Medical Research Council - London Institute of Medical Sciences

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Worms and Ladders

Understanding the conservation of structure rather than sequence during evolution reveals novel proteins

06 March 2022

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

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