Repeated MDA5 Gene Loss in Birds: An Evolutionary Perspective.
Viruses
; 13(11)2021 10 22.
Article
de En
| MEDLINE
| ID: mdl-34834938
ABSTRACT
Two key cytosolic receptors belonging to the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) family sense the viral RNA-derived danger signals RIG-I and melanoma differentiation-associated protein 5 (MDA5). Their activation establishes an antiviral state by downstream signaling that ultimately activates interferon-stimulated genes (ISGs). While in rare cases RIG-I gene loss has been detected in mammalian and avian species, most notably in the chicken, MDA5 pseudogenization has only been detected once in mammals. We have screened over a hundred publicly available avian genome sequences and describe an independent disruption of MDA5 in two unrelated avian lineages, the storks (Ciconiiformes) and the rallids (Gruiformes). The results of our RELAX analysis confirmed the absence of negative selection in the MDA5 pseudogene. In contrast to our prediction, we have shown, using multiple dN/dS-based approaches, that the MDA5 loss does not appear to have resulted in any compensatory evolution in the RIG-I gene, which may partially share its ligand-binding specificity. Together, our results indicate that the MDA5 pseudogenization may have important functional effects on immune responsiveness in these two avian clades.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Oiseaux
/
Délétion de gène
/
Protéines aviaires
/
Protéine-58 à domaine DEAD
Type d'étude:
Prognostic_studies
Limites:
Animals
/
Humans
Langue:
En
Journal:
Viruses
Année:
2021
Type de document:
Article
Pays d'affiliation:
République tchèque