Search Results
Results 201 - 250 of 1017
< 1 2 3 4 5 6 7 8 9 10 >
Dvash Tamar - - 2007
Human ESCs (HESCs) are self-renewing pluripotent cell lines that are derived from the inner cell mass of blastocyst-stage embryos. These cells can produce terminally differentiated cells representing the three embryonic germ layers. We thus hypothesized that during the course of in vitro differentiation of HESCs, progenitor-like cells are transiently formed. ...
Zhang Jin-Hua - - 2006
LIM homeodomain proteins Islet-1 and Lim-3 expression and their role in nervous tissue and endocrine glands have been reported; however, nothing is known concerning Islet-1 and Lim-3 expression in the developing pineal gland of the chick embryo. The aim of the present study was to determine the ontogeny of Islet-1 ...
Nesbitt Tresa - - 2006
Development of the epicardium is critical to proper heart formation. It provides all of the precursor cells that form the coronary system and supplies signals that stimulate cardiac myocyte proliferation. The epicardium forms from mesothelial cells associated with the septum transversum and is referred to as the proepicardium (PE). Two ...
Silva Andressa G - - 2007
This study reports the incidence of histological alterations in the posterior kidney and morphometric changes in the interrenal tissue of the Neotropical fish Astyanax altiparanae collected from an urban stream impaired by anthropogenic activities and from a clean site (reference). The histological alterations observed in fish kidney from the disturbed ...
Fernández-Terán M A - - 2006
Cell death and cell proliferation are basic cellular processes that need to be precisely controlled during embryonic development. The developing vertebrate limb illustrates particularly well how correct morphogenesis depends on the appropriate spatial and temporal balance between cell death and cell proliferation. Precise knowledge of the patterns of cell proliferation ...
Stephen Lesley J - - 2007
Eph proteins are receptor tyrosine kinases that control changes in cell shape and migration during development. We now describe a critical role for EphA3 receptor signaling in heart development as revealed by the phenotype of EphA3 null mice. During heart development mesenchymal outgrowths, the atrioventricular endocardial cushions, form in the ...
Soufan Alexandre T - - 2006
Increase in cell size and proliferation of myocytes are key processes in cardiac morphogenesis, yet their regionalization during development of the heart has been described only anecdotally. We have made quantitative reconstructions of embryonic chicken hearts ranging in stage from the fusion of the heart-forming fields to early formation of ...
Santiago-Martínez Edgardo - - 2006
Heart morphogenesis requires the coordinated regulation of cell movements and cell-cell interactions between distinct populations of cardiac precursor cells. Little is known about the mechanisms that organize cardiac cells into this complex structure. In this study, we analyzed the role of Slit, an extracellular matrix protein and its transmembrane receptors ...
Kakuda Tsutomu - - 2006
Campylobacter jejuni has an N-linked protein glycosylation pathway that is required for efficient cell invasion and chick gastrointestinal colonization by the microbe. In this study, we constructed insertion mutants of 22 putative glycoprotein genes and examined the ability of each to invade the human intestinal epithelial cell line INT-407. Among ...
Kern Christine B CB Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina 29425, - - 2006
The proteoglycan versican is essential to the formation of endocardial cushion mesenchyme by epithelial-mesenchymal transformation (EMT). A potentially important factor in the regulation of versican activity during cushion EMT is proteolysis by ADAMTS metalloproteinases. Using antibodies to the DPEAAE neoepitope created by ADAMTS proteolysis of versican, we detected the amino ...
Alibardi Lorenzo - - 2006
The present study deals with the cell structure and three-dimensional organization of barb and barbule cells within barb ridges of down feathers and juvenile feathers in the chick embryo. Juvenile feathers represent the second generation of feathers in the wing, and replace down feathers some weeks after hatching. Within the ...
Martín C - - 2006
During early stages of brain development, neuroepithelial stem cells undergo intense proliferation as neurogenesis begins. Fibroblast growth factor 2 (FGF2) has been involved in the regulation of these processes, and although it has been suggested that they work in an autocrine-paracrine mode, there is no general agreement on this because ...
Searls, Robert L.
Experiments have been done to determine the time in the development of the embryonic chick limb when the cells in the cartilage-forming area become “stabilized.” The particular criterion for stability used in this work was the ability of the cells to resist the influences in the limb which cause some ...
Fenichel Itay - - 2006
The purpose of this study is to illustrate the routes of migration of precartilaginous cells from the perichondrial ring of LaCroix, as a potential reservoir for growth-plate germ cells. Chondrocytes derived from the ring of LaCroix of young chicks' proximal tibia were cultured in vitro and transfected with adenovirus vector ...
Chuai Manli M Division of Cell and Developmental Biology, Wellcome Trust Biocentre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, - - 2006
Gastrulation in amniotes begins with extensive re-arrangements of cells in the epiblast resulting in the formation of the primitive streak. We have developed a transfection method that enables us to transfect randomly distributed epiblast cells in the Stage XI-XIII chick blastoderms with GFP fusion proteins. This allows us to use ...
Tirosh-Finkel Libbat - - 2006
During early embryogenesis, heart and skeletal muscle progenitor cells are thought to derive from distinct regions of the mesoderm (i.e. the lateral plate mesoderm and paraxial mesoderm, respectively). In the present study, we have employed both in vitro and in vivo experimental systems in the avian embryo to explore how ...
Ren Ruiyi - - 2006
Rho GTPases have been shown recently to be important for cell polarity and motility of the trunk mesoderm during gastrulation in Xenopus embryos. This work demonstrated that Rho and Rac have both distinct and overlapping roles in regulating cell shape, and the dynamic properties, polarity, and type of protrusive activity ...
Reynolds, Stephanie Beth 1978-
In vertebrate embryos, the ophthalmic trigeminal (opV) placode contributes sensory neurons to the trigeminal ganglion during development of the peripheral nervous system. FGFR4 is expressed transiently in the trigeminal placode as cells undergo an epithelial-mesenchymal transition and begin to migrate toward the condensing ganglion. Because of the restricted spatiotemporal expression ...
Sakaguchi Sae - - 2006
Hoxb8 has been suggestively implicated in the formation of the zone of polarizing activity (ZPA) in the limb bud. However, as hoxb8-/- mice did not show any defects in their limb development, the role of Hoxb8 during limb development has not been fully elucidated. Here, we report the identification of ...
Kawakami Masayoshi - - 2006
In this study we examined the role of cell-cell affinity in patterning the avian frontonasal mass-the facial prominence that forms the prenasal cartilage and premaxillary bone. Reconstituted cell pellets derived from undifferentiated, frontonasal mass mesenchyme were recombined with facial epithelium and grafted to host embryos to continue development. We determined ...
Santos-Bredariol Andréa Silveira - - 2006
Among several small Rho GTPases observed in the chick retina, RhoB was transiently expressed during development and mainly present in glial Müller cells in the adult. The aim of this study was to compare the distribution of RhoB in the chick and mouse adult retinas and to study its potential ...
Sellin Julia - - 2006
Drosophila melanogaster has become one of the important model systems to investigate the development and differentiation of the heart. After 24h after egg deposition (h AED), a simple tube-like organ is formed, consisting of essentially only two cell types, the contractile cardioblasts and non-myogenic pericardial cells. In contrast to the ...
Cuadros Miguel A - - 2006
The present study showed that the HIS-C7 monoclonal antibody, which recognizes the chick form of CD45, is a specific marker for macrophages/microglial cells in the developing and mature chick central nervous system (CNS). HIS-C7-positive cells were characterized according to their morphological features and chronotopographical distribution patterns within developing and adult ...
Masamizu Yoshito - - 2006
Notch signaling components such as the basic helix-loop-helix gene Hes1 are cyclically expressed by negative feedback in the presomitic mesoderm (PSM) and constitute the somite segmentation clock. Because Hes1 oscillation occurs in many cell types, this clock may regulate the timing in many biological systems. Although the Hes1 oscillator is ...
Oka Yumiko - - 2006
Formation of vertebrae occurs via endochondral ossification, a process involving condensation of precartilaginous cells. Here, we provide the first molecular evidence of mechanism that underlies initiation of this process by showing that the extracellular factor, Epimorphin, plays a role during early steps in vertebral cartilage condensation. Epimorphin mRNA is predominantly ...
Kraus Yulia - - 2006
The sea anemone Nematostella vectensis has recently been established as a new model system for the understanding of the evolution of developmental processes. In particular, the evolutionary origin of gastrulation and its molecular regulation are the subject of intense investigation. However, while molecular data are rapidly accumulating, no detailed morphological ...
Foltz Warren D - - 2006
Positive-contrast methods can augment negative-contrast methods for CMR evaluation of transplanted cell fate in vivo. This study correlated positive-contrast signal characteristics in the rabbit hind-limb with xenograft cell number (rat fibroblasts bearing endocytosed 1 microm Bang's particles) at different stages of Gd-DTPA administration and 1 mm2 in-plane resolution (2 minute ...
Devoto S H - - 2006
The somitic compartment that gives rise to trunk muscle and dermis in amniotes is an epithelial sheet on the external surface of the somite, and is known as the dermomyotome. However, despite its central role in the development of the trunk and limbs, the evolutionary history of the dermomyotome and ...
Suzuki Makoto - - 2006
Limb regeneration in amphibians is a representative process of epimorphosis. This type of organ regeneration, in which a mass of undifferentiated cells referred to as the "blastema" proliferate to restore the lost part of the amputated organ, is distinct from morphallaxis as observed, for instance, in Hydra, in which rearrangement ...
Brockes Jeremy P - - 2005
The regeneration of complex structures in adult salamanders depends on mechanisms that offer pointers for regenerative medicine. These include the plasticity of differentiated cells and the retention in regenerative cells of local cues such as positional identity. Limb regeneration proceeds by the local formation of a blastema, a growth zone ...
Geetha-Loganathan Poongodi - - 2006
Cells from the ventrolateral lip of the dermomyotome at limb levels undergo epithelio-mesenchymal transition and migrate as individual and undifferentiated cells into the limb buds. The precursor cells are under the influence of various signaling factors in the limb. Dorsal and ventral ectoderm influences various aspects of limb development. In ...
Kimura Wataru W Department of Biological Science, Tokyo Metropolitan University, 1-1 Minamiohsawa, Hachioji, Tokyo 192-0397, - - 2006
In vertebrates, the endoderm is established during gastrulation and gradually becomes regionalized into domains destined for different organs. Here, we present precise fate maps of the gastrulation stage chick endoderm, using a method designed to label cells specifically in the lower layer. We show that the first population of endodermal ...
Mashanov Vladimir S - - 2005
It has recently been shown that the whole spectrum of cell types constituting a multicellular organism can be generated from stem cells. Our study provides an example of an alternative mechanism of tissue repair. Injection of distilled water into the coelomic cavity of the holothurian Eupentacta fraudatrix results in the ...
Satoh Akira - - 2005
In Xenopus laevis, limb buds start to develop at a later point of the larval stage, prior to metamorphosis. This onset of limb development in Xenopus is totally different from that in amniotes such as birds and mammals, in which limb buds emerge at an early stage of embryogenesis, in ...
Tokuoka Miki - - 2005
Ascidian larval mesenchyme cells, comprising about 900 cells, are derived from the A7.6, B8.5 and B7.7 blastomere pairs in the 110-cell embryo. Previous studies showed that the properties of mesenchyme cells are not uniform among the three lines in embryos of Ciona savignyi and Ciona intestinalis. After metamorphosis, the larval ...
Carlson Bruce M - - 2005
This article presents some general principles underlying regenerative phenomena in vertebrates, starting with the epimorphic regeneration of the amphibian limb and continuing with tissue and organ regeneration in mammals. Epimorphic regeneration following limb amputation involves wound healing, followed shortly by a phase of dedifferentiation that leads to the formation of ...
Ding Lei - - 2005
We examined the migration and differentiation of cells expressing Olig3, a basic helix-loop-helix transcriptional factor, in the developing spinal cord. Distribution of Olig3 lineage cells was demonstrated with in situ hybridization and X-gal staining in an Olig3-lacZ knock-in mouse. Olig3-positive cells first appeared in the dorsal spinal cord, except for ...
Teddy Jessica M - - 2005
Our understanding of the molecular mechanisms that direct cell motility, cell division, and cell shaping has benefited from innovations in cell labeling and the ability to resolve intracellular dynamics with multispectral, high-resolution imaging. However, due to difficulties with in vivo cell marking and monitoring, most studies have been restricted to ...
Ignácio A R - - 2005
The distribution, morphology and morphometry of microglial cells in the chick cerebral hemispheres from embryonic day 4 (E4) to the first neonatal day (P1) were studied by histochemical labeling with a tomato (Lycopersicon esculentum) lectin. The histochemical analysis revealed lectin-reactive cells in the nervous parenchyma on day E4. Between E4 ...
Sepich Diane S - - 2005
Embryonic morphogenesis is accomplished by cellular movements, rearrangements, and cell fate inductions. Vertebrate gastrulation entails morphogenetic processes that generate three germ layers, endoderm, mesoderm, and ectoderm, shaped into head, trunk, and tail. To understand how cell migration mechanistically contributes to tissue shaping during gastrulation, we examined migration of lateral mesoderm ...
Stark D A - - 2005
Selective marking of a single cell within a living embryo is often difficult due to the inaccuracy and invasiveness of standard techniques. This unit describes a minimally invasive optical protocol that uses 405-nm laser light to photoactivate a variant of green fluorescent protein (PAGFP). This method takes advantage of the ...
Nebot-Cegarra Josep - - 2005
In order to analyse the patterns of cellular proliferation both in the mesenchyme of the urorectal septum (URS) and in the adjacent territories (posterior urogenital mesenchyme, anterior intestinal mesenchyme and cloacal folds mesenchyme), as well as their contribution to the process of cloacal division, a computer-assisted method was used to ...
Liang Hongyan - - 2007
Fibronectin alternative exon EIIIA is largely included in undifferentiated mesenchymal cells of the developing limb bud, whereas the exon is excluded in differentiated chondrocytes. Inclusion of exon EIIIA in chondrocytic cells is increased by overexpression of SRp40, and, to a lesser extent, SRp75, but not SRp55. RT-PCR analysis using real-time ...
Mittapalli Venugopal Rao - - 2005
Somitocoele cells previously have been shown to form the proximal part of the ribs, the intervertebral discs, and the intervertebral joints (synovial joints). To determine whether the somitocoele cells are necessary for the development of axial skeleton joints, we microsurgically ablated the somitocoele cells in epithelial somites of 2-day-old chick ...
Dow Joan - - 2005
OBJECTIVE: The number of viable transplanted cells in the heart is sharply decreased shortly after cell injection. The exact mechanics of cell loss are unclear. We hypothesized that immature cardiac cells transplanted directly into rat heart could be washed out via the cardiac vasculature, and carried to other organs. METHODS: ...
Fukuda Kimiko - - 2005
The formation of the vertebrate body plan begins with the differentiation of cells into three germ layers: ectoderm, mesoderm and endoderm. Cells in the endoderm give rise to the epithelial lining of the digestive tract, associated glands and respiratory system. One of the fundamental problems in developmental biology is to ...
Cui Cheng C Department of Physics, Biocomplexity Institute, Indiana University, 727 East Third Street, Swain Hall West 159, Bloomington, IN 47405-7105, - - 2005
We have investigated the patterns of tissue flow underlying the formation of the primitive streak in the chick embryo. Analysis of time-lapse sequences of brightfield images to extract the tissue velocity field and of fluorescence images of small groups of DiI-labelled cells have shown that epiblast cells move in two ...
Delfini Marie-Claire - - 2005
The regular spacing of somites during vertebrate embryogenesis involves a dynamic gradient of FGF signaling that controls the timing of maturation of cells in the presomitic mesoderm (PSM). How the FGF signal is transduced by PSM cells is unclear. Here, we first show that the FGF gradient is translated into ...
Barna Maria - - 2005
The vertebrate limb initially develops as a bud of mesenchymal cells that subsequently aggregate in a proximal to distal (P-D) sequence to give rise to cartilage condensations that prefigure all limb skeletal components. Of the three cardinal limb axes, the mechanisms that lead to establishment and patterning of skeletal elements ...
Oates Andrew C AC Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA. - - 2005
The first morphological sign of vertebrate postcranial body segmentation is the sequential production from posterior paraxial mesoderm of blocks of cells termed somites. Each of these embryonic structures is polarized along the anterior/posterior axis, a subdivision first distinguished by marker gene expression restricted to rostral or caudal territories of forming ...
< 1 2 3 4 5 6 7 8 9 10 >