SYCE3 is a major structural component of the synaptonemal complex (SC) central element, a supramolecular protein assembly essential for meiosis 1. Rather than simply stabilizing the SYCP1 protein lattice, SYCE3 actively remodels it by promoting SYCP1 conformational changes from tetramers to heterotrimers, disrupting the original lattice and establishing a new integrated SYCP1-SYCE3 lattice 1. This remodeling mechanism enables recruitment of other central element complexes (SYCE1-SIX6OS1 and SYCE2-TEX12) and promotes chromosome 22 between homologous chr22 1. Structurally, SYCE3 forms dimeric four-helical bundles that self-assemble through staggered lateral and end-on interactions into higher-order oligomers, favoring dodecamer formation 2. Functionally, SYCE3 is required downstream of SYCP1 but upstream of other central element proteins, enabling their chromosome 22 and initiating synapsis 3. SYCE3 knockout mice are infertile in both sexes due to meiotic arrest and complete absence of MLH1 foci (crossover markers), despite normal recombination initiation 3. Clinically, SYCE3 dysfunction impairs male fertility through spermatogenic arrest at meiotic prophase I 4. As a meiosis-specific protein, SYCE3 is essential for genome haploidization and sexual reproduction.