Synaptonemal complex

The synaptonemal complex (SC) is a protein structure that forms between homologous chromosomes (two pairs of sister chromatids) during meiosis and is thought to mediate chromosome pairing, synapsis, and recombination. It is now evident that the synaptonemal complex is not required for genetic recombination in some organisms. For instance, in protozoan ciliates such as Tetrahymena thermophila and Paramecium tetraurelia genetic crossover does not appear to require synaptonemal complex formation. Research has shown that not only does the SC form after genetic recombination but mutant yeast cells unable to assemble a synaptonemal complex can still engage in the exchange of genetic information. However, in other organisms like the C. elegans nematode, formation of chiasmata require the formation of the synaptonemal complex. It is currently thought that the SC functions primarily as a scaffold to allow interacting chromatids to complete their crossover activities. The synaptonemal complex is a tripartite structure consisting of two parallel lateral regions and a central element. The synaptonemal complex (SC) is a protein structure that forms between homologous chromosomes (two pairs of sister chromatids) during meiosis and is thought to mediate chromosome pairing, synapsis, and recombination. It is now evident that the synaptonemal complex is not required for genetic recombination in some organisms. For instance, in protozoan ciliates such as Tetrahymena thermophila and Paramecium tetraurelia genetic crossover does not appear to require synaptonemal complex formation. Research has shown that not only does the SC form after genetic recombination but mutant yeast cells unable to assemble a synaptonemal complex can still engage in the exchange of genetic information. However, in other organisms like the C. elegans nematode, formation of chiasmata require the formation of the synaptonemal complex. It is currently thought that the SC functions primarily as a scaffold to allow interacting chromatids to complete their crossover activities. The synaptonemal complex is a tripartite structure consisting of two parallel lateral regions and a central element. Three specific components of the synaptonemal complex have been characterized: SC protein-1 (SYCP1), SC protein-2 (SYCP2), and SC protein-3 (SYCP3). In humans, the SYCP1 gene is on chromosome 1p13; the SYCP2 gene is on chromosome 20q13.33; and the gene for SYCP3 is on chromosome 12q.