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Results 301 - 350 of 1004
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Wood Emily - - 2002
We report here that induction of ectoATPase by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is cell-type specific and not a generalized response to aryl hydrocarbon (Ah) receptor activation. TCDD increased [14C]-ATP and -ADP metabolism in two mouse hepatoma lines, Hepa1c1c7 and Hepa1-6 cells, but not in human hepatoma HepG2 or HuH-7 cells, human umbilical ...
Omi Minoru - - 2002
To examine the role of position-specific differences in cell-cell affinity, recombinant limb buds composed of dissociated and reaggregated cells derived from anterior (A) and posterior (P) limb bud fragments were analyzed. Dissociated anterior and/or posterior cells were differentially labeled, and their behavior was analyzed during recombinant limb bud outgrowth. We ...
da Silva Sara Morais - - 2002
The proximodistal identity of a newt limb regeneration blastema is respecified by exposure to retinoic acid, but its molecular basis is unclear. We identified from a differential screen the cDNA for Prod 1, a gene whose expression in normal and regenerating limbs is regulated by proximodistal location and retinoic acid: ...
Yang Xuesong - - 2002
During gastrulation in amniotes, epiblast cells ingress through the primitive streak and migrate away to form endodermal, mesodermal, and extraembryonic structures. Here we analyze the detailed movement trajectories of cells emerging at different anterior-posterior positions from the primitive streak, using in vivo imaging of the movement of GFP-tagged streak cells. ...
Goldstein Ronald S - - 2002
Human embryonic stem (ES) cells are pluripotent cells that can differentiate into a large array of cell types and, thus, hold promise for advancing our understanding of human embryology and for contributing to transplantation medicine. In this study, differentiation of human ES cells was examined in vivo by in ovo ...
Dudley Andrew T - - 2002
The 'progress zone' model provides a framework for understanding progressive development of the vertebrate limb. This model holds that undifferentiated cells in a zone of fixed size at the distal tip of the limb bud (the progress zone) undergo a progressive change in positional information such that their specification is ...
Eloy-Trinquet Sophie - - 2002
In this study, we investigated (in the early mouse embryo) the clonal properties of precursor cells which contribute to the segmented myotome, a structure derived from the somites. We used the laacZ method of single cell-labelling to visualise clones born before segmentation and bilateralisation. We found that clones which contribute ...
Sun Xin X Department of Anatomy and Program in Developmental Biology, School of Medicine, University of California at San Francisco, 94143-0452, - - 2002
To determine the role of fibroblast growth factor (FGF) signalling from the apical ectodermal ridge (AER), we inactivated Fgf4 and Fgf8 in AER cells or their precursors at different stages of mouse limb development. We show that FGF4 and FGF8 regulate cell number in the nascent limb bud and are ...
Chartier Aymeric - - 2002
The steps that lead to the formation of a single primitive heart tube are highly conserved in vertebrate and invertebrate embryos. Concerted migration of the two lateral cardiogenic regions of the mesoderm and endoderm (or ectoderm in invertebrates) is required for their fusion at the midline of the embryo. Morphogenetic ...
Kelly Kristine A - - 2002
During embryogenesis, left-right sidedness is established by asymmetric expression of laterality genes. A recent model predicts the presence of a functional midline that divides the left side of the embryonic disc from the right side, separating left- and right-inducing signals. We show evidence that this midline is formed from a ...
Kahane Nitza - - 2002
We have previously found that the postmitotic myotome is formed by two successive waves of myoblasts. A first wave of pioneer cells is generated from the dorsomedial region of epithelial somites. A second wave originates from all four edges of the dermomyotome but cells enter the myotome only from the ...
Ilyina Ekaterina A - - 2002
The paper proposes a possible molecular mechanism of cell fate specification during limb development. The mechanism is based on a step-by-step activation of cell determinants, which occurs at the transcriptional level. Activation of the next determinant (or reactivation of the previous one) occurs only after the next cell division, only ...
Kuroda Hiroki - - 2002
Prenotochord cell sorting is regarded as one of the first cell sorting events in early chordate development. We recently demonstrated that this sorting event occurs in vitro, although the mediator of this activity remains unidentified. Herein, we report the isolation of a full-length cDNA clone of Axial protocadherin (AXPC), the ...
Yasuda Yoshiko - - 2002
We have previously demonstrated that mRNAs for erythropoietin and the erythropoietin receptor temporarily express on the visceral yolk sacs on days 9-11 of gestation in mice. In order to investigate the sites of expression, we performed in situ hybridization on visceral yolk sacs. Visceral yolk sacs from 10-day-old mice embryos ...
G. Al-Mutary Mohsen
The chick embryos, after 24 h of incubation were treated in front of the head area with three different doses of tamoxifen (100, 200 or 400 <I>?</I>g). There were no effects of the tamoxifen on the low dose group while it caused around 16% of the sterility of embryos in ...
Warga Rachel M - - 2002
In this chapter, we will review the formation of the definitive endoderm, the population of cells that give rise to the lining of the digestive tract, its associated organs and the pharyngeal pouches. At the cellular level, we will describe the location and movement of endodermal cells from the onset ...
Dali Lisa A - - 2002
Somite formation is a lengthy process that begins at gastrulation and continues through tailbud stages to form approximately 50 pairs of somites in the frog, Xenopus laevis. In Xenopus, the somite primarily gives rise to myotome. We sought to determine whether the formation of somites and myotome requires a transient ...
Sanz-Ezquerro J J - - 2001
A detailed and precise picture is being pieced together about how the pattern of digits develops in vertebrate limbs. What is particularly exciting is that it will soon be possible to trace the process all the way from establishment of a signalling centre in a small bud of undifferentiated cells ...
Molina M R - - 2001
The homeobox gene tinman and the nuclear receptor gene seven-up are expressed in mutually exclusive dorsal vessel cells in Drosophila, however, the physiological reason for this distinction is not known. We demonstrate that tin and svp-lacZ expression persists through the larval stage to the adult stage in the same pattern ...
Kinder S J - - 2001
An organizer population has been identified in the anterior end of the primitive streak of the mid-streak stage embryo, by the expression of Hnf3beta, Gsc(lacZ) and Chrd, and the ability of these cells to induce a second neural axis in the host embryo. This cell population can therefore be regarded ...
Ninomiya H - - 2001
The direct developing frog, Eleutherodactylus coqui, develops from a large egg (diameter 3.5 mm). To investigate the effect of egg size on germ-layer formation, we studied mesoderm formation in E. coqui and compared it to that of Xenopus laevis (diameter 1.3 mm). First, we identified the position of prospective mesoderm ...
Männer J - - 2001
The internal organs of vertebrates show species-specific left-right (L-R) asymmetries. Questions on the embryonic origin of these asymmetries have been fascinating embryologists since the 19th century. During the past years, remarkable progress has been made in answering these questions. Evolutionary highly conserved molecular signaling cascades have been identified that start ...
Lee K K - - 2001
The growth arrest specific 1 (gas1) gene is highly expressed in quiescent mammalian cells (Schneider et al., 1988, Cell 54, 787-793). Overexpression of gas1 in normal and some cancer cell lines could inhibit G(0)/G(1) transition. Presently, we have examined the functions of this gene in the developing mouse embryo. The ...
Zhao Z - - 2001
A1 adenosine receptors (A1ARs) are expressed in the embryonic heart and influence cardiac function at early developmental stages. To test if A1ARs also affect cardiac structural development, we examined the effects of A1AR activation on heart formation. When pregnant mice were treated with the A1AR agonist, N(6)-cyclopentyladenosine (CPA), fetuses showed ...
Sejima H - - 2001
The embryonic epicardium is formed by the spreading of cells derived from the extracardiac proepicardial organ over the myocardial surface after transfer to the dorsal side of the myocardium via a bridge of villous projections. Using whole-heart immunostaining for keratin, we found that the chronology and pattern of epicardial formation ...
Denetclaw W F WF - - 2001
The morphogenetic cell movements responsible for growth and morphogenesis in vertebrate embryos are poorly understood. Myotome precursor cells undergo myotomal translocation; a key morphogenetic cell movement whereby myotomal precursor cells leave the dermomyotome epithelium and enter the subjacent myotome layer where myogenic differentiation ensues. The precursors to the embryonic epaxial ...
Schmidt C - - 2001
Somitogenesis in all vertebrates involves a mesenchymal to epithelial transition of segmental plate cells. Such a transition involves cells altering their morphology and their adhesive properties. The Eph family of receptor tyrosine kinases has been postulated to regulate cytoskeletal organization. In this study, we show that a receptor belonging to ...
Lawson A - - 2001
The formation and progression of the primitive streak are key events of avian gastrulation. We examine these processes in detail, using various morphological approaches. We show that formation of the primitive streak occurs locally at the caudal midline of the area pellucida, as cells in the caudal midline undergo an ...
Teshigawara K - - 2001
The presence and possible physiological roles of alpha-melanocyte-stimulating hormone (alpha-MSH) in the peripheral tissues of birds have not been established. By a combination of RT-PCR, immunocytochemistry and in situ hybridization, we have examined alpha-MSH expression in the eye of the chicken during development. In the 1-day-old chick, alpha-MSH was expressed ...
Giudicelli F - - 2001
The Krox-20 gene encodes a zinc finger transcription factor, which has been shown previously, by targeted inactivation in the mouse, to be required for the development of rhombomeres (r) 3 and 5 in the segmented embryonic hindbrain. In the present work, Krox-20 was expressed ectopically in the developing chick hindbrain ...
Hatcher C J - - 2001
Mutations in human TBX5, a member of the T-box transcription factor gene family, cause congenital cardiac septation defects and isomerism in autosomal dominant Holt-Oram syndrome. To determine the cellular function of TBX5 in cardiogenesis, we overexpressed wild-type and mutant human TBX5 isoforms in vitro and in vivo. TBX5 inhibited cell ...
Oda H - - 2001
Invagination of the epithelial cell sheet of the prospective mesoderm in Drosophila gastrulation is a well-studied, relatively simple morphogenetic event that results from dynamic cell shape changes and cell movements. However, these cell behaviors have not been followed at a sufficiently short time resolution. We examined mesoderm invagination in living ...
Gabrielli M G - - 2001
The expression of carbonic anhydrase in the chorioallantoic membrane (CAM) of the chick embryo was investigated by means of the histochemical localisation of the enzyme catalytic sites and the immunohistochemical identification of its isoenzymatic forms. The results show that carbonic anhydrase is developmentally expressed in a subset of cells both ...
A. G. Pillay
The research work was conducted to study the behaviour of dark and light neurones in the geniculate ganglion during development and growth in chick, The dark and light cells are differentiated in each group according to the intensity of cytoplasmic stain. The tiny cells are newly formed cells that are ...
Chedrawy, Edgar George.
Cellular cardiomyoplasty (cell therapy for myocardial regeneration) targets the basic pathophysiology of heart failure and represents a novel means of augmenting cardiomyocyte number and contractile function of the failing heart.
Smith J C - - 2001
The mesoderm of the amphibian embryo is formed through an inductive interaction in which cells of the vegetal hemisphere of the embryo act on overlying equatorial cells. My laboratory is studying the Brachyury gene, which plays a key role in this interaction, being both necessary and sufficient for normal mesoderm ...
Boettger T - - 2001
The development of avian embryos is characterized by the large amount of yolk present from the one-cell stage until late phases of organogenesis. In the chick, an axis of bilateral symmetry is established already before egg laying, when the egg rotates in the uterus. There is evidence for an active ...
Czyz J - - 2001
Chick embryo fibroblasts (CEFs) spontaneously form multicellular and multilayered sheets suspended on the network of glass fibres which are stabilized by fibronectin containing protein deposits located at cell-to-cell contacts. The cells situated within the sheets are surrounded by the neighbouring cells and their mechanical equilibrium is stabilised by intercellular "parabaric" ...
Fornaro M - - 2001
Cell migration from the olfactory neuroepithelium is a very peculiar phenomenon in the development of the nervous system. In this paper, we provide evidence that, in the chick embryo, migration of cells from the olfactory neuroepithelium begins earlier than previously reported, namely at the same time as the first olfactory ...
Hong J T - - 2000
In the present study, the effects of ochratoxin A (OTA) on cytotoxicity, cell differentiation, and other cell functions in the embryonic midbrain cells, which are dopaminergic, were compared to those in the limb bud cells, which are nondopaminergic, to assess the selectivity of OTA central action. Twelve-day rat embryo midbrain ...
Velloso C P - - 2000
The remarkable regenerative ability of adult urodele amphibians depends in part of the plasticity of differentiated cells at the site of injury. Limb regeneration proceeds by formation of a mesenchymal growth zone or blastema under the wound epidermis at the end of the stump. Previous work has shown that when ...
Wei Y - - 2000
In amniote embryos, cells from a rostral portion of the primitive streak migrate anterolaterally and establish the heart field mesoderm, from which two cardiac cell lineages, cardiomyocytes and endocardial endothelial cells, differentiate. The endoderm underlying the heart field has been postulated as the source of several paracrine factors that may ...
Canning D R - - 2000
Avian gastrulation is dependent on the ingression of outer layer cells into the interior of the embryo by means of a transient structure referred to as the primitive streak. As the growing streak progresses through the central area pellucida of the blastoderm, selective de-epithelialization of epiblast cells results in the ...
Weinhold B - - 2000
The serum response factor (SRF) transcription factor is essential for murine embryogenesis. SRF+(-/-) embryos stop developing at the onset of gastrulation, lacking detectable mesoderm. This developmental defect may reflect cell-autonomous impairment of SRF(-/-) embryonic cells in mesoderm formation. Alternatively, it may be caused by a non-cell-autonomous defect superimposed upon inappropriate ...
Stickney H L - - 2000
A full understanding of somite development requires knowledge of the molecular genetic pathways for cell determination as well as the cellular behaviors that underlie segmentation, somite epithelialization, and somite patterning. The zebrafish has long been recognized as an ideal organism for cellular and histological studies of somite patterning. In recent ...
Huang R - - 2000
Controversy has surrounded the process of resegmentation of cervico-occipital somites. We have reinvestigated this topic by grafting single somites of quail embryos homotopically into chick embryos. Somites one to five contribute to the skull. Somites one and two contribute to the parasphenoid, which develops by direct ossification in a non-segmental ...
Wei H - - 2000
AIM: To characterize a swelling-activated chloride current, I(Cl, swell), in white Leghorn chick heart cells and the effects of chlorpromazine (CPZ) effects. METHODS: The patch-clamp technique in the whole-cell configuration was used. RESULTS: Hyposmotic swelling elicited I(Cl, swell) in white Leghorn chick heart cells. The current amplitude increased from (452 ...
Grim M - - 2000
We have investigated the developmental origin and ultrastructure of avian Merkel cells by electron microscopy and chick/quail transplantation experiments. On embryonic day 3, chick leg primordia were homotopically grafted onto Japanese quail host embryo. Fourteen days later, quail cells that had migrated into grafted chick legs were identified according to ...
Franciosi J P - - 2000
BACKGROUND: This laboratory previously demonstrated that placement of fibroblast growth factor-2 (FGF-2)-soaked beads adjacent to the developing ventricle at stage 24 caused cardiovascular anomalies by embryonic day 15. We sought to characterize early cellular changes that may suggest mechanisms for the abnormalities observed at day 15. Because levels of both ...
Hirata M - - 2000
We examined the temporospatial pattern of naturally occurring apoptosis in chick embryos to five days of incubation (H.H. stages 1-25; Hamburger and Hamilton, 1951) using TUNEL labeling. The initial TUNEL-positive structure was the embryonic shield at stage 1. Apoptotic cells became ubiquitously present within embryos by stage 3, which is ...
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