Blastoderm: A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Gastrula: The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.Blastodisc: A small whitish spot on the surface of the EGG YOLK where cleavage begins. Upon fertilization the cytoplasm streams from the vegetal pole away from the yolk to the animal pole where cleavage will occur. This germinal area eventually flattens into a layer of cells (BLASTODERM) that covers the yolk completely.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Body Patterning: The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Tribolium: A genus of small beetles of the family Tenebrionidae; T. confusum is the "confused flour beetle".Genes, Insect: The functional hereditary units of INSECTS.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Coturnix: A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.Insect Proteins: Proteins found in any species of insect.Heteroptera: A suborder of HEMIPTERA, called true bugs, characterized by the possession of two pairs of wings. It includes the medically important families CIMICIDAE and REDUVIIDAE. (From Dorland, 28th ed)Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.Quail: Common name for two distinct groups of BIRDS in the order GALLIFORMES: the New World or American quails of the family Odontophoridae and the Old World quails in the genus COTURNIX, family Phasianidae.Fushi Tarazu Transcription Factors: Fushi tarazu transcription factors were originally identified in DROSOPHILA. They are found throughout ARTHROPODS and play important roles in segmentation and CENTRAL NERVOUS SYSTEM development.Organizers, Embryonic: Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).Blastula: An early non-mammalian embryo that follows the MORULA stage. A blastula resembles a hollow ball with the layer of cells surrounding a fluid-filled cavity (blastocele). The layer of cells is called BLASTODERM.Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.Vitelline Membrane: The plasma membrane of the egg.Nodal Signaling Ligands: Members of the transforming growth factor superfamily that play a role in pattern formation and differentiation during the pregastrulation and GASTRULATION stages of chordate development. Several nodal signaling ligands are specifically involved in the genesis of left-right asymmetry during development. The protein group is named after a critical region of the vertebrate embryo PRIMITIVE STREAK referred to as HENSEN'S NODE.Cleavage Stage, Ovum: The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.Insect Hormones: Hormones secreted by insects. They influence their growth and development. Also synthetic substances that act like insect hormones.Homeodomain Proteins: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).Germ Cells: The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.Aminopterin: A folic acid derivative used as a rodenticide that has been shown to be teratogenic.Germ Layers: The three primary germinal layers (ECTODERM; ENDODERM; and MESODERM) developed during GASTRULATION that provide tissues and body plan of a mature organism. They derive from two early layers, hypoblast and epiblast.Embryonic Induction: The complex processes of initiating CELL DIFFERENTIATION in the embryo. The precise regulation by cell interactions leads to diversity of cell types and specific pattern of organization (EMBRYOGENESIS).Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Clothing: Fabric or other material used to cover the body.NicaraguaOvum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Cell Nucleus Division: The process by which the CELL NUCLEUS is divided.Arthropods: Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Primitive Streak: A linear band of rapidly proliferating cells that begins near the posterior end of an embryo and grows cranially. Primitive streak is formed during GASTRULATION by the convergent migration of primary ectodermal cells (EPIBLAST). The knot at the tip of the streak is called HENSEN NODE.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Mesoderm: The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Endoderm: The inner of the three germ layers of an embryo.Anemia, Sickle Cell: A disease characterized by chronic hemolytic anemia, episodic painful crises, and pathologic involvement of many organs. It is the clinical expression of homozygosity for hemoglobin S.Gastrulation: A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.Gap Junctions: Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions.Connexins: A group of homologous proteins which form the intermembrane channels of GAP JUNCTIONS. The connexins are the products of an identified gene family which has both highly conserved and highly divergent regions. The variety contributes to the wide range of functional properties of gap junctions.Connexin 43: A 43-kDa peptide which is a member of the connexin family of gap junction proteins. Connexin 43 is a product of a gene in the alpha class of connexin genes (the alpha-1 gene). It was first isolated from mammalian heart, but is widespread in the body including the brain.Intercellular Junctions: Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)Carbenoxolone: An agent derived from licorice root. It is used for the treatment of digestive tract ulcers, especially in the stomach. Antidiuretic side effects are frequent, but otherwise the drug is low in toxicity.Electrical Synapses: Specialized junctions between NEURONS which connect the cytoplasm of one neuron to another allowing direct passage of an ion current.

The Drosophila melanogaster homologue of the Xeroderma pigmentosum D gene product is located in euchromatic regions and has a dynamic response to UV light-induced lesions in polytene chromosomes. (1/342)

The XPD/ERCC2/Rad3 gene is required for excision repair of UV-damaged DNA and is an important component of nucleotide excision repair. Mutations in the XPD gene generate the cancer-prone syndrome, xeroderma pigmentosum, Cockayne's syndrome, and trichothiodystrophy. XPD has a 5'- to 3'-helicase activity and is a component of the TFIIH transcription factor, which is essential for RNA polymerase II elongation. We present here the characterization of the Drosophila melanogaster XPD gene (DmXPD). DmXPD encodes a product that is highly related to its human homologue. The DmXPD protein is ubiquitous during development. In embryos at the syncytial blastoderm stage, DmXPD is cytoplasmic. At the onset of transcription in somatic cells and during gastrulation in germ cells, DmXPD moves to the nuclei. Distribution analysis in polytene chromosomes shows that DmXPD is highly concentrated in the interbands, especially in the highly transcribed regions known as puffs. UV-light irradiation of third-instar larvae induces an increase in the signal intensity and in the number of sites where the DmXPD protein is located in polytene chromosomes, indicating that the DmXPD protein is recruited intensively in the chromosomes as a response to DNA damage. This is the first time that the response to DNA damage by UV-light irradiation can be visualized directly on the chromosomes using one of the TFIIH components.  (+info)

Cell death in the avian blastoderm: resistance to stress-induced apoptosis and expression of anti-apoptotic genes. (2/342)

We investigated the expression of an apoptotic cell death program in blastodermal cells prior to gastrulation and the susceptibility of these cells to stress-induced cell death. A low frequency (3.1%) of apoptotic blastodermal cells was observed in Hoechst 33342-vitally stained cytological preparations of complete blastoderms from unincubated eggs. These cells showed the stereotypic features of apoptosis including a progression of nuclear changes, cell shrinkage and blebbing, and the formation of apoptotic bodies. Prolonged storage of eggs at 12 degrees C induced apoptosis in blastodermal cells (14%). A modest amount of apoptosis (10%) was also induced at the heat shock temperature of 48 degrees C, but not at 45 degrees C. Etoposide and other potent cytotoxic drugs failed to induce apoptosis in the blastodermal cells after 4 h of exposure. Progressively more apoptosis was induced at 8 and 24 h, but it did not exceed 35% of the cells. We detected transcripts for the anti-apoptotic genes bcl-2, bcl-xL, and hsp70. The developmental expression of these genes, especially hsp70, correlated with the delayed and limited stress-induction of apoptosis. These studies reveal the capacity of pre-streak blastodermal cells to engage in apoptosis and their relative resistance to stress conditions. This may be due to the prominent expression of hsp70 and/or multiple cell death genes which primarily antagonize cell death.  (+info)

Reconstitution of the organizer is both sufficient and required to re-establish a fully patterned body plan in avian embryos. (3/342)

Lateral blastoderm isolates (LBIs) at the late gastrula/early neurula stage (i.e., stage 3d/4) that lack Hensen's node (organizer) and primitive streak can reconstitute a functional organizer and primitive streak within 10-12 hours in culture. We used LBIs to study the initiation and regionalization of the body plan. A complete body plan forms in each LBI by 36 hours in culture, and normal craniocaudal, dorsoventral, and mediolateral axes are re-established. Thus, reconstitution of the organizer is sufficient to re-establish a fully patterned body plan. LBIs can be modified so that reconstitution of the organizer does not occur. In such modified LBIs, tissue-type specific differentiation (with the exception of heart differentiation) and reconstitution of the body plan fail to occur. Thus, the reconstitution of the organizer is not only sufficient to re-establish a fully patterned body plan, it is also required. Finally, our results show that formation and patterning of the heart is under the control of the organizer, and that such control is exerted during the early to mid-gastrula stages (i.e., stages 2-3a), prior to formation of the fully elongated primitive streak.  (+info)

Timing and cell interactions underlying neural induction in the chick embryo. (4/342)

Previous studies on neural induction have identified regionally localized inducing activities, signaling molecules, potential competence factors and various other features of this important, early differentiation event. In this paper, we have developed an improved model system for analyzing neural induction and patterning using transverse blastoderm isolates obtained from gastrulating chick embryos. We use this model to establish the timing of neural specification and the spatial distribution of perinodal cells having organizer activity. We show that a tissue that acts either as an organizer or as an inducer of an organizer is spatially co-localized with the prospective neuroectoderm immediately rostral to the primitive streak in the early gastrula. As the primitive streak elongates, this tissue with organizing activity and the prospective neuroectoderm rostral to the streak separate. Furthermore, we show that up to and through the mid-primitive streak stage (i.e., stage 3c/3+), the prospective neuroectoderm cannot self-differentiate (i.e. , express neural markers and acquire neural plate morphology) in isolation from tissue with organizer activity. Signals from the organizer and from other more caudal regions of the primitive streak act on the rostral prospective neuroectoderm and the latter gains potency (i.e., is specified) by the fully elongated primitive streak stage (i.e., stage 3d). Transverse blastoderm isolates containing non-specified, prospective neuroectoderm provide an improved model system for analyzing early signaling events involved in neuraxis initiation and patterning.  (+info)

Analysis of an even-skipped rescue transgene reveals both composite and discrete neuronal and early blastoderm enhancers, and multi-stripe positioning by gap gene repressor gradients. (5/342)

The entire functional even-skipped locus of Drosophila melanogaster is contained within a 16 kilobase region. As a transgene, this region is capable of rescuing even-skipped mutant flies to fertile adulthood. Detailed analysis of the 7.7 kb of regulatory DNA 3' of the transcription unit revealed ten novel, independently regulated patterns. Most of these patterns are driven by non-overlapping regulatory elements, including ones for syncytial blastoderm stage stripes 1 and 5, while a single element specifies both stripes 4 and 6. Expression analysis in gap gene mutants showed that stripe 5 is restricted anteriorly by Kruppel and posteriorly by giant, the same repressors that regulate stripe 2. Consistent with the coregulation of stripes 4 and 6 by a single cis-element, both the anterior border of stripe 4 and the posterior border of stripe 6 are set by zygotic hunchback, and the region between the two stripes is 'carved out' by knirps. Thus the boundaries of stripes 4 and 6 are set through negative regulation by the same gap gene domains that regulate stripes 3 and 7 (Small, S., Blair, A. and Levine, M. (1996) Dev. Biol. 175, 314-24), but at different concentrations. The 3' region also contains a single element for neurogenic expression in ganglion mother cells 4-2a and 1-1a, and neurons derived from them (RP2, a/pCC), suggesting common regulators in these lineages. In contrast, separable elements were found for expression in EL neurons, U/CQ neurons and the mesoderm. The even-skipped 3' untranslated region is required to maintain late stage protein expression in RP2 and a/pCC neurons, and appears to affect protein levels rather than mRNA levels. Additionally, a strong pairing-sensitive repression element was localized to the 3' end of the locus, but was not found to contribute to efficient functional rescue.  (+info)

A transcription unit at the ken and barbie gene locus encodes a novel Drosophila zinc finger protein. (6/342)

We describe a novel Drosophila transcription unit, located in chromosome region 60A. It encodes a zinc finger protein that is expressed in distinct spatial and temporal patterns during embryogenesis. Its initial expression occurs in a stripe at the anterior and the posterior trunk boundary, respectively. The two stripes are activated and spatially controlled by gap-gene activities. The P-element of the enhancer trap line l(2)02970 is inserted in the 5'-region of the transcript and causes a ken and barbie (ken) phenotype, associated with malformation of male genital structures.  (+info)

Induction of the mesendoderm in the zebrafish germ ring by yolk cell-derived TGF-beta family signals and discrimination of mesoderm and endoderm by FGF. (7/342)

The endoderm forms the gut and associated organs, and develops from a layer of cells which emerges during gastrula stages in the vertebrate embryo. In comparison to mesoderm and ectoderm, little is known about the signals which induce the endoderm. The origin of the endoderm is intimately linked with that of mesoderm, both by their position in the embryo, and by the molecules that can induce them. We characterised a gene, zebrafish gata5, which is expressed in the endoderm from blastula stages and show that its transcription is induced by signals originating from the yolk cell. These signals also induce the mesoderm-expressed transcription factor no tail (ntl), whose initial expression coincides with gata5 in the cells closest to the blastoderm margin, then spreads to encompass the germ ring. We have characterised the induction of these genes and show that ectopic expression of activin induces gata5 and ntl in a pattern which mimics the endogenous expression, while expression of a dominant negative activin receptor abolishes ntl and gata5 expression. Injection of RNA encoding a constitutively active activin receptor leads to ectopic expression of gata5 and ntl. gata5 is activated cell-autonomously, whereas ntl is induced in cells distant from those which have received the RNA, showing that although expression of both genes is induced by a TGF-beta signal, expression of ntl then spreads by a relay mechanism. Expression of a fibroblast growth factor (eFGF) or a dominant negatively acting FGF receptor shows that ntl but not gata5 is regulated by FGF signalling, implying that this may be the relay signal leading to the spread of ntl expression. In embryos lacking both squint and cyclops, members of the nodal group of TGF-beta related molecules, gata5 expression in the blastoderm is abolished, making these factors primary candidates for the endogenous TGF-beta signal inducing gata5.  (+info)

Characterization of Ca2+-dependent phospholipase A2 activity during zebrafish embryogenesis. (8/342)

We have developed a simple fluorescent assay for detection of phospholipase A2 (PLA2) activity in zebrafish embryos that utilizes a fluorescent phosphatidylcholine substrate. By using this assay in conjunction with selective PLA2 inhibitors and Western blot analysis, we identified the principal activity in zebrafish embryogenesis as characteristic of the Ca2+-dependent cytosolic PLA2 (cPLA2) subtype. Embryonic cPLA2 activity remained constant from the 1-cell stage until the onset of somitogenesis, at which time it increased sharply. This increase was preceded by the expression of a previously identified zebrafish cPLA2 homologue (Nalefski, E., Sultzman, L., Martin, D., Kriz, R., Towler, P., Knopf, J., and Clark, J. (1994) J. Biol. Chem. 269, 18239-18249). By using a quenched BODIPY-labeled phosphatidylcholine that fluoresces only upon cleavage by PLA2, lipase activity was visualized in the cells of living embryos where it localized to perinuclear membranes.  (+info)

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In avian gastrulation, Kollers sickle is a local thickening of cells at the posterior edge of the upper layer of the area pellucida called the epiblast. Kollers sickle is crucial for avian development, due to its critical role in inducing the differentiation of various avian body parts. Kollers sickle induces primitive streak and Hensens node, which are major components of avian gastrulation. Avian gastrulation is a process by which developing cells in an avian embryo move relative to one another in order to form the three germ layers (endoderm, mesoderm, and ectoderm). The thickening of the epiblast in Kollers sickle acts as a margin separating sheets of cells from posterior side of avian blastoderms from hypoblasts and area opaca endoderm. The blastoderm is a single layer of cells, and the hypoblast and area opaca endoderm cells lie directly below the blastoderm. Kollers sickle arises from the midpoint, between the hypoblast cells and the area opaca endoderm. As blastoderm cells migrate ...
The prototype of the Cdx family of homeodomain transcription factors is the Drosophila caudal protein. The initial maternal expression of caudal mRNA is ubiquitous and a posterior to anterior gradient of the protein develops during the syncytial blastoderm stage and persists until the onset of cellularization. Zygotic expression, which commences in the cellular blastoderm stage, is also localized to the posterior in a region which gives rise to terminal abdominal structures and the hindgut. During later embryonic development, expression of caudal is found in the midgut, hindgut and Malpigian tubules (MacDonald and Struhl, 1986; Mlodzik and Gehring, 1987).. Caudal homologues have been identified in a wide range of animal groups. A caudal‐related gene with a similar posterior expression pattern has been cloned from the short or intermediate germ band insect Bombyx mori and homologues are present in other invertebrates, including the nematode worm Caenorhabditis elegans and the annelid worm ...
This image shows a chicken (Gallus gallus) embryo undergoing gastrulation in stage four (18-19 hrs after laying) according to the Hamburger-Hamilton staging series. At this point in time the chicken embryo is a blastoderm (shown in blue). The first magnification of the embryo shows that the blastoderm cell layers have thickened to form the primitive streak and Hensens node. The primitive streak extends from the posterior (P) region to the anterior (A) region. The second rectangular magnification shows the blastoderm cross-sectioned through the primitive streak.. Format: Graphics Subject: Processes, Organisms, Theories ...
This image shows a chicken (Gallus gallus) embryo undergoing gastrulation in stage four (18-19 hrs after laying) according to the Hamburger-Hamilton staging series. At this point in time the chicken embryo is a blastoderm (shown in blue). The first magnification of the embryo shows that the blastoderm cell layers have thickened to form the primitive streak and Hensens node. The primitive streak extends from the posterior (P) region to the anterior (A) region. The second rectangular magnification shows the blastoderm cross-sectioned through the primitive streak.. Format: Graphics Subject: Processes, Organisms, Theories ...
Immediately following fertilisation in Drosophilaand many other arthropods, the embryo undergoes a series of rapid syncytial nuclear divisions
The establishment of cell polarity is crucial for building and maintaining multicellular organisms. In Drosophila, the protein kinase Par-1 is thought to be critically involved in establishing polarity but, because par-1 mutants die early in development, the function of the kinase is poorly characterized. Now, on p. 711, Richard Carthew and colleagues use RNAi to characterize the role of Par-1 in Drosophila embryos and eye imaginal discs. By depleting maternal and zygotic Par-1, they discover that it restricts the adherens junctions that link neighbouring cells to an apical position within blastoderm cells, thus revealing a role for it in establishment of cell polarity. Other RNAi experiments indicate that Par-1 is not essential for maintaining epithelial cell polarity once it is established. However, since Par-1 overexpression disrupts polarity, Par-1 must play some role in maintenance of polarity. Finally, the authors use immunostaining and epistasis analysis to uncover a novel role for Par-1: ...
An association of MBD2/3 with RPD3 and MI-2 has been suggested previously, based on results from co-immunoprecipitation experiments (Tweedie et al. 1999). Biochemical fractionation of protein extracts also suggested the presence of MBD2/3Δ in the Drosophila MI-2/NuRD complex (Ballestar et al. 2001; Marhold et al. 2004a). MBD2/3 associates with DNA during embryogenesis. During cleavage and syncytial blastoderm stages, MBD2/3 is excluded from DNA. This pattern changes dramatically during cellular blastoderm, when the protein forms Epigenetic Regulation in Drosophila 29 bright foci that precisely colocalize with DNA (Marhold et al. Until recently, the ability of the protein to bind methylated DNA has only been analyzed in a very restricted experimental context. All in vitro assays were performed with probes that were methylated at CpGs, which does not reflect the endogenous pattern of DNA methylation in the fly. In addition, the binding of MBD2/3 to Drosophila DNA had not been investigated in ...
Though all insects possess a highly conserved adult body plan, this morphological conservation belies an underlying developmental diversity that gives rise to this body plan. For example, insects are described as being `short, `intermediate or `long germband and show fundamental differences in how their body segments are generated (Davis and Patel, 2002; Krause, 1939; Sander et al., 1985). Long germband segmentation is evolutionarily derived and in this form of embryogenesis, all body segments are specified early and simultaneously during the blastoderm stage. As short and intermediate germ segmentation is found throughout the insects, whereas the long germ type is restricted to the higher insects, it is likely that a form of short or intermediate germband segmentation is evolutionarily ancestral (Davis and Patel, 2002). In this mode of segmentation, only the anterior-most segments are specified during the blastoderm stage, leaving the rest of the body plan to be specified later in ...
Polarization of epithelial cells depends on a hierarchical process whereby specific membrane-associated proteins become targeted to specialized membrane domains. Here, we describe a novel Drosophila protein, Discs Lost (DLT), that plays a crucial role in the polarization of embryonic epithelia during cellular blastoderm formation. At subsequent stages of development, DLT interacts with the apical determinant Crumbs (CRB) and the laterally localized protein Neurexin IV (NRX IV). Mutations in dlt or double-stranded RNA interference lead to aberrant localization of CRB and NRX IV and cause a concomitant loss of epithelial cell polarity. Hence, DLT is required to establish and maintain cell polarity and participates in different molecular complexes that define apical and lateral membrane domains ...
The even-skipped (eve) pair-rule gene plays a key role in the establishment of the anterior-posterior segmental pattern of the Drosophila embryo. The continuously changing pattern of eve expression can be resolved into two phases. Early expression consists of seven broad stripes in the blastoderm embryo, while late expression, which occurs after cellularization, consists of narrow stripes with sharp anterior borders that coincide with the odd-numbered parasegment boundaries. Previous studies have shown that these two phases are controlled by separate classes of cis elements in the eve promoter. Early stripes are expressed by multiple stripe-specific elements under the control of maternal-effect genes and gap genes, while late stripes are expressed by a single regulatory element, the late element, under the control of pair-rule genes including eve itself. We report here that paired (prd), a pair-rule gene which had been considered to be below eve in the regulatory hierarchy of pair-rule genes, ...
Using a cell marker mutation the cell lineage of the muscles of the Drosophila head are traced out. Three sets of muscles separated by lineage restrictions are observed, even when cells are marked as early as the blastoderm stage. Each set underlies the derivatives of one of the three pairs of imaginal discs which differentiate to form the epidermis of the adult head. Clones of the homoeotic mutation engrailed (en^10) were apparently normal in the muscles of the head. The muscle clone frequency, at the blastoderm stage, in each hemisegment of the fly is similar, indicating an equal partitioning of cells during segmentation. ...
p120 localization during the syncytial development and cellularization differs from that of Arm. (A-J) Syncytial blastoderm (A and B) and cellularizing embryo
Blasto*derm (?), n. [Gr. sprout + E. derm.] Biology|Biol. The germinal membrane in an ovum, from which the embryo is developed. &a...
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Complete information for TENM3 gene (Protein Coding), Teneurin Transmembrane Protein 3, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
to explain why she returned to singing and how she chose her rather bloodsoaked repertoire.. In addition to her own recording career, Shirley Collins played an important role in music history when she accompanied legendary musicologist ...
The cascade of segmentation refinement is mostly a matter of gene expression. Transcription regulators are expressed in various places along the body axis, and their combination, overlapping in some places, absent in others, dictates (through their binding to enhancers at DNA of target genes, thus activating them) a refined pattern for the next step, which consists mostly of another set of transcription regulators. The "gap" genes each regulate portions of the ~seven broad bands of expression, and their combinations activate the next set of "pair-rule" genes that are typically expressed in the same seven bands, which over time (involving mutual back and forth regulation) resolve to and help form fourteen parasegments, each of which comprise the front half of one future physical segment, and the back half of another. Lastly, a set of "segment-polarity" genes are activated in one-cell wide stripes to specify one or the other side of each of these fourteen parasegments, preparatory to the more ...
Ventral Hypoblast movie: The animal pole is toward the top, face on view of ventral side (dorsal is on the opposite side of embryo).. Scatter labeling of cells with the flourescent probe, Bodipy-dextran, allows many individual cells to be followed through time. Cells in the ventral hypoblast appear to be spreading away from the plane of view. This is caused by their convergence toward the dorsal side which is 180 degrees away on the opposite side of the embryo. Remember, not all of the cells are labeled in the embryo; the holes that you see between the cells are filled with cells that are not labeled with the flourescent probe.. ...
View Notes - Lecture 21x from BIO 432 at BC. 4/25/13 Messenger RNA expression patterns of two pair-rule genes, even-skipped (red) and fushi tarazu (black) in the Drosophila blastoderm Specific
Calcium signaling are conserved from invertebrates to vertebrates and plays critical roles in many molecular mechanisms of embryogenesis and postnatal development. As a critical component of the signaling pathway, the RyR medicated calcium-induced calcium release signaling system, has been well studied along with their regulator FK506-binding protein 12 (FKBP12/Calstabin). Lack of FKBP12 is known to result in lethal cardiac dysfunction in mouse. However, precisely how FKBP12 is regulated and effects calcium signaling in Drosophila melanogaster remains largely unknown. In this study, we identified both temporal and localization changes in expression of DmFKBP12, a translational and transcriptional regulator of Drosophila RyR (DmRyR) and FKBP12, through embryonic development. DmFKBP12 is first expressed at the syncytial blastoderm stage and undergoes increased expression during the cellular blastoderm and early gastrulation stages. At late gastrulation, DmFKBP12 expression begins to decline until it
Sections of embryos of this stage show how the entoderm has spread out and become organized into a coherent layer of cells merging peripherally with the inner margin of the germ wall and overlapping it to a certain extent (Fig. 13, C, £, F)s The cavity between the yolk and the entoderm which has been called the gastroccele is now termed the primitive gut. The yolk floor of the primitive gut does not •show in sections prepared by the usual methods. The reasons for this are to be found in the relations of the embryo to the -^ yolk A^efore it is removed for sectioning^ In the entire central region of the blastoderm lie yolk is separated from the entoderm by the cavity of the primitive gut. When the embryo is removed from the yolk sphere the yolk floor of the primitive gut, not being adherent to the blastoderm, is left behind. In contrast the peripheral part of the blastoderm Ues closely applied to the yolk. Some yolk adheres to this part of the blastoderm when it is removed. This ...
Esta tesis revela la regulación transcripcional del gen gap giant (gt) en el embrión blastodermal de Drosophila por ingeniería inversa: un modelo matemático infiere los mecanismos subyacentes de datos cuantitativos de expresión recopilados en un fondo genético silvestre. El modelo se amolda a mRNA reportero controlado por elementos reguladores en cis (CRE) de gt. Es una herramienta potente para investigar cómo se forma el patrón a nivel molecular por los sitios de unión de factores de transcripción y permite predecir la expresión en cepas mutantes. La presente tesis esclarece la regulación diferencial de dos CRE adyacentes de gt y presenta la primera evidencia experimental de auto-activación de gt mediante mutagénesis de sus elementos reguladores. Tras la optimización de los parámetros en un fondo de tipo silvestre, el modelo predice correctamente los cambios observados en mutantes de Krüppel y tailless. Otras contribuciones reglamentarias sugeridas por el modelo son confirmadas por la
Next we talked about how living things are made up of tiny cells, and looked at an egg as a rare example of a cell thats big enough to see with our eyes. Luckily I had half a dozen slightly-out-of-date eggs to hand because it took the children a few goes to crack their eggs without breaking the yolk!. Before we cracked the eggs we looked at them through magnifying glasses and noted the tiny holes in the shell through which air and water pass. Then we talked about the parts of the egg and their purpose, and found the tiny white blastodisc in the yolk and the tail-like chalaza which anchors the cell, neither of which I have ever noticed before! Wed lost J to lego by the time it came to drawing the egg, but C enjoyed colouring and labelling hers, and I left Js page blank - who knows when he might decide to come back to it with a wave of enthusiasm!. ...
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In a series of tissue cultures of fragments taken from different parts of young chick embryos, at various stages, it was found that differentiation frequently occurred, the characteristic cells of highly specialised tissues appearing in cultures in which they could not possibly have been present at explantation. The most striking differentiations were the development of red blood corpuscles, capillary vessels, nerve cells with axons and of rhythmically contracting cardiac muscle. This paper describes a simple method by which may be obtained regularly and quickly the development of very large numbers of red cells, and an account is given of the histology of the cultures. It is intended to be introductory to a physiological study, now in progress, of the conditions of hæmatopoiesis Literature. Erythropoiesis in vitro has been reported by several authors, but it has not been thoroughly investigated and, with the exceptions of the works of Slonimski (1930, a, 1931) and Shipley (1915-16), the ...
These reference sequences exist independently of genome builds. Explain. These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above. ...
The protein encoded by this gene belongs to the tenascin family and teneurin subfamily. It is expressed in the neurons and may function as a cellular signal transducer. Several alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009] ...
In the chick embryo, the primitive streak is the first axial structure to develop. The initiation of primitive streak formation in the posterior area pellucida is influenced by the adjacent posterior marginal zone (PMZ). We show here that chick Vg1 (cVg1), a member of the TGFbeta family of signallin …
In the infertile egg, on the left, the nucleus is merely a light spot on the yolk. The egg on the right is fertilized. In the fertilized egg the ovum has fused with a sperm to begin forming an embryo. By the time the fertilized egg is laid, many cells are divided on the surface of the yolk and formed a blastoderm. Can you see the difference between the nucleus of the infertile egg and the blastoderm of the fertilized egg? Both are indicated by the blue arrow. ...
Can anyone please help me out..I just cant understand this gastrulation stage ...my books too confusing..cant understand how the hypoblast forms the yolk sack? and what exactly are area pelucidia and area opaca? cant understand primitive streak as well as hensen node....arghh...and google is not helping! any recommendations for a book or website ...
My first year, I didnt own anything. Borrowed a 1206 and 10ft. no-till drill to plant 7 acres of soybeans. Hired the spraying and harvest from a local friend. Used that income to pay for inputs for this year, when I expanded to 40 acres. Over last winter, I purchased a 7-row/18" no-till planter ($300), 12ft. Oliver disc ($400), 16ft. harrowgator ($350), White 7300 combine/13ft. grain platform ($Free), and 1973 IH Loadstar 1700 grain truck ($1,300). Overall, less invested than most guys have in a pair of tires. I had my Ford 6000 tractor to begin with, but I borrowed a 5520 JD too. Hired my spraying, but a sprayer will ABSOLUTELY be purchased this fall. Need to control resistant weeds better than my custom guy does ...
Why and how genetic canalization evolves in gene regulatory networks. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
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1. Grafts consisting of pieces of primitive streak from blastoderms in the primitive streak stage were placed under the primitive streak of blastoderms also in this stage.. 2. Various effects of the host on the graft are described, particularly the reversal of the antero-posterior orientation of the graft, the alteration of the regional character of the graft so as to conform with the host tissues at the same level, the suppression of differentiation in the posterior end of the primitive streak, and the incorporation of the graft tissues into the host.. 3. A considerable number of inductions occurred, since the host axis often apparently shifts to one side of the graft. The inductions are of two kinds, the normal evocation by graft mesoderm, resulting usually in the formation of superfluous neural tissue; and the complementary induction of a normal secondary axis, which it is supposed is most often due to the preliminary induction of a primitive streak in the host.. 4. Various effects of the ...
5,855-867. ,and Sanchez, L. The scute (T4) gene acts as a numerator element of the X:A signal that determines the state of activity of Sex-lethal in Drosophila. EMBO J. 8,3079-3086. ,and Sanchez, L. Gap gene properties of the pair-rule gene runt during Drosophila segmentation. Genet. Res. 59,189- 198. , and Gergen, J. P. Zygotic expression of the Drosophila segmentation gene runt antagonizes the activity of the maternal morphogen bicoid. Submitted. , Brown, J. , Scott, M. , and Wu, C. A sequence-specific DNA-binding protein that activates fushi turazu segmentation gene expression. Cells, cap tissue is induced to form mesoderm and an organizer (Fig. 2C) (Nieuwkoop, 1969). Using the animal cap assay, several growth factors and secreted molecules have been implicated in mesodermal induction (Fig. 2) (see review in Green and Smith, 1991). , 1990). , 1993). , 1988), but when combined with activin, produces mesoderm of dorsal character (Cooke, 1989). , 1992). Bone morphogenetic protein4 (BMP-4), ...
Davies, Alexander S. (2012) The naming of the Roo: an essay on the contribution of artists to the biological exploration of the new world. In: Preserving the Humboldt tradition of scholarship in Australasia: proceedings of the fourteenth Biennial Conference of the Australian Association of von Humboldt fellows, pp. 31-34. From: Fourteenth Biennial Conference of the Australian Association of von Humboldt Fellows, 30 September - 2 October 2011, Randwick, NSW, Australia. Devney, Carol A., Kondrad, Shannon L., Stebbins, Katherine R., Brittingham, Kevin D., Hoffman, David J., and Heinz, Gary H. (2009) A saltwater flotation technique to identify unincubated eggs. Journal of Fields Ornithology, ...
1. Specimens are described which demonstrate the induction of neural plateby (a) the mesodermal part of the primitive streak, (b) the head process and sinus rhomboidalis, and (c) neural plate.. 2. The neural plate which was induced by the mesodermal part of the primitive streak was in reversed orientation as regards the host embryo. Thus the orientation of the embryo must be already fixed in the mesodermal part of the streak, and must in this case have overcome any influence which the host may be able to exert.. 3. The same embryo was more complete than indicated by the presumptive fate of the tissue which induced it, whence it is concluded that the chick organiser,like the amphibian, shows a tendency to complete itself, and to this extent behaves like part of a harmonious equipotential system.. 4. Grafts of the anterior part of the embryonic axis (head process and neuralplate) into the anterior part of the host blastoderm, have induced structures which in nearly all cases give indications of ...
The nuclear cycle in plants and animals consists in the alternation of two mechanically stable systems, the resting nucleus and the metaphase chromosomes. The regularity of this alternation and the constancy of the bodies taking part in it has led to the assumption that it depends on a "permanence" of the positional relationship of essential elements in these bodies, that is, on a property of passing on the same structure from mother to daughter nucleus and from mother to daughter organism by the structure reproducing its like without change. This assumption has been vindicated by the demonstration at a particular nuclear division, meiosis, in the transitional and generally unstable stages of prophase between the resting nucleus and the metaphase chromosomes, of a linear arrangement of particles which is constant both in individuals and in races. The inference of this constant arrangement of particles depends on evidence of form and of function. When the inference is from form the particles are ...
The avian equivalent of Spemanns organizer, Hensens node, begins to lose its ability to induce a nervous system from area opaca epiblast cells at stage 4+, immediately after the full primitive streak stage. From this stage, the node is no longer able to induce regions of the nervous system anterior to the hindbrain. Stage 4+ is marked by the emergence from the node of a group of cells, the prechordal mesendoderm. Does the prechordal region possesses the lost functions of the organizer? The prechordal region does not have neural inducing ability, as it is unable to divert extraembryonic epiblast cells to a neural fate. However, it can confer more anterior character to prospective hindbrain cells of the host, making them acquire expression of the forebrain markers tailless and Otx-2. It can also rescue the expression of Krox-20 and Otx-2 from nervous system induced by an older (stage 5) node in extraembryonic epiblast. These properties reflect a true change of fate of cells rather than ...
Hard work by American and international companies has produced a great deal of innovative equipment in support of Coalition forces engaged in the Global War on Terror. They have also been doing their part to support domestic LE agencies in securing the homeland and fighting crime. An important part of the process of supplying operators with the very best gear is allowing industry representatives to get face-to-face time with the personnel who use the gear in the field. One great way to do this is through symposia and tradeshows.. Tactical Weapons recently had the opportunity to attend the SPEC OPS EAST 2008 Warfighter Symposium and Expo that was held November 18-20 in Fayetteville, NC. The SPEC OPS expo was put on by the folks of the Lodestar Group and their subsidiary DefenseTradeshows.com. The SPEC OPS expo and the other events sponsored by Lodestar allow defense contractors to form partnerships in a person-to-person environment and interact with military and law enforcement professionals. ...
Nature Segmentation in silico "A new mathematical biology is emerging. Building on experimental data from developing organisms, it uses the power of computational methods to explore the properties of real gene networks.". "Our understanding of gene networks is at an early stage. We perceive their complexity only after it has been filtered by the limitations of the techniques used to study them. Genome databases and DNA-chip technology, which enables huge numbers of genes to be screened for activity, will undoubtedly provide more, and much more complicated, data than anything produced by Drosophila genetics. If a relatively simple gene network such as the segment-polarity system is hard to understand intuitively, we can be certain that modelling will be essential to make sense of the flood of new data.. But this will not be elegant theoretical modelling: rather, it will be rooted in the arbitrary complexity of evolved organisms. The task will require a breed of biologist-mathematician as familiar ...
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Dr. Hughes treatment is family based and focused on facilitating the childs ability to establish a secure attachment with his/her caregivers. Developmental attachment theory and research is the primary model for relationship development and trauma resolution. Dan blends various approaches in his treatment modality. These include strategic and structural family therapy, Ericksonian hypnotherapy (utilization principle), psychodynamic principles, psychodrama, interventions congruent with Theraplay, and narrative work. He actively communicates empathy and acceptance of the individual child while providing him/her with the comforting and containment needed to explore and resolve past trauma and shame-related experiences. At the same time he is actively facilitating the childs ability to form positive, reciprocal relationships with his/her parents. Within the safety of these relationships, the child is able to finally face and resolve his/her past traumas. Also, as the child gradually develops a ...
TY - CHAP. T1 - The mechanisms underlying primitive streak formation in the chick embryo. AU - Chuai,Manli. AU - Weijer,Cornelis J.. PY - 2008. Y1 - 2008. N2 - Formation of the primitive streak is one of the key events in the early development of amniote embryos. The streak is the site where during gastrulation the mesendoderm cells ingress to take up their correct topographical positions in the embryo. The process of streak formation can be conveniently observed in the chick embryo, where the streak forms as an accumulation of cells in the epiblast in the posterior pole of the embryo and extends subsequently in anterior direction until it covers 80% of the epiblast. A prerequisite for streak formation is the differentiation of mesoderm, which is induced in the epiblast at the interface between the posterior Area Opaca and Area Pellucida in a sickle shaped domain overlying Kollers sickle. Current views on the molecular mechanisms of mesoderm induction by inducing signals from the Area Opaca and ...
A Lockheed 18-56-23 Lodestar plane, registered N33366, was damaged beyond repair in an accident 7,5 km NW of Londonderry, OH, United States of America. There were two crew members on board. The airplane operated on a flight from Tulsa International Airport, OK (TUL) to Pittsburgh International Airport, PA (PIT).
The identification of developmental stages in fish eggs from plankton samples is often complicated by deformation of the embryos due to mechanical stress during the sampling procedure and by dehydration during formaldehyde fixation. The effects of formaldehyde fixation and mechanical stress on Baltic cod eggs (Gadus morhua callarias L.) were examined separately by visually comparing the morphological features of treated vs. live eggs of identical ontogenetic age. Microphotographs were made concurrently for documentation. In stage IA eggs, mechanical treatment resulted in scattered blastodiscs surrounded by single cells, while in further advanced stages the yolk membrane collapsed entirely, the yolk coagulated and the embryo extending over the yolk shrank. Formaldehyde fixation caused the yolk and the blastodisc or embryo to darken, and in some cases crystalline enclosures occurred. Eggs mechanically deformed during handling were clearly distinguishable from those that died prior to catching; ...
Remarkably, a motif corresponding to the Tramtrack (TTK) binding motif was discovered with the de novo approach. TTK is a maternal repressor, which is progressively titrated as the NC ratio increases during early mitotic cycles, thereby releasing the expression of zygotic genes [5]. Surprisingly, the TTK binding motif is found over-represented in the sequences of pre-cellular activated blastoderm genes and of the genes with the discrete signature "Lu u s D s s H ", but not in the sequences of genes known to depend on the NC ratio, which might be explained by the intervention of some other factors in this mechanism [5].. The TTK protein has been reported to physically interact with TRL proteins and to repress TRL-mediated even-skipped activation [20]. TTK could act either directly by binding DNA and repressing the transcription of specific target genes, or indirectly by repressing an activator such as Trl. Interestingly, the TTK motif is significantly under-represented (sig = 5) in upstream ...
Just as Hox genes regulate realisator genes, they are in turn regulated themselves by gap genes and pair-rule genes, which are in their turn regulated by maternally-supplied mRNA. This results in a transcription factor cascade: maternal factors activate gap or pair-rule genes; gap and pair-rule genes activate Hox genes; then, finally, Hox genes activate realisator genes that cause the segments in the developing embryo to differentiate. Regulation is achieved via protein concentration gradients, called morphogenic fields. For example, high concentrations of one maternal protein and low concentrations of others will turn on a specific set of gap or pair-rule genes. In flies, stripe 2 in the embryo is activated by the maternal proteins Bicoid and Hunchback, but repressed by the gap proteins Giant and Kruppel. Thus, stripe 2 will only form wherever there is Bicoid and Hunchback, but not where there is Giant and Kruppel.[21]. MicroRNA strands located in Hox clusters have been shown to inhibit more ...
Description: Responsible for the management and coordination of the leaders circle program, including the identification, cultivation, solicitation and stewardship of its members. Arrange quarterly functions highlighting different funding opportunities for SJHMC. Manage a grateful patient program to help identify, cultivate, and solicit potential major gift benefactors. This would include, but not be limited to, reviewing daily census reports, identifying two or more patients to visit on a daily basis, visiting or assigning other development officers to visit, preparing follow up get-well cards after release, and solicitation via direct mail within two months of release. This position will also develop, implement and evaluate a sophisticated donor recognition program including but not limited to donor walls, plaques, donor gifts, and individual donor recognition; maintain information in Raisers Edge to insure accurate recognition lists and reports; work in conjunction with all fund raising ...
With three different hole sections; Also with function of cutting and holding; Precise; Wont hurt optical fiber; With safe lock
This colorful insect is used for behavioral and life cycle studies. Illustrates incomplete metamorphosis. Easy to keep and culture. Per 12. Desired Date of Arrival can be entered …
We have used carbocyanine dyes (DiI and DiO) to generate fate maps for the epiblast layer of the chick embryo between stage X and the early primitive streak stage (stages 2-3). The overall distribution of presumptive cell types in these maps is similar to that described for other laboratory species …
TY - JOUR. T1 - Localization of transcripts from the wingless gene in whole Drosophila embryos. AU - Baker, N. E.. PY - 1988/1/1. Y1 - 1988/1/1. N2 - In situ hybridization has been used to detect transcription in whole Drosophila embryos. Improved results have been obtained by incubating the hybridized embryos in liquid emulsion prior to autoradiographic exposure. This technique has been used to map the distribution of transcripts from the segment-polarity gene wingless (wg), which is transcribed in a stripe in each segment of the trunk region. By the extended germband stage additional areas of transcription in the head and caudal regions define a total of 21 domains, comprising the foregut, six regions in the head, three thoracic and ten abdominal segments, and the hindgut. At the end of the extended germband stage, the pattern of wg transcription is no longer uniform in the dorsoventral axis: wg transcripts are absent from the lateral epidermis. This pattern of wg transcription is discussed ...
Nodal, a known mesodermal inducer of the TGFB superfamily,[18] has been implicated in streak formation. Mouse embryos mutant for Nodal fail to gastrulate and lack most mesoderm,[19] but more than playing a role in mesoderm induction, Nodal regulates the induction and/or maintenance of the primitive streak.[19] In the presence of hypoblast, Nodal is unable to induce ectopic streaks in the chick embryo, while its removal, induces expression of Nodal, Chordin and Brachyury,[13] suggesting that the hypoblast must have a certain inhibitory effect on Nodal signaling. Indeed, the multifunctional antagonist of Nodal, Wnt and BMP signaling, Cerberus (produced in the hypoblast) and Cerberus-Short (which inhibits only Nodal), through its effect on Nodal signaling, inhibits streak formation.[13] Eventually, the hypoblast gets displaced anteriorly by the moving endoblast, allowing streak formation at the posterior end. At the anterior end, the presence of the hypoblast and the antagonists it secretes, such ...
Description: This position is responsible for providing specialized counseling, analyzing, and reevaluating financial aid data, and awarding financial aid services to students enrolled in College of Medicine programs. This position will collaborate with the Associate Director, College of Medicine Financial Aid, in the administration of the Arizona Medical Student Loan Program, the Health Professions Scholarship and Loan Programs, the College of Medicine Scholarship Program, and submits required reports to the Liaison Committee for Medical Education, the Board of Medical Student Loans, and the Department of Health and Human Services. This position reports to the Director of Academic Services, Office of Admissions and Student Affairs.. Qualifications: Minimum: 1) Bachelors degree in a field appropriate to the area of assignment AND four years experience in financial aid awarding, or working with financial aid programs; OR, 2) Masters degree in field appropriate to area of assignment AND three ...
161. Carex opaca (F. J. Hermann) P. E. Rothrock & Reznicek, Novon. 11: 223. 2001. Carex bicknellii Britton var. opaca F. J. Hermann, Sida 5: 49. 1972. Plants densely cespitose, to 200 culms together; rhizomes appearing elongate only in old clumps. Culms 50-115 cm; vegetative culms few, inconspicuous, usually fewer than 12 leaves, not strikingly 3-ranked. Leaves: sheaths glabrous, hyaline sometimes brown tinged band near collar, the summits U-shaped to truncate, ± equaling the base of the blade; distal ligules 1.5-5.4 mm; blades 3-6 per fertile culm, 3.5-40 cm × 1.5-4.6 mm. Inflorescences open, erect to slightly arching, pale or golden brown, 2.4-5.5(-6.4) cm × 6.5-21 mm; proximal internode 4-13(-18) mm; 2d internode 3-11 mm; proximal bracts scalelike, with bristle tips to 1.5 cm. Spikes 4-8(-10), distinct, ovoid, 10-22 × 4-11 mm, base rounded to tapered, apex rounded to acute. Pistillate scales pale brown with narrow yellow-green to brown midstripe, lanceolate to narrowly ovate, (3.6-)3.9-5 ...
A unit containing a cluster of eggs, with enough nymphs and adults to illustrate the life cycle of Oncopeltius fasciatus. Desired Date of Arrival can be entered during checkout. If …
Resting from shin splints might be torturous and you might feel restless and antsy, but its better to stay off your legs (or crosstrain) for a few weeks rather than not being able to run ever again.. Stage X: Recovery. Im starting my recovery phase now. Ive rested for about five weeks since the half marathon in early October, only doing short (1-2 mi) jogs to assess how things are going and crosstraining to keep up my aerobic-ness. I waited until I didnt feel any unusual shin pain during the shorter runs before attempting longer ones last week, starting with a few 3 milers. They were okay, but I feel like Ive reset myself by about three months, which is a little discouraging.. Im sticking with it, though. Yesterday I did 5 miles, but definitely starting feeling some twinges near the end. Forcing myself to go shorter and slower than I know Im capable of will be challenging, but my fear of my shin splints returning trumps almost everything else!. If I couldve done anything differently ...
Surkova, S., Blagov, M., Janssens, H., Kosman, D., Kozlov, K.N., Manu, Myasnikova, E., Vanario-Alonso, C.E., and Samsonova, M ...
A transverse section through an embryo chick (26 hours). Labels: a, epiblast; b, mesoblast; c, hypoblast; d, central portion of mesoblast, which is here fused with epiblast; e, primitive groove; f, dorsal ridge.. ...
El Centro Nacional de Biotecnología es un centro estratégico del Consejo Superior de Investigaciones Científicas con un objetivo mixto académico y de transferencia de tecnología en el área de la Biotecnología.
Out of respect for the stunning visuals and family entertainment value of Disneys 34th animated feature, I can do no less than recommend The Hunchback of Notre Dame. Sadly, however, this is the least-enjoyable animated feature to come from the ...
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The primitive streak in peri-implantation embryos forms the mesoderm and endoderm and controls cell differentiation. The metabolic cues regulating primitive streak formation remain largely unknown. Here we utilised a mouse embryonic stem (ES) cell differentiation system and a library of well-characterised drugs to identify these metabolic factors. We found that statins, which inhibit the mevalonate metabolic pathway, suppressed primitive streak formation in vitro and in vivo. Using metabolomics and pharmacologic approaches we identified the downstream signalling pathway of mevalonate and revealed that primitive streak formation requires protein farnesylation but not cholesterol synthesis. A tagging-via-substrate approach revealed that nuclear lamin B1 and small G proteins were farnesylated in embryoid bodies and important for primitive streak gene expression. In conclusion, protein farnesylation driven by the mevalonate pathway is a metabolic cue essential for primitive streak formation ...
TY - JOUR. T1 - Imaging of transgenic cricket embryos reveals cell movements consistent with a syncytial patterning mechanism. AU - Nakamura, Taro. AU - Yoshizaki, Masato. AU - Ogawa, Shotaro. AU - Okamoto, Haruko. AU - Shinmyo, Yohei. AU - Bando, Tetsuya. AU - Ohuchi, Hideyo. AU - Noji, Sumihare. AU - Mito, Taro. PY - 2010/9/3. Y1 - 2010/9/3. N2 - The mode of insect embryogenesis varies among species, reflecting adaptations to different life history strategies [1, 2]. In holometabolous insects, which include the model systems, such as the fruit fly and the red flour beetle, a large proportion of the blastoderm produces an embryo, whereas hemimetabolous embryos generally arise from a small region of the blastoderm [3]. Despite their importance in evolutionary studies, information of early developmental dynamics of hemimetabolous insects remains limited. Here, to clarify how maternal and gap gene products act in patterning the embryo of basal hemimetabolous insects, we analyzed the dynamic ...
The dorsal gastrula organizer plays a fundamental role in establishment of the vertebrate axis. We demonstrate that the zebrafish bozozok (boz) locus is required at the blastula stages for formation of the embryonic shield, the equivalent of the gastrula organizer and expression of multiple organizer-specific genes. Furthermore, boz is essential for specification of dorsoanterior embryonic structures, including notochord, prechordal mesendoderm, floor plate and forebrain. We report that boz mutations disrupt the homeobox gene dharma. Overexpression of boz in the extraembryonic yolk syncytial layer of boz mutant embryos is sufficient for normal development of the overlying blastoderm, revealing an involvement of extraembryonic structures in anterior patterning in fish similarly to murine embryos. Epistatic analyses indicate that boz acts downstream of ß-catenin and upstream to TGF-ß signaling or in a parallel pathway. These studies provide genetic evidence for an essential function of a ...
P.617 left column bottom paragraph: A survey of all credible published estimates that [Biggin] could find for four well studied species suggests that most animal transcription factors are expressed at 10,000-300,000 molecules per nucleus (Table 1). These estimates are further supported by [his] own experience and that of many other biochemists who have purified additional endogenous transcription factors with similar yields to the proteins in Table 1. P.620 right column bottom paragraph: The data in Table 1 may be biased toward easily studied proteins, so the identification of transcription factors expressed at lower levels may identify better candidates for Coselective DNA Binding-based regulation. In Ftz expressing blastoderm nuclei. Note-primary source abstract and p.1024 right column top paragraph give ~20,000 rather than 50,000 copies/nucleus ...
Protocol for performing ATAC-seq on nuclei isolated from Drosophila melanogaster stage 5 embryos that were flash frozen and then cut in half along the anterior-posterior midline....
0132] In summary, embodiments of the invention provide for [0133] a canalization device that does not need an open channel or an opening in an occluded lumen before insertion, which is not possible with an ordinary stent--hitherto the occluded site had to be opened, e.g. by a drill or rather rigid guidewire; [0134] extensions of the canalization device that have an advantageous shape, like: spikes, loops, triangles, blades, which furthermore have sharp edges in the front. The extensions are located on the inside of the canalization device when implanted, thus preventing tissue damage upon finalized implantation; [0135] spontaneous inversion of the canalization device outside in is provided due to built in memory characteristics of the device, either by a shape memory or elasticity/resiliency effect; [0136] the canalization device is able to pull itself into solid tissue, which is advantageous as only the initial transition of states is triggered and the remaining tissue penetration may be ...
Hard, dull and mostly spiny leaves of small size. Trees maintain a narrow upright shape. Fruit is red. Gender is male. This holly doesnt do as well as oth
Coeloblastula n. pl. -lae Gr. koilos, hollow blastos, bud 1. A hollow blastula a blastula without qualification. 2. (PO-RIF Calcarea) The simple type of
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Potresti notare che i puntatori nulli sono variamente indicati in uno di questi tre modi: 0, 0L e NULL. In C, NULL è definito come un puntatore nullo di tipo void. Ma in C++ ciò non è possibile a causa di un controllo di tipo più stretto. Perciò, moderne implementazioni del C++ lo rendono come un "magico" puntatore nullo costante il quale può essere assegnato a qualunque altro puntatore. Daltra parte le implementazioni più vecchie di C++ semplicemente lo associano a 0 o 0L, il quale non tiene conto di alcuna sicurezza di tipo - si potrebbe assegnarlo ad una variabile intera, ovviamente sbagliando. ...
Intr-o buna zi, stand la taclale ca de obicei, maestrul zen Bernie Glassman ii spune actorului Jeff Bridges ca „the Dude, personajul acestuia din filmul-cult Marele Lebowski, este considerat de multi budisti un maestru zen.
Goal: To realise at least seven pilot projects for ZEN concepts in Norway that will serve as: innovation hubs for co-creation between researchers and building professionals, property developers, municipalities, energy companies, building owners, and users; living labs to verify, document and optimize the real-life performance of the solutions developed in the ZEN Centre; lighthouse projects to learn, inspire, and disseminate ZEN-related knowledge. ...
The nagging sense watching Westworld now is that the first season was, in hindsight, as good as its going to get, and once it reached the center of the maze, there was no obvious path left to follow ...
A Canavalia ensiformis é uma leguminosa altamente resistente ao ataque de insetos, e contribuindo para essa resistência, a planta possui isoformas de urease, que são proteínas que apresentam atividade entomotóxica. Essa toxicidade é dependente de uma ativação proteolítica da molécula por enzimas digestivas do inseto, do tipo catepsinas, e subseqüente liberação de peptídeos internos, os quais possuem a ação inseticida. A partir dessa informação foi construído um peptídeo recombinante com base na seqüência da urease, chamado Jaburetox-2Ec, o qual é tóxico para insetos resistentes e suscetíveis a urease intacta. O hemíptero Oncopeltus fasciatus é um dos nossos modelos de estudo. O objetivo deste trabalho foi identificar as principais peptidases digestivas de ninfas de O. fasciatus, auxiliando na elucidação do mecanismo de ação inseticida dessas toxinas, além de estudar os efeitos da urease intacta e do peptídeo derivado sobre órgãos isolados. Quando alimentadas ...
Preparation of Chromatin Assembly Extracts from Preblastoderm Drosophila Embryos -- Analysis of Reconstituted Chromatin Using a Solid-Phase Approach -- In Vivo Chromatin Decondensation Assays: Molecular Genetic Analysis of Chromatin Unfolding Characteristics of Selected Proteins -- DNA Methyltransferase Probing of Chromatin Structure Within Populations and on Single Molecules -- Visualization of the Expression of HMGN Nucleosomal Binding Proteins in the Developing Mouse Embryo and in Adult Mouse Tissues -- Drug-Induced Premature Chromosome Condensation (PCC) Protocols: Cytogenetic Approaches in Mitotic Chromosome and Interphase Chromatin -- Analysis of DNA Topology in Yeast Chromatin -- Preparation and Analysis of Uniquely Positioned Mononucleosomes -- Monitoring DNA Breaks in Optically Highlighted Chromatin in Living Cells by Laser Scanning Confocal Microscopy -- Methods to Study Transcription-Coupled Repair in Chromatin -- Cytometric Analysis of DNA Damage: Phosphorylation of Histone H2AX as a ...
Yolk syncytial layer cell nuclei exhibit convergence and extension behaviors during late gastrulation. Video made available by Mark Cooper through Ze...
The yolk syncytial layer (YSL) is a novel embryonic structure that is unique to teleost fishes like the zebrafish. How existing genetic mechanisms can change to contribute to the generation of morphological novelties such ...
Binding of pumilio to maternal hunchback mRNA is required for posterior patterning in Drosophila embryos. Developmental regulation of vesicle transport in Drosophila embryos: forces and kinetics
The broad interest of the laboratory aims to further our understanding of how several genetic interactions come into play at the earliest stages of development to build the developing embryo. Primitive streak formation is reputed as being the most important time in ones life since it generates the three germ layers of the embryo proper. The progenitor cells of these three germ layers ingress into the embryonic organiser and the primitive streak where they form resident populations of stem cells for multiple tissue types. One main focus of the laboratory will be to gain a deeper understanding of the mechanism of regulation of these stem cells both in the mouse and the chick system. We will initially try to identify the location of the stem cell pools. We will then investigate the function of potential candidate signalling pathways involved in i)maintaining this stem cell state and ii) biasing these progenitors to contribute daughter cells to specific tissues inthe developing embryonic ...
To understand how a person can so easily change the foundation of knowledge and belief for events after receiving new information, three cognitive models of hindsight bias have been reviewed.[20] The three models are SARA (Selective Activation and Reconstructive Anchoring), RAFT (Reconstruction After Feedback with Take the best) and CMT (Causal Model Theory). SARA and RAFT focus on distortions or changes in a memory process, while CMT focuses on probability judgments of hindsight bias.. The SARA model, created by Rüdiger Pohl and associates, explains hindsight bias for descriptive information in memory and hypothetical situations.[20][21] SARA assumes that people have a set of images to draw their memories from. They suffer from the hindsight bias due to selective activation or biased sampling of that set of images. Basically, people only remember small, select amounts of information-and when asked to recall it later, use that biased image to support their own opinions about the situation. The ...
Staining is first detected at cleavage stage 12, prior to cellularization about 45 minutes prior to gastrulation. The yolk nuclei are strongly stained and remain so. Broad general staining forms first, but bands develop and soon narrow. Staining appears in odd numbered stripes, complementary to that found in Fushi tarazu, in even numbered stripes. Strongest staining appears in the anterior. As germ band elongation begins [Images], seven new bands are added between the seven original ones. The new bands show weaker staining. During elongation, new staining is detected near the posterior end in an area that includes the presumptive proctodeum. FTZ staining appears in clusters, two clusters per segment, one on either side of the ventral midline. In addition, one neuroblast cell in the interior of each segment is stained. Additional neuroblasts become stained later, six or seven on each side of the hemisegment. Only 13-15 neurons are stained by EVE antibody in each of the three thoracic and first ...
E hyaloid vessels. doi:10.1371/journal.pone.0053970.gused immunohistochemistry of melanocyte and melanoma cell specific markers HMB45 and Melan-A. Since in the early chick embryo neural crest cells have not yet differentiated, they do not express markers of the…. ...
Contemporary Biochemistry: Craig Smibert - University of Toronto - Global analysis of mRNA/protein interactions in the early Drosophila embryo
A hunchback either becomes impotent or burns in a fire of lasciviousness that never cools for a single instant, like the heat of hell.
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Is our judgement of prior events an accurate assessment of the past? Or is it a cognitive trap, an illusion created by a minefield of biases?
Developmental homeostasis developmental homeostasis canalization (q.v.). developmental homology anatomical similarity due to derivation from a common embryological source; e.g., the halteres of flies are developmentally homologous to the hind wings ...
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Slidin into the DMs! BJ Novak is in a relationship with a 21-year-old Instagram model he met online, and, according to Page Six, its a bit of an odd pairing.
Gjenerata e fundit e barnave, të zhvilluara duke përdorur teknologji moderne farmaceutike, lehtësojnë vuajtjet njerëzore, zvogëlojnë rrezikun e
After fertilization, lineage specification is governed by a complicated molecular network in which permissiveness and repression of expression of pluripotency- and differentiation-associated genes are regulated by epigenetic modifications. DNA methylation operates as a very stable repressive mark in this process. In this study, we investigated the relationship between DNA methylation and expression of pluripotency-associated genes (OCT4, NANOG and SOX2), a trophectoderm (TE)-specific gene (ELF5), and genes associated with neural differentiation (SOX2 and VIMENTIN) in porcine Day 10 (E10) epiblast, hypoblast, and TE as well as in epiblast-derived neural progenitor cells (NPCs). We found that OCT4, NANOG, and SOX2 were highly expressed in the epiblast and hypoblast, while VIMENTIN was only highly expressed in the epiblast. Moreover, low expression of OCT4, NANOG, SOX2 and VIMENTIN was noted in the TE. Most CpG sites of OCT4, NANOG, SOX2 and VIMENTIN displayed low methylation levels in the epiblast ...
After fertilization, the egg repeatedly undergoes cell division, leading to a ball of cells with 2, 4, 8, 16, 32 cells, and so on. However, for development into a fully formed embryo, the ball must undergo a process called gastrulation, whereby it is transformed into a hollow, ball-like, three-layered structure. Initiation of gastrulation requires the primitive streak.. To shed light on primitive streak formation, the team applied a tool that uses clusters of mouse embryonic stem cells to mimic embryo development. By applying a wide range of drugs to these embryo mimics, they identified a number of drugs that stopped the embryonic cells from developing and differentiating normally. Some of the drugs block the functioning of the mevalonate pathway, so the team looked at whether, and how, this metabolic pathway is linked to the primitive streak.. When we applied the drugs statins, which are extremely useful for lowering cholesterol levels, to the embryo mimics, they stopped differentiating ...
Authors: David A Simpson, Amelia J Thompson, Mark Kowarsky, Nida F Zeeshan, Michael SJ Barson, Liam T Hall, Yan Yan, Stefan Kaufmann, Brett C Johnson, Takeshi Ohshima, Frank Caruso, Robert E Scholten, Robert B Saint, Michael J Murray, Lloyd CL Hollenberg
Sobczyk GJ, Wang J, Weijer CJ (2014) SILAC-based proteomic quantification of chemoattractant-induced cytoskeleton dynamics on a second to minute timescale. Nat Commun. 2014 Feb 26;5:3319. doi: 10.1038/ncomms4319. Chuai M, Hughes D, Weijer CJ (2012) Collective Epithelial and Mesenchymal Cell Migration during Early Embryogenesis. Current Genetics 13 (2012) 267-27. Sandersius SA, Chuai M, Weijer CJ, Newman TJ. (2011) A chemotactic dipole mechanism for large-scale vortex motion during primitive streak formation in the chick embryo. Phys Biol. Aug;8(4):045008. Epub 2011 Jul 12.. Sandersius SA, Chuai M, Weijer CJ, Newman TJ (2011) Correlating cell behavior with tissue topology in embryonic epithelia. PLoS One Apr 29;6(4):e18081.. Davidson L, Maccario H, Perera NM, Yang X, Spinelli L, Tibarewal P, Glancy B, Gray A, Weijer CJ, Downes CP and Lesie NR (2010) Suppression of cellular proliferation and invasion by the concerted lipid and protein phosphatase activities of PTEN. Oncogene ...
Any given slice from the blastoderm is able to generate a complete axis until the time of gastrulation and primitive streak ... SPRATT NT Jr; HAAS H. (1960). "Integrative mechanisms in development of the early chick blastoderm. I. REgulative potentiality ...
The word syncytium in animal embryology is used to refer to the coenocytic blastoderm of invertebrates. Coenocytic cells are ... At first, the nuclei of the early embryo rapidly and synchronously divide in the "syncytial" blastoderm and then migrate ... blastoderms, i.e. early on the embryos exhibit incomplete cell division. The nuclei undergo S-phase (DNA replication) and ... the egg is called a cellular blastoderm. The pole cells - the germline anlage - are the first cells to separate fully. Certain ...
... cell membranes form around the nuclei of the syncytial blastoderm converting it to a cellular blastoderm. The expression ... This process sets up a gradient between the ventral and dorsal side of the blastoderm embryo with the repression or induction ... At the dorsal side of the embryo, blastoderm nuclei where this is little or no nuclear dorsal protein express zerknüllt, ... At the ventral end of the embryo, blastoderm nuclei exposed to high concentrations of dorsal protein induce the transcription ...
It has been demonstrated that gap gene expression in the Drosophila blastoderm exhibit a property called as canalization, a ... "Mechanisms of gap gene expression canalization in the Drosophila blastoderm". BMC Systems Biology. 5 (118). doi:10.1186/1752- ...
Bellairs R. (1953a). Studies on the development of the foregut in the chick blastoderm. 1. The presumptive foregut area. J. ... Bellairs R. (1953b). Studies on the development of the foregut in the chick blastoderm. 2. The morphogenetic movements. J. ...
The blastoderm is a single layer of cells, and the hypoblast and area opaca endoderm cells lie directly below the blastoderm. ... As blastoderm cells migrate anteriorly they push primary hypoblast cells and form a secondary hypoblast known as the endoblast ... By implanting a fragment of quail Koller's sickle into a chicken blastoderm, Drs. Callebaut and Van Nueten observed the ... Callebaut, M; Van Nueten, E (1994). "Rauber's (Koller's) sickle: The early gastrulation organizer of the avian blastoderm". ...
Fires, which uses Fires of Yavimaya with Saproling Burst and Blastoderm. Dredge, which uses Bazaar of Baghdad and cards with ...
The larger question she addressed was what the developmental potential was of portions of the early chick blastoderm, when ... Reddick ML (1937). The differentiation of portions of the chick blastoderm in chorio-allantoic grafts. Thesis for Degree of the ... "The differentiation of portions of the chick blastoderm in chorio-allantoic grafts". Robert W. Woodruff Library. University of ... with a thesis studying the embryo chick blastoderm. After gaining her Masters, Reddick began teaching biology at Spelman in ...
Her dissertation was titled "Thyroid Forming Potencies of the Early Chick Blastoderm." Dr. Rudnick spent most of her academic ... Dorothea Rudnick, "Thyroid Forming Potencies of the Early Chic Blastoderm" (University of Chicago 1931). "Dorothea Rudnick" in ...
... fish blastoderm, frog embryos, rabbit ovary, re-aggregating cells, cockroach hemocyte capsules, rabbit skin, chick embryos, ... "Gap junction-mediated transfer of left-right patterning signals in the early chick blastoderm is upstream of Shh asymmetry in ... "Differentiation of the junctional complex of surface cells in the developing Fundulus blastoderm". J. Cell Biol. 48 (3): 455-72 ...
Interior cells of the blastoderm move towards the outer cells, thus "intercalating" with each other. The blastoderm begins to ... Studies on Fundulus demonstrated that the YSL is capable of undergoing epiboly even when the blastoderm has been removed, but ... of the blastoderm which will eventually form the embryo's three germ layers (ectoderm, mesoderm, and endoderm). The EVL, YSL, ... that the blastoderm cannot undergo epiboly in the absence of the YSL. In zebrafish, there is a microtubule array in the yolk ...
... and engrailed in the Drosophila blastoderm". Cell. 44 (6): 949-957. doi:10.1016/0092-8674(86)90018-8. Forbes, AJ; Nakano, Y; ...
The blastoderm now consists of three layers, named from without inward: ectoderm, mesoderm, and endoderm; each has distinctive ... The blastula is usually a spherical layer of cells (the blastoderm) surrounding a fluid-filled or yolk-filled cavity (the ...
These actomyosin rings invaginate to separate all nuclei for one another in the syncytial blastoderm. Anillin has a unique ...
"The homeobox gene goosecoid and the origin of organizer cells in the early chick blastoderm". Cell. 74 (4): 645-59. doi:10.1016 ...
Additionally, the term may refer to any ovum in which the blastoderm splits into three layers. All "higher" and "intermediate" ...
He presents here several figures and illustrations of the cleavage of the blastoderm in reptiles and birds. He examines in ...
This axis is defined by the creation of a pH difference "inside" and "outside" of the blastoderm between the subgerminal space ... the lighter yolk components will be near one end of the blastoderm and will become the future posterior. The molecular basis of ...
Distinct tissue areas were recognized that grew and gave rise to specific structures, including the blastoderm, or chick origin ...
The blastoderm develops into the epiblast and hypoblast and it is between these layers that the blastocoel will form. The shape ... and mammalian blastoderm-stage embryos. A blastocoel (alt. spelling blastocoele, blastocele) is also termed the blastocyst ...
Many of the cards with Fading were quite powerful; the cards Parallax Wave, Parallax Tide, Blastoderm, Saproling Burst, and ...
... and engrailed in the Drosophila blastoderm". Cell. 44 (6): 949-957. doi:10.1016/0092-8674(86)90018-8. The Interactive Fly: http ...
As the blastoderm cells undergo epiboly around the yolk the internalization of cells at the blastoderm margin start to form ... Once blastoderm cells have covered almost half of the yolk cell, thickening throughout the margin of deep cells occurs. The ... This layer forms when the cells at the vegetal pole of the blastoderm combine with the yolk cell underneath it. Later in ... The second cell population is the enveloping layer which is made of superficial cells from the blastoderm that eventually form ...
This undergoes a period of divisions to form a ball or sheet of similar cells called a blastula or blastoderm. These cell ...
He identified the citricula as the point in the yolk from which the embryo develops and the blastoderm surrounding the embryo. ...
Blasto*derm (?), n. [Gr. sprout + E. derm.] Biology|Biol. The germinal membrane in an ovum, from which the embryo is developed. &a...
The blastoderm is a term for cell layers found in blastulas. A blastoderm is the layer of cells formed at one pole of ... The blastoderm is composed of two layers, the epiblast and the hypoblast, which enclose the fluid-filled blastocoel cavity. ... At the animal pole (containing less yolk than the vegetal pole), the zygote divides and subdivides, forming the blastoderm, ... separates sheets of cells from the posterior end of the blastoderm from the underlying hypoderm and area opaca endoderm. This ...
Determination of Blastoderm Cells in Drosophila melanogaster. L.-N. Chan and W. Gehring ... A method for culturing blastoderm cells of Drosophila in vivo has been developed that allows these cells to differentiate into ... By intermixture of genetically marked cells from bisected and whole embryos, it was shown that blastoderm cells are restricted ... The influence on the blastoderm fate map of maternal-effect genes that affect the antero-posterior pattern in Drosophila ...
The early blastoderm of Drosophila is a syncytium in which about 6000 nuclei become localized in the peripheral cytoplasm. ... Cell membrane formation during the cellularization of the syncytial blastoderm of Drosophila. D Loncar and S J Singer ... We speculate that these vesicles are all derived from the Golgi apparatus and are moved about in the blastoderm by interactions ... Cell membrane formation during the cellularization of the syncytial blastoderm of Drosophila ...
... Shaila Kotadia, University of California at Santa Cruz, ... Mazumdar A and Mazumdar M (2002) How one becomes many: blastoderm cellularization in Drosophila melanogaster. BioEssays 11: ... Kotadia, Shaila, Crest, Justin, Tram, Uyen, Riggs, Blake, and Sullivan, William(Sep 2010) Blastoderm Formation and ...
A blastoderm fate map of compartments and segments of the Drosophila head.. Struhl G1. ... The major results are: (1) For both the proboscis and eye-antenna, blastoderm cells giving rise to the anterior compartment are ... These results suggest that at the blastoderm stage, the Drosophila head consists of a series of six segment primordia of ... This paper reports a gynandromorph fate map of the blastoderm primordia forming the compartments and segments of the adult head ...
Transcription factors bind thousands of active and inactive regions in the Drosophila blastoderm.. Li XY1, MacArthur S, Bourgon ... The new targets include most of the microRNAs (miRNAs) transcribed in the blastoderm, as well as all major zygotically ... However, these poorly bound regions are, collectively, far more distant from genes transcribed in the blastoderm than highly ... Transcription Factors Bind Thousands of Active and Inactive Regions in the Drosophila Blastoderm ...
Cis-acting elements in the 2 kbp second intron directed expression in the dorsal and terminal regions of the blastoderm, acted ... Embryonic expression patterns of the Drosophila decapentaplegic gene: separate regulatory elements control blastoderm ... in patterns indistinguishable from the patterns of endogenous dpp expression in the dorsal and terminal cells at the blastoderm ...
What is embryonic blastoderm? Meaning of embryonic blastoderm medical term. What does embryonic blastoderm mean? ... Looking for online definition of embryonic blastoderm in the Medical Dictionary? embryonic blastoderm explanation free. ... embryonic blastoderm. em·bry·on·ic blas·to·derm. that part of the blastoderm that takes part in the formation of the embryonic ... Embryonic blastoderm , definition of embryonic blastoderm by Medical dictionary https://medical-dictionary.thefreedictionary. ...
A-C) A dorsal view of pnr mRNA at blastoderm stage. Wild-type (A), scw mutant (B), and dpp mutant embryos (C). pnr is expressed ... Early (A-C), middle (D-F), and late (G-I) blastoderm stages, lateral view (A-C) and dorsal view (D-I). Note that Dpp protein is ... Dpp-HA Protein Forms a Dorsal Stripe during Cellularization of the Blastoderm Embryo. (A-I) Dpp-HA staining in a Dpp-HA ... Facilitated transport of a Dpp/Scw heterodimer by Sog/Tsg leads to robust patterning of the Drosophila blastoderm embryo.. ...
... - A Blastoderm is the layer of cells formed at one pole of the yolky egg of birds. The yolk prevents the division ... blastoderm - [blas′tōdʉrm΄, blas′tədʉrm΄] n. [ BLASTO + DERM] the part of a fertilized ovum that gives rise to the germinal ... Blastoderm - Blas to*derm, n. [Gr. blasto s sprout + E. derm.] (Embryology) the early stage of an embryo after the first ... blastoderm - In many eggs with a large amount of yolk, cell division (cleavage) is restricted to a superficial layer of the ...
... - A Blastoderm is the layer of cells formed at one pole of the yolky egg of birds. The yolk prevents the division ... blastoderm - [blas′tōdʉrm΄, blas′tədʉrm΄] n. [ BLASTO + DERM] the part of a fertilized ovum that gives rise to the germinal ... blastoderm. early embryonic tissue composed of blastomeres arranged in a sheet-like fashion; used to refer to embryonic tissue ... Blastoderm - Blas to*derm, n. [Gr. blasto s sprout + E. derm.] (Embryology) the early stage of an embryo after the first ...
Kinds of blastoderm are bilaminar blastoderm, embryonic blastoderm, extraembryonic blastoderm, and trilaminar blastoderm. Also ... blastoderm. (redirected from blastodermic). Also found in: Dictionary, Thesaurus, Encyclopedia. blastoderm. [blas´to-derm] a ... so that the blastoderm forms on one side of the yolk mass, initially as a small blastodisc.. blastoderm. the layer of cells ... blastoderm. (blăs′tə-dûrm′). n.. 1. The layer of cells that develops on the surface of the yolk in an avian or reptilian egg ...
Temporal regulation of gene expression in the blastoderm Drosophila embryo Glenn K. Yasuda, 1,3 Jayne Baker, 2 and Gerold ... The anterior two-thirds of the embryo has moderate levels of maternal message concentrated at the basal side of the blastoderm ... 62: Lamb, M.M. and C.D. Laird Increase in nuclear poly(a)- containing RNA at syncytial blastoderm in Drosophila melanogaster ... 1 Temporal regulation of gene expression in the blastoderm Drosophila embryo Glenn K. Yasuda, 1,3 Jayne Baker, 2 and Gerold ...
Activation of posterior gap gene expression in the Drosophila blastoderm ... Activation of posterior gap gene expression in the Drosophila blastoderm Rivera-Pomar, R., Lu, X. G., Perrimon, N., Taubert, H ... Jaeckle, H. (1995). Activation of posterior gap gene expression in the Drosophila blastoderm. Nature, 376(6537), 253-256. ...
Blastoderm. Carbonize. Arrest. Army Ants. Bonehoard. Desert. 7. Befoul. Augur of Bolas. Brooding Saurian. Chandra, the ...
derm definition, variant of -dermatous, usually with nouns (melanoderm; pachyderm), or variant of -dermis (blastoderm; ectoderm ... variant of -dermatous, usually with nouns (melanoderm; pachyderm), or variant of -dermis (blastoderm; ectoderm; mesoderm). ...
Blastoderm explants. Request a detailed protocol Embryos were injected with ndr2, H2B-RFP, and/or membrane GFP RNA (and MOs) at ... Blastoderm explants exhibit asymmetric Nodal signaling. The gene expression patterns observed in ndr2-expressing explants ... Nodal ligands promote ex vivo C and E of blastoderm explants.. (A) Diagram of injection and explantation of zebrafish embryos ... The blastoderm explants described in this study provide a robust, simplified model of axial extension in which a signaling ...
Blastoderm Theory. This takes into account the cell layers in our embryological development. We have 3 layers at this stage: ...
Drosophila melanogaster : variation of embryo size and blastoderm stage nuclear number with temperature ... Drosophila melanogaster : variation of embryo size and blastoderm stage nuclear number with temperature. ... there was a positive correlation between embryo size and the number of nuclei present at the periphery of the blastoderm stage ... Drosophila melanogaster : variation of embryo size and blastoderm stage nuclear number with... ...
Other articles where Blastoderm is discussed: blastula: …epithelial (covering) layer, called the blastoderm, enclosing a fluid- ...
In arthropods, the arrangement of genes within the Hom-C complex is similar to that found in the phylum chordata. The expression pattern of the Antennapedia (Ant) gene in lobster is similar to that of the Drosophila Ant gene, but there are some differences. You wonder whether the differences are due to the DNA cis-regulatory elements that direct expression of the Ant genes in these two organisms. Alternatively, the differences might be due to the Lobster and Drosophila transcription factors that regulate Ant expression. Design a set of experiments to distinguish between these possibilities. For each experiment, provide possible outcomes and interpret what each result would mean. Describe any control experiments that would be important. Assume that it is feasible to generate transgenic lobsters ...
The gnathal segments derive from a region of the blastoderm between 60% and 70% egg length (EL) dorsally and 60% and 80% ... Segmental organisation of the head in the embryo of Drosophila melanogaster : A blastoderm fate map of the cuticle structures ... This information enabled us to translate the spatial distribution of blastoderm defects into a fate map of segment anlagen. ... blastoderm and the extended germ band. The ensuing defects were scored in the cuticle pattern of the head of the first-instar ...
Any given slice from the blastoderm is able to generate a complete axis[17] until the time of gastrulation and primitive streak ... SPRATT NT Jr; HAAS H. (1960). "Integrative mechanisms in development of the early chick blastoderm. I. REgulative potentiality ...
In Vitro Preparation of the Early Squid Blastoderm. Marthy, Hans-Jürg (et al.) ...
  • By intermixture of genetically marked cells from bisected and whole embryos, it was shown that blastoderm cells are restricted in their potential for forming adult epidermal structures. (pnas.org)
  • We find that these sequence-specific DNA binding proteins bind with quantitatively different specificities to highly overlapping sets of several thousand genomic regions in blastoderm embryos. (nih.gov)
  • (C) Quantification of H3K4me3 and H3K27me3 in the cellular blastoderm and gastrulating embryos by Western blotting. (nih.gov)
  • Transcription is first detected along the dorsal side of early syncytial blastoderm embryos. (nih.gov)
  • Treating embryos with the microtubule depolymerizing agent nocodazole completely blocks epiboly of the YSL and partially blocks epiboly of the blastoderm, while treating with the microtubule stabilizing agent taxol blocks epiboly of all cell layers. (wikipedia.org)
  • A blastocoel is a fluid-filled cavity that forms in the animal hemisphere of early amphibian and echinoderm embryos, or between the epiblast and hypoblast of avian, reptilian, and mammalian blastoderm-stage embryos. (wikipedia.org)
  • Further work into this with miR-6-depleted blastoderm embryos found pole cell formation at the posterior end of the anteroposterior axis to be disrupted, despite normality of both cellularisation and early pattern formation. (wikipedia.org)
  • Blastoderm - 1 Morula, 2 Blastula Die Blastula (von griechisch Blastos: der Keim, die Knospe, der Spross) ist ein frühes Embryonalstadium Vielzelliger Tiere, das auf das Morula Stadium folgt und die Furchung abschließt. (enacademic.com)
  • The blastula is usually a spherical layer of cells (the blastoderm) surrounding a fluid-filled or yolk-filled cavity (the blastocoel). (wikipedia.org)
  • A common feature of a vertebrate blastula is that it consists of a layer of blastomeres, known as the blastoderm, which surrounds the blastocoele. (wikipedia.org)
  • The major results are: (1) For both the proboscis and eye-antenna, blastoderm cells giving rise to the anterior compartment are positioned anterior to cells giving rise to the posterior compartment. (nih.gov)
  • This result suggests that the relative anteroposterior position of blastoderm cells constitutes the positional basis for the segregation of anterior and posterior polyclones in different segments. (nih.gov)
  • The new targets include most of the microRNAs (miRNAs) transcribed in the blastoderm, as well as all major zygotically transcribed dorsal-ventral patterning genes, whose expression we show to be quantitatively modulated by anterior-posterior factors. (nih.gov)
  • The selector gene, engrailed (en), is a key determinant in boundary formation between the anterior and posterior compartments. (wikipedia.org)
  • The blastoderm is composed of two layers, the epiblast and the hypoblast, which enclose the fluid-filled blastocoel cavity. (wikipedia.org)
  • The second rectangular magnification shows the blastoderm cross-sectioned through the primitive streak. (asu.edu)
  • Cis-acting elements in the 2 kbp second intron directed expression in the dorsal and terminal regions of the blastoderm, acted on a heterologous promoter, the P-element promoter, and responded to pattern information derived from the maternal effect dorsal/ventral patterning genes. (nih.gov)
  • Distinct tissue areas were recognized that grew and gave rise to specific structures, including the blastoderm, or chick origin. (wikipedia.org)
  • This paper reports a gynandromorph fate map of the blastoderm primordia forming the compartments and segments of the adult head. (nih.gov)
  • In addition to the segment anlagen, the regions of the presumptive dorsal pouch, anterior lobe and post-oral epithelium, whose morphogenetic movements during head involution result in the characteristic acephalic appearance of the larva, have been projected onto the blastoderm fate map. (scienceopen.com)
  • Assuming that all segment primordia are of equal length in the blastoderm, the proboscis and eye-antennal primordia are separated by a gap in which three other segment primordia might fit. (nih.gov)