Drivers of avian genomic change revealed by evolutionary rate decomposition

Nature, Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

Modern birds have diversified into a striking array of forms, behaviours and ecological roles. Analyses molecular evolutionary rates can reveal the links between genomic phenotypic change1–4, but disentangling drivers rate variation at whole-genome scale has been difficult. Using comprehensive estimates traits across family-level phylogeny birds5,6, we find that genome-wide mutation lineages are predominantly explained by clutch size generation length, whereas genes is driven content guanine cytosine. Here, to subsets dominate in birds, estimated influence individual on decomposed axes gene-specific rates. We most occurs along recent branches tree, associated with present-day families birds. Additional tests show rapid changes microchromosomes immediately after Cretaceous–Palaeogene transition. These apparent pulses evolution consistent major genetic machineries for meiosis, heart performance, RNA splicing, surveillance translation, correlate diversity reflected increased tarsus length. Collectively, our analyses paint nuanced picture avian evolution, revealing ancestors diverse underwent related mutation, gene usage niche expansion early Palaeogene period. Genomic identify dominant driving

Language: Английский

Holostean genomes reveal evolutionary novelty in the vertebrate immunoproteasome that have implications for MHCI function

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 3, 2024

Abstract Holosteans (gars and bowfins) have emerged as valuable models for understanding early vertebrate evolution, offering insights into diverse topics ranging from genomic architecture to molecular processes. These lineages also exhibit unusual features in their immune response, combining elements seen both tetrapods ray-finned fishes. However, the repertoire of holosteans remains relatively unexplored. Here, we investigate evolution PSMB8, a core component immunoproteasome responsible cleaving intracellular proteins peptides presentation by MHC class I molecules. We identify two holostean PSMB8 types—S type K type—that are unique among vertebrates. types likely cause significant biochemical changes S1 binding pocket involved antigen cleavage which could result novel I. Integrating comparative analyses across major fish demonstrates that bowfins gars independently evolved S within separate paralog lineages, while PSMB8-K is an evolutionary novelty found only gars. Our results provide new perspectives haplotypes role peptide processing, immunity presentation.

Language: Английский