PT  - JOURNAL ARTICLE
AU  - Simone Köhler
AU  - Michal Wojcik
AU  - Ke Xu
AU  - Abby F. Dernburg
TI  - Dynamic molecular architecture of the synaptonemal complex
AID  - 10.1101/2020.02.16.947804
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2020.02.16.947804
4099  - http://biorxiv.org/content/early/2022/11/14/2020.02.16.947804.short
4100  - http://biorxiv.org/content/early/2022/11/14/2020.02.16.947804.full
AB  - During meiosis, pairing between homologous chromosomes is stabilized by the assembly of a protein lattice known as the synaptonemal complex (SC). The SC ensures the formation of crossovers between homologous chromosomes and also regulates their distribution. However, how the SC regulates crossover formation remains elusive. We isolated an unusual mutation in C. elegans that disrupts crossover interference but not the assembly of the SC. This mutation alters the unique C-terminal domain of an essential SC protein, SYP-4, a likely ortholog of the vertebrate SC protein SIX6OS1. To characterize the structure of the SC in wild-type and mutant animals, we use three-dimensional STochastic Optical Reconstruction Microscopy (3D-STORM) to interrogate the molecular architecture of the SC in intact germline tissue from C. elegans. The approach enabled us to define positions of protein epitopes with respect to the 3D architecture of this complex. Using a probabilistic mapping approach to analyze super-resolution image data, we detect a marked structural transition in wild-type animals that coincides with crossover designation. We also found that our syp-4 mutant subtly perturbs SC architecture. Our findings add to growing evidence that the SC is an active material whose molecular organization contributes to chromosome-wide crossover regulation.Competing Interest StatementThe authors have declared no competing interest.