Why do sex chromosomes progressively lose recombination?

Trends in Genetics, Journal Year: 2024, Volume and Issue: 40(7), P. 564 - 579

Published: April 27, 2024

Language: Английский

Tracing the evolution and genomic dynamics of mating-type loci inCryptococcuspathogens and closely related species

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 16, 2025

Sexual reproduction in basidiomycete fungi is governed by MAT loci ( P/R and HD ), which exhibit remarkable evolutionary plasticity, characterized expansions, rearrangements, gene losses often associated with mating system transitions. The sister genera Cryptococcus Kwoniella provide a powerful framework for studying evolution owing to their diverse reproductive strategies distinct architectures, spanning bipolar tetrapolar systems either linked or unlinked loci. Building on recent large-scale comparative genomic analyses, we generated additional chromosome-level assemblies uncovering trajectories shaping organization. Contrasting the small-scale expansions acquisitions observed , our analyses revealed independent of locus possibly driven pheromone duplications. Notably, these coincided an enrichment AT-rich codons pronounced GC-content reduction, likely recombination suppression relaxed codon usage selection. Diverse modes linkage were also identified, including three previously unrecognized transitions: one resulting pseudobipolar arrangement two leading bipolarity. All transitions involved translocations. In configuration, remained same chromosome but genetically unlinked, whereas additionally featured rearrangements that fused into nonrecombining region. Mating assays confirmed sexual cycle C. decagattii demonstrating its ability undergo sporulation. Progeny analysis K. mangrovensis substantial ploidy variation aneuploidy, stemming from haploid-diploid mating, yet evidence loss heterozygosity indicates meiotic exchange occurs despite irregular segregation. Our findings underscore importance continued diversity sampling provides further convergent basidiomycetes, offering new insights genetic chromosomal changes driving

Language: Английский

Evolution of a bipolar sexual compatibility system in Marasmius

Mycologia, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 15

Published: Dec. 11, 2024

Sexual compatibility in the Basidiomycota is governed by genetic identity at one or two loci, resulting systems called bipolar and tetrapolar. The loci are known as

Language: Английский