Search Results
Results 1 - 50 of 764
1 2 3 4 5 6 7 8 9 10 >
Ross Benjamin D BD Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA; Basic Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N. A2-025, Seattle, WA 98109, - - 2014
Female meiosis presents unique opportunities for competition between chromosomes for evolutionary dominance. A new study reveals that centromere strength dictates meiotic success, driving karyotype evolution and reproductive isolation in mice.
Anaya Gabriel G Laboratory of Animal Genomics, MERAGEM (AGR-158) Research Group, Department of Genetics, University of Córdoba, - - 2014
Horses are characterized as having a greater rate of chromosomal abnormalities than other species, which are mainly related to the sex chromosome pair and produce a series of different anomalies known as disorders in sexual development (DSD). In the present study, three Pura Raza Española (PRE) and one Menorquín (MEN) ...
Mank Judith E JE Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United - - 2014
Intralocus sexual conflict and intragenomic conflict both affect sex chromosome evolution and can in extreme cases even cause the complete turnover of sex chromosomes. Additionally, established sex chromosomes often become the focus of heightened conflict. This creates a tangled relationship between sex chromosomes and conflict with respect to cause and ...
Schmid Michael M Department of Human Genetics, Biocenter, University of Würzburg, Würzburg, - - 2014
The chromosomes of the turnip-tailed gecko Thecadactylus rapicauda from the Falcón State in northern Venezuela were examined by means of conventional staining, a variety of banding techniques and in situ hybridization with an 18S + 28S rDNA probe. In female specimens, C-banding analyses detected a cryptic W sex chromosome-associated interstitial ...
Dufresnes Christophe C Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015, - - 2014
Occasional XY recombination is a proposed explanation for the sex-chromosome homomorphy in European tree frogs. Numerous laboratory crosses, however, failed to detect any event of male recombination, and a detailed survey of NW-European Hyla arborea populations identified male-specific alleles at sex-linked loci, pointing to the absence of XY recombination in ...
Valenzuela Nicole N Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, - - 2014
Sex determination is triggered by factors ranging from genotypic (GSD) to environmental (ESD), or both GSD + EE (GSD susceptible to environmental effects), and its evolution remains enigmatic. The presence/absence of sex chromosomes purportedly separates species at the ESD end of the continuum from the rest (GSD and GSD + ...
Ahmed Sophia S Integrative Biology of Marine Models, CNRS UMR 8227, Sorbonne Universités, UPMC Université Paris 6, Station Biologique de Roscoff, CS 90074, 29688 Roscoff, France; Medical Biology Centre, Queens University Belfast, Belfast BT9 7BL, Northern Ireland, - - 2014
A common feature of most genetic sex-determination systems studied so far is that sex is determined by nonrecombining genomic regions, which can be of various sizes depending on the species. These regions have evolved independently and repeatedly across diverse groups. A number of such sex-determining regions (SDRs) have been studied ...
Bajic Vladan V University of Belgrade, Institute for Nuclear Sciences "Vinca", Department of Radiobiology and Molecular Genetics, Belgrade, - - 2014
X-chromosome instability has been a long established feature in Alzheimer's disease (AD). Premature centromere division and aneuploidy of the X-chromosome has been found in peripheral blood lymphocytes and neuronal tissue in female AD patients. Interestingly, only one chromosome of the X pair has been affected. These results raised a question, ...
Herrera Paul P Biosciences, University of Exeter Cornwall Campus, Penryn, TR10 9FE, - - 2014
Female multiple mating, known as polyandry, is ubiquitous and occurs in a wide variety of taxa. Polyandry varies greatly from species in which females mate with one or two males in their lifetime to species in which females may mate with several different males on the same day. As multiple ...
Lima Thiago G TG Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, - - 2014
The two 'rules of speciation', Haldane's rule and the large X-effect, describe the genetic basis of postzygotic isolation, and have led to the realization that sex chromosomes play an important role in this process. However, a range of sex determination mechanisms exists in nature, not always involving sex chromosomes. Based ...
Kumbıçak Zübeyde Z Department of Molecular Biology and Genetics, Faculty of Science and Art, Nevşehir Hacı Bektaş Veli University, 50300, Nevşehir, - - 2014
In this study, the karyotypes of six spider species from Turkey belonging to the families Gnaphosidae, Salticidae, Thomisidae, and Zodariidae were analyzed. Male chromosomal features including diploid chromosome numbers and sex chromosome systems were determined as 2n=22, X1X20 in Drassyllus sur Tuneva & Esyunin, 2003, Nomisia exornata (C. L. Koch, ...
Asgharian Hosseinali H Program in Molecular and Computational Biology, Department of Biological Sciences, University of Southern California Los Angeles, CA, - - 2014
Wolbachia causes the feminization of chromosomally male embryos in several species of crustaceans and insects, including the leafhopper Zyginidia pullula. In contrast to the relatively well-established ecological aspects of male feminization (e.g., sex ratio distortion and its consequences), the underlying molecular mechanisms remain understudied and unclear. We embarked on an ...
Ali Rola H RH Department of Pathology, Faculty of Medicine, Health Sciences Center, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait. - - 2014
Gender-related differences in colorectal cancer (CRC) are not fully understood. Recent studies have shown that CRC arising in females are significantly associated with CpG island methylator phenotype (CIMP-high). Using array comparative genomic hybridization, we analyzed a cohort of 116 CRCs (57 males, 59 females) for chromosomal copy number aberrations (CNA) ...
Jouyan Najmeh N Human Genetic Research Group, Iranian Academic Center for Education, Culture and Research, Fars Province Branch, Shiraz, Iran. ; Institute of Biochemistry and Biophysics, Tehran University, Tehran, - - 2012
Chromosome abnormality (CA) including Sex chromosomes abnormality (SCAs) is one of the most important causes of disordered sexual development and infertility. SCAs formed by numerical or structural alteration in X and Y chromosomes, are the most frequently CA encountered at both prenatal diagnosis and at birth. This study describes cytogenetic ...
Skinner B M - - 2012
It is generally believed that the organization of avian genomes remains highly conserved in evolution as chromosome number is constant and comparative chromosome painting demonstrated there to be very few interchromosomal rearrangements. The recent sequencing of the zebra finch (Taeniopygia guttata) genome allowed an assessment of the number of intrachromosomal ...
Suh Alexander - - 2011
The vast majority of extant birds possess highly differentiated Z and W sex chromosomes. Nucleotide sequence data from gametologs (homologs on opposite sex chromosomes) suggest that this divergence occurred throughout early bird evolution via stepwise cessation of recombination between identical sex chromosomal regions. Here we investigated avian sex chromosome differentiation ...
Velichko Artem K - - 2011
Heterochromatin protein 1 (HP1) was discovered as a protein essential for maintaining the silent transcriptional status of genes located within or close to centromeric regions of Drosophila chromosomes. Mammals express three variants of HP1; of these, HP1α is a direct homolog of Drosophila HP1. The prevailing view states that HP1 ...
Carneiro Miguel M CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, 4485-661, Vairão, Portugal. - - 2010
Studies of gene flow between closely related taxa can provide insight into the genetic basis of speciation. To evaluate the importance of the X chromosome in reproductive isolation between subspecies of the European rabbit and to study the genomic scale over which islands of differentiation extend, we resequenced a total ...
Dimitriadis Emilios K - - 2010
Mitosis ensures equal genome segregation in the eukaryotic lineage. This process is facilitated by microtubule attachment to each chromosome via its centromere. In centromeres, canonical histone H3 is replaced in nucleosomes by a centromere-specific histone H3 variant (CENH3), providing the unique epigenetic signature required for microtubule binding. Due to recent ...
Yamagishi Yuya - - 2010
For proper partitioning of chromosomes in mitosis, the chromosomal passenger complex (CPC) including Aurora B and survivin must be localized at the center of paired kinetochores, at the site called the inner centromere. It is largely unknown what defines the inner centromere and how the CPC is targeted to this ...
Tanno Yuji - - 2010
Shugoshin (Sgo) is a conserved centromeric protein. Mammalian Sgo1 collaborates with protein phosphatase 2A (PP2A) to protect mitotic cohesin from the prophase dissociation pathway. Although another shugoshin-like protein, Sgo2, is required for the centromeric protection of cohesion in germ cells, its precise molecular function remains largely elusive. We demonstrate that ...
Obado Samson O - - 2011
Topoisomerase-II accumulates at centromeres during prometaphase, where it resolves the DNA catenations that represent the last link between sister chromatids. Previously, using approaches including etoposide-mediated topoisomerase-II cleavage, we mapped centromeric domains in trypanosomes, early branching eukaryotes in which chromosome segregation is poorly understood. Here, we show that in bloodstream form ...
Qi Lili - - 2010
The evolution of five chromosomes of Brachypodium distachyon from a 12-chromosome ancestor of all grasses by dysploidy raises an interesting question about the fate of redundant centromeres. Three independent but complementary approaches were pursued to study centromeric region homologies among the chromosomes of Brachypodium, wheat, and rice. The genes present ...
Tsukahara Tatsuya - - 2010
Successful partition of replicated genomes at cell division requires chromosome attachment to opposite poles of mitotic spindle (bi-orientation). Any defects in this regulation bring about chromosomal instability, which may accelerate tumour progression in humans. To achieve chromosome bi-orientation at prometaphase, the chromosomal passenger complex (CPC), composed of catalytic kinase Aurora ...
Wang Fangwei F Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Smith Building, 1 Jimmy Fund Way, Boston, MA 02115, - - 2010
Aurora B is a component of the chromosomal passenger complex (CPC) required for correct spindle-kinetochore attachments during chromosome segregation and for cytokinesis. The chromatin factors that recruit the CPC to centromeres are unknown, however. Here we show that phosphorylation of histone H3 threonine 3 (H3T3ph) by Haspin is necessary for ...
Ryu Hyunju H Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, - - 2010
SUMO conjugation of cellular proteins is essential for proper progression of mitosis. PIASy, a SUMO E3 ligase, is required for mitotic SUMOylation of chromosomal proteins, yet the regulatory mechanism behind the PIASy-dependent SUMOylation during mitosis has not been determined. Using a series of truncated PIASy proteins, we have found that ...
Stimpson Kaitlin M - - 2010
Genome rearrangement often produces chromosomes with two centromeres (dicentrics) that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since ...
Stimpson Kaitlin M - - 2010
The centromere is a complex chromosomal locus where the kinetochore is formed and microtubules attach during cell division. Centromere identity involves both genomic and sequence-independent (epigenetic) mechanisms. Current models for how centromeres are formed and, conversely, turned off have emerged from studies of unusual or engineered chromosomes, such as neocentromeres, ...
Dubin Manu - - 2010
The centromeric histone H3 variant (CenH3) serves to target the kinetochore to the centromeres and thus ensures correct chromosome segregation during mitosis and meiosis. The Dictyostelium H3-like variant H3v1 was identified as the CenH3 ortholog. Dictyostelium CenH3 has an extended N-terminal domain with no similarity to any other known proteins ...
Bassett Emily A EA Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, - - 2010
The nearly ubiquitous presence of repetitive centromere DNA sequences across eukaryotic species is in paradoxical contrast to their apparent functional dispensability. Centromeric chromatin is spatially delineated into the kinetochore-forming array of centromere protein A (CENP-A)-containing nucleosomes and the inner centromeric heterochromatin that lacks CENP-A but recruits the aurora B kinase ...
Mehta Gunjan D - - 2010
The centromere is a genetic locus, required for faithful chromosome segregation, where spindle fibers attach to the chromosome through kinetochore. Loss of centromere or formation of multiple centromeres on a single chromosome leads to chromosome missegregation or chromosome breakage, respectively, which are detrimental for fitness and survival of a cell. ...
Ewers Elisabeth - - 2010
Twenty-five dicentric small supernumerary marker chromosomes (sSMC) derived from #13/21, #14, #15, #18, and #22 were studied by immunohistochemistry for their centromeric activity. Centromere protein (CENP)-B was applied as marker for all centromeres and CENP-C to label the active ones. Three different 'predominant' activation patterns could be observed, i.e., centric ...
Manning Amity L - - 2010
Chromosome instability (CIN) is a common feature of tumor cells. By monitoring chromosome segregation, we show that depletion of the retinoblastoma protein (pRB) causes rates of missegregation comparable with those seen in CIN tumor cells. The retinoblastoma tumor suppressor is frequently inactivated in human cancers and is best known for ...
Lukaszewski A J - - 2010
Centromeres are responsible for the proper behavior of chromosomes in cell divisions. In meiosis the process is more complicated than in mitosis, as each chromosome in a bivalent has 2 sister centromeres and their behavior has to be strictly coordinated. Here, the behavior of sister centromeres in univalents in wheat ...
Guerra M - - 2010
The centromere appears as a single constriction at mitotic metaphase in most eukaryotic chromosomes. Holokinetic chromosomes are the exception to this rule because they do not show any centromeric constrictions. Holokinetic chromosomes are usually forgotten in most reviews about centromeres, despite their presence in a number of animal and plant ...
Shang Wei-Hao - - 2010
The centromere is essential for faithful chromosome segregation by providing the site for kinetochore assembly. Although the role of the centromere is conserved throughout evolution, the DNA sequences associated with centromere regions are highly divergent among species and it remains to be determined how centromere DNA directs kinetochore formation. Despite ...
Zhang Wenli - - 2010
A chromosome with two functional centromeres is cytologically unstable and can only be stabilized when one of the two centromeres becomes inactivated via poorly understood mechanisms. Here, we report a transmissible chromosome with multiple centromeres in wheat. This chromosome encompassed one large and two small domains containing the centromeric histone ...
Ellermeier Chad - - 2010
During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essential in most species for proper homologue segregation. Nevertheless, recombination is ...
van der Waal Maike S - - 2010
Comment on: Becker M, et al. Cell Cycle 2010; 1360-72.
Bardhan Amit - - 2010
A period of pairing between nonhomologous centromeres occurs early in meiosis in a diverse collection of organisms. This early, homology-independent, centromere pairing, referred to as centromere coupling in budding yeast, gives way to an alignment of homologous centromeres as homologues synapse later in meiotic prophase. The regulation of centromere coupling ...
Dalal Yamini - - 2010
The centromere is perhaps the most iconic feature on a eukaryotic chromosome. An amateur enthusiast equipped with a light microscope can easily identify the center of each metacentric chromosome, marking the spot responsible for accurate genome segregation. This review will highlight findings that provide novel insights into how centromeres are ...
Shi Jinghua - - 2010
Centromeres are the most dynamic regions of the genome, yet they are typified by little or no crossing over, making it difficult to explain the origin of this diversity. To address this question, we developed a novel CENH3 ChIP display method that maps kinetochore footprints over transposon-rich areas of centromere ...
Axelsson E - - 2010
As all four meiotic products give rise to sperm in males, female meiosis result in a single egg in most eukaryotes. Any genetic element with the potential to influence chromosome segregation, so that it is preferentially included in the egg, should therefore gain a transmission advantage; a process termed female ...
Gorbsky Gary J GJ Cell Cycle & Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA. - - 2010
A cell undergoing mitosis is presented with a potentially catastrophic situation when a DNA double-strand break creates a chromosome fragment that lacks connection to a centromere. Royou et al. (2010) now reveal that this cellular crisis is averted in fruit fly neuroblasts by thin chromatin tethers that hold on to ...
Glynn Macdara - - 2010
The faithful replication of DNA and the accurate segregation of genomic material from one generation to the next is critical in the maintenance of genomic stability. This chapter will describe the structure and assembly of an epigenetically inherited locus, the centromere, and its role in the processes by which sister ...
Zlotina A - - 2010
Despite the progress of the chicken (Gallus gallus) genome sequencing project, the centromeric sequences of most macrochromosomes remain unknown. This makes it difficult to determine centromere positions in the genome sequence assembly. Using giant lampbrush chromosomes from growing oocytes, we analyzed in detail the pericentromeric region of chicken chromosome 3. ...
Alonso Alicia - - 2010
BACKGROUND: Centromeres are responsible for the proper segregation of replicated chromatids during cell division. Neocentromeres are fully functional ectopic human centromeres that form on low-copy DNA sequences and permit analysis of centromere structure in relation to the underlying DNA sequence. Such structural analysis is not possible at endogenous centromeres because ...
Pironon Nathalie - - 2010
BACKGROUND: The mode of evolution of the highly homogeneous Higher-Order-Repeat-containing alpha satellite arrays is still subject to discussion. This is also true of the CENP-A associated repeats where the centromere is formed. RESULTS: In this paper, we show that the molecular mechanisms by which these arrays evolve are identical in ...
Obeso David - - 2010
Over the past thirty years several reports of the pairing or association of non-homologous centromeres during meiotic prophase have appeared in the literature. Recently, the homology-independent pairwise association of centromeres, termed centromere coupling, was also reported in budding yeast. It seems paradoxical that centromeres would pair with non-homologous partners during ...
Lynch Denise B - - 2010
The G + C content at synonymous codon positions (GC3s) in genes varies along chromosomes in most eukaryotes. In Saccharomyces cerevisiae, regions of high GC3s are correlated with recombination hot spots, probably due to biased gene conversion. Here we examined how GC3s differs among groups of related yeast species in ...
1 2 3 4 5 6 7 8 9 10 >