synaptonemal complex , S.C. (Abkürzung)

In cell development the synaptonemal complex disappears during the late prophase of meiosis I.

During leptotene, lateral elements of the synaptonemal complex assemble.

It is now evident that the synaptonemal complex is not required for genetic recombination.

The synaptonemal complex is a tripartite structure consisting of two parallel lateral regions and a central element.

Recombination produces chiasmata which hold chromosomes together after the synaptonemal complex dissolves.

Spread preparations of synaptonemal complexes (SC) are obtained through surface tension on an aqueous solution.

Then the intervening regions of the chromosome are brought together, and may be connected by a protein-RNA complex called the synaptonemal complex.

At this stage, the synapsis (pairing/coming together) of homologous chromosomes takes place, facilitated by assembly of central element of the synaptonemal complex.

Research has shown that not only does it form after genetic recombination but mutant yeast cells unable to assemble a synaptonemal complex can still engage in the exchange of genetic information.

Because the chromosomes cannot be distinguished in the synaptonemal complex, the actual act of crossing over is not perceivable through the microscope, and chiasmata are not visible until the next stage.

Chromosome movement to accommodate recombination places homologous chromosomes close enough to each other for a protein complex (synaptonemal complex), consisting of a protein (ZIP1/ZYP1 depending on species), to hold them together.

The synaptonemal complex is a protein structure that forms between homologous chromosomes (two pairs of sister chromatids) during meiosis and that is thought to mediate chromosome pairing, synapsis, and recombination (crossing-over).

The synaptonemal complex (SC) was described by Montrose J. Moses in 1956 in primary spermatocytes of crayfish and by D. Fawcett in spermatocytes of pigeon, cat and man.

Synapsis begins before the synaptonemal complex develops, and is not completed until near the end of prophase I. Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome.

The introduction of a simple and rapid surface microspreading technique for the visualization of the synaptonemal complex at meiotic prophase in insect spermatocytes (36) has revolutionized our understanding of the behaviour of chromosomes during this important stage of meiosis.