The role of centromeric repeats and transcripts in kinetochore assembly and function.

Centromeres are the chromosomal domains, where the kinetochore protein complex is formed, mediating proper segregation of chromosomes during cell division. Although the function of centromeres has remained conserved during evolution, centromeric DNA is highly variable, even in closely related species. In addition, the composition of the kinetochore complexes varies among organisms.

Holocentromeres can consist of merely a few megabase-sized satellite arrays.

The centromere is the chromosome region where microtubules attach during cell division. In contrast to monocentric chromosomes with one centromere, holocentric species usually distribute hundreds of centromere units along the entire chromatid. We assembled the chromosome-scale reference genome and analyzed the holocentromere and (epi)genome organization of the lilioid Chionographis japonica.

High temperature increases centromere-mediated genome elimination frequency and enhances haploid induction in Arabidopsis.

Double haploid production is the most effective way to create true-breeding lines in a single generation. In Arabidopsis, haploid induction via mutation of the centromere-specific histone H3 (cenH3) has been shown when the mutant is outcrossed to the wild-type, and the wild-type genome remains in the haploid progeny. However, factors that affect haploid induction are still poorly understood.

Haploid induction by nanobody-targeted ubiquitin-proteasome-based degradation of EYFP-tagged CENH3 in Arabidopsis thaliana.

The generation of haploid plants accelerates the crop breeding process. One of the haploidization strategies is based on the genetic manipulation of endogenous centromere-specific histone 3 (CENH3). To extend the haploidization toolbox, we tested whether targeted in vivo degradation of CENH3 protein can be harnessed to generate haploids in Arabidopsis thaliana.

Optimization of quantitative reverse transcription PCR method for analysis of weakly expressed genes in crops based on rapeseed.

Rapeseed () is an allopolyploid hybrid (AACC genome) of turnip rape (, genome: AA) and vegetable cabbage (, genome: CC). Rapeseed oil is one of the main vegetable oils used worldwide for food and other technical purposes. Therefore, breeding companies worldwide are interested in developing rapeseed varieties with high yields and increased adaptation to harsh climatic conditions such as heat and prolonged drought.

Engineered degradation of EYFP-tagged CENH3 via the 26S proteasome pathway in plants.

Determining the function of proteins remains a key task of modern biology. Classical genetic approaches to knocking out protein function in plants still face limitations, such as the time-consuming nature of generating homozygous transgenic lines or the risk of non-viable loss-of-function phenotypes. We aimed to overcome these limitations by acting downstream of the protein level.

Unequal contribution of two paralogous CENH3 variants in cowpea centromere function.

In most diploids the centromere-specific histone H3 (CENH3), the assembly site of active centromeres, is encoded by a single copy gene. Persistance of two CENH3 paralogs in diploids species raises the possibility of subfunctionalization. Here we analysed both CENH3 genes of the  diploid dryland crop cowpea.

Functional Divergence of Microtubule-Associated TPX2 Family Members in .

TPX2 (Targeting Protein for Xklp2) is an evolutionary conserved microtubule-associated protein important for microtubule nucleation and mitotic spindle assembly. The protein was described as an activator of the mitotic kinase Aurora A in humans and the AURORA1 (AUR1) kinase. In contrast to animal genomes that encode only one TPX2 gene, higher plant genomes encode a family with several gene members (TPXL).

Deregulated Phosphorylation of CENH3 at Ser65 Affects the Development of Floral Meristems in .

Several histone variants are posttranslationally phosphorylated. Little is known about phosphorylation of the centromere-specific histone 3 (CENH3) variant in plants. We show that CENH3 of is phosphorylated by Aurora3, predominantly at serine 65.

TPX2-LIKE PROTEIN3 Is the Primary Activator of α-Aurora Kinases and Is Essential for Embryogenesis.

Aurora kinases are key regulators of mitosis. Multicellular eukaryotes generally possess two functionally diverged types of Aurora kinases. In plants, including Arabidopsis (), these are termed α- and β-Auroras.

State-of-the-art and novel developments of in vivo haploid technologies.

The ability to generate (doubled) haploid plants significantly accelerates the crop breeding process. Haploids have been induced mainly through the generation of plants from cultivated gametophic (haploid) cells and tissues, i.e.

[Perspective Directions in Management of Severe Group Two Pulmonary Hypertension].

Purpose: To compare immediate results of mitral valve surgery in patients with severe pulmonary hypertension with versus without concomitant pulmonary artery denervation.

Materials And Methods: From January to December 2015 30 patients were randomly assigned into two groups. Patients of one group underwent mitral valve surgery (comparison group), in the other group mitral valve surgery was accompanied by pulmonary artery ablation (ablation group).

Targeting of Arabidopsis KNL2 to Centromeres Depends on the Conserved CENPC-k Motif in Its C Terminus.

KINETOCHORE NULL2 (KNL2) is involved in recognition of centromeres and in centromeric localization of the centromere-specific histone cenH3. Our study revealed a cenH3 nucleosome binding CENPC-k motif at the C terminus of KNL2, which is conserved among a wide spectrum of eukaryotes. Centromeric localization of KNL2 is abolished by deletion of the CENPC-k motif and by mutating single conserved amino acids, but can be restored by insertion of the corresponding motif of Arabidopsis CENP-C.

A rise of ploidy level influences the rate of cytomixis in tobacco male meiosis.

The effect of plant ploidy level on the rate of cytomixis in microsporogenesis has been analyzed with the help of a unique model, the collection of tobacco plants of different ploidies (2n = 2x = 24, 4x = 48, 6x = 72, and 8x = 96). As has been shown, the rate of cytomixis proportionally increases in 6x and 8x cytotypes, being rather similar in 2x and 4x plants. The rate of cytomixis is highly variable, differing even in the genetically identical plants grown under the same conditions.

[Aortic valve replacement with stentless bioprosthesis: surgical technique and early outcomes].

Aim: To evaluate prospectively the hemodynamic performance of «BiolAB Mono» stentless bioprosthesis implanted into aortic position.

Material And Methods: Twenty seven patients (mean age 71 (67; 73); 17 women) with severe aortic stenosis underwent, aortic valve replacement with «BioLAB Mono» stentless bioprosthesis from 2012 to 2014. The valves- were implanted into supraannular position using continuous polypropylene suture.

[Aortic valve replacement with stentless bioprosthesis].

Aim: To evaluate prospectively the hemodynamic performance of «BioLAB Mono» stentless bioprosthesis implanted into aortic position.

Material And Methods: Twenty seven patients (mean age 71 (67; 73); 17 women) with severe aortic stenosis underwent aortic valve replacement with «BioLAB Mono» stentless bioprosthesis from 2012 to 2014. The valves were implanted into supra-annular position using continuous polypropylene suture.

[PATHOGENETIC TREATMENT OF CHRONIC NONBACTERIAL PROSTATITIS COMPLICATED BY SPERM DISORDERS].

This study examines the efficacy and safety of the natural complex of multi-component biologically active dietary supplement Prostatinol in the pathogenetic treatment of 45 patients with chronic nonbacterial Prostatitis complicated by sperm disorders. Within 4 weeks 25 patients of the treatment group and 20 patients of the control group received Prostatinol or traditional anti-inflammatory therapy correspondingly. The results were evaluated at weeks 4 and 12 after treatment cessation.

Aurora Kinases Throughout Plant Development.

Aurora kinases are evolutionarily conserved key mitotic determinants in all eukaryotes. Yeasts contain a single Aurora kinase, whereas multicellular eukaryotes have at least two functionally diverged members. The involvement of Aurora kinases in human cancers has provided an in-depth mechanistic understanding of their roles throughout cell division in animal and yeast models.

Cytomixis doesn't induce obvious changes in chromatin modifications and programmed cell death in tobacco male meiocytes.

Cytomixis is a poorly studied process of nuclear migration between plant cells. It is so far unknown what drives cytomixis and what is the functional state of the chromatin migrating between cells. Using immunostaining, we have analyzed the distribution of posttranslational histone modifications (methylation, acetylation, and phosphorylation) that reflect the functional state of chromatin in the tobacco microsporocytes involved in cytomixis.

Point mutation impairs centromeric CENH3 loading and induces haploid plants.

The chromosomal position of the centromere-specific histone H3 variant CENH3 (also called "CENP-A") is the assembly site for the kinetochore complex of active centromeres. Any error in transcription, translation, modification, or incorporation can affect the ability to assemble intact CENH3 chromatin and can cause centromere inactivation [Allshire RC, Karpen GH (2008) Nat Rev Genet 9 (12):923-937]. Here we show that a single-point amino acid exchange in the centromere-targeting domain of CENH3 leads to reduced centromere loading of CENH3 in barley, sugar beet, and Arabidopsis thaliana.

Altered expression of Aurora kinases in Arabidopsis results in aneu- and polyploidization.

Aurora is an evolutionary conserved protein kinase family involved in monitoring of chromosome segregation via phosphorylation of different substrates. In plants, however, the involvement of Aurora proteins in meiosis and in sensing microtubule attachment remains to be proven, although the downstream components leading to the targeting of spindle assembly checkpoint signals to anaphase-promoting complex have been described. To analyze the three members of Aurora family (AtAurora1, -2, and -3) of Arabidopsis we employed different combinations of T-DNA insertion mutants and/or RNAi transformants.

Centromeres and kinetochores of Brassicaceae.

The centromere-the primary constriction of monocentric chromosomes-is essential for correct segregation of chromosomes during mitosis and meiosis. Centromeric DNA varies between different organisms in sequence composition and extension. The main components of centromeric and pericentromeric DNA of Brassicaceae species are centromeric satellite repeats.

Anti-phosphorylated histone H2AThr120: a universal microscopic marker for centromeric chromatin of mono- and holocentric plant species.

Based on the analysis of 20 different monocot and eudicot species, we propose that the centromeric distribution of the phosphorylated histone H2AThr120 is evolutionary highly conserved across species with mono- and holocentric chromosomes. Therefore, antibodies recognizing the phosphorylated threonine 120 of the histone H2A can serve as a universal marker for the cytological detection of centromeres of mono- and holokinetic plant species. In addition, super resolution microscopy of signals specific to the centromere-specific histone H3 variant CENH3 and to H2AThr120ph revealed that these histone variants are incorporated into different nucleosomes, which form distinct, partly intermingled chromatin domains.

[The mithral valve replacement with biological prostheses: early and long-term results].

442 patients underwent the mitral valve replacement (MVR) with KemCor and PeriCor stented bioprostheses. The study results justified the preference of the "totally biological" PeriCor valve in patients with active infectious endocarditis. The longest follow-up period was 11 years, the mean follow-up was 51±34 months.

Arabidopsis kinetochore null2 is an upstream component for centromeric histone H3 variant cenH3 deposition at centromeres.

The centromeric histone H3 variant cenH3 is an essential centromeric protein required for assembly, maintenance, and proper function of kinetochores during mitosis and meiosis. We identified a kinetochore null2 (KNL2) homolog in Arabidopsis thaliana and uncovered features of its role in cenH3 loading at centromeres. We show that Arabidopsis KNL2 colocalizes with cenH3 and is associated with centromeres during all stages of the mitotic cell cycle, except from metaphase to mid-anaphase.