Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Compartments

  • acidic compartment
  • anatomical compartment
  • b cell compartment
  • b-cell compartment
  • body compartment
  • cell compartment
  • cellular compartment
  • central compartment
  • cytoplasmic compartment
  • cytosolic compartment
  • dendritic compartment
  • different cellular compartment
  • different compartment
  • different subcellular compartment
  • effect compartment
  • endocytic compartment
  • endomembrane compartment
  • endosomal compartment
  • environmental compartment
  • extracellular compartment
  • fat compartment
  • fetal compartment
  • fluid compartment
  • golgi compartment
  • interstitial compartment
  • intracellular compartment
  • lateral compartment
  • lung compartment
  • lymphoid compartment
  • lysosomal compartment
  • matrix compartment
  • medial compartment
  • membrane compartment
  • mitochondrial compartment
  • nuclear compartment
  • other compartment
  • peripheral compartment
  • plant compartment
  • presynaptic compartment
  • proliferative compartment
  • single compartment
  • somato-dendritic compartment
  • stem cell compartment
  • storage compartment
  • stromal compartment
  • subcellular compartment
  • tissue compartment
  • vascular compartment

  • Terms modified by Compartments

  • compartment boundary
  • compartment fire
  • compartment model
  • compartment syndrome

  • Selected Abstracts

    Toxicokinetics of sediment-associated polybrominated diphenylethers (flame retardants) in benthic invertebrates (Lumbriculus variegatus, oligochaeta)

    Matti T. Leppänen
    Abstract Polybrominated diphenylethers (PBDEs) are ubiquitous environmental contaminants showing rapid temporal increase in some sample types. The compounds are known to biomagnify in aquatic food webs and are assumed to archive into sediments and soils. Currently, no direct evidence indicates whether sediment-associated PBDEs are available for biota. The aim of the present study was to explore the uptake and elimination of two common congeners (47 and 99) in sediment-inhabiting invertebrates to shed light on possible bioavailability of sediment-associated PBDEs. Two clean lake sediments were spiked with environmentally relevant concentrations of 14C-labeled tetra- and pentabromo diphenylether, and oligochaetes (Lumbriculus variegatus) were exposed for three or four weeks to allow kinetic accumulation calculations. Subsequent depuration tests were performed after three weeks of exposure to obtain depuration rates. Both congeners were clearly bioavailable, and only slight differences in steady-state tissue concentrations were found between the four sediment-ingesting oligochaete treatments (biota sediment accumulation factors [BSAFs], 3.0,3.7). The tetrabromo diphenylether-exposed oligochaetes that did not ingest sediment had clearly lower influx rates (0.1 vs 1,3 nmol h -1) than sediment-ingesting worms. Also, the estimated BSAF (1.8) was statistically different from that of the sediment-ingesting oligochaetes. These findings support the significance of feeding behavior in bioaccumulation of very hydrophobic organic contaminants. Depuration of both congeners was biphasic, indicating two kinetically different compartments in L. variegatus. Compartment A made up 73 to 92% of total radioactivity in tissues and had relatively fast depuration rates (half-lives, 10.5,47.5 h); the smaller compartment B had very slow depuration rates. No significant biotransformation of PBDEs was evident. The present study clearly demonstrates that the sediment-associated PBDEs, like other hydrophobic organic contaminants of environmental concern, are not totally sequestered from sediment-inhabiting oligochaetes and are subject to trophic transfer. [source]

    The Advent of the Secret Ballot in Britain and France, 1789,1914: From Public Assembly to Private Compartment

    HISTORY, Issue 308 2007
    These days the secret ballot is taken for granted and it is often seen as the natural complement of universal, democratic suffrage. Its emergence, however, was just as contested and varied as the franchise and raised similar issues concerning the nature and practice of citizenship. This article focuses on the emergence of the secret ballot in Britain and France, two countries with a long history of parliamentary and local elections. In Britain, the secret ballot was introduced in 1872, while in France, which introduced universal male suffrage in 1848, it was as late as 1913 before envelope and polling booth rendered the vote completely secure. This study documents the varied polling practices employed in both countries prior to the onset of the secret ballot. It also highlights the contentious nature of polling reform. For some, the secret ballot was regarded as a means of safeguarding electoral independence and eliminating corruption. Others, including radicals, argued quite the opposite: that secret voting was an affront to honourable, public-spirited citizenship. In the end, full secrecy was achieved as part of the broader process of domesticating and disciplining the exercise of a mass franchise. [source]

    Pharmacokinetics of Intravenous Alcohol: Two Compartment, Dual Michaelis-Menten Elimination

    ALCOHOLISM, Issue 4 2000
    Susan E. Shoaf
    No abstract is available for this article. [source]

    Gene and Protein Expression Profiling of the Microvascular Compartment in Experimental Autoimmune Encephalomyelitis in C57BI/6 and SJL Mice

    BRAIN PATHOLOGY, Issue 1 2005
    Carsten Alt
    Dysfunction of the blood-brain barrier (BBB) is a hallmark of inflammatory diseases of the central nervous system (CNS) such as multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). The molecular mechanisms leading to BBB breakdown are not well understood. In order to find molecules involved in this process, we used oligonucleotide microarrays and proteomics to analyze gene and protein expression of the microvascular compartment isolated from brains of C57BI/6 and SJL/N mice afflicted with EAE and the microvascular compartment isolated from healthy controls. Out of the 6500 known genes and expressed sequence tags (ESTs) studied, expression of 288 genes was found to be changed. Of these genes 128 were altered in the microvascular compartment in both EAE models. Six proteins were identified to be present at altered levels. In addition to the expected increased expression of genes coding for molecules involved in leukocyte recruitment, genes not yet ascribed to EAE pathogenesis were identified. Thus, proteomics and gene array screens of the microvascular compartment are valid approaches, that can be used to define novel candidate molecules involved in EAE pathogenesis at the level of the BBB. [source]

    ChemInform Abstract: Vectorial Growth/Regulations in a {P8W48}-Type Polyoxotungstate Compartment: Trapped Unusual Molybdenum Oxide Acts as a Handle.

    CHEMINFORM, Issue 11 2010
    Filipa L. Sousa
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Cancellous Bone Remodeling Occurs in Specialized Compartments Lined by Cells Expressing Osteoblastic Markers

    Ellen M. Hauge
    Abstract We describe a sinus, referred to as a bone remodeling compartment (BRC), which is intimately associated with cancellous bone remodeling. The compartment is lined on its marrow side by flattened cells and on its osseous side by the remodeling bone surface, resembling a roof of flattened cells covering the bone surface. The flat marrow lining cells are in continuity with the bone lining cells at the margins of the BRC. We examined a large number of diagnostic bone biopsy specimens received during recent years in the department. Furthermore, 10 patients (8 women and 2 men, median age 56 [40,69] years) with the high turnover disease of primary hyperparathyroidism who were treated with parathyroidectomy and followed for 3 years were included in the histomorphometric study. Bone samples for the immuno-enzyme staining were obtained from an amputated extremity of child. The total cancellous bone surface covered by BRC decreases by 50% (p < 0.05) following normalization of turnover and is paralleled by a similar 50% decrease in remodeling surface (p < 0.05). The entire eroded surface and two-thirds of the osteoid surface are covered by a BRC. BRC-covered uncompleted walls are 30% (p < 0.05) thinner than those without a BRC. This indicates that the BRC is invariably associated with the early phases of bone remodeling, that is, bone resorption, whereas it closes during the late part of bone formation. Immuno-enzyme staining shows that the flat marrow lining cells are positive for alkaline phosphatase, osteocalcin, and osteonectin, suggesting that they are bone cells. The first step in cancellous bone remodeling is thought to be the lining cells digesting the unmineralized matrix membrane followed by their disappearance and the arrival of the bone multicellular unit (BMU). We suggest that the lining cell barrier persists during bone remodeling; that the old lining cells become the marrow lining cells, allowing bone resorption and bone formation to proceed under a common roof of lining cells; that, at the end of bone formation, new bone lining cells derived from the flattened osteoblasts replace the marrow lining cells thereby closing the BRC; and that the two layers of lining cells eventually becomes a single layer. The integrity of the osteocyte-lining cell system is reestablished by the new generation of lining cells. The BRC most likely serves multiple purposes, including efficient exchange of matrix constituents and minerals, routing, monitoring, or modulating bone cell recruitment, and possibly the anatomical basis for the coupling of bone remodeling. [source]

    Cell-free Protein Synthesis through Solubilisate Exchange in Water/Oil Emulsion Compartments

    CHEMBIOCHEM, Issue 8 2004
    Adriana V. Pietrini Dr.
    Abstract This work is aimed at finding conditions under which synthetic compartments used as cell models can fuse with each other and allow reagents contained in the different compartments to react. This goal seems to be best achieved by the use of water in oil emulsions (w/o) with dimensions in the range of 30,60 ,m. In particular, cell-free EGFP (enhanced green fluorescent protein) synthesis takes place in Tween 80/Span 80 w/o emulsions, and the extent of the reaction can be monitored directly by fluorescence. The medium is mineral oil, containing 0.5,% v/v aqueous solution. Different premixing configurations of the components (plasmid, amino acids, E. Coli extract) are used and compared. The in vitro synthesis of EGFP in emulsion droplets proceeds for 1 h, and the yield is 7.5 ng,,L,1protein. EGFP synthesis in aqueous solution takes place for at least 5 h. The yield is 10.5 ng,,L,1protein after 1 h and 15.8 ng,,L,1protein after 5 h.The results with the w/o emulsions show that solubilisate exchange takes place among the different water droplets, but it is not possible to demonstrate clearly that a true fusion takes place. [source]

    ChemInform Abstract: Ring-Closing Olefin Metathesis in the Aqueous Phase of Amphiphilic Conetworks Consisting of Fluorophilic and Hydrophilic Compartments.

    CHEMINFORM, Issue 7 2009
    Eva M. Hensle
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    The lateral intercellular space as osmotic coupling compartment in isotonic transport

    ACTA PHYSIOLOGICA, Issue 1 2009
    E. H. Larsen
    Abstract Solute-coupled water transport and isotonic transport are basic functions of low- and high-resistance epithelia. These functions are studied with the epithelium bathed on the two sides with physiological saline of similar composition. Hence, at transepithelial equilibrium water enters the epithelial cells from both sides, and with the reflection coefficient of tight junction being larger than that of the interspace basement membrane, all of the water leaves the epithelium through the interspace basement membrane. The common design of transporting epithelia leads to the theory that an osmotic coupling of water absorption to ion flow is energized by lateral Na+/K+ pumps. We show that the theory accounts quantitatively for steady- and time dependent states of solute-coupled fluid uptake by toad skin epithelium. Our experimental results exclude definitively three alternative theories of epithelial solute,water coupling: stoichiometric coupling at the molecular level by transport proteins like SGLT1, electro-osmosis and a ,junctional fluid transfer mechanism'. Convection-diffusion out of the lateral space constitutes the fundamental problem of isotonic transport by making the emerging fluid hypertonic relative to the fluid in the lateral intercellular space. In the Na+ recirculation theory the ,surplus of solutes' is returned to the lateral space via the cells energized by the lateral Na+/K+ pumps. We show that this theory accounts quantitatively for isotonic and hypotonic transport at transepithelial osmotic equilibrium as observed in toad skin epithelium in vitro. Our conclusions are further developed for discussing their application to solute,solvent coupling in other vertebrate epithelia such as small intestine, proximal tubule of glomerular kidney and gallbladder. Evidence is discussed that the Na+ recirculation theory is not irreconcilable with the wide range of metabolic cost of Na+ transport observed in fluid-transporting epithelia. [source]

    Effects of immersion water temperature on whole-body fluid distribution in humans

    ACTA PHYSIOLOGICA, Issue 1 2004
    J. M. Stocks
    Abstract Aim:, In this study, we quantified acute changes in the intracellular and extracellular fluid compartments during upright neutral- and cold-water immersion. We hypothesized that, during short-term cold immersion, fluid shifts would be wholly restricted to the extracellular space. Methods:, Seven males were immersed 30 days apart: control (33.3 ° SD 0.6 °C); and cold (18.1 ° SD 0.3 °C). Posture was controlled for 4 h prior to a 60-min seated immersion. Results:, Significant reductions in terminal oesophageal (36.9 ° ± 0.1 °,36.3 ° ± 0.1 °C) and mean skin temperatures (30.3 ° ± 0.3 °,23.0 ° ± 0.3 °C) were observed during the cold, but not the control immersion. Both immersions elicited a reduction in intracellular fluid [20.17 ± 6.02 mL kg,1 (control) vs. 22.72 ± 9.90 mL kg,1], while total body water (TBW) remained stable. However, significant plasma volume (PV) divergence was apparent between the trials at 60 min [12.5 ± 1.0% (control) vs. 6.1 ± 3.1%; P < 0.05], along with a significant haemodilution in the control state (P < 0.05). Plasma atrial natriuretic peptide concentration increased from 18.0 ± 1.6 to 58.7 ± 15.1 ng L,1 (P < 0.05) during cold immersion, consistent with its role in PV regulation. We observed that, regardless of the direction of the PV change, both upright immersions elicited reductions in intracellular fluid. Conclusion:, These observations have two implications. First, one cannot assume that PV changes reflect those of the entire extracellular compartment. Second, since immersion also increases interstitial fluid pressure, fluid leaving the interstitium must have been rapidly replaced by intracellular water. [source]

    Comparison of bone marrow and peripheral blood ZAP-70 status examined by flow cytometric immunophenotyping in patients with chronic lymphocytic leukemia

    CYTOMETRY, Issue 4 2006
    Rachel Sheridan
    Abstract Background: The mutational status of the immunoglobulin heavy chain variable gene in patients with chronic lymphocytic leukemia correlates with prognosis. Patients with mutated IgVH genes fare better than those with unmutated genes. Gene expression profiling studies identified the tyrosine kinase ZAP-70 to be expressed in unmutated CLL samples. Flow cytometric examination of ZAP-70 expression in tumor cells has been proposed to be a convenient surrogate marker for IgVH mutational status. However, a few studies have shown a small number of discordant results between ZAP-70 positivity, IgVH mutational status, and clinical outcome. There have been no reported studies comparing bone marrow samples with peripheral blood for ZAP-70 expression in CLL patients. Methods: We searched our flow cytometry files from October 2004 through April 2006 and identified CLL in 311 bone marrow and peripheral blood specimens from 256 patients. We defined ZAP-70 positivity as greater than 30% of the CD19+ B-cells above the isotype control value that coexpress ZAP-70. Statistical analyses were performed using the Fisher exact test and student t -test. Results: A significantly greater number of bone marrow specimens were positive for ZAP-70 when compared with the number of peripheral blood specimens. Of all the ZAP-70 negative specimens, CLL cells from bone marrow had a greater mean percentage of ZAP-70 positive cells when compared with the CLL cells from peripheral blood. Finally, six patients were identified who were ZAP-70 positive in the bone marrow but ZAP-70 negative in the peripheral blood. Conclusions: These results may be due to either an increase in the false positive rate in bone marrow specimens or to an intrinsic feature of CLL cells in the compartment that is biologically distinct from peripheral tumor cells. As prognosis and treatment decisions may be based on ZAP-70 results from either specimen type, it is prudent to further examine this observation. © 2006 International Society for Analytical Cytology [source]

    Actin on DNA,An ancient and dynamic relationship,

    CYTOSKELETON, Issue 8 2010
    Kari-Pekka Skarp
    Abstract In the cytoplasm of eukaryotic cells the coordinated assembly of actin filaments drives essential cell biological processes, such as cell migration. The discovery of prokaryotic actin homologues, as well as the appreciation of the existence of nuclear actin, have expanded the scope by which the actin family is utilized in different cell types. In bacteria, actin has been implicated in DNA movement tasks, while the connection with the RNA polymerase machinery appears to exist in both prokaryotes and eukaryotes. Within the nucleus, actin has further been shown to play a role in chromatin remodeling and RNA processing, possibly acting to link these to transcription, thereby facilitating the gene expression process. The molecular mechanism by which actin exerts these newly discovered functions is still unclear, because while polymer formation seems to be required in bacteria, these species lack conventional actin-binding proteins to regulate the process. Furthermore, although the nucleus contains a plethora of actin-regulating factors, the polymerization status of actin within this compartment still remains unclear. General theme, however, seems to be actin's ability to interact with numerous binding partners. A common feature to the novel modes of actin utilization is the connection between actin and DNA, and here we aim to review the recent literature to explore how this connection is exploited in different contexts. [source]

    Myosin16b: The COOH-tail region directs localization to the nucleus and overexpression delays S-phase progression

    CYTOSKELETON, Issue 1 2007
    Richard S. Cameron
    Abstract Rat Myo16a and Myo16b comprise the founding members of class XVI myosin and are characterized by an N-terminal ankyrin repeat domain thought to mediate an association with protein phosphatase 1 catalytic subunits 1, and 1,. Myo16b is the principal isoform and reveals predominant expression in developing neural tissue. Here, we use COS-7 cells as a model system to develop an understanding of Myo16b function. We find that Myo16b displays predominant localization in the nucleus of cells transitioning through interphase, but is not associated with processes of mitosis. Using a panel of EGFP-Myo16b-expression plasmids in transient transfection studies, we identified the COOH-terminal residues 1616,1912 as necessary and solely sufficient to target Myo16b to the nucleus. We show that the Myo16b-tail region directs localization to a nuclear compartment containing profilin and polymerized actin, which appears to form a three-dimensional meshwork through the depth of the nucleus. Further, we demonstrate that this compartment localizes within euchromatic regions of the genome and contains proliferating cell nuclear antigen (PCNA) and cyclin A, both markers of S-phase of the cell cycle. Cells transiently expressing Myo16b or Myo16b-tail region show limited incorporation of BrdU, delayed progression through S-phase of the cell cycle, and curtailed cellular proliferation. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source]

    Cutaneous melanoma: estimating survival and recurrence risk based on histopathologic features

    David E. Elder
    ABSTRACT:, The prognosis of melanoma is best understood in terms of a model of tumor progression, in which most melanomas may evolve through two major phases of progression: from a lesion that is nontumorigenic and has little or no capacity for metastasis; to a more advanced lesion that is tumorigenic and may have capacity for metastasis. The likelihood of metastasis varies with a number of attributes of the primary melanoma, including the phase of progression, the Breslow tumor thickness, mitotic rate, and host response to the tumorigenic compartment of the lesion, Clark's level of invasion, and other factors. When distant metastasis has occurred, the prognosis for the patient is very poor. In this monograph, the focus will be the discussion of factors related to the prognosis of melanomas that at diagnosis are clinically localized to the primary site. [source]

    The Allantoic Core Domain: New insights into development of the murine allantois and its relation to the primitive streak

    Karen M. Downs
    Abstract The whereabouts and properties of the posterior end of the primitive streak have not been identified in any species. In the mouse, the streak's posterior terminus is assumed to be confined to the embryonic compartment, and to give rise to the allantois, which links the embryo to its mother during pregnancy. In this study, we have refined our understanding of the biology of the murine posterior primitive streak and its relation to the allantois. Through a combination of immunostaining and morphology, we demonstrate that the primitive streak spans the posterior extraembryonic and embryonic regions at the onset of the neural plate stage (,7.0 days postcoitum, dpc). Several hours later, the allantoic bud emerges from the extraembryonic component of the primitive streak (XPS). Then, possibly in collaboration with overlying allantois-associated extraembryonic visceral endoderm, the XPS establishes a germinal center within the allantois, named here the Allantoic Core Domain (ACD). Microsurgical removal of the ACD beyond headfold (HF) stages resulted in the formation of allantoic regenerates that lacked the ACD and failed to elongate; nevertheless, vasculogenesis and vascular patterning proceeded. In situ and transplantation fate mapping demonstrated that, from HF stages onward, the ACD's progenitor pool contributed to the allantois exclusive of the proximal flanks. By contrast, the posterior intraembryonic primitive streak (IPS) provided the flanks. Grafting the ACD into TC/TC hosts, whose allantoises are significantly foreshortened, restored allantoic elongation. These results revealed that the ACD is essential for allantoic elongation, but the cues required for vascularization lie outside of it. On the basis of these and previous findings, we conclude that the posterior primitive streak of the mouse conceptus is far more complex than was previously believed. Our results provide new directives for addressing the origin and development of the umbilical cord, and establish a novel paradigm for investigating the fetal/placental relationship. Developmental Dynamics 238:532,553, 2009. © 2009 Wiley-Liss, Inc. [source]

    Zebrafish mutants with disrupted early T-cell and thymus development identified in early pressure screen

    Nikolaus S. Trede
    Abstract Generation of mature T lymphocytes requires an intact hematopoietic stem cell compartment and functional thymic epithelium. We used the zebrafish (Danio rerio) to isolate mutations that affect the earliest steps in T lymphopoiesis and thymic organogenesis. Here we describe the results of a genetic screen in which gynogenetic diploid offspring from heterozygous females were analyzed by whole-mount in situ hybridization for the expression of rag-1. To assess immediately if a global defect in hematopoiesis resulted in the mutant phenotype, ,-embryonic globin expression was simultaneously assayed for multilineage defects. In this report, we present the results obtained with this strategy and show representative mutant phenotypes affecting early steps in T-cell development and/or thymic epithelial cell development. We discuss the advantage of this strategy and the general usefulness of the zebrafish as a model system for vertebrate lymphopoiesis and thymic organogenesis. Developmental Dynamics 237:2575,2584, 2008. © 2008 Wiley-Liss, Inc. [source]

    Drosophila melanogaster p24 genes have developmental, tissue-specific, and sex-specific expression patterns and functions

    Kara A. Boltz
    Abstract Genes encoding members of the p24 family of intracellular trafficking proteins are present throughout animal and plant lineages. However, very little is known about p24 developmental, spatial, or sex-specific expression patterns or how localized expression affects function. We investigated these problems in Drosophila melanogaster, which contains nine genes encoding p24 proteins. One of these genes, logjam (loj), is expressed in the adult female nervous system and ovaries and is essential for oviposition. Nervous system-specific expression of loj, but not ovary-specific expression, rescues the behavioral defect of mutants. The Loj protein localizes to punctate structures in the cellular cytoplasm. These structures colocalize with a marker specific to the intermediate compartment and cis -Golgi, consistent with experimental evidence from other systems suggesting that p24 proteins function in intracellular transport between the endoplasmic reticulum and Golgi. Our findings reveal that Drosophila p24 transcripts are developmentally and tissue-specifically expressed. CG31787 is male-specifically expressed gene that is present during the larval, pupal, and adult stages. Female CG9053 mRNA is limited to the head, whereas males express this gene widely. Together, our studies provide experimental evidence indicating that some p24 genes have sex-specific expression patterns and tissue- and sex-limited functions. Developmental Dynamics 236:544,555, 2007. © 2006 Wiley-Liss, Inc. [source]

    Analysis of pancreatic endocrine development in GDF11-deficient mice

    Darwin S. Dichmann
    Abstract Here, we examine the role of GDF11 in pancreatic development. Using in situ hybridization and reverse transcriptase-polymerase chain reaction analyses, we show that Gdf11 transcripts are expressed in embryonic pancreas epithelium before the secondary transition but decrease rapidly afterward. To determine the function of GDF11 during pancreas development, we analyzed Gdf11,/, mouse embryos. In such embryos, pancreas size is twofold reduced at embryonic day (E) 18 compared with wild-type littermates. Quantification of the different tissue compartments shows a specific hypoplasia of the exocrine compartment, while the endocrine and ductal compartments are unaffected. Notably, NGN3+ endocrine precursor cells are increased fourfold at E18, although the amount of endocrine cells in the pancreas of these animals is unchanged compared with wild-type littermates. Similarly, the maturation of endocrine cells as well as the ratio between ,- and ,-cells appears normal. Developmental Dynamics 235:3016,3025, 2006. © 2006 Wiley-Liss, Inc. [source]

    Cells of all somitic compartments are determined with respect to segmental identity

    Marlyse Dieuguie Fomenou
    Abstract Development of somite cells is orchestrated by two regulatory processes. Differentiation of cells from the various somitic compartments into different anlagen and tissues is regulated by extrinsic signals from neighboring structures such as the notochord, neural tube, and surface ectoderm. Morphogenesis of these anlagen to form specific structures according to the segmental identity of each somite is specified by segment-specific positional information, based on the Hox -code. It has been shown that following experimental rotation of presomitic mesoderm or newly formed somites, paraxial mesodermal cells adapt to the altered signaling environment and differentiate according to their new orientation. In contrast, presomitic mesoderm or newly formed somites transplanted to different segmental levels keep their primordial segmental identity and form ectopic structures according to their original position. To determine whether all cells of a segment, including the dorsal and ventral compartment, share the same segmental identity, presomitic mesoderm or newly formed somites were rotated and transplanted from thoracic to cervical level. These experiments show that cells from all compartments of a segment are able to interpret extrinsic local signals correctly, but form structures according to their original positional information and maintain their original Hox expression in the new environment. Developmental Dynamics 233:1386,1393, 2005. © 2005 Wiley-Liss, Inc. [source]

    Runx3 is involved in hair shape determination

    Eli Raveh
    Abstract Transcriptional regulators of the Runx family play critical roles in normal organ development and, when mutated, lead to genetic diseases and cancer. Runx3 functions during cell lineage decisions in thymopoiesis and neurogenesis and mediates transforming growth factor-, signaling in dendritic cells. Here, we study the function of Runx3 in the skin and its appendages, primarily the hair follicle, during mouse development. Runx3 is expressed predominantly in the dermal compartment of the hair follicles as they form and during the hair cycle, as well as in the nail and sweat gland skin appendages. Distinct expression is also detected periodically in isolated cells of the epidermis and in melanocytes, populating the hair bulb. Runx3 -deficient mice display a perturbation of the normal hair coat, which we show to be due to hair type and hair shape changes. Thus, one of the functions of Runx3 in skin may be to regulate the formation of the epithelial derived structural hair by affecting dermal to epidermal interactions. Developmental Dynamics 233:1478,1487, 2005. © 2005 Wiley-Liss, Inc. [source]

    Reciprocal chemokine receptor and ligand expression in the human placenta: Implications for cytotrophoblast differentiation

    Penelope M. Drake
    Abstract At the onset of pregnancy, the human placenta, which forms the interface between the embryo/fetus and the mother, must rapidly develop into a life-sustaining organ. The many unusual processes entailed in placental development include the poorly understood phenomenon of maternal tolerance of the hemiallogeneic cells of the conceptus, including, most remarkably, placental trophoblasts that invade the uterine wall. To investigate whether this fetal organ exerts control over the maternal immune system at the level of leukocyte trafficking, we examined placental expression of chemokines, well-known cytokine regulators of leukocyte movements. In situ hybridization revealed abundant expression of 13 chemokines in the stromal but not the trophoblast compartment of chorionic villi. Potential roles for these molecules include recruitment of the resident macrophage (Hofbauer cell) population to the villi. In parallel, cytotrophoblast production of a panel of nine chemokine receptors was assessed by using RNase protection assays. The numerous receptors detected suggested the novel possibility that the paracrine actions of chemokine ligands derived from either the villous stroma or the decidua could mediate general aspects of placental development, with specific contributions to cytotrophoblast differentiation along the pathway that leads to uterine invasion. Developmental Dynamics 229:877,885, 2004. © 2004 Wiley-Liss, Inc. [source]

    Cell proliferation during blastema formation in the regenerating teleost fin

    Leonor Santos-Ruiz
    Abstract Epimorphic regeneration in teleost fins occurs through the establishment of a balanced growth state in which a blastema gives rise to all the mesenchymal cells, whereas definite areas of the epidermis proliferate leading to its extension, thus, allowing the enlargement of the whole structure. This type of regeneration involves specific mechanisms that temporally and spatially regulate cell proliferation. To understand how the blastema is formed and how this growth situation is set up, we investigated cell proliferation patterns in the regenerating fin of the goldfish Carassius auratus from the time of amputation to that of blastema formation by using proliferating cell nuclear antigen immunostaining and bromodeoxyuridine labeling. Wound closure and apical epidermal cap formation took place by epidermal migration and re-arrangement, without the contribution of cell proliferation. As soon as the apical cap had formed, the epidermis started to proliferate at its lateral surfaces, in which all layers maintained cycling for the duration of the studied process. The distal epidermal cap, on the contrary, presented very few cycling cells, and its cytoarchitecture was indicative of continuous remodeling due to ray growth. The basal layer of this epidermal cap showed a typical morphology and remained nonproliferative whilst in contact with the proliferating blastema. Proliferation in the mesenchymal compartment of the ray started far from the amputation plane. Subsequently, cycling cells approached that location, until they formed the blastema in contact with the apical epidermal cap. Differences observed between the epidermis and mesenchyma, regarding activation of the cell cycle and the establishment of proliferative patterns, suggest that differential mechanisms regulate cell proliferation in each of these compartments during the initial stages of regeneration. © 2002 Wiley-Liss, Inc. [source]

    Morphogenetic domains in the yolk syncytial layer of axiating zebrafish embryos

    Leonard A. D'Amico
    Abstract The yolk syncytial layer (YSL) of the teleostean yolk cell is known to play important roles in the induction of cellular mesendoderm, as well as the patterning of dorsal tissues. To determine how this extraembryonic endodermal compartment is subdivided and morphologically transformed during early development, we have examined collective movements of vitally stained YSL nuclei in axiating zebrafish embryos by using four-dimensional confocal microscopy. During blastulation, gastrulation, and early segmentation, zebrafish YSL nuclei display several highly patterned movements, which are organized into spatially distinct morphogenetic domains along the anterior-posterior and dorsal-ventral axes. During the late blastula period, with the onset of epiboly, nuclei throughout the YSL initiate longitudinal movements that are directed along the animal-vegetal axis. As epiboly progresses, nuclei progressively recede from the advancing margin of the epibolic YSL. However, a small group of nuclei is retained at the YSL margin to form a constricting blastoporal ring. During mid-gastrulation, YSL nuclei undergo convergent-extension behavior toward the dorsal midline, with a subset of nuclei forming an axial domain that underlies the notochord. These highly patterned movements of YSL nuclei share remarkable similarities to the morphogenetic movements of deep cells in the overlying zebrafish blastoderm. The macroscopic shape changes of the zebrafish yolk cell, as well as the morphogenetic movements of its YSL nuclei, are homologous to several morphogenetic behaviors that are regionally expressed within the vegetal endodermal cell mass of gastrulating Xenopus embryos. In contrast to the cellular endoderm of Xenopus, the dynamics of zebrafish YSL show that a syncytial endodermal germ layer can express a temporal sequence of morphogenetic domains without undergoing progressive steps of cell fate restriction. © 2001 Wiley-Liss, Inc. [source]

    Multiple mechanisms mediate motor neuron migration in the zebrafish hindbrain

    Stephanie M. Bingham
    Abstract The transmembrane protein Van gogh-like 2 (Vangl2) is a component of the noncanonical Wnt/Planar Cell Polarity (PCP) signaling pathway, and is required for tangential migration of facial branchiomotor neurons (FBMNs) from rhombomere 4 (r4) to r5-r7 in the vertebrate hindbrain. Since vangl2 is expressed throughout the zebrafish hindbrain, it might also regulate motor neuron migration in other rhombomeres. We tested this hypothesis by examining whether migration of motor neurons out of r2 following ectopic hoxb1b expression was affected in vangl2, (trilobite) mutants. Hoxb1b specifies r4 identity, and when ectopically expressed transforms r2 to an "r4-like" compartment. Using time-lapse imaging, we show that GFP-expressing motor neurons in the r2/r3 region of a hoxb1b -overexpressing wild-type embryo migrate along the anterior-posterior (AP) axis. Furthermore, these cells express prickle1b (pk1b), a Wnt/PCP gene that is specifically expressed in FBMNs and is essential for their migration. Importantly, GFP-expressing motor neurons in the r2/r3 region of hoxb1b -overexpressing trilobite mutants and pk1b morphants often migrate, even though FBMNs in r4 of the same embryos fail to migrate longitudinally (tangentially) into r6 and r7. These observations suggest that tangentially migrating motor neurons in the anterior hindbrain (r1-r3) can use mechanisms that are independent of vangl2 and pk1b functions. Interestingly, analysis of tri; val double mutants also suggests a role for vangl2 -independent factors in neuronal migration, since the valentino mutation partially suppresses the trilobite mutant migration defect. Together, the hoxb1b and val experiments suggest that multiple mechanisms regulate motor neuron migration along the AP axis of the zebrafish hindbrain. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2010 [source]

    Mutagenesis studies in transgenic Xenopus intermediate pituitary cells reveal structural elements necessary for correct prion protein biosynthesis

    Jos W.G. van Rosmalen
    Abstract The cellular prion protein (PrPC) is generally accepted to be involved in the development of prion diseases, but its physiological role is still under debate. To obtain more insight into PrPC functioning, we here used stable Xenopus transgenesis in combination with the proopiomelanocortin (POMC) gene promoter to express mutated forms of Xenopus PrPC fused to the C-terminus of the green fluorescent protein (GFP) specifically in the neuroendocrine Xenopus intermediate pituitary melanotrope cells. Similar to GFP-PrPC, the newly synthesized GFP-PrPCK81A mutant protein was stepwise mono- and di-N-glycosylated to 48- and 51-kDa forms, respectively, and eventually complex glycosylated to yield a 55-kDa mature form. Unlike GFP-PrPC, the mature GFP-PrPCK81A mutant protein was not cleaved, demonstrating the endoproteolytic processing of Xenopus PrPC at lysine residue 81. Surprisingly, removal of the glycosylphosphatidylinositol (GPI) anchor signal sequence or insertion of an octarepeat still allowed N-linked glycosylation, but the GFP-PrPC,GPI and GFP-PrPCocta mutant proteins were not complex glycosylated and not cleaved, indicating that the GPI/octa mutants did not reach the mid-Golgi compartment of the secretory pathway. The transgene expression of the mutant proteins did not affect the ultrastructure of the melanotrope cells nor POMC biosynthesis and processing, or POMC-derived peptide secretion. Together, our findings reveal the evolutionary conservation of the site of metabolic cleavage and the importance of the presence of the GPI anchor and the absence of the octarepeat in Xenopus PrPC for its correct biosynthesis. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source]

    Olfactory preference for own mother and litter in 1-day-old rabbits and its impairment by thermotaxis

    Jessica Serra
    Abstract We investigated the ability of rabbit pups to display preferences towards various elements of their postnatal environment during the stage of confinement in the nest. Subjects were submitted to a two-choice test during the first week after birth to assess if they could detect and discriminate between does, litters of pups, or nesting materials of the same developmental stage. On D1 and D7, pups were attracted to any lactating doe, litter, or nest when compared to an empty compartment. When two stimuli were opposed, pups preferred their own nest to an alien one on D1 and D7 but not their mother nor their siblings when opposed to alien does or pups. However, additional tests indicated that this lack of preference for kin conspecifics resulted from a predominant attraction to thermal cues over individual odors. Indeed, pups were strongly attracted to a warm compartment (37°C) than to a cooler one (20°C) and once thermal cues were controlled for in the testing situation, the pups were specifically attracted to odors of their own mother's hair and of their siblings. No preference was observed towards the mother's uterine secretions. In conclusion, pups can recognize olfactory cues emanating from their mother and their siblings the day after birth. The preference for nesting materials would reflect in major part the combined attraction to maternal and sibling odors present in the nest. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 542,553, 2008. [source]

    Histology and biochemical composition of the autotomy mantle of Ficus ficus (Mesogastropoda: Ficidae)

    ACTA ZOOLOGICA, Issue 2 2002
    L. L. Liu
    Abstract When the foot of the figsnail Ficus ficus is mechanically stimulated, a portion of the mantle on the side of the inner lip, recognized as the autotomy tissue, swells then autotomizes. Studies of the behaviour and population dynamics of mantle autotomy in F. ficus have previously been reported, but here, a detailed description of the structure of the autotomy tissue is presented for the first time. Whether or not this autotomy tissue has the secondary function of a storage compartment was also investigated through analysis of its biochemical composition. Figsnails were collected from the coast of Kaohsiung, Taiwan. Histological observations indicated that the most obvious feature of the autotomy tissue is the extensive network of muscle fibres and connective tissues. In the swollen autotomy tissue, not only do the epithelia rupture, but the connective tissue expands threefold on the dorsal side and 15-fold on the ventral side. Chemical analysis of body composition indicated that the average contents of protein, lipid, carbohydrate and ash in the foot, mantle and autotomy tissue are in the range of 55.6,76.5%, 0.6,14.1%, 2.0,27.9% and 6.5,13.5%, respectively, with the caloric value ranging from 4.7 to 5.5 kcal g,1 dry wt. The content of carbohydrate in the autotomy tissue is much less than that in the foot and mantle, i.e. 2.0,6.8% vs. 13.0,27.9%. There is no indication that the autotomy tissue serves as an energy reserve. Hence, it is suggested that the autotomy tissue functions only as a defensive weapon. [source]

    Determination of the operational pH value of a buffering membrane by an isoelectric trapping separation of a carrier ampholyte mixture

    ELECTROPHORESIS, Issue 5 2008
    Robert Y. North
    Abstract The operational pH value of a buffering membrane used in an isoelectric trapping separation is determined by installing the membrane as the separation membrane into a multicompartmental electrolyzer operated in the two-separation compartment configuration. A 3compartments and a binary isoelectric trapping separation is completed. A set of pI markers and a sufficient amount of a pI<3 auxiliary ampholyte is added to the aliquot collected from the anodic separation compartment of the electrolyzer. The same set of pI markers and a sufficient amount of a 10compartment of the electrolyzer. Both mixtures are then analyzed by CIEF: the pI markers whose pI values fall into the pI range of the carrier ampholytes trapped in the respective separation compartments become separated from each other, yielding two calibration lines. The pI markers whose pI values fall outside the range of the trapped carrier ampholytes appear merged into single bands at the extremes of the pH gradients. The pI values of the merged bands determined from the two calibration lines yield the operational pH value of the buffering membrane. [source]

    Toward an integrated microchip sized 2-D polyacrylamide slab gel electrophoresis device for proteomic analysis

    ELECTROPHORESIS, Issue 3 2007
    Zuzana Demianová
    Abstract We describe a miniaturized instrument capable of performing 2-DE. Our miniaturized device is able to perform IEF and polyacrylamide slab gel electrophoresis (PASGE) in the same unit. It consists of a compartment for a first-dimensional IEF gel, which is connected to a second-dimensional PASGE gel. The focused samples are automatically transferred from the IEF gel to the PASGE gel by electromigration. Our preliminary experiments show that the device is able to focus and separate a mixture of proteins in approximately 1,h, excluding the time required for the staining procedure. On average, the gel-to-gel retardation factor,(Rf) variation was 6.2% (±0.9%) and pI variation was 2.5% (±0.6%). Separated protein spots were excised from stained gels, digested with trypsin, and further identified by MS, thus enabling direct proteomic analysis of the separated proteins. [source]

    Synaptic vesicle proteins under conditions of rest and activation: Analysis by 2-D difference gel electrophoresis

    ELECTROPHORESIS, Issue 17 2006
    Jacqueline Burré
    Abstract Synaptic vesicles are organelles of the nerve terminal that secrete neurotransmitters by fusion with the presynaptic plasma membrane. Vesicle fusion is tightly controlled by depolarization of the plasma membrane and a set of proteins that may undergo post-translational modifications such as phosphorylation. In order to identify proteins that undergo modifications as a result of synaptic activation, we induced massive exocytosis and analysed the synaptic vesicle compartment by benzyldimethyl- n -hexadecylammonium chloride (BAC)/SDS-PAGE and difference gel electrophoresis (DIGE) followed by MALDI-TOF-MS. We identified eight proteins that revealed significant changes in abundance following nerve terminal depolarization. Of these, six were increased and two were decreased in abundance. Three of these proteins were phosphorylated as detected by Western blot analysis. In addition, we identified an unknown synaptic vesicle protein whose abundance increased on synaptic activation. Our results demonstrate that depolarization of the presynaptic compartment induces changes in the abundance of synaptic vesicle proteins and post-translational protein modification. [source]