211 research outputs found
Esperanto for histones : CENP-A, not CenH3, is the centromeric histone H3 variant
The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres
The Drosophila RAD21 cohesin persists at the centromere region in mitosis
‘Cohesin’ is a highly conserved multiprotein complex thought to be the primary effector of sister-chromatid cohesion in all eukaryotes. Cohesin complexes in budding yeast hold sister chromatids together from S phase until anaphase, but in metazoans, cohesin proteins dissociate from chromosomes and redistribute into the whole cell volume during prophase, well before sister chromatids separate (reviewed in [1 and 2]). Here we address this apparent anomaly by investigating the cell-cycle dynamics of DRAD21, the Drosophila orthologue of the Xenopus XRAD21 and Saccharomyces cerevisiae Scc1p/Mcd1p cohesins [3]. Analysis of DRAD21 in S2 Drosophila tissue culture cells and live embryos expressing a DRAD21–green fluorescent protein (GFP) fusion revealed the presence of four distinct subcellular pools of DRAD21: a cytoplasmic pool; a chromosome-associated pool which dissociates from chromatin as chromosomes condense in prophase; a short-lived centrosome-associated pool present during metaphase–anaphase; and a centromere-proximal pool which remains bound to condensed chromosomes, is found along the junction of sister chromatids between kinetochores, and persists until the metaphase–anaphase transition. We conclude that in Drosophila, and possibly all metazoans, a minor pool of cohesin remains bound to centromere-proximal chromatin after prophase and maintains sister-chromatid cohesion until the metaphase–anaphase transition
Recent evolutions of gender, state feminism and care models in Latin America and Europe
Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004This chapter presents and characterises the way in which, in the twenty-first century, after years of feminist struggles inside and outside of institutions, gender relations are organised in the different countries of the INCASI project (on the European side, Spain, Italy, Finland, France and the United Kingdom, on the side of the South American Southern Cone, Argentina, Brazil, Chile and Uruguay). It pays special attention to the implementation of feminist issues on political agendas, and in particular the assignment of women to unpaid care work-an aspect of the power continuum that we look to relate to other aspects. Gradually and for almost a century all countries in both continents have granted women the status of subjects, citizens and employees. However, the conditions, challenges and timelines of this process differ considerably from one continent to another, so they need to be addressed separately. The neoliberal era did not have the same impact in Europe as it did in South America (nor was it exactly the same between particular European countries or among South American ones)
The Chromosomal Passenger Complex Activates Polo Kinase at Centromeres
INCENP acts as a protein scaffold that integrates the functions of two crucial mitotic kinases, Aurora B and Polo, at centromeres of mitotic chromosomes
The Chromosomal Passenger Complex Activates Polo Kinase at Centromeres
INCENP acts as a protein scaffold that integrates the functions of two crucial mitotic kinases, Aurora B and Polo, at centromeres of mitotic chromosomes
Drosophila Genes That Affect Meiosis Duration Are among the Meiosis Related Genes That Are More Often Found Duplicated
Using a phylogenetic approach, the examination of 33 meiosis/meiosis-related genes in 12 Drosophila species, revealed nine independent gene duplications, involving the genes cav, mre11, meiS332, polo and mtrm. Evidence is provided that at least eight out of the nine gene duplicates are functional. Therefore, the rate at which Drosophila meiosis/meiosis-related genes are duplicated and retained is estimated to be 0.0012 per gene per million years, a value that is similar to the average for all Drosophila genes. It should be noted that by using a phylogenetic approach the confounding effect of concerted evolution, that is known to lead to overestimation of the duplication and retention rate, is avoided. This is an important issue, since even in our moderate size sample, evidence for long-term concerted evolution (lasting for more than 30 million years) was found for the meiS332 gene pair in species of the Drosophila subgenus. Most striking, in contrast to theoretical expectations, is the finding that genes that encode proteins that must follow a close stoichiometric balance, such as polo, mtrm and meiS332 have been found duplicated. The duplicated genes may be examples of gene neofunctionalization. It is speculated that meiosis duration may be a trait that is under selection in Drosophila and that it has different optimal values in different species
Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variant
The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres
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