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Results 401 - 450 of 1057
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Cimini Daniela - - 2005
Proper chromosome segregation is required to maintain the appropriate number of chromosomes from one cell generation to the next and to prevent aneuploidy, the condition in which a cell has gained or lost one or several chromosomes during cell division. Aneuploidy is a hallmark associated with birth defects and cancer, ...
Capela Delphine - - 2005
The NodD1 regulon of Sinorhizobium meliloti was determined through the analysis of the S. meliloti transcriptome in response to the plant flavone luteolin and the overexpression of nodD1. Nine new genes regulated by both NodD1 and luteolin were identified, demonstrating that NodD1 controls few functions behind nodulation in S. meliloti.
Delanoue Renald - - 2005
Molecular motors actively transport many types of cargo along the cytoskeleton in a wide range of organisms. One class of cargo is localized mRNAs, which are transported by myosin on actin filaments or by kinesin and dynein on microtubules. How the cargo is kept at its final intracellular destination and ...
Utter Brian - - 2005
We present experiments on the doublon growth morphology in directional solidification. Samples used are succinonitrile with small amounts of poly(ethylene oxide), acetone, or camphor as the solute. Doublons, or symmetry-broken dendrites, are generic diffusion-limited growth structures expected at large undercooling and low anisotropy. Low anisotropy growth is achieved by selecting ...
Shannon Katie B - - 2005
How microtubules act to position the plane of cell division during cytokinesis is a topic of much debate. Recently, we showed that a subpopulation of stable microtubules extends past chromosomes and interacts with the cell cortex at the site of furrowing, suggesting that these stabilized microtubules may stimulate contractility. To ...
Xiong May P - - 2005
Yeast cytosine deaminase (yCD) was cloned, expressed, and purified by affinity chromatography. We have characterized the products resulting from covalent attachment of 2-4 PEG chains on yCD and determined the major and minor isomers for each respective conjugate. The results show that for non-covalently associated homodimers, it is possible to ...
Blackledge Todd A - - 2005
Spider silks are among the strongest and toughest known materials, but investigation of these remarkable properties has been confined largely to orb-weaving spiders. We investigated the mechanical performance of silk from the cobweb-weaving spider Latrodectus hesperus. Both silk from the scaffolding region of the web and sticky gumfooted capture lines ...
Yang Zhenye - - 2005
Mitosin (also named CENP-F) is a large human nuclear protein transiently associated with the outer kinetochore plate in M phase. Using RNA interference and fluorescence microscopy, we showed that mitosin depletion attenuated chromosome congression and led to metaphase arrest with misaligned polar chromosomes whose kinetochores showed few cold-stable microtubules. Kinetochores ...
Régnier Vinciane V Department of Biochemistry, Oxford University, South Parks Road, OX1 3QU Oxford, United Kingdom. - - 2005
CENP-A is an evolutionarily conserved, centromere-specific variant of histone H3 that is thought to play a central role in directing kinetochore assembly and in centromere function. Here, we have analyzed the consequences of disrupting the CENP-A gene in the chicken DT40 cell line. In CENP-A-depleted cells, kinetochore protein assembly is ...
Wellner Robert B - - 2005
AQP5 and AQP8 possess targeting/retention motifs which mediate their localization to the apical and basolateral membranes, respectively, of polarized MDCK-II cells. As targeting/retention motifs have been localized to the N- or C-termini of other AQPs, we sought the location of such motifs in AQPs 5 and 8 by exchanging their ...
Cheeseman Iain M - - 2005
During chromosome segregation, kinetochores form dynamic connections with spindle microtubules. In vertebrates, these attachments require the activities of a number of outer kinetochore proteins, including CENP-F [1, 2] and the widely conserved microtubule-associated protein CLASP [3]. Here, we investigate the functional relationship between HCP-1/2, two redundant CENP-F-like proteins, and CLASP(CLS-2) ...
Kops Geert J P L GJ Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093, - - 2005
The mitotic checkpoint ensures that chromosomes are divided equally between daughter cells and is a primary mechanism preventing the chromosome instability often seen in aneuploid human tumors. ZW10 and Rod play an essential role in this checkpoint. We show that in mitotic human cells ZW10 resides in a complex with ...
Wei Ronnie R - - 2005
The four-protein Ndc80 complex, an essential kinetochore component conserved from yeast to humans, plays an indispensable role in proper chromosome alignment and segregation during mitosis. In higher eukaryotes, the homologous complex probably resides in the middle domain of the trilaminar kinetochore, linking centromeric heterochromatin with microtubule-associated structures. We have prepared ...
Detrembleur Christine - - 2005
The energy cost of gait (C) is greater in amputee than in normal subjects. Our objective was to assess the influence of lower speed, inefficient pendulum mechanism and disturbed smoothness of centre of body mass (CM(b)) displacement on C in unilateral amputees and to have a better understanding the relationship ...
Mowlavi Arian A Plastic Surgery Institute, Southern Illinois University, School of Medicine, Springfield, USA. - - 2005
The "pixie" ear deformity can be recognized by its "stuck on" or "pulled" appearance, which is caused by the extrinsic pull of the medial cheek and jawline skin flaps at the earlobe attachment point, the otobasion inferius. The tension results in migration of the otobasion inferius from a posterior cephalad ...
Meraldi Patrick - - 2005
The spindle checkpoint ensures faithful chromosome segregation by linking the onset of anaphase to the establishment of bipolar kinetochore-microtubule attachment. The checkpoint is mediated by a signal transduction system comprised of conserved Mad, Bub and other proteins. In this study, we use live-cell imaging coupled with RNA interference to investigate ...
Tanaka Tomoyuki U - - 2005
For proper chromosome segregation, sister kinetochores must attach to microtubules extending from opposite spindle poles prior to anaphase onset. This state is called sister kinetochore bi-orientation or chromosome bi-orientation. The mechanism ensuring chromosome bi-orientation lies at the heart of chromosome segregation, but is still poorly understood. Recent evidence suggests that ...
Mitchison T J - - 2005
In Xenopus extract meiotic spindles, microtubules slide continuously towards their minus ends, a process called poleward flux. This article discusses recent progress in determining the mechanism of poleward flux, and its functions in spindle organization and generating force on chromosomes. Bipolar organization is required for flux and inhibition of the ...
Kose Sedat - - 2005
Studies on the mechanisms of atrioventricular nodal reentrant tachycardia (AVNRT) have yet to clarify whether the slow and fast pathways connect directly with the atria or via an upper common pathway. Although a "final common pathway" connecting the slow and fast pathways to the proximal His bundle was thought to ...
Wang Yan - - 2005
Transections of the entorhinal afferent fibers to hippocampus, perforant path (PP), result in the denervation in specific hippocampal subregions, which is followed by a series of plastic events including axon sprouting and reactive synaptogenesis. Many growth-associated molecules are thought to participate in these events. In the present study, we proved ...
Paliulis Leocadia V - - 2005
The distinctive behaviors of chromosomes in mitosis and meiosis depend upon differences in kinetochore position. Kinetochore position is well established except for a critical transition between meiosis I and meiosis II. We examined kinetochore position during the transition and compared it with the position of kinetochores in mitosis. Immunofluorescence staining ...
Delville Alfred - - 2005
We have applied a restricted grand canonical Monte Carlo procedure to describe, in the framework of the primitive model, the counterion exchange mechanism between diffuse layers of counterions surrounding segregated charged lamellae. The net charge transfer between the dense and dilute domains is shown to vary as a function of ...
Saunders D S - - 2005
This paper examines the views of Erwin Bünning and Tony Lees on the mechanism of photoperiodic time measurement, the former advocating a circadian basis for the phenomenon and the latter a non-circadian hourglass-like timer. This difference in opinion led to a protracted split among workers on photoperiodism, some supporting an ...
Higuchi Toru - - 2005
Microtubules of the mitotic spindle form the structural basis for chromosome segregation. In metaphase, microtubules show high dynamic instability, which is thought to aid the 'search and capture' of chromosomes for bipolar alignment on the spindle. Microtubules suddenly become more stable at the onset of anaphase, but how this change ...
Wells Jonathan - - 2005
A microtubule-dependent polar ejection force that pushes chromosomes away from spindle poles during prometaphase is observed in animal cells but not in the cells of higher plants. Elongating microtubules and kinesin-like motor molecules have been proposed as possible causes, but neither accounts for all the data. In the hypothesis proposed ...
Kawabe Tetsuji - - 2005
Using the Riemannian geometric approach to Hamiltonian systems, we show that the empirical indicator of chaos proposed by Kosloff and Rice [J. Chem. Phys. 74, 1947 (1981)], an improved version of the well-known Toda-Brumer criterion, is equivalent to sectional curvature of the Jacobi equation when the Eisenhart metric is chosen ...
Clark B - - 2005
The purpose of this study is to evaluate the changes in structural anatomy of cadaver pelves, with specific emphasis on axial rotation, resulting from the application of TPO plates differing by type, angle and orientation. Nine cadaver pelves procedure: The degree of axial rotation was determined for three different pelvic ...
Nielsen Heidi - - 2004
Sputum samples from cystic fibrosis (CF) patients were investigated by oscillatory, creep and steady shear rheological techniques over a range of time scales from 10(-3) to 10(6) s. The viscoelastic changes obtained by mixing sputa with the actin-filament-severing protein gelsolin and with the thiol-reducing agent dithiothreitol (DTT) were also investigated. ...
Cimini Daniela - - 2004
Merotelic kinetochore orientation is a kinetochore misattachment in which a single kinetochore is attached to microtubules from both spindle poles instead of just one. It can be favored in specific circumstances, is not detected by the mitotic checkpoint, and induces lagging chromosomes in anaphase. In mammalian cells, it occurs at ...
Maiato Helder H Laboratory of Cell Regulation, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201-0509, - - 2005
The motion of a chromosome during mitosis is mediated by a bundle of microtubules, termed a kinetochore fibre (K-fibre), which connects the kinetochore of the chromosome to a spindle pole. Once formed, mature K-fibres maintain a steady state length because the continuous addition of microtubule subunits onto microtubule plus ends ...
Sudhop Thomas - - 2005
Recent insights in the role of ATP-binding cassette (ABC) transporters ABCG5 and ABCG8, the discovery of ezetimibe, the first approved direct cholesterol absorption inhibitor, as well as the identification of Niemann-Pick C1 Like 1 (NPC1L1) protein as sterol transporter in the gut, focused attention on sterol transport processes in the ...
Jäger Hubert - - 2005
The centromere-specific histone H3 variant CENP-A plays a crucial role in kinetochore specification and assembly. We chose a genetic approach to identify interactors of the Drosophila CENP-A homolog CID. Overexpression of cid in the proliferating eye imaginal disk results in a rough eye phenotype, which is dependent on the ability ...
Hatori Kuniyuki - - 2004
The actomyosin motor as a principal functional component of cell motility is highly coordinated in regulating the participating molecular components. At the same time, it has to be flexible and plastic enough to accommodate itself to a wide variety of operational conditions. We prepared two different types of actomyosin systems. ...
Bondi Liz - - 2004
Drawing on interviews with practitioners involved in voluntary-sector counselling in Scotland, this paper explores contradictions associated with the professionalisation of counselling in the UK. Five meanings of the term "professional" are identified. Those in support of professionalisation aim to bring these different meanings into close alignment, whereas those with reservations ...
Takishita Kiyotaka - - 2004
Although most photosynthetic dinoflagellates have plastids with peridinin, the three dinoflagellate genera Karenia, Karlodinium, and Takayama possess anomalously pigmented plastids that contain fucoxanthin and its derivatives (19'-hexanoyloxy-fucoxanthin and 19'-butanoyloxy-fucoxanthin) instead of the peridinin. This pigment composition is similar to that of haptophytes. All peridinin-containing dinoflagellates investigated so far have at ...
Maiato Helder H Wadsworth Center, New York State Department of Health, Albany 12201, - - 2004
It is now clear that a centrosome-independent pathway for mitotic spindle assembly exists even in cells that normally possess centrosomes. The question remains, however, whether this pathway only activates when centrosome activity is compromised, or whether it contributes to spindle morphogenesis during a normal mitosis. Here, we show that many ...
Banks Jennifer D - - 2004
During cell division, the proper formation of a bipolar spindle and its function to segregate chromosomes requires precise coordination of microtubule-stabilizing and destabilizing activities. Globally destabilized, dynamic microtubules radiating from duplicated centrosomes are locally regulated by chromosomes. Proteins at the kinetochore of each sister chromatid mediate a dynamic attachment, allowing ...
DeLuca Jennifer G JG Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. - - 2005
A major goal in the study of vertebrate mitosis is to identify proteins that create the kinetochore-microtubule attachment site. Attachment sites within the kinetochore outer plate generate microtubule dependent forces for chromosome movement and regulate spindle checkpoint protein assembly at the kinetochore. The Ndc80 complex, comprised of Ndc80 (Hec1), Nuf2, ...
Pearson Chad G - - 2004
With a single microtubule attachment, budding-yeast kinetochores provide an excellent system for understanding the coordinated linkage to dynamic microtubule plus ends for chromosome oscillation and positioning. Fluorescent tagging of kinetochore proteins indicates that, on average, all centromeres are clustered, distinctly separated from their sisters, and positioned equidistant from their respective ...
Sakai Satoki - - 2005
To analyse the effects of current income on the nature of size-number trade-off and optimal offspring size, we developed a model in which offspring grow by absorbing current income and reserves. The offspring continue to grow while the current income is available or the reserves exist, and they cease to ...
Kadura Sheila - - 2005
During mitosis, the spindle assembly checkpoint (SAC) responds to faulty attachments between kinetochores and the mitotic spindle by imposing a metaphase arrest until the defect is corrected, thereby preventing chromosome missegregation. A genetic screen to isolate SAC mutants in fission yeast yielded point mutations in three fission yeast SAC genes: ...
Niccoli Teresa - - 2004
During vegetative growth of the fission yeast Schizosaccharomyces pombe, microtubules nucleate from multiple microtubule organising centres (MTOCs) close to the nucleus, polymerising until they reach the end of the cell and then shrinking back to the cell centre. In response to mating pheromone, S. pombe undergoes a morphological switch from ...
Trautmann Susanne - - 2004
The S. pombe Cdc14-related phosphatase Clp1p/Flp1p regulates G2/M transition by antagonizing CDK activity and is essential for coordinating the nuclear division cycle with cytokinesis through the cytokinesis checkpoint. At the G2/M transition, Clp1p/Flp1p is released from the nucleolus and SPB and distributes throughout the nucleus to the spindle and the ...
Vanoosthuyse Vincent - - 2004
Several lines of evidence suggest that kinetochores are organizing centers for the spindle checkpoint response and the synthesis of a "wait anaphase" signal in cases of incomplete or improper kinetochore-microtubule attachment. Here we characterize Schizosaccharomyces pombe Bub3p and study the recruitment of spindle checkpoint components to kinetochores. We demonstrate by ...
Maiato Helder H Laboratory of Cell Regulation, NYSDH-Division of Molecular Medicine, Wadsworth Center, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, - - 2004
The kinetochore is a control module that both powers and regulates chromosome segregation in mitosis and meiosis. The kinetochore-microtubule interface is remarkably fluid, with the microtubules growing and shrinking at their point of attachment to the kinetochore. Furthermore, the kinetochore itself is highly dynamic, its makeup changing as cells enter ...
Hauf Silke - - 2004
Kinetochores are the major point of contact between spindle microtubules and chromosomes. They are assemblies of more than 50 different proteins and take part in regulating and controlling their own interaction with the spindle. We review recent advance in understanding how kinetochores are properly placed onto the chromosome, and how ...
Wang Hongmei H CAS Key Laboratory for Structure Biology and Hefei National Laboratory for Physical Sciences at Microscale, Hefei 230027, - - 2004
Chromosome segregation in mitosis is orchestrated by dynamic interaction between spindle microtubules and the kinetochore, a multiprotein complex assembled onto centromeric DNA of the chromosome. Here we show that Zwint-1 is required and is sufficient for kinetochore localization of Zeste White 10 (ZW10) in HeLa cells. Zwint-1 specifies the kinetochore ...
LaFountain James R JR - - 2004
Microtubule flux in spindles of insect spermatocytes, long-used models for studies on chromosome behavior during meiosis, was revealed after iontophoretic microinjection of rhodamine-conjugated (rh)-tubulin and fluorescent speckle microscopy. In time-lapse movies of crane-fly spermtocytes, fluorescent speckles generated when rh-tubulin incorporated at microtubule plus ends moved poleward through each half-spindle and ...
Moreno Pedro R - - 2004
BACKGROUND: Growth of atherosclerotic plaques is accompanied by neovascularization from vasa vasorum microvessels extending through the tunica media into the base of the plaque and by lumen-derived microvessels through the fibrous cap. Microvessels are associated with plaque hemorrhage and may play a role in plaque rupture. Accordingly, we tested this ...
Powers James - - 2004
Holocentric chromosomes assemble kinetochores along their length instead of at a focused spot. The elongated expanse of an individual holocentric kinetochore and its potential flexibility heighten the risk of stable attachment to microtubules from both poles of the mitotic spindle (merotelic attachment), and hence aberrant segregation of chromosomes. Little is ...
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