Comparative Genomics Reveals Genetic Adaptations to Diving-Associated Foraging in Anseriformes.

Diving behavior in waterfowl represents a remarkable physiological adaptation requiring extensive genetic modifications to cope with hypoxic and high-pressure underwater environments. We analyzed 25 Anseriformes genomes, representing diverse foraging strategies, and identified 13,873 orthogroups with 7991 single-copy orthogroups across all species. Comparative genomic analysis revealed significant positive selection signatures in diving waterfowl, with GO and KEGG enrichment analyses highlighting key functional adaptations in metabolic regulation, transmembrane and immune responses. Metabolic pathways showed enrichment in insulin secretion and peptide hormone regulation, while transport mechanisms dominated molecular functions, including ion channels and solute transporters essential for maintaining cellular homeostasis under hypoxic conditions. Neural adaptations were evident through enrichment of postsynaptic density components and neurotransmitter transport systems. We identified nine genes with shared amino acid substitutions across diving species, including critical genes PLB1, PKD1, and GPR34. These findings demonstrate convergent molecular evolution in diving waterfowl, revealing the genetic basis underlying successful aquatic foraging strategies.