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 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 Chromosome interaction over a distance in meiosis

2015 ◽  
Vol 2 (2) ◽  
pp. 150029 ◽  
Author(s):  
Mary Brady ◽  
Leocadia V. Paliulis
Keyword(s):  
Cell Division ◽  
Sex Chromosomes ◽  
Sister Chromatid ◽  
Daughter Cell ◽  
Sister Chromatid Cohesion ◽  
Sister Chromatids ◽  
Physical Connection ◽  
Chromatid Cohesion ◽  
Different Types ◽  
Random Segregation

The challenge of cell division is to distribute partner chromosomes (pairs of homologues, pairs of sex chromosomes or pairs of sister chromatids) correctly, one into each daughter cell. In the ‘standard’ meiosis, this problem is solved by linking partners together via a chiasma and/or sister chromatid cohesion, and then separating the linked partners from one another in anaphase; thus, the partners are kept track of, and correctly distributed. Many organisms, however, properly separate chromosomes in the absence of any obvious physical connection, and movements of unconnected partner chromosomes are coordinated at a distance. Meiotic distance interactions happen in many different ways and in different types of organisms. In this review, we discuss several different known types of distance segregation and propose possible explanations for non-random segregation of distance-segregating chromosomes.

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 Genetic Interactions Between mei-S332 and ord in the Control of Sister-Chromatid Cohesion

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1467-1476
Author(s):  
Sharon E Bickel ◽  
Daniel P Moore ◽  
Cary Lai ◽  
Terry L Orr-Weaver
Keyword(s):  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Double Mutant ◽  
Sex Chromosome ◽  
Meiotic Chromosome ◽  
Sister Chromatid Cohesion ◽  
Gene Products ◽  
Wild Type ◽  
Chromatid Cohesion ◽  
Males And Females

Abstract The Drosophila mei-S332 and ord gene products are essential for proper sister-chromatid cohesion during meiosis in both males and females. We have constructed flies that contain null mutations for both genes. Double-mutant flies are viable and fertile. Therefore, the lack of an essential role for either gene in mitotic cohesion cannot be explained by compensatory activity of the two proteins during mitotic divisions. Analysis of sex chromosome segregation in the double mutant indicates that ord is epistatic to mei-S332. We demonstrate that ord is not required for MEI-S332 protein to localize to meiotic centromeres. Although overexpression of either protein in a wild-type background does not interfere with normal meiotic chromosome segregation, extra ORD+ protein in mei-S332 mutant males enhances nondisjunction at meiosis II. Our results suggest that a balance between the activity of mei-S332 and ord is required for proper regulation of meiotic cohesion and demonstrate that additional proteins must be functioning to ensure mitotic sister-chromatid cohesion.

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 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.

scholarly journals A role for the Smc3 hinge domain in the maintenance of sister chromatid cohesion

2018 ◽  
Vol 29 (3) ◽  
pp. 339-355 ◽  
Author(s):  
Brett Robison ◽  
Vincent Guacci ◽  
Douglas Koshland
Keyword(s):  
Sister Chromatid ◽  
Sister Chromatid Cohesion ◽  
Chromatid Cohesion ◽  
Cohesin Subunit ◽  
Hinge Domain

A screen of cohesin subunit Smc3 reveals that its hinge is a nexus controlling the maintenance of sister chromatid cohesion and condensation.

Meiotic sister chromatid cohesion in holocentric sex chromosomes of three heteropteran species is maintained in absence of axial elements

Chromosoma ◽  
2000 ◽  
Vol 109 (1-2) ◽  
pp. 35-43 ◽  
Author(s):  
José A. Suja ◽  
Angel L. del Cerro ◽  
Jesús Page ◽  
Julio S. Rufas ◽  
Juan L. Santos
Keyword(s):  
Sex Chromosomes ◽  
Sister Chromatid ◽  
Sister Chromatid Cohesion ◽  
Chromatid Cohesion
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