Abstract:
:Certain embryonic tissue masses and cell aggregates behave like deformable solids during brief experimental manipulations but like viscous liquids in long-term organ cultures. To investigate these seemingly paradoxical physical properties, we have mechanically deformed cell aggregates derived from several embryonic chick organs by centrifuging them against solid substrata. Aggregate shapes during brief centrifugation were observed directly in a microscope-centrifuge. In addition, techniques were devised for fixing cell aggregates during prolonged centrifugation. Evidence presented here shows that these fixative-injection procedures accurately preserve the prefixation shapes of living centrifuged aggregates. According to a simple viscous-liquid model for cell aggregates, cohering cells slide past one another when external forces and/or tissue surface tensions cause gradual rearrangements in aggregate conformations. In earlier experiments, 2 types of behaviour predicted from this model were confirmed for several embryonic chick tissues subjected to prolonged centrifugation. First, initially flat aggregates rounded up against the centrifugal force to adopt the same shapes that initially round aggregates reached by flattening. Second, the relative roundness of centrifuged aggregates of different tissues at shape equilibrium correlated with the relative positions that these tissues assumed when they were combined in aggregate-spreading and cell-sorting experiments. By contrast, the brief centrifugation experiments described here provide some support for a simple elastic-solid model in which aggregate shape changes are accompanied by cell deformations rather than cell redistributions. In particular, since cell migration tends to occur quite slowly, the very rapid aggregate flattening observed during the first few minutes of centrifugation presumably requires cell stretching. Moreover, since they do also round up very rapidly following brief centrifugation, these aggregates exhibit considerable elasticity that presumably reflects the swift relaxation of cell stretching as the centrifugal force is removed. Athough both elastic-solid and viscous-liquid properties can be recognized in cell aggregates, we note that, in the prolonged centrifugation experiments described here, rapid initial aggregate flattening is followed by much more gradual, continued flattening. Similarly, after prolonged centrifugation, rapid partial aggregate rounding-up is also followed by much more gradual, continued rounding-up during subsequent culture at Ig. Such rapid-then-slow shape changes contradict both simple elastic-solid and simple viscous-liquid models for cell aggregates. These bimodal shape changes are instead consistent with both compound-viscoelastic-solid and elasticoviscous-liquid models for cell aggregates, although only the latter can also account for long-term liquid-like aggregate behaviour...
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Phillips HM,Steinberg MSsubject
Has Abstractpub_date
1978-04-01 00:00:00pages
1-20eissn
0021-9533issn
1477-9137journal_volume
30pub_type
杂志文章abstract::In order to determine whether fibronexus morphogenesis is involved in the establishment of more normal cellular morphology and substrate adhesion patterns in Nil/HSV transformed fibroblasts induced by treatment with exogenous fibronectin (FN), this system was studied with electron microscopy (EM), immunocytochemistry,...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1982-08-01 00:00:00
abstract::Recently, we have presented evidence that proliferating blood vessels produce and deposit fibronectin in situ during the angiogenesis of wound repair. This report extends these observations by demonstrating that human endothelial cells from both large and small vessels depend on fibronectin for their adherence in vitr...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1986-06-01 00:00:00
abstract::Insulin-like growth factor-1 (IGF-1) has been shown to induce skeletal muscle hypertrophy, to prevent the loss of muscle mass with ageing and to improve the muscle phenotype of dystrophic mice. We previously developed a model of IGF-1-induced hypertrophy of human myotubes, in which hypertrophy was not only characteriz...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.03371
更新日期:2007-02-15 00:00:00
abstract::The compartmentalization of second messenger-activated protein kinases contributes to the fidelity of hormone-mediated signal transduction events. For example, the cAMP-dependent protein kinase is tethered at specific intracellular locations through association with A-kinase anchoring proteins (AKAPs). We now report t...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1999-08-01 00:00:00
abstract::Loss of tissue organization is a hallmark of the early stages of cancer, and there is considerable interest in proteins that maintain normal tissue architecture. Prostate epithelial cells cultured in Matrigel form three-dimensional acini that mimic aspects of prostate gland development. The organization of these struc...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.119388
更新日期:2013-04-15 00:00:00
abstract::The contact site A (csA) glycoprotein is a strictly developmentally regulated plasma membrane component responsible for the EDTA-stable (Ca(2+)-independent) form of intercellular adhesion in Dictyostelium discoideum. Using inverse polymerase chain reaction and a terminator vector we have isolated a 1.6 kb genomic frag...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1992-06-01 00:00:00
abstract::Kalirin, one of the few Rho guanine nucleotide exchange factors (GEFs) that contains spectrin-like repeats, plays a critical role in axon extension and maintenance of dendritic spines. PC12 cells were used to determine whether Cdk5, a critical participant in both processes, regulates the action of Kalirin. Expression ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.016089
更新日期:2008-08-01 00:00:00
abstract::A key step in cell migration is the dynamic formation and disassembly of adhesions at the front and the concomitant movement and release of adhesions in the rear of the cell. Fibroblasts maintained in the absence of serum have stable adhesions within the rear of the cell and exhibit reduced trailing-edge retraction re...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.020941
更新日期:2008-03-15 00:00:00
abstract::When HeLa cells are lysed in solutions containing a non-ionic detergent and 2 M-NaCl, structures are released that retain many of the morphological features of nuclei. These nucleoids contain all the nuclear RNA and DNA but few of the proteins characteristic of chromatin. Their DNA is supercoiled and so intact. Using ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1981-08-01 00:00:00
abstract::The molecular mechanisms regulating skeletal muscle regeneration and differentiation are not well understood. We analyzed the expression of connexins (Cxs) 40, 43 and 45 in normal and regenerating tibialis anterior muscle and in primary cultures of differentiating myoblasts in adult and newborn mice, respectively. Cxs...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01553
更新日期:2005-01-01 00:00:00
abstract::During cytokinesis, the central spindle, a bundle of interdigitated anti-parallel microtubules between separating chromosomes, recruits various cytokinetic regulator proteins to the cleavage region. Here, we show that the level of protein ubiquitylation is strikingly and transiently elevated in Aurora B kinase-positiv...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.027417
更新日期:2008-04-15 00:00:00
abstract::We have previously shown that the total actin content of tumorigenic HeLa/fibroblast somatic cell hybrids is significantly lower than that of the non-tumorigenic hybrid cells. A measure of actin synthesis, relative to total protein synthesis, was obtained for these cells to determine whether the reduced actin content ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1985-06-01 00:00:00
abstract::The influence of extracellular environmental factors on preimplantation rat blastocysts was tested by determining the number of embryos which escaped from their zonae pellucidae, followed by attachment and outgrowth of trophoblast giant cells, after 72 h in culture Uterine luminal ocmponents from individual females, o...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1977-06-01 00:00:00
abstract::We have isolated suppressors of the deletion allele of delta-tubulin, uni3-1, in the biflagellate green alga Chlamydomonas reinhardtii. The deletion of delta-tubulin produces cells that assemble zero, one or two flagella and have basal bodies composed primarily of doublet rather than triplet microtubules. Flagellar nu...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.00859
更新日期:2004-01-15 00:00:00
abstract::Intercellular propagation of signals through connexin32-containing gap junctions is of major importance in physiological processes like nerve activity-dependent glucose mobilization in liver parenchymal cells and enzyme secretion from pancreatic acinar cells. In these cells, as in other organs, more than one type of c...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:2000-04-01 00:00:00
abstract::To evaluate the relative mobilities of cell surface glycoconjugates during myogenesis we have studied the redistribution of fluorescein-conjugated plant lectins on L6 rat myogenic cells. Previous experiments had demonstrated that the receptors for the lectins soybean agglutinin (SBA), wheat germ agglutinin, concanaval...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1986-07-01 00:00:00
abstract::Microinjected GTP gamma S revealed three distinct steps in the exocytic transport of the temperature sensitive glycoprotein of vesicular stomatitis virus (ts-O45-G) from the ER to the cell surface in intact Vero cells. While COPII dependent export of ts-O45-G from the ER is blocked in cells injected with recombinant p...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1998-07-01 00:00:00
abstract::Microtubules stimulate contractile-ring formation in the equatorial cortex and simultaneously suppress contractility in the polar cortex; how they accomplish these differing activities is incompletely understood. We measured the behavior of GFP-actin in mammalian cells treated with nocodazole under conditions that eit...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.027052
更新日期:2008-07-15 00:00:00
abstract::In chicken oocytes, proteins of the K/J family or their analogs, such as are known to be involved in mRNA processing in humans, are closely associated with nascent C-rich RNA transcripts on the loops of lampbrush chromosomes. Using labelled single stranded nucleotide probes and an antibody to protein K, these C-rich t...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1995-04-01 00:00:00
abstract::Ena/VASP proteins are actin-binding proteins that localize to actin stress fibres, the tips of filopodia and the lamellipodial leading edge. In the past few years, a number of seemingly conflicting studies have confused the Ena/VASP field, pointing to roles for these proteins in both promotion and inhibition of actin-...
journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:10.1242/jcs.00218
更新日期:2002-12-15 00:00:00
abstract::Focal adhesions are complex multi-molecular structures that link the actin cytoskeleton to the extracellular matrix through integrin adhesion receptors and play a key role in regulation of many cellular functions. LAR (also known as PTPRF) is a receptor protein tyrosine phosphatase that regulates PDGF signalling and l...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.191379
更新日期:2016-08-01 00:00:00
abstract::Using a polyclonal antibody against purified zymogen granule membrane components from rat pancreas a cDNA coding for the 29 kDa protein (ZG29p) was identified by immunoscreening of a hormonally stimulated pancreas cDNA library. Western blot analysis suggests that ZG29p is a pancreas-specific protein and immunofluoresc...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1999-08-01 00:00:00
abstract::Multinucleated muscle fibres arise by fusion of precursor cells called myoblasts. We previously showed that CKIP-1 ectopic expression in C2C12 myoblasts increased cell fusion. In this work, we report that CKIP-1 depletion drastically impairs C2C12 myoblast fusion in vitro and in vivo during zebrafish muscle developmen...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.101048
更新日期:2012-08-15 00:00:00
abstract::The adapter protein CD2-associated protein (CD2AP) functions in various signaling and vesicle trafficking pathways, including endosomal sorting and/or trafficking and degradation pathways. Here, we investigated the role of CD2AP in insulin-dependent glucose transporter 4 (Glut4, also known as SLC2A4) trafficking and g...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.175075
更新日期:2015-12-15 00:00:00
abstract::Fe-S clusters act as co-factors of proteins with diverse functions, for example, in DNA repair. Downregulation of the cytosolic iron-sulfur protein assembly (CIA) machinery promotes genomic instability through the inactivation of multiple DNA repair pathways. Furthermore, CIA deficiencies are associated with so far un...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.211433
更新日期:2018-06-27 00:00:00
abstract::Centrioles organise centrosomes and cilia, and these organelles have an important role in many cell processes. In flies, the centriole protein Ana1 is required for the assembly of functional centrosomes and cilia. It has recently been shown that Cep135 (also known as Bld10) initially recruits Ana1 to newly formed cent...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.186460
更新日期:2016-07-01 00:00:00
abstract::Polarization of the motile cell is associated with the formation of a distinct plasma membrane domain, the pseudopod, whose stabilization determines the directionality of cell movement. The rapid movement of cells over a substrate requires that an essential aspect of cell motility must be the supply of the necessary m...
journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:
更新日期:1999-06-01 00:00:00
abstract::Previously, we showed that an integral component of stored mRNP particles in Xenopus oocytes, Xp54, is a DEAD-box RNA helicase with ATP-dependent RNA-unwinding activity. Xp54 belongs to small family of helicases (DDX6) that associate with mRNA molecules encoding proteins required for progress through meiosis. Here we ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:2002-01-15 00:00:00
abstract::Desmoplakin is an intracellular component of desmosomes which plays a role in the anchorage of intermediate filaments to these structures. We report here that, despite the absence of desmosomes, cultured endothelial cells from human umbilical vein express desmoplakin I and II both at mRNA and protein level. Desmoplaki...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1996-08-01 00:00:00
abstract::BMP2 stimulates bone formation and signals preferably through BMP receptor (BMPR) 1A, whereas GDF5 is a cartilage inducer and signals preferably through BMPR1B. Consequently, BMPR1A and BMPR1B are believed to be involved in bone and cartilage formation, respectively. However, their function is not yet fully clarified....
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.246934
更新日期:2020-08-21 00:00:00