Formation of the synaptonemal complex – a zipper-like structure that physically links homologous chromosomes – is a crucial event during meiosis. During its formation, transverse filaments composed of synaptonemal complex protein 1 (SYCP1) bridge the gap between two lateral elements and a central element. Until now, no proteins exclusive to this central element had been identified, but, on , Howard Cooke and colleagues describe two new mouse proteins – SYCE1 (synaptonemal complex central element 1) and CESC1 (central element synaptonemal complex 1) – that are recruited to the central element by SYCP1. The authors identified SYCE1 and CESC1 by using data from microarray expression profiling and show that both proteins localize exclusively to the central element of the synaptonemal complex. Other experiments reveal that SYCE1 and CESC1 form a complex with SYCP1. The authors hypothesize that, by separating and reinforcing the transverse filaments, SYCE1 and CESC1 help to assemble a robust synaptonemal complex that is, nevertheless, able to twist sufficiently to facilitate recombination during meiosis.
