The evolutionary path of the epithelial sodium channel δ-subunit in Cetartiodactyla points to a role in sodium sensing.

ABSTRACT: The epithelial sodium channel (ENaC) is essential for osmoregulation in tetrapod vertebrates. There are four ENaC-subunits (α, β, γ, δ) which form αβγ- or δβγ-ENaCs. While αβγ-ENaC is a 'maintenance protein' controlling sodium homeostasis, δβγ-ENaC might represent a 'stress protein' monitoring high sodium concentrations. The δ-subunit emerged with water-to-land transition of vertebrates. We examined ENaC evolution in Cetartiodactyla, a group including even-toed ungulates and cetaceans (whales, dolphins and porpoises) which returned to marine environments in the Eocene. Genes for α-, β-, and γ-ENaC are intact across Cetartiodactyla. While SCNN1D (δ-ENaC) is intact in terrestrial Artiodactyla, it is a pseudogene in cetaceans. A unique fusion of SCNN1D exons 11 and 12 is observed in the Antil

SUBMITTER: Zahnow F 

PROVIDER: S-EPMC12227717 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature