Characterization of the cardiac phospholipidome of small cetaceans provides adaptational insight and a foundation for indirect population health screening

Abstract

AbstractThe maintenance of a tightly regulated heart lipidome is a general hallmark of mammal health. However, in the case of cetaceans, heart tissue lipid composition remains obscure. This work represents a first in‐depth state‐of‐the‐art characterization of the lipid content of small cetacean hearts, namely those of Delphinus delphis, Phocoena phocoena, and Stenella coeruleoalba. Phospholipid classes identified were similar to those found in terrestrial mammals. Regarding fatty acid profiles, they revealed a much higher n‐3 fatty acid content than that reported for terrestrial counterparts. Phospholipidome characterization allowed identification of 198 lipid species, including phospholipids, lysophospholipids, and sphingomyelins, generally characterized by a high content of species with esterified n‐3 fatty acids. The cardiac lipid profile of the three cetacean species is similar in terms of lipid classes, fatty acids, and even molecular lipid species present. However, quantitative differences suggest a divergence of S. coeruleoalba from the other species in terms of fatty acid and phospholipid profile. The identified differences regarding terrestrial counterparts will contribute to better understanding the details of small cetacean cardiac physiology. Moreover, the characterization of cardiac phospholipidome may represent an opportunity to establish lipidomic‐based practical tools to reliably and reproducibly assess small cetacean health population status by remote sampling.