doi.org/10.5061/dryad.c866t1g8q
The calcareous shell and sessile lifestyle are the representative phenotypes of many molluscs, which happen to be present in barnacles, a group of unique crustaceans. The origin of these phenotypes is unclear, but it may be embodied in the convergent genetics of such distant groups (interphylum). Herein, we perform comprehensive comparative genomics analysis in barnacles and molluscs, and reveal a genome-wide strong convergent molecular evolution between them, including coexpansion of biomineralisation and organic matrix genes for shell formation, and origination of lineage-specific orphan genes for settlement. Notably, the expanded biomineralisation gene encoding alkaline phosphatase evolves a novel, highly conserved motif that may trigger the origin of barnacle shell formation. Unlike molluscs, barnacles adopt novel organic matrices and cement proteins for shell formation and settlement, respectively, and their calcareous shells have potentially originated from the cuticle system of crustaceans. Therefore, our study corroborates the idea that selection pressures driving convergent evolution may strongly act in organisms inhabiting similar environments regardless of phylogenetic distance. The convergence signatures shed light on the origin of the shell and sessile lifestyle of barnacles and molluscs. In addition, notable nonconvergence signatures are also present and may contribute to morphological and functional specificities.
National Natural Science Foundation of China, Award: 42176105
National Natural Science Foundation of China, Award: 31830100
National Natural Science Foundation of China, Award: 41876167