scholarly journals MER3 is required for normal meiotic crossover formation, but not for presynaptic alignment in rice

2009 ◽  
Vol 122 (12) ◽  
pp. 2055-2063 ◽  
Author(s):  
K. Wang ◽  
D. Tang ◽  
M. Wang ◽  
J. Lu ◽  
H. Yu ◽  
...  
Keyword(s):  
Meiotic Crossover

scholarly journals Distinct prophase arrest mechanisms in human male meiosis

2017 ◽  
Author(s):  
Sabrina Z. Jan ◽  
Aldo Jongejan ◽  
Cindy M. Korver ◽  
Saskia K. M. van Daalen ◽  
Ans M. M. van Pelt ◽  
...  
Keyword(s):  
Genomic Stability ◽  
Male Meiosis ◽  
Type I ◽  
Type Ii ◽  
Meiotic Arrest ◽  
Homologous Chromosomes ◽  
Xy Body ◽  
Chromosome Synapsis ◽  
Human Male ◽  
Meiotic Crossover

To prevent chromosomal aberrations to be transmitted to the offspring, strict meiotic checkpoints are in place to remove aberrant spermatocytes. However, in about 1% of all males these checkpoints cause complete meiotic arrest leading to azoospermia and subsequent infertility. We here unravel two clearly distinct meiotic arrest mechanisms that act during the prophase of human male meiosis. Type I arrested spermatocytes display severe asynapsis of the homologous chromosomes, disturbed XY-body formation and increased expression of the Y-chromosome encoded gene ZFY and seem to activate a DNA damage pathway leading to induction of p63 mediated spermatocyte elimination. Type II arrested spermatocytes display normal chromosome synapsis, normal XY-body morphology and meiotic crossover formation but have a lowered expression of several cell cycle regulating genes and fail to properly silence the X-chromosome encoded gene ZFX. Discovery and understanding of these meiotic arrest mechanisms increases our knowledge on how genomic stability is guarded during human germ cell development.

scholarly journals Molecular basis of the dual role of the Mlh1-Mlh3 endonuclease in MMR and in meiotic crossover formation

2021 ◽  
Vol 118 (23) ◽  
pp. e2022704118
Author(s):  
Jingqi Dai ◽  
Aurore Sanchez ◽  
Céline Adam ◽  
Lepakshi Ranjha ◽  
Giordano Reginato ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Molecular Basis ◽  
Crystal Packing ◽  
Critical Role ◽  
Holliday Junctions ◽  
Dual Roles ◽  
Terminal Domain ◽  
C Terminus ◽  
Meiotic Crossover

In budding yeast, the MutL homolog heterodimer Mlh1-Mlh3 (MutLγ) plays a central role in the formation of meiotic crossovers. It is also involved in the repair of a subset of mismatches besides the main mismatch repair (MMR) endonuclease Mlh1-Pms1 (MutLα). The heterodimer interface and endonuclease sites of MutLγ and MutLα are located in their C-terminal domain (CTD). The molecular basis of MutLγ’s dual roles in MMR and meiosis is not known. To better understand the specificity of MutLγ, we characterized the crystal structure of Saccharomyces cerevisiae MutLγ(CTD). Although MutLγ(CTD) presents overall similarities with MutLα(CTD), it harbors some rearrangement of the surface surrounding the active site, which indicates altered substrate preference. The last amino acids of Mlh1 participate in the Mlh3 endonuclease site as previously reported for Pms1. We characterized mlh1 alleles and showed a critical role of this Mlh1 extreme C terminus both in MMR and in meiotic recombination. We showed that the MutLγ(CTD) preferentially binds Holliday junctions, contrary to MutLα(CTD). We characterized Mlh3 positions on the N-terminal domain (NTD) and CTD that could contribute to the positioning of the NTD close to the CTD in the context of the full-length MutLγ. Finally, crystal packing revealed an assembly of MutLγ(CTD) molecules in filament structures. Mutation at the corresponding interfaces reduced crossover formation, suggesting that these superstructures may contribute to the oligomer formation proposed for MutLγ. This study defines clear divergent features between the MutL homologs and identifies, at the molecular level, their specialization toward MMR or meiotic recombination functions.

Hed1 Promotes Meiotic Crossover Formation in Saccharomyces cerevisiae

2017 ◽  
Vol 27 (2) ◽  
pp. 405-411
Author(s):  
Yoon-Ju Kong ◽  
Jeong-Hwan Joo ◽  
Keun Pil Kim ◽  
Soogil Hong
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Crossover

scholarly journals CXXC finger protein 1-mediated histone H3 lysine-4 trimethylation is essential for proper meiotic crossover formation in mice

Development ◽  
2020 ◽  
Vol 147 (6) ◽  
pp. dev183764 ◽  
Author(s):  
Yu Jiang ◽  
Hui-Ying Zhang ◽  
Zhen Lin ◽  
Ye-Zhang Zhu ◽  
Chao Yu ◽  
...  
Keyword(s):  
Histone H3 ◽  
Finger Protein ◽  
Meiotic Crossover ◽  
Cxxc Finger Protein 1
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