Building bridges to move recombination complexes

18 juin 2019Proceedings of the National Academy of Sciences

DOI : 10.1073/pnas.1901237116

Auteurs

Emeline Dubois, Arnaud De Muyt, Jessica L. Soyer, Karine Budin, Mathieu Legras, Tristan Piolot, Robert Debuchy, Nancy Kleckner, Denise Zickler, Eric Espagne

Résumé

Significance

The central feature of meiosis is pairing and recombination of homologous maternal and paternal chromosomes (homologs). Homolog axes become first coaligned at a certain distance; they then synapse by synaptonemal complex (SC) formation. We show that the structural and molecular pathway by which chromosomes transit from coalignment to the SC state in the fungus Sordaria macrospora involves the formation of robust interaxis bridges comprising axis component Spo76/Pds5, recombination proteins, and the evolutionary-conserved Zip2-Zip4 complex. Zip2-Zip4 mediates the recombination complex/structure interface from coalignment onward. These findings solve the conundrum of how recombination complexes move from on-axis localization at coalignment to between-axis localization on SC central regions and provoke new ideas about the molecular and mechanistic nature of SC nucleation.