Additional Funding Sources
The project described was supported by the Research Experience for Undergraduates Program Site: Molecular and organismal evolution at the University of Idaho under Award No. 1757826.
Abstract
Sexual selection is the specific form of selection that acts upon an organism’s ability to reproduce. Theory predicts that stronger sexual selection will result in a higher average dN/dS value (a metric that measures selection in a given gene) across an organism’s protein-coding genome due to increased positive selection; however, this prediction has not yet been tested on real genomic data. The fish family Syngnathidae provides the ideal model system to test this prediction. Within this family, the genus Syngnathus (pipefish) is under strong sexual selection due to a polygamous mating system, while the sister genus Hippocampus (seahorses) is under weaker sexual selection due to a monogamous mating system. In this study, we use a comparative genomics approach with three Hippocampus species (H. comes, H. kuda, H. whitei) and three Syngnathus species (S. acus, S. rostellatus, S. typhle) to demonstrate that pipefish species have a higher average dN/dS value across their protein-coding genome than seahorse species. This result supports the theoretical prediction that strength of sexual selection is positively associated with average dN/dS. Additionally, our results demonstrate that sexual selection alone can be a powerful force in driving genomic evolution.
Comparing Signatures of Sexual Selection in Seahorse and Pipefish Genomes
Sexual selection is the specific form of selection that acts upon an organism’s ability to reproduce. Theory predicts that stronger sexual selection will result in a higher average dN/dS value (a metric that measures selection in a given gene) across an organism’s protein-coding genome due to increased positive selection; however, this prediction has not yet been tested on real genomic data. The fish family Syngnathidae provides the ideal model system to test this prediction. Within this family, the genus Syngnathus (pipefish) is under strong sexual selection due to a polygamous mating system, while the sister genus Hippocampus (seahorses) is under weaker sexual selection due to a monogamous mating system. In this study, we use a comparative genomics approach with three Hippocampus species (H. comes, H. kuda, H. whitei) and three Syngnathus species (S. acus, S. rostellatus, S. typhle) to demonstrate that pipefish species have a higher average dN/dS value across their protein-coding genome than seahorse species. This result supports the theoretical prediction that strength of sexual selection is positively associated with average dN/dS. Additionally, our results demonstrate that sexual selection alone can be a powerful force in driving genomic evolution.