HGNC Approved Gene Symbol: SYCE3Cytogenetic location: 22q13.33 Genomic coordinates (GRCh38): 22:50,551,111-50,562,918 (from NCBI)▼ DescriptionSYCE3 is a crit...
HGNC Approved Gene Symbol: SYCE3
Cytogenetic location: 22q13.33 Genomic coordinates (GRCh38): 22:50,551,111-50,562,918 (from NCBI)
SYCE3 is a critical component of the synaptonemal complex, a meiosis-specific structure that mediates synapsis of homologous chromosomes and is essential for their proper recombination and segregation (Schramm et al., 2011).
▼ Cloning and Expression
Schramm et al. (2011) cloned mouse Syce3, and by database analysis, they identified orthologs in several vertebrates, including human. The deduced 88-amino acid mouse and human proteins share 90% identity, and both have a conserved coiled-coil region, a tyrosine phosphorylation site, and a serine phosphorylation site. RT-PCR analysis of 12 mouse tissues detected Syce3 in testis and embryonic ovary only. Syce3 expression in pubertal mouse testis first began on day 12, at the onset of prophase I of meiosis, and persisted in older animals. Immunoelectron microscopy localized Syce3 at the central element of the synaptonemal complex, where it colocalized with another central element protein, Syce1 (611486), in a continuous pattern along the synapsed chromosomes.
▼ Gene Function
Schramm et al. (2011) found that chromosome loading of Syce3 in mice appeared to require Sycp1 (602162). Cotransfection and immunoprecipitation experiments revealed that Syce3 interacted directly with Syce1 and possibly with Syce2 (611487).
Hartz (2014) mapped the SYCE3 gene to chromosome 22q13.33 based on an alignment of the SYCE3 sequence (GenBank BC127859) with the genomic sequence (GRCh37).
▼ Animal Model
Schramm et al. (2011) found that, although Syce3 -/- mice were indistinguishable from wildtype, both male and female Syce3 -/- mice were infertile. Syce3 deletion had no effect on initiation of meiotic recombination, but progression was severely impaired, and initiation of synapsis was blocked, resulting in meiotic arrest, complete absence of Mlh1 (120436) foci, and loss of meiotic cells to apoptosis. In Syce3 -/- pachytene-like spermatocytes, incorrect alignment of autosomes was rare, but sex chromosomes were frequently unpaired, both Syce1 and Syce2 were completely absent at axial elements, and gamma-H2ax (H2AFX; 601772) showed altered dynamics. Embryonic Syce3 -/- oocytes showed similar defects. Schramm et al. (2011) concluded that SYCE3 is required for initiation of central element assembly, chromosome loading of central element-specific proteins, and homologous recombination.