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Results 501 - 550 of 1806
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Weaver Molly M Howard Hughes Medical Institute and Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305-5307, - - 2008
During Drosophila metamorphosis, most larval cells die. Pupal and adult tissues form from imaginal cells, tissue-specific progenitors allocated in embryogenesis that remain quiescent during embryonic and larval life. Clonal analysis and fate mapping of single, identified cells show that tracheal system remodeling at metamorphosis involves a classical imaginal cell population ...
Guha Arjun - - 2008
For many organs, the processes of renewal and regeneration recruit stem cells to replace differentiated, postmitotic cells, but the capacity of an organ's differentiated cells to divide and contribute is uncertain. Most cells of the Drosophila adult are the descendants of dedicated precursors that divide and replace larval cells that ...
Le Garrec Jean-François - - 2008
Metazoan development critically depends on a surprisingly short list of conserved pathways. How can such ubiquitous systems regulate a variety of cell-biological events at various developmental stages in different tissues and in different organisms? In the fruit fly, the planar cell polarity (PCP) pathway regulates widely different processes. It is ...
Batista Manuel F - - 2008
The vertebrate spinal cord contains distinct classes of cells that form at precise dorsal-ventral locations and express specific combinations of transcription factors. In amniotes, V2 cells develop in the ventral spinal cord, just dorsal to motoneurons. All V2 cells develop from the same progenitor domain and hence are initially molecularly ...
Baker Nicholas E - - 2008
Cell competition can occur when cells of different genotypes share the same developing compartment, with one genotype displacing the other as a result of a proliferative advantage. Studies of cell competition in Drosophila have identified an active process of cell assassination and corpse engulfment, and also roles for Myc and ...
Mitchell Naomi - - 2008
The steroid hormone Ecdysone is crucial for developmental cell death, proliferation and morphogenesis in Drosophila. Herein, we delineate a molecular pathway linking Ecdysone signalling to cell cycle regulation in the Drosophila developing wing. We present evidence that the Ecdysone-inducible zinc-finger transcription factor Crol provides a crucial link between the Ecdysone ...
Vincent Stephane S Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, - - 2008
A fundamental concept in development is that secreted molecules such as Wingless (Wg) and Hedgehog (Hh) generate pattern by inducing cell fate. By following markers of cellular identity posterior to the Wg- and Hh-expressing cells in the Drosophila dorsal embryonic epidermis, we provide evidence that neither Wg nor Hh specifies ...
Hashiguchi Megumi - - 2008
Formation of the dorsal organizer (Spemann organizer) is an important process in early vertebrate development. In zebrafish, two molecular cascades--Bozozok/Dharma (Boz) and Nodal signaling--act in parallel to induce the dorsal organizer. However, the complete molecular mechanism regulating this event remains unclear. Here we report that zebrafish cell lines derived from ...
Ghiglione Christian - - 2008
Small GTPases of the Ras-like (Ral) family are crucial for signalling functions in both normal and cancer cells; however, their role in a developing organism is poorly understood. Here, we identify the Drosophila Ral homologue RalA as a new key regulator of polar-cell differentiation during oogenesis. Polar cells have a ...
Szpurka Hadrian - - 2008
Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal disorder of haematopoietic stem cells caused by somatic PIGA mutations, resulting in a deficiency in glycosylphosphatidylinositol-anchored proteins (GPI-AP). Because GPI-AP associate with lipid rafts (LR), lack of GPI-AP on PNH cells may result in alterations in LR-dependent signalling. Conversely, PNH cells are a ...
Baia Gilson S - - 2008
The Notch signaling cascade is deregulated in diverse cancer types. Specific Notch function in cancer is dependent on the cellular context, the particular homologs expressed, and cross-talk with other signaling pathways. We have previously shown that components of the Notch signaling pathway are deregulated in meningiomas. However, the functional consequence ...
Singhvi Aakanksha - - 2008
Understanding how neurons adopt particular fates is a fundamental challenge in developmental neurobiology. To address this issue, we have been studying a Caenorhabditis elegans lineage that produces the HSN motor neuron and the PHB sensory neuron, sister cells produced by the HSN/PHB precursor. We have previously shown that the novel ...
Bershad Anya K - - 2008
During the course of development cells undergo division producing a variety of cell types. Proliferation and differentiation are dependent on both genetic programs, encoded by the cellular genome, and environmental cues produced by the local cellular environment imposing local selection pressures on cells. We explore the role that cellular signals ...
Guner Burcu - - 2008
The vertebrate adenohypophysis forms as a placode at the anterior margin of the neural plate, requiring both hedgehog (Hh) and fibroblast growth factor (Fgf) mediated cell-cell signaling for induction and survival of endocrine cell types. Using small molecule inhibitors to modulate signaling levels during zebrafish development we show that graded ...
Stach Thomas - - 2008
A key problem in understanding deuterostome evolution has been the origin of the chordate body plan. A biphasic life cycle with a sessile adult and a free-swimming larva is traditionally considered ancestral in chordates with subsequent neotenic loss of the sessile adult stage. Molecular phylogenies challenged this view, suggesting that ...
Morrison Brad E BE Dept. of Molecular and Cell Biology, University of Texas at Dallas, 2601 N. Floyd Road, Richardson, TX 75080, - - 2008
Mice lacking histone deacetylase 9 (HDAC9) and its truncated variant, HDRP, exhibit post-axial polydactyly that manifests as an extra big toe on the right hind foot. Polydactyly in HDAC9/ HDRP knockout mice occurs with incomplete penetrance and affects both genders similarly. Because polydactyly can result from overactivity of sonic hedgehog ...
Krens S F Gabby - - 2008
The MAPKs are key regulatory signaling molecules in many cellular processes. Here we define differential functions for ERK1 and ERK2 MAPKs in zebrafish embryogenesis. Morpholino knockdown of ERK1 and ERK2 resulted in cell migration defects during gastrulation, which could be rescued by co-injection of the corresponding mRNA. Strikingly, Erk2 mRNA ...
Oda Hiroki - - 2008
In the insect Drosophila embryo, establishment of maternal transcription factor gradients, rather than cell-cell interactions, is fundamental to patterning the embryonic axes. In contrast, in the chelicerate spider embryo, cell-cell interactions are thought to play a crucial role in the development of the embryonic axes. A grafting experiment by Holm ...
Mundy Gregory R - - 2008
The Hedgehog (Hh) pathway is important for skeletal patterning and morphogenesis during embryonic development. Papers by Ohba et al. and Mak et al. in this edition of Developmental Cell suggest that Hh signaling may exert delicate control over the activities of osteoclasts and osteoblasts, the cell types primarily responsible for ...
Starz-Gaiano Michelle - - 2008
In both normal development and in a variety of pathological conditions, epithelial cells can acquire migratory and invasive properties. Border cells in the Drosophila ovary provide a genetically tractable model for elucidating the mechanisms controlling such behaviors. Here we report the identification of a mutant, apontic (apt), in which the ...
Hlubek Andrea - - 2008
The highly conserved GTP-binding proteins Cdc42 and Rac1 regulate cytokinesis, establishment of cell polarity and vesicular trafficking. In the dimorphic fungus Ustilago maydis, Rac1 is required for cell polarity and budding, while Cdc42 is essential for cell separation during cytokinesis. The same cell separation defect is also observed in mutants ...
Schlichting Karin - - 2008
During Drosophila eye development, cell differentiation is preceded by the formation of a morphogenetic furrow, which progresses across the epithelium from posterior to anterior. Cells within the morphogenetic furrow are apically constricted and shortened along their apical-basal axis. However, how these cell shape changes and, thus, the progression of the ...
Fukuhara Shigetomo - - 2008
Tie2 belongs to the receptor tyrosine kinase family and functions as a receptor for Angiopoietin-1 (Ang1). Gene-targeting analyses of either Ang1 or Tie2 in mice reveal a critical role of Ang1-Tie2 signalling in developmental vascular formation. It remains elusive how the Tie2 signalling pathway plays distinct roles in both vascular ...
Wang Qian - - 2008
Altered Notch signaling seems linked with medulloblastoma (MB) formation and resveratrol exhibits anti-medulloblastoma effects. However, the influence of resveratrol in Notch signaling of MB cells has not been described. This issue was addressed here by checking Notch1 and Notch2 statuses in three MB cell lines with and without resveratrol treatment. ...
Llense Flora - - 2008
Collective cell movement is a mechanism for invasion identified in many developmental events. Examples include the movement of lateral-line neurons in Zebrafish, cells in the inner blastocyst, and metastasis of epithelial tumors [1]. One key model to study collective migration is the movement of border cell clusters in Drosophila. Drosophila ...
Losick Richard R Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, - - 2008
Fundamental to living cells is the capacity to differentiate into subtypes with specialized attributes. Understanding the way cells acquire their fates is a major challenge in developmental biology. How cells adopt a particular fate is usually thought of as being deterministic, and in the large majority of cases it is. ...
Rasmussen Jeffrey P JP Fred Hutchinson Cancer Research Center, Seattle, WA 98109, - - 2008
During organogenesis of the C. elegans digestive system, epithelial cells within a cyst-like primordium develop diverse shapes through largely unknown mechanisms. We here analyze two adjacent, dorsal epithelial cells, called pm8 and vpi1, that remodel their shapes and apical junctions to become donut-shaped, or toroidal, single-cell tubes. pm8 and vpi1 ...
Hozumi Katsuto - - 2008
GATA3 and Notch1 are essential for T cell development at the earliest stage, but their mutual roles in this process remain to be clarified. In this study, we demonstrated that impairment of T lymphopoiesis in hematopoietic progenitor cells (HPC) of GATA3-deficient fetal liver (FL) on day 11.5 of gestation (E11.5) ...
Sato Makoto - - 2008
In Drosophila melanogaster, one of the most derived species among holometabolous insects, undifferentiated imaginal cells that are set-aside during larval development are thought to proliferate and replace terminally differentiated larval cells to constitute adult structures. Essentially all tissues that undergo extensive proliferation and drastic morphological changes during metamorphosis are thought ...
Keller Thomas T Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, - - 2008
One poorly understood mechanism of developmental patterning involves the intermingled differentiation of different cell types that then sort out to generate pattern. Examples of this are known in nematodes and vertebrates, and in Dictyostelium it is the major mechanism. However, a general problem with this mechanism is the possibility that ...
Weber Michele - - 2008
B cell receptor (BCR) recognition of membrane-bound antigen initiates a spreading and contraction response, the extent of which is controlled through the formation of signaling-active BCR-antigen microclusters and ultimately affects the outcome of B cell activation. We followed a genetic approach to define the molecular requirements of BCR-induced spreading and ...
Seifert Ashley W - - 2008
Congenital malformations of anorectal and genitourinary (collectively, anogenital) organs occur at a high frequency in humans, however the lineage of cells that gives rise to anogenital organs remains poorly understood. The penile urethra has been reported to develop from two cell populations, with the proximal urethra developing from endoderm and ...
Mueller Philipp - - 2008
T cell homeostasis is essential for the functioning of the vertebrate immune system, but the intracellular signals required for T cell homeostasis are largely unknown. We here report that the WD-repeat protein family member coronin-1, encoded by the gene Coro1a, is essential in the mouse for T cell survival through ...
Bao Zhirong Z Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA. - - 2008
As a fundamental process of development, cell proliferation must be coordinated with other processes such as fate differentiation. Through statistical analysis of individual cell cycle lengths of the first 8 out of 10 rounds of embryonic cell division in Caenorhabditis elegans, we identified synchronous and invariantly ordered divisions that are ...
Albig Allan R AR Department of Life Sciences, 600 Chestnut St., Indiana State University, Terre Haute, IN 47809, USA. - - 2008
Angiogenesis is highly sensitive to the composition of the vascular microenvironment, however, our understanding of the structural and matricellular components of the vascular microenvironment that regulate angiogenesis and the molecular mechanisms by which these molecules function remains incomplete. Our previous results described a novel pro-angiogenic activity for Microfibril-Associated Glycoprotein-2 (MAGP-2), ...
Suzuki Takayuki - - 2008
The zone of polarizing activity is the primary signaling center controlling anterior-posterior patterning of the amniote limb bud. The autopodial interdigits (IDs) are secondary signaling centers proposed to determine digit identity by acting on the cells of the digital ray. Here, we focus on events accompanying digital fate determination and ...
David R - - 2008
ES-cell-based cardiovascular repair requires an in-depth understanding of the molecular mechanisms underlying the differentiation of cardiovascular ES cells. A candidate cardiovascular-fate inducer is the bHLH transcription factor MesP1. As one of the earliest markers, it is expressed specifically in almost all cardiovascular precursors and is required for cardiac morphogenesis. Here ...
Jia Gengxiang - - 2008
Sexual reproduction requires the specification of cells with distinct fates in plants and animals. The EMS1 (also known as EXS) leucine-rich repeat receptor-like kinase (LRR-RLK) and TPD1 small protein play key roles in regulating somatic and reproductive cell fate determination in Arabidopsis anthers. Here, we show that ectopic expression of ...
Pasha F A - - 2008
N-Phenyl benzamides are potent antibacterial agents. They are active against both Gram-positive and Gram-negative bacteria. The Gram-positive bacteria have strong and thick cell wall while the Gram-negative bacterial have thin and permeable cell wall. The DFT based QSAR reveals that molecular weight and total energy significantly contribute to activity against ...
Salipante Stephen J SJ Department of Genome Sciences, University of Washington, Seattle, Washington 98195, - - 2008
Mutations are an inevitable consequence of cell division. Similarly to how DNA sequence differences allow inferring evolutionary relationships between organisms, we and others have recently demonstrated how somatic mutations may be exploited for phylogenetically reconstructing lineages of individual cells during development in multicellular organisms. However, a problem with such "phylogenetic ...
Hayward Penelope - - 2008
The Wnt and Notch signalling pathways represent two major channels of communication used by animal cells to control their identities and behaviour during development. A number of reports indicate that their activities are closely intertwined during embryonic development. Here, we review the evidence for this relationship and suggest that Wnt ...
Hallmann Armin - - 2008
The sex-inducer of the spherical green alga Volvox carteri is one of the most potent biological effector molecules known: it is released into the medium by sexual males and triggers the switch to the sexual cleavage program in the reproductive cells of vegetatively grown males and females even at concentrations ...
Zikmundová Jana - - 2008
A new application is described of a dual photometric/contactless conductivity detector to CE determination of incompletely separated compounds. These compounds are differentiated when one of them provides signals in both the cells of the detector, whereas the other yields a signal in only one cell. The technique has been applied ...
Nallamothu Gouthami G Medical University of South Carolina, Hollings Cancer Center, 86 Jonathan Lucas St., Room 330, Charleston, SC 29425, - - 2008
Border cell migration during Drosophila melanogaster oogenesis is a highly pliable model for studying epithelial to mesenchymal transition and directional cell migration. The process involves delamination of a group of 6 to 10 follicle cells from the epithelium followed by guided migration and invasion through the nurse cell complex toward ...
Yamashita Yukiko M - - 2008
The ability of dividing cells to produce daughters with different fates is an important developmental mechanism conserved from bacteria to fungi, plants, and metazoan animals. Asymmetric outcomes of a cell division can be specified by two general mechanisms: asymmetric segregation of intrinsic fate determinants or asymmetric placement of daughter cells ...
Yin Chunyue - - 2008
During vertebrate gastrulation, convergence and extension (C&E) movements narrow and lengthen the embryonic tissues, respectively. In zebrafish, regional differences of C&E movements have been observed; however, the underlying cell behaviors are poorly understood. Using time-lapse analyses and computational modeling, we demonstrate that C&E of the medial presomitic mesoderm is achieved ...
Furman D P - - 2008
A strictly determined number of external sensory organs, macrochaetes, acting as mechanoreceptors, are orderly located on drosophila head and body. Totally, they form the bristle pattern, which is a species-specific characteristic of drosophila.Each mechanoreceptor comprises four specialized cells derived from the single sensory organ precursor (SOP) cell. The conserved bristle ...
Tucker Jennifer A JA Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6058, - - 2008
Patterning of the vertebrate anteroposterior (AP) axis proceeds temporally from anterior to posterior. How dorsoventral (DV) axial patterning relates to AP temporal patterning is unknown. We examined the temporal activity of BMP signaling in patterning ventrolateral cell fates along the AP axis, using transgenes that rapidly turn "off" or "on" ...
Bosch Manel - - 2008
Following a period of neglect, there has been a resurgence of interest in Drosophila imaginal discs as a model with which to analyze the relationships between growth and pattern formation during regeneration. To broaden our understanding of this process, we used cell lineage techniques to trace the origin of blastema ...
Chapman Gavin - - 2008
Somitogenesis is a term that encompasses somite formation, patterning and differentiation and it is a process that is fundamental to the formation of the axial skeleton in vertebrates. Notch signalling is a mechanism used to specify cell fate in many different contexts, with signalling occurring between cells in contact. Notch ...
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