title: Progression of meiotic recombination requires structural maturation of the central element of the synaptonemal complex.
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.
authors.affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, Stockholm, Sweden.
authors.forename: Geert
authors.initials: G
authors.lastname: Hamer
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Ewelina
authors.initials: E
authors.lastname: Bolcun-Filas
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Cooke
authors.forename: Ricardo
authors.initials: R
authors.lastname: Benavente
authors.forename: Christer
authors.initials: C
authors.lastname: Höög
mesh_terms: D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D003434:Crossing Over, Genetic; D053903:DNA Breaks, Double-Stranded; D007150:Immunohistochemistry; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D011995:Recombination, Genetic; D013573:Synaptonemal Complex / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; C515820:TEX12 protein, mouse