Holocentric chromosomes reshape genome evolution and meiosis

We report three new studies that together provide a comprehensive view of how holocentric chromosomes influence genome evolution, karyotype dynamics, and meiotic recombination.

1. Using a pangenome framework, we show that holocentric centromeres are built on highly dynamic repeat landscapes that evolve rapidly across genomes.

These repeat-based centromeres provide a flexible chromosomal architecture that tolerates extensive structural variation.

2. Extending this approach, we demonstrate that karyotype evolution and meiotic recombination landscapes are tightly linked in holocentric systems.

Structural rearrangements are not merely tolerated but are coupled to changes in recombination distribution, highlighting a deep connection between chromosome structure and meiotic regulation.

3. Finally, we describe an extreme meiotic outcome in the holocentric plant Rhynchospora tenuis, where chromosomes segregate faithfully without crossovers, effectively mimicking clonal reproduction despite sexual reproduction.

This finding challenges canonical views of meiosis and underscores the evolutionary plasticity enabled by holocentric chromosome organization.

Together, these studies establish holocentric chromosomes as a powerful system for understanding how centromere architecture shapes genome evolution and meiotic strategies.

 

Preprints:

•  https://doi.org/10.64898/2026.01.17.700053 
• https://doi.org/10.64898/2026.01.17.700048 
• https://doi.org/10.64898/2026.01.17.700054