Paper in eLife from Owen Davies

Owen Davies' work leads to a new model for the structure of the synaptonemal complex that holds homologous chromosomes together in meiosis.

A molecular model for the role of SYCP3 in meiotic chromosome organisation

Johanna Liinamaria, Syrjänen, Luca Pellegrini, Owen Richard Davies

eLife 2014;3:e02963    DOI:   

The synaptonemal complex (SC) is an evolutionarily-conserved protein assembly that holds together homologous chromosomes during prophase of the first meiotic division. Whilst essential for meiosis and fertility, the molecular structure of the SC has proved resistant to elucidation. The SC protein SYCP3 has a crucial but poorly understood role in establishing the architecture of the meiotic chromosome. Here we show that human SYCP3 forms a highly-elongated helical tetramer of 20 nm length. N-terminal sequences extending from each end of the rod-like structure bind double-stranded DNA, enabling SYCP3 to link distant sites along the sister chromatid. We further find that SYCP3 self-assembles into regular filamentous structures that resemble the known morphology of the SC lateral element. Together, our data form the basis for a model in which SYCP3 binding and assembly on meiotic chromosomes leads to their organisation into compact structures compatible with recombination and crossover formation.

Published: June 20, 2014

Last modified: Tue, 04 Aug 2015 16:10:56 BST