scholarly journals The Cdc14 Phosphatase Controls Resolution of Recombination Intermediates and Crossover Formation during Meiosis

2021 ◽  
Vol 22 (18) ◽  
pp. 9811 ◽  
Author(s):  
Paula Alonso-Ramos ◽  
David Álvarez-Melo ◽  
Katerina Strouhalova ◽  
Carolina Pascual-Silva ◽  
George B. Garside ◽  
...  

Meiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. The coordinated resolution of meiotic recombination intermediates is required for crossover formation, ultimately necessary for the accurate completion of both rounds of chromosome segregation. Numerous master kinases orchestrate the correct assembly and activity of the repair machinery. Although much less is known, the reversal of phosphorylation events in meiosis must also be key to coordinate the timing and functionality of repair enzymes. Cdc14 is a crucial phosphatase required for the dephosphorylation of multiple CDK1 targets in many eukaryotes. Mutations that inactivate this phosphatase lead to meiotic failure, but until now it was unknown if Cdc14 plays a direct role in meiotic recombination. Here, we show that the elimination of Cdc14 leads to severe defects in the processing and resolution of recombination intermediates, causing a drastic depletion in crossovers when other repair pathways are compromised. We also show that Cdc14 is required for the correct activity and localization of the Holliday Junction resolvase Yen1/GEN1. We reveal that Cdc14 regulates Yen1 activity from meiosis I onwards, and this function is essential for crossover resolution in the absence of other repair pathways. We also demonstrate that Cdc14 and Yen1 are required to safeguard sister chromatid segregation during the second meiotic division, a late action that is independent of the earlier role in crossover formation. Thus, this work uncovers previously undescribed functions of the evolutionary conserved Cdc14 phosphatase in the regulation of meiotic recombination.

2009 ◽  
Vol 37 (3) ◽  
pp. 519-526 ◽  
Author(s):  
Stephen C. West

Four-way DNA intermediates, known as Holliday junctions, are formed during mitotic and meiotic recombination, and their efficient resolution is essential for proper chromosome segregation. Bacteria, bacteriophages and archaea promote Holliday junction resolution by the introduction of symmetrically related nicks across the junction, in reactions mediated by Holliday junction resolvases. In 2008, after a search that lasted almost 20 years, a Holliday junction resolvase was identified in humans. The protein, GEN1, was identified using MS following the brute-force fractionation of extracts prepared from human cells grown in tissue culture. GEN1 fits the paradigm developed from studies of prokaryotic Holliday junction resolvases, in that it specifically recognizes junctions and resolves them using a mechanism similar to that exhibited by the Escherichia coli RuvC protein.


Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Larry A Gilbertson ◽  
Franklin W Stahl

Abstract We tested predictions of the double-strand break repair (DSBR) model for meiotic recombination by examining the segregation patterns of small palindromic insertions, which frequently escape mismatch repair when in heteroduplex DNA. The palindromes flanked a well characterized DSB site at the ARC4 locus. The “canonical” DSBR model, in which only 5′ ends are degraded and resolution of the four-stranded intermediate is by Holliday junction resolvase, predicts that hDNA will frequently occur on both participating chromatids in a single event. Tetrads reflecting this configuration of hDNA were rare. In addition, a class of tetrads not predicted by the canonical DSBR model was identified. This class represented events that produced hDNA in a “trans” configuration, on opposite strands of the same duplex on the two sides of the DSB site. Whereas most classes of convertant tetrads had typical frequencies of associated crossovers, tetrads with trans hDNA were parental for flanking markers. Modified versions of the DSBR model, including one that uses a topoisomerase to resolve the canonical DSBR intermediate, are supported by these data.


2009 ◽  
Vol 138 (1) ◽  
pp. 78-89
Author(s):  
Samira Fekairi ◽  
Sarah Scaglione ◽  
Charly Chahwan ◽  
Ewan R. Taylor ◽  
Agnès Tissier ◽  
...  

1987 ◽  
Vol 105 (6) ◽  
pp. 2433-2446 ◽  
Author(s):  
D F Kubai

Meiosis I in males of the Dipteran Sciara coprophila results in the nonrandom distribution of maternally and paternally derived chromosome sets to the two division products. Based on an earlier study (Kubai, D.F. 1982. J. Cell Biol. 93:655-669), I suggested that the meiosis I spindle does not play a direct role in the nonrandom sorting of chromosomes but that, instead, haploid sets are already separated in prophase nuclei well before the onset of spindle formation. Here I report more direct evidence that this hypothesis is true; this evidence was gained from ultrastructural reconstruction analyses of the arrangement of chromosomes in germ line nuclei (prophase nuclei in spermatogonia and spermatocytes) of males heterozygous for an X-autosome chromosome translocation. Because of this translocation, the maternal and paternal chromosome sets are distinguishable, so it is possible to demonstrate that (a) the two haploid chromosome sets occupy distinct maternal and paternal nuclear compartments and that (b) nuclei are oriented so that the two haploid chromosome sets have consistent relationships to a well-defined cellular axis. The consequences of such nonrandom aspects of nuclear structure for chromosome behavior on premeiotic and meiotic spindles are discussed.


2017 ◽  
Author(s):  
Ye Hong ◽  
Maria Velkova ◽  
Nicola Silva ◽  
Marlène Jagut ◽  
Viktor Scheidt ◽  
...  

AbstractHomologous recombination is essential for crossover (CO) formation and accurate chromosome segregation during meiosis. It is of considerable importance to work out how recombination intermediates are processed leading to CO and non-crossover (NCO) outcome. Genetic analysis in budding yeast and Caenorhabditis elegans indicates that the processing of meiotic recombination intermediates involves a combination of nucleases and DNA repair enzymes. We previously reported that in C. elegans meiotic Holiday junction resolution is mediated by two redundant pathways, conferred by the SLX-1 and MUS-81 nucleases, and by the HIM-6 Blooms helicase in conjunction with the XPF-1 endonucleases, respectively. Both pathways require the scaffold protein SLX-4. However, in the absence of all these enzymes residual processing of meiotic recombination intermediates still occurs and CO formation is reduced but not abolished. Here we show that the LEM-3 nuclease, mutation of which by itself does not have an overt meiotic phenotype, genetically interacts with slx-1 and mus-81 mutants, the respective double mutants leading to 100% embryonic lethality. LEM-3 and MUS-81 act redundantly, their combined loss leading to a reduced number of early meiotic recombination intermediates, to a delayed disassembly of foci associated with CO designated sites, and to the formation of univalents linked by SPO-11 dependent chromatin bridges (dissociated bivalents). However, LEM-3 foci do not co-localize with ZHP-3 a marker that congresses into CO designated sites. In addition, neither CO frequency nor distribution is altered in lem-3 single mutants or in combination with mus-81 or slx-4 mutations, indicating that LEM-3 drives NCO outcome. Finally, we found persistent chromatin bridges during meiotic divisions in lem-3; slx-4 double mutants. Supported by the localization of LEM-3 between dividing meiotic nuclei, this data suggests that LEM-3 is able to process erroneous recombination intermediates that persist into the second meiotic divisions.Author SummaryMeiotic recombination is required for genetic diversity and for the proper chromosome segregation. Recombination intermediates, such as Holliday junctions (HJs), are generated and eventually resolved to produce crossover (CO) and non-crossover (NCO). While an excess of meiotic double-strand breaks is generated, most breaks are repaired without leading to a CO outcome and usually only one break for each chromosome pair matures into a CO-designated site in Caenorhabditis elegans. Resolution of meiotic recombination intermediates and CO formation have been reported to be highly regulated by several structure-specific endonucleases and the Bloom helicase. However, little is known about enzymes involved in the NCO recombination intermediate resolution. In this study, we found that a conserved nuclease LEM-3/Ankle1 acts in parallel to the SLX-1/MUS-81 pathway to process meiotic recombination intermediates. Mutation of lem-3 has no effect on CO frequency and distribution, indicating LEM-3 functions as a nuclease promoting NCO outcome. Interestingly, a prominent localization of LEM-3 is found between dividing meiotic nuclei. We provide evidence that LEM-3 is also involved in processing remaining, erroneous recombination intermediates during meiotic divisions.


2019 ◽  
Author(s):  
Paula Alonso-Ramos ◽  
David Álvarez-Melo ◽  
Katerina Strouhalova ◽  
Carolina Pascual-Silva ◽  
George B. Garside ◽  
...  

AbstractMeiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. Effective and coordinated resolution of meiotic recombination intermediates is necessary to accomplish both rounds of successful chromosome segregation. Cdc14 is an evolutionarily conserved dual-specificity phosphatase required for mitotic exit and meiotic progression. Mutations that inactivate the phosphatase lead to meiotic failure. Here, we have identified previously undescribed roles of Cdc14 in ensuring correct meiotic recombination. We found that recombination intermediates accumulate during prophase I when Cdc14 is depleted. Furthermore, Cdc14 plays a role in correct homolog disjunction at the end of anaphase I, both by modulating the timely removal of arm-cohesion between sister chromatids and by promoting elimination of SPO11-dependent entanglements. We also demonstrate that Cdc14 is required for correct sister chromatid segregation during the second meiotic division, independent of centromeric cohesion but dependent on the correct reduplication of SPBs during meiosis II, and on the activity of the Holliday Junction resolvase Yen1/GEN1. Timely activation of Yen1/GEN1 in anaphase I and II is impaired in the meiosis defective allele, cdc143HA. Based on these new findings, we propose previously undescribed functions of Cdc14 in the regulation of meiotic recombination; roles that are independent of sister chromatid cohesion, spindle dynamics and the metabolism of gamete morphogenesis.Author SummaryMeiotic recombination is fundamental for sexual reproduction, with efficient and orchestrated resolution of recombination intermediates critical for correct chromosome segregation. Homologous recombination is initiated by the introduction of programmed DNA Double-Strand Breakds (DSBs) followed by the formation of complex branched DNA intermediates, including double Holliday Junctions (dHJs). These recombination intermediates are eventually repaired into crossover or non-crossover products. In some cases, unresolved recombination intermediates, or toxic repair products, might persist until the metaphase to anaphase transition, requiring a set of late-acting repair enzymes to process them. Unrestrained activity of these enzymes, however, is equally detrimental for genome integrity, thus several layers of regulation tightly control them. For example, in budding yeast meiosis, Yen1/GEN1 is mainly activated during the second meiotic division, although how it is activated is unknown. Here, we have identified that the phosphatase Cdc14 is required during meiotic divisions for timely nuclear localization and activation of Yen1 in budding yeast meiosis. Additionally, we have been able to identify previously undescribed roles of Cdc14 in controlling meiotic recombination. Strikingly, we found that levels of recombination intermediates increase during prophase I in cdc14 meiotic deficient cells, indicating that Cdc14 plays a direct role in monitoring meiotic DSB repair, possibly in Yen1-independent manner. Resolution of recombination intermediates in the absence of Cdc14 is dependent on SGS1 and MUS81/MMS4, otherwise accumulating different types of aberrant recombination intermediates and a highly reduced efficiency in CO formation. Deficient resolution of JMs in cdc14 meiotic cells, together with difficulties in SPB reduplication, likely contribute to the missegregation problems observed during the second meiotic division.


Genetics ◽  
1992 ◽  
Vol 130 (1) ◽  
pp. 59-69
Author(s):  
J Bhargava ◽  
J Engebrecht ◽  
G S Roeder

Abstract A mutation at the REC102 locus was identified in a screen for yeast mutants that produce inviable spores. rec102 spore lethality is rescued by a spo13 mutation, which causes cells to bypass the meiosis I division. The rec102 mutation completely eliminates meiotically induced gene conversion and crossing over but has no effect on mitotic recombination frequencies. Cytological studies indicate that the rec102 mutant makes axial elements (precursors to the synaptonemal complex), but homologous chromosomes fail to synapse. In addition, meiotic chromosome segregation is significantly delayed in rec102 strains. Studies of double and triple mutants indicate that the REC102 protein acts before the RAD52 gene product in the meiotic recombination pathway. The REC102 gene was cloned based on complementation of the mutant defect and the gene was mapped to chromosome XII between CDC25 and STE11.


2009 ◽  
Vol 138 (1) ◽  
pp. 63-77
Author(s):  
Jennifer M. Svendsen ◽  
Agata Smogorzewska ◽  
Mathew E. Sowa ◽  
Brenda C. O'Connell ◽  
Steven P. Gygi ◽  
...  

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