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Updated: Jul 3, 2026

Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II
Published on: February 26, 2018
Progression of meiotic recombination requires structural maturation of the central element of the synaptonemal
Geert Hamer1, Hong Wang, Ewelina Bolcun-Filas
1Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, Stockholm, Sweden.
Abstract:
The synaptonemal complex is an elaborate meiosis-specific supramolecular protein assembly that promotes chromosome synapsis and meiotic recombination. We inactivated the meiosis-specific gene Tex12 and found that TEX12 is essential for progression of meiosis in both male and female germ cells. Structural analysis of the synaptonemal complex in Tex12-/- meiocytes revealed a disrupted central element structure, a dense structure residing between the synapsed homologous chromosomes. Chromosome synapsis is initiated at multiple positions along the paired homologous chromosomes in Tex12-/- meiotic cells, but fails to propagate along the chromosomes. Furthermore, although meiotic recombination is initiated in Tex12-/- meiotic cells, these early recombination events do not develop into meiotic crossovers. Hence, the mere initiation of synapsis is not sufficient to support meiotic crossing-over. Our results show that TEX12 is a component of the central element structure of the synaptonemal complex required for propagation of synapsis along the paired homologous chromosomes and maturation of early recombination events into crossovers.
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