Natural selection directing molecular evolution in vertebrate viral sensors

• Published in: Developmental and comparative immunology Vol. 154; p. 105147
• Main Authors: Melepat, Balraj, Li, Tao, Vinkler, Michal
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.05.2024
• Subjects: Evolutionary adaptation; Innate immunity; Molecular evolution; Pattern recognition receptor; Positive selection; Virus detection; Molecular evolution; Innate immunity; Virus detection; Positive selection; Evolutionary adaptation; Pattern recognition receptor
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2024.105147

Diseases caused by pathogens contribute to molecular adaptations in host immunity. Variety of viral pathogens challenging animal immunity can drive positive selection diversifying receptors recognising the infections. However, whether distinct virus sensing systems differ across animals in their evolutionary modes remains unclear. Our review provides a comparative overview of natural selection shaping molecular evolution in vertebrate viral-binding pattern recognition receptors (PRRs). Despite prevailing negative selection arising from the functional constraints, multiple lines of evidence now suggest diversifying selection in the Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs) and oligoadenylate synthetases (OASs). In several cases, location of the positively selected sites in the ligand-binding regions suggests effects on viral detection although experimental support is lacking. Unfortunately, in most other PRR families including the AIM2-like receptor family, C-type lectin receptors (CLRs), and cyclic GMP-AMP synthetase studies characterising their molecular evolution are rare, preventing comparative insight. We indicate shared characteristics of the viral sensor evolution and highlight priorities for future research. •We review natural selection acting on vertebrate receptors recognising viruses.•Positive selection targets both ligand-binding and signalling domains.•Receptors binding viral nucleic acids show less positive selection than others.•To majority of receptor genes we have limited information on molecular evolution.•Molecular adaptations clarify evolution of diversity in animal immunity.