RT Journal Article
SR Electronic
T1 Synaptonemal complex protects double-Holliday junctions during meiosis
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2024.09.14.613089
DO 10.1101/2024.09.14.613089
A1 Tang, Shangming
A1 Koo, Jennifer
A1 Pourhosseinzadeh, Mohammad
A1 Nguyen, Emerald
A1 Liu, Natalie
A1 Ma, Christopher
A1 Lu, Hanyu
A1 Lee, Monica
A1 Hunter, Neil
YR 2024
UL http://biorxiv.org/content/early/2024/09/15/2024.09.14.613089.abstract
AB Chromosomal linkages formed through crossover recombination are essential for accurate segregation of homologous chromosomes during meiosis1. DNA events of recombination are spatially and functionally linked to structural components of meiotic chromosomes2. Imperatively, biased resolution of double-Holliday junction (dHJ) intermediates into crossovers3,4 occurs within the synaptonemal complex (SC), the meiosis-specific structure that mediates homolog synapsis during the pachytene stage5,6. However, the SC’s role in crossing over remains unclear. Here we show that SC promotes crossover-specific resolution by protecting dHJs from unscheduled and aberrant resolution. When key SC components are conditionally inactivated during pachytene, dHJs are resolved into noncrossover products by Sgs1-Top3-Rmi1 (STR), the yeast ortholog of the human BLM complex7. Cohesin, the core component of SC lateral elements, plays a primary role in chromatin organization and is required to maintain both SCs and crossover recombination complexes (CRCs) during pachytene. SC central region component Zip1 is required to maintain CRCs even when dHJs are stabilized by inactivating STR. Reciprocally, SC stability requires continuous presence of CRCs, an unanticipated interdependence with important implications for SC dynamics. In conclusion, through hierarchical and interdependent functions of its key components, the SC enables crossover-specific dHJ resolution and thereby ensures the linkage and segregation of homologous chromosomes.Competing Interest StatementThe authors have declared no competing interest.