Gamete interaction protein evolution evinces Pantherines hybridizing history

FRANCISCO PISCIOTTANO; CAMPOS, MARÍA CLARA; PENNA, CLEMENTINA; BRUQUE, DAVID; GABALDÓN, TONI; SARAGÜETA, PATRICIA

MOLECULAR ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023

0962-1083

The jaguar (Panthera onca) is the most relevant predator in South America and a criticallyendangered species in Argentina. Genomic, evolutionary and functional studies of this species are strategic to gain biological insights and support conservation efforts. Recent comparative genomic analysis revealed a history of hybridization among extant big cats, which indicates an absence of inter-specific isolation barriers. The molecular basis of this inter-species crossing and the evolution of pantherine gamete interaction Zona Pellucida proteins (ZP) and IZUMO1R were uncovered. A chromosome-resolved jaguar genome assembly was used to resolve ZP genes loci and reconstruct the evolutionary history of these proteins. Exploring sequence variability in more that 30 Carnivora species, Feliformia displays significant lower diversity than its sister taxa, Caniformia, for all studied proteins except ZP4. Molecular evolution of ZP3 and ZP2, subunits directly involved in sperm-recognition, resembled similar phylogenetic histories, displaying signatures of positive selection for Carnivores and Caniformes subtrees, but not among Pantherines or Feliformes. On the other hand, structural cross-linking ZP subunits, ZP1 and ZP4, displayed different evolutionary histories. The fusion protein IZUMO1R was found to be deprived of diversifying selection signatures along the evolutionary history of all studied phylogenetic groups. These results strengthen the idea that ZPs are proteins more related to specific-specificity isolation than IZUMO1R. Altogether, our findings indicate that sperm-oocyte interaction and fusion proteins lack the degree of diversification necessary to establish a prezygotic reproductive isolation barrier between pantherines, which would explain the events of hybridization, a strategy that would salvage them from extinction. (EN REVISIÓN)