Now showing items 1-20 of 50

  • Arp2/3 complex inhibition radically alters lamellipodial actin architecture, suspended cell shape, and the cell spreading process 

    Henson, John H.; Yeterian, Mesrob; Weeks, Richard M.; Medrano, Angela E.; Brown, Briana L.; Geist, Heather L.; Pais, Mollyann D.; Oldenbourg, Rudolf; Shuster, Charles B. (American Society for Cell Biology, 2015-01-07)
    Recent studies have investigated the dendritic actin cytoskeleton of the cell edge's lamellipodial (LP) region by experimentally decreasing the activity of the actin filament nucleator and branch former, the Arp2/3 complex. ...
  • Bipolarization and poleward flux correlate during xenopus extract spindle assembly 

    Mitchison, Timothy J.; Maddox, P.; Groen, Aaron C.; Cameron, L.; Perlman, Z.; Ohi, Ryoma; Desai, A.; Salmon, Edward D.; Kapoor, Tarun M. (American Society for Cell Biology, 2004-09-22)
    We investigated the mechanism by which meiotic spindles become bipolar and the correlation between bipolarity and poleward flux, using Xenopus egg extracts. By speckle microscopy and computational alignment, we find that ...
  • Calyculin-A induces cleavage in a random plane in unfertilized sea urchin eggs 

    Goda, Makoto; Inoue, Shinya; Mabuchi, Issei (Marine Biological Laboratory, 2009-02)
    Calyculin-A (CLA), a protein phosphatase inhibitor, has been known to induce cleavage resembling normal furrowing in unfertilized sea urchin eggs. In CLA-treated eggs, actin filaments and myosin assemble to form a contractile ...
  • Chromosome malorientations after meiosis II arrest cause nondisjunction 

    Janicke, Marie A.; Lasko, Loren; Oldenbourg, Rudolf; LaFountain, James R. (American Society for Cell Biology, 2007-02-21)
    This study investigated the basis of meiosis II nondisjunction. Cold arrest induced a fraction of meiosis II crane fly spermatocytes to form (n + 1) and (n – 1) daughters during recovery. Live-cell liquid crystal polarized ...
  • Chromosomes can congress to the metaphase plate before biorientation 

    Kapoor, Tarun M.; Lampson, Michael A.; Hergert, Polla; Cameron, Lisa; Cimini, Daniela; Salmon, Edward D.; McEwen, Bruce F.; Khodjakov, Alexey (2005-12-09)
    The stable propagation of genetic material during cell division depends on the congression of chromosomes to the spindle equator before the cell initiates anaphase. It is generally assumed that congression requires that ...
  • Compression regulates mitotic spindle length by a mechanochemical switch at the poles 

    Dumont, Sophie; Mitchison, Timothy J. (2009-05)
    Although the molecules involved in mitosis are becoming better characterized, we still lack an understanding of the emergent mechanical properties of the mitotic spindle. For example, we cannot explain how spindle length ...
  • Conditional knockout of the Menkes disease copper transporter demonstrates its critical role in embryogenesis 

    Wang, Yanfang; Zhu, Sha; Weisman, Gary A.; Gitlin, Jonathan D.; Petris, Michael J. (Public Library of Science, 2012-08-10)
    The transition metal, copper (Cu), is an enzymatic cofactor required for a wide range of biochemical processes. Its essentiality is demonstrated by Menkes disease, an X-linked copper deficiency disorder characterized by ...
  • Directly probing the mechanical properties of the spindle and its matrix 

    Gatlin, Jesse C.; Matov, Alexandre; Danuser, Gaudenz; Mitchison, Timothy J.; Salmon, Edward D. (Rockefeller University Press, 2010-02-22)
    Several recent models for spindle length regulation propose an elastic pole to pole spindle matrix that is sufficiently strong to bear or antagonize forces generated by microtubules and microtubule motors. We tested this ...
  • Ena/VASP proteins have an anti-capping independent function in filopodia formation 

    Applewhite, Derek A.; Barzik, Melanie; Kojima, Shin-ichiro; Svitkina, Tatyana M.; Gertler, Frank B.; Borisy, Gary G. (American Society for Cell Biology, 2007-05-02)
    Filopodia have been implicated in a number of diverse cellular processes including growth-cone path finding, wound healing, and metastasis. The Ena/VASP family of proteins has emerged as key to filopodia formation but the ...
  • Entropy-driven formation of a chiral liquid-crystalline phase of helical filaments 

    Barry, Edward; Hensel, Zach; Dogic, Zvonimir; Shribak, Michael; Oldenbourg, Rudolf (American Physical Society, 2006-01-11)
    We study the liquid-crystalline phase behavior of a concentrated suspension of helical flagella isolated from Salmonella typhimurium. Flagella are prepared with different polymorphic states, some of which have a pronounced ...
  • A fiber-optic phase-randomizer for microscope illumination by laser 

    Ellis, Gordon W. (Rockefeller University Press, 1979-11)
  • Flexible and dynamic nucleosome fiber in living mammalian cells 

    Nozaki, Tadasu; Kaizu, Kazunari; Pack, Chan-Gi; Tamura, Sachiko; Tani, Tomomi; Hihara, Saera; Nagai, Takeharu; Takahashi, Koichi; Maeshima, Kazuhiro (Landes Bioscience, 2013-08-12)
    Genomic DNA is organized three dimensionally within cells as chromatin and is searched and read by various proteins by an unknown mechanism; this mediates diverse cell functions. Recently, several pieces of evidence, ...
  • Force and length in the mitotic spindle 

    Dumont, Sophie; Mitchison, Timothy J. (2009-07)
    The mitotic spindle assembles to a steady-state length at metaphase through the integrated action of molecular mechanisms that generate and respond to mechanical forces. While molecular mechanisms that produce force have ...
  • Functional overlap of microtubule assembly factors in chromatin-promoted spindle assembly 

    Groen, Aaron C.; Maresca, Thomas J.; Gatlin, Jesse C.; Salmon, Edward D.; Mitchison, Timothy J. (American Society for Cell Biology, 2009-04-15)
    Distinct pathways from centrosomes and chromatin are thought to contribute in parallel to microtubule nucleation and stabilization during animal cell mitotic spindle assembly, but their full mechanisms are not known. We ...
  • Functional states of kinetochores revealed by laser microsurgery and fluorescent speckle microscopy 

    LaFountain, James R.; Cohan, Christopher S.; Oldenbourg, Rudolf (American Society of Cell Biology, 2011-10-26)
    The impact of mechanical forces on kinetochore motility was investigated using laser microsurgery to detach kinetochores with associated chromatin (K fragment) from meiotic chromosomes in spermatocytes from the crane fly ...
  • Image simulation for biological microscopy : microlith 

    Mehta, Shalin B.; Oldenbourg, Rudolf (Optical Society, 2014-05-13)
    Image simulation remains under-exploited for the most widely used biological phase microscopy methods, because of difficulties in simulating partially coherent illumination. We describe an open-source toolbox, microlith ...
  • Intrinsic dynamic behavior of fascin in filopodia 

    Aratyn, Yvonne S.; Schaus, Thomas E.; Taylor, Edwin W.; Borisy, Gary G. (American Society for Cell Biology, 2007-08-01)
    Recent studies showed that the actin cross-linking protein, fascin, undergoes rapid cycling between filopodial filaments. Here, we used an experimental and computational approach to dissect features of fascin exchange and ...
  • Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes 

    LaFountain, James R.; Oldenbourg, Rudolf (American Society for Cell Biology, 2014-02-26)
    We use liquid crystal polarized light imaging to record the life histories of single kinetochore (K-) fibers in living crane-fly spermatocytes, from their origins as nascent K-fibers in early prometaphase to their fully ...
  • The light-sensitive conductance of melanopsin-expressing Joseph and Hesse cells in amphioxus 

    Pulido, Camila; Malagon, Gerardo; Ferrer, Camilo; Chen, Jun Kui; Angueyra, Juan Manuel; Nasi, Enrico; Gomez, Maria del Pilar (Rockefeller University Press, 2011-12-26)
    Two types of microvillar photoreceptors in the neural tube of amphioxus, an early chordate, sense light via melanopsin, the same photopigment as in “circadian” light detectors of higher vertebrates. Because in amphioxus ...
  • Maloriented bivalents have metaphase positions at the spindle equator with more kinetochore microtubules to one pole than to the other 

    LaFountain, James R.; Oldenbourg, Rudolf (American Society for Cell Biology, 2004-09-22)
    To test the "traction fiber" model for metaphase positioning of bivalents during meiosis, kinetochore fibers of maloriented bivalents, induced during recovery from cold arrest, were analyzed with a liquid crystal polarizing ...