BACKGROUND In response to DNA damage, fission yeast, mammalian cells, and cells of the Drosophila gastrula inhibit Cdk1 to delay the entry into mitosis. In contrast, budding yeast delays metaphase-anaphase transition by stabilization of an anaphase inhibitor, Pds1p. A variation of the second response is seen in Drosophila cleavage embryos; when nuclei enter mitosis with damaged DNA, centrosomes...

The clinical efficacy of evaluating genetic anomalies in metaphase cells versus interphase nuclei for multiple myeloma (MM) is poorly understood. Therefore, survival for 154 patients with newly diagnosed untreated MM was compared with results from analysis of metaphase and interphase cells. Metaphases were studied by conventional cytogenetics and fluorescent-labeled DNA probes (fluorescence in ...

BACKGROUND Radiation-induced chromosome aberrations lead to a plethora of detrimental effects at cellular level. Chromosome aberrations provide broad spectrum of information ranging from probability of malignant transformation to assessment of absorbed dose. Studies mapping differences in radiation sensitivities between human chromosomes are seldom undertaken. Consequently, health risk assessme...

By means of time-lapse microcinematography, metaphase arrest was studied in synchronized NHIK 3025 cells in contact with 5-chloropyrimidin-2-one (NY 3000) or vincristine. A dose-dependent prolongation of mitosis was found for both substances, and the fraction of cells able to escape mitotic arrest declined gradually as the concen tration of NY 3000 or vincristine was increased. Significant prol...

We have quantitatively studied the dynamic behavior of kinetochore fiber microtubules (kMTs); both turnover and poleward transport (flux) in metaphase and anaphase mammalian cells by fluorescence photoactivation. Tubulin derivatized with photoactivatable fluorescein was microinjected into prometaphase LLC-PK and PtK1 cells and allowed to incorporate to steady-state. A fluorescent bar was genera...

Mouse oocytes were placed in Hepes-T6 containing 7.5 μg/ml cytochalasin B and 5μg/ml Hoechst prior to enucleation, and enucleation was performed on oocytes using the manipulator. The oocyte held in place by gentle suction of a holding pipette (oocyte diameter approx.70 μm). The metaphase spindle (arrow) is aspirated into an enucleation pipette (1).

Cell division depends on the fine control of both microtubule dynamics and microtubule organisation. The microtubule bundling protein MAP65 is a ;midzone MAP' essential for the integrity of the anaphase spindle and cell division. Arabidopsis thaliana MAP65-1 (AtMAP65-1) binds and bundles microtubules by forming 25 nm cross-bridges. Moreover, as AtMAP65-1 bundles microtubules in interphase, anap...

Metaphase chromosome alignment is a key step of animal cell mitosis. The molecular mechanism leading to this equatorial positioning is still not fully understood. Forces exerted at kinetochores and on chromosome arms drive chromosome movements that culminate in their alignment on the metaphase plate. In this paper, we show that Xkid, a kinesin-like protein localized on chromosome arms, plays an...

Thirty-four antinuclear antibody (ANA) positive systemic lupus erythematosus (SLE) sera were tested for antibodies to double-stranded DNA (dsDNA) simultaneously using Farr, haemagglutination, Crithidia luciliae (CL) kinetoplast fluorescence and human metaphase chromosome fluorescence assays. Significant correlation (p less than 0 x 05) was found between the Farr and CL assays, with the two fluo...

We have produced metaphase spindles and induced them to enter anaphase in vitro. Sperm nuclei were added to frog egg extracts, allowed to replicate their DNA, and driven into metaphase by the addition of cytoplasm containing active maturation promoting factor (MPF) and cytostatic factor (CSF), an activity that stabilizes MPF. Addition of calcium induces the inactivation of MPF, sister chromatid...