Worms and Ladders

First observed over 60 years ago, the synaptonemal complex is a ladder-like structure made of proteins that’s formed to join each chromosome pair when germ cells (egg or sperm) divide. Despite being an essential structure in eukaryotes (organisms whose cells have a clearly defined nucleus) the synaptonemal complex has a puzzling paradox. While its ladder-like ultrastructure with regularly spaced ‘rungs’ has remained conserved over time and species, the proteins that make up the synaptonemal structure evolve rapidly, making them hard to pinpoint using traditional methods. To break this paradox, scientists turned to other less conventional yet highly conserved features of protein evolution such as their coiled-coil structure and length. Doing so, enabled them to identify a new protein (magenta) found in the rungs of the synaptonemal complexes of the free-living roundworms Pristionchus pacificus.

Written by Katy Pallister

Katy Pallister

Writer

Katy is a freelance science educator, presenter, writer and producer based in London. She is a former Engagement and Events Officer at the MRC LMS.

• Image from work by Lisa E Kursel, Henry D Cope and Ofer Rog
• School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, Salt Lake City, UT, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, November 2021