scholarly journals Pds5 is required for homologue pairing and inhibits synapsis of sister chromatids during yeast meiosis

2009 ◽  
Vol 186 (5) ◽  
pp. 713-725 ◽  
Author(s):  
Hui Jin ◽  
Vincent Guacci ◽  
Hong-Guo Yu
Keyword(s):  
Sister Chromatid ◽  
Morphological Changes ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Strand Breaks ◽  
Meiotic Chromosomes ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Cohesin Subunit ◽  
Yeast Meiosis

During meiosis, homologues become juxtaposed and synapsed along their entire length. Mutations in the cohesin complex disrupt not only sister chromatid cohesion but also homologue pairing and synaptonemal complex formation. In this study, we report that Pds5, a cohesin-associated protein known to regulate sister chromatid cohesion, is required for homologue pairing and synapsis in budding yeast. Pds5 colocalizes with cohesin along the length of meiotic chromosomes. In the absence of Pds5, the meiotic cohesin subunit Rec8 remains bound to chromosomes with only minor defects in sister chromatid cohesion, but sister chromatids synapse instead of homologues. Double-strand breaks (DSBs) are formed but are not repaired efficiently. In addition, meiotic chromosomes undergo hypercondensation. When the mitotic cohesin subunit Mcd1 is substituted for Rec8 in Pds5-depleted cells, chromosomes still hypercondense, but synapsis of sister chromatids is abolished. These data suggest that Pds5 modulates the Rec8 activity to facilitate chromosome morphological changes required for homologue synapsis, DSB repair, and meiotic chromosome segregation.

scholarly journals Eco1-dependent cohesin acetylation anchors chromatin loops and cohesion to define functional meiotic chromosome domains

2021 ◽  
Author(s):  
Rachael E Barton ◽  
Lucia F Massari ◽  
Daniel Robertson ◽  
Adele L Marston
Keyword(s):  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Meiotic Chromosome ◽  
Chromatin Loops ◽  
Meiotic Chromosomes ◽  
Sister Chromatids ◽  
Gamete Formation ◽  
Chromosome Domains ◽  
Chromatid Cohesion ◽  
Cohesin Subunit

Cohesin organizes the genome by forming intra-chromosomal loops and inter-sister chromatid linkages. During gamete formation by meiosis, chromosomes are reshaped to support crossover recombination and two consecutive rounds of chromosome segregation. Here we show that Eco1 acetyltransferase positions both chromatin loops and sister chromatid cohesion to organize meiotic chromosomes into functional domains in budding yeast. Eco1 acetylates the Smc3 cohesin subunit in meiotic S phase to establish chromatin boundaries, independently of DNA replication. Boundary formation by Eco1 is critical for prophase exit and for the maintenance of cohesion until meiosis II, but is independent of the ability of Eco1 to antagonize the cohesin-release factor, Wpl1. Conversely, prevention of cohesin release by Wpl1 is essential for centromeric cohesion, kinetochore monoorientation and co-segregation of sister chromatids in meiosis I. Our findings establish Eco1 as a key determinant of chromatin boundaries and cohesion positioning, revealing how local chromosome structuring directs genome transmission into gametes.

scholarly journals The Multiple Roles of Cohesin in Meiotic Chromosome Morphogenesis and Pairing

2009 ◽  
Vol 20 (3) ◽  
pp. 1030-1047 ◽  
Author(s):  
Gloria A. Brar ◽  
Andreas Hochwagen ◽  
Ly-sha S. Ee ◽  
Angelika Amon
Keyword(s):  
Sister Chromatid ◽  
Meiotic Prophase ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Multiple Roles ◽  
Axis Formation ◽  
Chromatid Cohesion ◽  
Cohesin Subunit ◽  
Chromosome Axis ◽  
Segregation Of Chromosomes

Sister chromatid cohesion, mediated by cohesin complexes, is laid down during DNA replication and is essential for the accurate segregation of chromosomes. Previous studies indicated that, in addition to their cohesion function, cohesins are essential for completion of recombination, pairing, meiotic chromosome axis formation, and assembly of the synaptonemal complex (SC). Using mutants in the cohesin subunit Rec8, in which phosphorylated residues were mutated to alanines, we show that cohesin phosphorylation is not only important for cohesin removal, but that cohesin's meiotic prophase functions are distinct from each other. We find pairing and SC formation to be dependent on Rec8, but independent of the presence of a sister chromatid and hence sister chromatid cohesion. We identified mutations in REC8 that differentially affect Rec8's cohesion, pairing, recombination, chromosome axis and SC assembly function. These findings define Rec8 as a key determinant of meiotic chromosome morphogenesis and a central player in multiple meiotic events.

scholarly journals Shugoshin is essential for meiotic prophase checkpoints in C. elegans

2018 ◽  
Author(s):  
Tisha Bohr ◽  
Christian R. Nelson ◽  
Stefani Giacopazzi ◽  
Piero Lamelza ◽  
Needhi Bhalla
Keyword(s):  
Sister Chromatid ◽  
Meiotic Prophase ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Chromosomal Protein ◽  
Loss Of Function ◽  
Chromosome Architecture ◽  
C Elegans ◽  
Meiotic Chromosomes ◽  
Chromatid Cohesion

AbstractThe conserved factor Shugoshin is dispensable in C. elegans for the two-step loss of sister chromatid cohesion that directs the proper segregation of meiotic chromosomes. We show that the C. elegans ortholog of Shugoshin, SGO-1, is required for checkpoint activity in meiotic prophase. This role in checkpoint function is similar to that of the meiotic chromosomal protein, HTP-3. Null sgo-1 mutants exhibit additional phenotypes similar to that of a partial loss of function allele of HTP-3: premature synaptonemal complex disassembly, the activation of alternate DNA repair pathways and an inability to recruit a conserved effector of the DNA damage pathway, HUS-1. SGO-1 localizes to pre-meiotic nuclei, when HTP-3 is present but not yet loaded onto chromosome axes, suggesting an early role in regulating meiotic chromosome metabolism. We propose that SGO-1 acts during pre-meiotic replication to ensure fully functional meiotic chromosome architecture, rendering these chromosomes competent for checkpoint activity and normal progression of meiotic recombination. Given that most research on Shugoshin has been focused on its regulation of sister chromatid cohesion in meiosis, this novel role may be conserved but previously uncharacterized in other organisms. Further, our findings expand the repertoire of Shugoshin’s functions beyond coordinating regulatory activities at the centromere.

scholarly journals Scc2 regulates gene expression by recruiting cohesin to the chromosome as a transcriptional activator during yeast meiosis

2011 ◽  
Vol 22 (12) ◽  
pp. 1985-1996 ◽  
Author(s):  
Weiqiang Lin ◽  
Hui Jin ◽  
Xiuwen Liu ◽  
Kristin Hampton ◽  
Hong-Guo Yu
Keyword(s):  
Gene Expression ◽  
Sister Chromatid ◽  
Gene Activation ◽  
Transcriptional Activator ◽  
Sister Chromatid Cohesion ◽  
Dependent Manner ◽  
Chromatid Cohesion ◽  
Cohesin Subunit ◽  
Yeast Meiosis ◽  
Target Promoters

To tether sister chromatids, a protein-loading complex, including Scc2, recruits cohesin to the chromosome at discrete loci. Cohesin facilitates the formation of a higher-order chromosome structure that could also influence gene expression. How cohesin directly regulates transcription remains to be further elucidated. We report that in budding yeast Scc2 is required for sister-chromatid cohesion during meiosis for two reasons. First, Scc2 is required for activating the expression of REC8, which encodes a meiosis-specific cohesin subunit; second, Scc2 is necessary for recruiting meiotic cohesin to the chromosome to generate sister-chromatid cohesion. Using a heterologous reporter assay, we have found that Scc2 increases the activity of its target promoters by recruiting cohesin to establish an upstream cohesin-associated region in a position-dependent manner. Rec8-associated meiotic cohesin is required for the full activation of the REC8 promoter, revealing that cohesin has a positive feedback on transcriptional regulation. Finally, we provide evidence that chromosomal binding of cohesin is sufficient for target-gene activation during meiosis. Our data support a noncanonical role for cohesin as a transcriptional activator during cell differentiation.

Phosphorylation of histone H3 is correlated with changes in the maintenance of sister chromatid cohesion during meiosis in maize, rather than the condensation of the chromatin

2000 ◽  
Vol 113 (18) ◽  
pp. 3217-3226 ◽  
Author(s):  
E. Kaszas ◽  
W.Z. Cande
Keyword(s):  
Sister Chromatid ◽  
Meiotic Chromosome ◽  
Histone H3 ◽  
Sister Chromatid Cohesion ◽  
Chromosome Condensation ◽  
Mitotic Chromosomes ◽  
Sister Chromatids ◽  
H3 Phosphorylation ◽  
Chromatid Cohesion ◽  
Metaphase I

Meiotic chromosome condensation is a unique process, characterized by dramatic changes in chromosome morphology that are required for the correct progression of pairing, synapsis, recombination and segregation of sister chromatids. We used an antibody that recognizes a ser 10 phosphoepitope on histone H3 to monitor H3 phosphorylation during meiosis in maize meiocytes. H3 phosphorylation has been reported to be an excellent marker for chromosome condensation during mitotic prophase in animal cells. In this study, we find that on maize mitotic chromosomes only pericentromeric regions are stained; there is little staining on the arms. During meiosis, chromosome condensation from leptotene through diplotene occurs in the absence of H3 phosphorylation. Instead, the changes in H3 phosphorylation at different stages of meiosis correlate with the differences in requirements for sister chromatid cohesion at different stages. Just before nuclear envelope breakdown, histone H3 phosphorylation is seen first in the pericentromeric regions and then extends through the arms at metaphase I; at metaphase II only the pericentromeric regions are stained. In afd1 (absence of first division), a mutant that is defective in many aspects of meiosis including sister chromatid cohesion and has equational separation at metaphase I, staining is restricted to the pericentromeric regions during metaphase I and anaphase I; there is no staining at metaphase II or anaphase II. We conclude that changes in the level of phosphorylation of ser10 in H3 correspond to changes in the cohesion of sister chromatids rather than the extent of chromosome condensation at different stages of meiosis.

scholarly journals Meiotic sex chromosome cohesion and autosomal synapsis are supported by Esco2

2020 ◽  
Vol 3 (3) ◽  
pp. e201900564 ◽  
Author(s):  
François McNicoll ◽  
Anne Kühnel ◽  
Uddipta Biswas ◽  
Kai Hempel ◽  
Gabriela Whelan ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Sister Chromatid ◽  
Sex Chromosome ◽  
Sister Chromatid Cohesion ◽  
Mouse Strains ◽  
Meiotic Chromosomes ◽  
Chromosome Synapsis ◽  
Chromatid Cohesion ◽  
Sex Chromatin ◽  
Cohesin Subunit

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion.

scholarly journals Double or nothing: a Drosophila mutation affecting meiotic chromosome segregation in both females and males.

Genetics ◽  
1994 ◽  
Vol 136 (3) ◽  
pp. 953-964 ◽  
Author(s):  
D P Moore ◽  
W Y Miyazaki ◽  
J E Tomkiel ◽  
T L Orr-Weaver
Keyword(s):  
Cell Death ◽  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Aberrant Chromosome ◽  
Chromatid Cohesion ◽  
Meiotic Nondisjunction ◽  
Lethal Allele ◽  
Meiosis I

Abstract We describe a Drosophila mutation, Double or nothing (Dub), that causes meiotic nondisjunction in a conditional, dominant manner. Previously isolated mutations in Drosophila specifically affect meiosis either in females or males, with the exception of the mei-S332 and ord genes which are required for proper sister-chromatid cohesion. Dub is unusual in that it causes aberrant chromosome segregation almost exclusively in meiosis I in both sexes. In Dub mutant females both nonexchange and exchange chromosomes undergo nondisjunction, but the effect of Dub on nonexchange chromosomes is more pronounced. Dub reduces recombination levels slightly. Multiple nondisjoined chromosomes frequently cosegregate to the same pole. Dub results in nondisjunction of all chromosomes in meiosis I of males, although the levels are lower than in females. When homozygous, Dub is a conditional lethal allele and exhibits phenotypes consistent with cell death.

scholarly journals SOLO: a meiotic protein required for centromere cohesion, coorientation, and SMC1 localization in Drosophila melanogaster

2010 ◽  
Vol 188 (3) ◽  
pp. 335-349 ◽  
Author(s):  
Rihui Yan ◽  
Sharon E. Thomas ◽  
Jui-He Tsai ◽  
Yukihiro Yamada ◽  
Bruce D. McKee
Keyword(s):  
Drosophila Melanogaster ◽  
Sister Chromatid ◽  
Sister Chromatid Cohesion ◽  
Early Prophase ◽  
Wild Type ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Mutant Phenotypes ◽  
Meiosis I ◽  
Novel Protein

Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles. However, the meiotic cohesion apparatus in Drosophila melanogaster remains largely uncharacterized. We describe a novel protein, sisters on the loose (SOLO), which is essential for meiotic cohesion in Drosophila. In solo mutants, sister centromeres separate before prometaphase I, disrupting meiosis I centromere orientation and causing nondisjunction of both homologous and sister chromatids. Centromeric foci of the cohesin protein SMC1 are absent in solo mutants at all meiotic stages. SOLO and SMC1 colocalize to meiotic centromeres from early prophase I until anaphase II in wild-type males, but both proteins disappear prematurely at anaphase I in mutants for mei-S332, which encodes the Drosophila homologue of the cohesin protector protein shugoshin. The solo mutant phenotypes and the localization patterns of SOLO and SMC1 indicate that they function together to maintain sister chromatid cohesion in Drosophila meiosis.

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