During an accumulation regime of a small telomere-truncated B chromosome, a derivative with large variations in size and multiple punctate centromere loci exhibiting amplified copy numbers was discovered. Multiple centromere satellite loci or transgene signals were documented in amplified chromosomes, suggesting over-replication. Immunolocalization studies revealed multiple foci of biochemical ...

Uniparental chromosome elimination occurs in several interspecific hybrids of plants. We studied the mechanism underlying selective elimination of the paternal chromosomes during the early development of Hordeum vulgare × Hordeum bulbosum embryos. The following conclusions regarding the role of the centromere-specific histone H3 variant (CENH3) in the process of chromosome elimination were draw...

Transcriptional inactivation of the budding yeast centromere has been a widely used tool in studies of chromosome segregation and aneuploidy. In haploid cells when an essential chromosome contains a single conditionally inactivated centromere (GAL-CEN), cell growth rate is slowed and segregation fidelity is reduced; but colony formation is nearly 100%. Pedigree analysis revealed that only 30% o...

We developed techniques that allow us to construct novel variants of Saccharomyces cerevisiae chromosomes. These modified chromosomes have precisely determined structures. A metacentric derivative of chromosome III which lacks the telomere-associated X and Y' elements, which are found at the telomeres of most yeast chromosomes, behaves normally in both mitosis and meiosis. We made a circularly ...

Centromeres are highly specialized chromatin domains that enable chromosome segregation and orchestrate faithful cell division. Human centromeres are composed of tandem arrays of α-satellite DNA, which spans up to several megabases. Little is known about the mechanisms that maintain integrity of the long arrays of α-satellite DNA repeats. Here, we monitored centromeric repeat stability in human...

In the fission yeast Schizosaccharomyces pombe, the centromeres of each chromosome are clustered together and attached to the nuclear envelope near the site of the spindle pole body during interphase. The mechanism and functional importance of this arrangement of chromosomes are poorly understood. In this paper, we identified a novel nuclear protein, Csi1, that localized to the site of centrome...

We investigated the structural requirements of the centromere from chromosome III (CEN3) of Saccharomyces cerevisiae by analyzing the ability of chromosomes with CEN3 mutations to segregate properly during meiosis. We analyzed diploid cells in which one or both copies of chromosome III carry a mutant centromere in place of the wild-type centromere and found that some alterations in the length, ...

The faithful alignment of homologous chromosomes during meiotic prophase requires the coordination of DNA double-strand break (DSB) repair with large-scale chromosome reorganization. Here we identify the phosphatase PP4 (Pph3/Psy2) as a mediator of this process in Saccharomyces cerevisiae. In pp4 mutants, early stages of crossover repair and homology-independent pairing of centromeres are coord...

We describe the generation of 11 monoclonal antibodies that bind to the centromere/kinetochore region of human mitotic chromosomes. These antibodies were raised against mitotic chromosome scaffolds and screened for centromere/kinetochore binding by indirect immunofluorescence against purified chromosomes. Immunoblot analyses with these antibodies revealed that all of the antigens are greater th...

  Preparation of chromosome spreads and karyotype analysis in Blicca bjoerkna transcaucasica were carried out using 0.01% solution of colchicines and Phytohaemagglutinin (PHA) (20 µg g-1 body weight). The gill and kidney tissues were collected and let to stand in a hypotonic solution of 0.075 M KCl and then treated with a fixative (Carnoy's solution) in three steps. The chromosomes spreads were...