Buds

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Buds

  • chick limb bud
  • dormant bud
  • end bud
  • fin bud
  • flower bud
  • limb bud
  • tail bud
  • taste bud
  • tooth bud
  • wing bud

  • Terms modified by Buds

  • bud break
  • bud burst
  • bud development
  • bud set
  • bud stage

  • Selected Abstracts


    Improvement in health-related quality of life with fluticasone propionate compared with budesonide or beclomethasone dipropionate in adults with severe asthma

    RESPIROLOGY, Issue 3 2003
    Carolyn RUTHERFORD
    Objective: Changes in health-related quality of life (HRQoL) were evaluated in adults with severe asthma following inhaled corticosteroid treatment with high-dose beclomethasone dipropionate or budesonide (BDP/BUD) and compared with fluticasone propionate taken at approximately half the dose of BDP/BUD. Methodology: HRQoL was assessed as part of an open, multicentre, randomized, parallel-group study in Australia evaluating the safety and efficacy of switching to fluticasone propionate (FP) 1000,2000 µg/day (n = 67) compared with remaining on BDP/BUD ,1750 µg/day (n = 66) for 6 months. Patients completed two HRQoL questionnaires, the Asthma Quality of Life Questionnaire (AQLQ) and the Medical Outcomes Study Short Form-36 (SF-36), at baseline and at weeks 12 and 24. A change in AQLQ score of ,0.5 was considered to be clinically meaningful. Results: There were significant improvements in HRQoL with FP on four of the eight dimensions on the SF-36 (i.e. physical functioning, general health, role-emotional, and mental health), while there were no significant improvements in HRQoL in the BDP/BUD group. Overall, patients in the FP group experienced significantly greater improvement (P < 0.001) in AQLQ scores at weeks 12 and 24 compared with the BDP/BUD group. On the individual domains of the AQLQ, there were significant treatment differences (P < 0.01) in favour of FP in three of the four domains (activity limitations [0.92], symptoms [0.73], and emotional function [1.02]). Mean differences between groups for overall score and these three domains were also clinically meaningful. Conclusion: Patients with severe asthma who received FP (at approximately half the dose of BDP/BUD) experienced statistically significant, as well as clinically meaningful, improvements in their HRQoL. [source]


    Improved safety with equivalent asthma control in adults with chronic severe asthma on high-dose fluticasone propionate

    RESPIROLOGY, Issue 3 2001
    Norbert Berend
    Objective: High-dose inhaled corticosteroids (ICS) have been associated with the same side-effects as oral corticosteroids. Beclomethasone dipropionate (BDP) and budesonide (BUD) in doses greater than 2000 ,g/day are used regularly in severe asthma, despite the fact that safety and efficacy data at such high doses are limited. Fluticasone propionate (FP) has been promoted as being twice as potent clinically as BDP or BUD at doses of 2000 ,g/day or less with a similar safety profile. The aim of this study was to compare the efficacy and safety of FP with BDP and BUD in 133 symptomatic adult asthmatics requiring at least 1750 ,g/day of BDP or BUD. Methodology: Patients fulfilling the entry criteria were randomized to receive either their regular ICS medication or FP at approximately half the microgram dose for 6 months in an open, parallel group study. The primary efficacy measure was based on morning peak expiratory flow measurements recorded by patients on daily record cards, while determination of safety was based on a number of endpoints including changes in bone turnover indices, the incidence of topical side-effects and assessments of quality of life. Results: It was shown that patients who were switched to FP, but not those continuing with BDP or BUD, had significant increases in levels of morning serum cortisol and the urine cortisol:creatinine ratio while maintaining asthma control. Serum osteocalcin and the pyridinoline:creatinine ratio, as well as the deoxypyridinoline:creatinine ratio, were also shown to increase only in the FP group. Subjective assessments such as quality of life score, the incidence and ease of bruising, and reports of hoarseness also favoured the FP group. Conclusions: It is concluded that, at the doses studied and with the delivery devices used clinically, FP is at least as effective as BDP/BUD in the management of severe asthma and may offer clinical advantages with respect to steroid-related adverse effects. [source]


    ANTIOXIDANT ACTIVITIES AND HYPOLIPIDEMIC EFFECTS OF AN AQUEOUS EXTRACT FROM FLOWER BUDS OF CLEISTOCALYX OPERCULATUS (ROXB.) MERR.

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 6 2009
    AND PERRY
    ABSTRACT The antioxidant activities and hypolipidemic effects of aqueous extract from Cleistocalyx operculatus flower buds (COB) (Roxb.) Merr. and Perry, a commonly used material for drink preparation in Vietnam, were investigated in vitro and in diabetic rats. In vitro, the aqueous extract of COB which has highest phenolic and flavonoid contents showed a strong antioxidant effect and highest pancreatic lipase inhibitory activity when compared with green tea and guava leaf extracts. Oral administration of aqueous extract from COB (500 mg/kg body weight/day) on streptozotocin-induced diabetic rats for 8 weeks resulted in significant reduction in the levels of glucose, total cholesterol and triglyceride in plasma as well as the concentration of glucose and sorbitol in the lens. In addition, COB showed significant recovery in the activities of antioxidant enzymes (superoxide dismutase, glutathione S-transferase) and glutathione level in liver with markedly decrease in the lipid peroxide level in liver and lens of the COB-treated diabetic rats. These results indicated that COB showed antioxidant activities, prevention of sorbitol accumulation in lens and hypolipidemic effects in addition to its antidiabetic effects and may be considered as a promising material for the prevention of diabetic complications and metabolic syndrome. PRACTICAL APPLICATIONS In recent years, research on traditional medicinal plants for the management of diabetes has attracted the interest of medical scientists. A suitable plant material for antidiabetes and prevention of diabetic complications should possess various biological components, such as antihyperglycemia, antioxidant activities and antihyperlipidemia, without side effects. In this study, the aqueous extract from Cleistocalyx operculatus flower buds (COB) with high polyphenolic and flavonoid content has shown beneficial biological functions in vitro and in diabetic rats, including antioxidant activity, hypolipidemic and hypoglycemic effects. The results of our study suggest that COB might have a potential role in the management of the prediabetic state and the prevention of diabetic complications. Therefore, there is the possibility for the development of C. operculatus as a beverage for the prevention of diabetes, as well as the prevention of the metabolic syndrome. [source]


    Frost Injury as a Possible Inciting Factor in Bud and Shoot Necroses of Fraxinus excelsior L.

    JOURNAL OF PHYTOPATHOLOGY, Issue 9 2005
    P. M. Pukacki
    Abstract Large numbers of European ash have died in Poland in all age classes during the last ten years. The characteristic symptom occurring on shoots of planted and self-sown seedlings was bark necroses starting from the shoot apex, necrotic buds, or leaf and twig scars. The results showed that in the bud tissue of cold acclimated European ash extracellular and intracellular ice formation occurred at approximately ,9 and ,32°C, respectively. In deacclimated plants in spring water supercooling is limited by the heterogenous ice nucleation temperature and consequently the cold tolerance is ,9 to ,4°C for bud tissues and ,13 to ,9°C for shoots. Isolations of fungi were performed from dead buds and from necroses occurring on the main stem. Alternaria alternata, Fusarium lateritium and Phomopsis scobina were among the fungi occurring in both these organs at frequencies of more than 7%. Cylindrocarpon heteronemum, Diplodia mutila and Tubercularia vulgaris from necroses were only isolated in frequencies; 3.3, 1.2 and 5.4%, respectively. It seems likely that freezing injury is the inciting factor, which combined with fungal colonization manifests itself as fatal damage to European ash buds and shoots. [source]


    This Bud's For You: Understanding International Intellectual Property Law Through the Ongoing Dispute over the Budweiser Trademark

    JOURNAL OF LEGAL STUDIES EDUCATION, Issue 1 2006
    Robert C. Bird
    [source]


    Incidence, Aggressiveness and In Planta Interactions of Botrytis cinerea and other Filamentous Fungi Quiescent in Grape Berries and Dormant Buds in Central Washington State

    JOURNAL OF PHYTOPATHOLOGY, Issue 7 2002
    F. M. Dugan
    Abstract Recovery of quiescent filamentous fungi from non-symptomatic grape berries and dormant buds demonstrated dominance of Alternaria, Aureobasidium, Cladosporium, Ulocladium and other dematiaceous hyphomycetes. Up to 78% of berries contained fungi prior to harvest. Botrytis cinerea was recovered from 0.2 to 0.5% of surface-disinfested berries just subsequent to fruit set, and 1.6,4.8% of surface-disinfested, over-wintered dormant buds. In laboratory inoculations of mature grape berries with strains of Alternaria, Aureobasidium, Cladosporium, Ulocladium and Botrytis, only the latter was aggressive in rotting berry fruits. Inoculations with B. cinerea alone and in combination with strains of Alternaria, Aureobasidium, Cladosporium and Ulocladium recovered from grape demonstrated that prior occupation of wound sites by the latter fungi resulted in reduced lesion size compared to inoculation with B. cinerea alone. [source]


    Morphology of the Lingual Dorsal Surface and Oral Taste Buds in Italian Lizard (Podarcis sicula)

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010
    F. Abbate
    Summary With 4 figures The Italian lizard (Podarcis sicula) is the most diffused reptile in Italy, but it is also present in other European countries. This lizard belongs to the Lacertidae family, lives near walls, slants and along the borders of the paths; its diet includes bugs and aracnids. No data are so far available in literature about the three-dimensional morphology of the tongue of Podarcis sicula, therefore the aim of the present paper was to study by scanning electron and light microscopy the three-dimensional characteristics of the dorsal lingual surface and moreover the presence of chemosensory receptors like the taste buds in the oral cavity. Our results demonstrate that the Podarcis sicula tongue is a triangular muscular membranous organ, dorsoventrally flattened and that three different areas can be observed: a bifid apex, a body and a root. No papillae were observed in the apex, characterized by a flattened mucosa and by two deep median pouches. In the body cylindrical papillae with a flat surface are present, aborally gradually substituted by imbricated papillae. Foliate-like papillae were observed in the lateral parts of the tongue body. No sensory structures were showed on the lingual dorsal surface, while they were numerous in the oral cavity, particularly on the gingival epithelium. The light microscopy shows, on the dorsal surface, a stratified pavimentous not keratinized epithelium, conversely keratinized along the ventral surface. Many caliciform cells on the lateral parts of the papillae, deputed to the secretion of mucus, were also observed. Therefore, the results obtained in this paper could give a contribution to the knowledge of the tongue anatomy in a species widely diffused in different European countries and could be of help for clinical purposes in reptiles. [source]


    Live-cell analysis of mitotic spindle formation in taxol-treated cells

    CYTOSKELETON, Issue 8 2008
    Jessica E. Hornick
    Abstract Taxol functions to suppress the dynamic behavior of individual microtubules, and induces multipolar mitotic spindles. However, little is known about the mechanisms by which taxol disrupts normal bipolar spindle assembly in vivo. Using live imaging of GFP-, tubulin expressing cells, we examined spindle assembly after taxol treatment. We find that as taxol-treated cells enter mitosis, there is a dramatic re-distribution of the microtubule network from the centrosomes to the cell cortex. As they align there, the cortical microtubules recruit NuMA to their embedded ends, followed by the kinesin motor HSET. These cortical microtubules then bud off to form cytasters, which fuse into multipolar spindles. Cytoplasmic dynein and dynactin do not re-localize to cortical microtubules, and disruption of dynein/dynactin interactions by over-expression of p50 "dynamitin" does not prevent cytaster formation. Taxol added well before spindle poles begin to form induces multipolarity, but taxol added after nascent spindle poles are visible,but before NEB is complete,results in bipolar spindles. Our results suggest that taxol prevents rapid transport of key components, such as NuMA, to the nascent spindle poles. The net result is loss of mitotic spindle pole cohesion, microtubule re-distribution, and cytaster formation. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source]


    Evolution and persistence of the cilium

    CYTOSKELETON, Issue 12 2007
    Peter Satir
    Abstract The origin of cilia, a fundamental eukaryotic organelle, not present in prokaryotes, poses many problems, including the origins of motility and sensory function, the origins of nine-fold symmetry, of basal bodies, and of transport and selective mechanisms involved in ciliogenesis. We propose the basis of ciliary origin to be a self-assembly RNA enveloped virus that contains unique tubulin and tektin precursors. The virus becomes the centriole and basal body, which would account for the self-assembly and self-replicative properties of these organelles, in contrast to previous proposals of spirochaete origin or endogenous differentiation, which do not readily account for the centriole or its properties. The viral envelope evolves into a sensory bud. The host cell supplies the transport machinery and molecular motors to construct the axoneme. Polymerization of cytoplasmic microtubules in the 9 + 0 axoneme completes the 9 + 2 pattern. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source]


    How to make a zone of polarizing activity: Insights into limb development via the abnormality preaxial polydactyly

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2007
    Robert E. Hill
    Early in vertebrate limb development, a program initiates that polarizes the limb along the antero-posterior axis. The mesenchyme at the posterior margin is ultimately responsible for the asymmetry due to a region called the zone of polarizing activity (ZPA). The ZPA produces and secretes the molecule SHH, which coordinates the patterning of the resulting digits. Preaxial polydactyly (PPD) is a commonly occurring limb abnormality; investigating the genetic basis of this defect has provided insights into our understanding of digit patterning. PPD disrupts limb asymmetry by producing an ectopic ZPA at the opposite margin of the limb bud. Mutations in the long-range, limb-specific regulatory element of the Shh gene are responsible for the defect. Genetic analysis of this limb abnormality provides an important approach in understanding the mechanisms that control digit patterning. [source]


    Growth and differentiation of the developing limb bud from the perspective of chondrogenesis

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2007
    Hirohito Shimizu
    Limb skeletal elements develop from a cartilage template, which is formed by the process termed chondrogenesis. This process is crucial in determining the shape and size of definitive bones in vertebrates. During chondrogenesis, aggregated mesenchymal cells undergo a highly organized process of proliferation and maturation along with secretion of extracellular matrix followed by programmed cell death and replacement by bone. The molecular mechanisms underlying this sophisticated process have been extensively studied. It has been demonstrated that several transcription factors such as Sox genes and Runx genes are indispensable for the major steps in chondrogenesis. Additionally, a number of signaling molecules including Bmps, Fgfs and Ihh/PTHrP are known to regulate chondrogenesis through highly coordinated interactions. This review is meant to provide an overview of the current knowledge of chondrogenesis with particular emphasis on the cellular and molecular aspects. [source]


    Functional retinoid receptors in budding ascidians

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2000
    Mika Kamimura
    A homolog of retinoid X receptors (RXR), named PmRXR, was cloned from the budding ascidian, Polyandrocarpa misakiensis. Gel-shift assays revealed that PmRXR and a previously identified P. misakiensis retinoic acid receptor (PmRAR) formed a complex to bind vertebrate-type retinoic acid response element (RARE). Transfection assays were carried out using a reporter gene containing a RARE upstream of lacZ. Two chimeric effector genes were constructed by placing PmRXR and PmRAR cDNA fragments (containing the DNA-binding, ligand-binding and ligand-dependent transactivation domains) downstream of the human RXR, and RAR, cDNA (covering the N-terminal coding region), respectively. Each chimeric cDNA was ligated to a notochord-specific enhancer. In case the embryos were transfected with all three transgenes and treated with retinoic acid (RA), the reporter gene was activated in the notochord cells. The result suggests that the PmRXR/PmRAR complex functions as an RA-dependent transcriptional activator. The PmRXR mRNA was detected in a mesenchymal cell type, called glomerulocyte, in the developing Polyandrocarpa bud. As this cell type has been shown to express PmRAR mRNA, it seems possible that the PmRXR/PmRAR complex mediates RA signaling in this cell type to induce the expression of genes involved in the morphogenesis of the developing bud. [source]


    Churchill and Sip1a repress fibroblast growth factor signaling during zebrafish somitogenesis

    DEVELOPMENTAL DYNAMICS, Issue 2 2010
    Fatma O. Kok
    Abstract Cell-type specific regulation of a small number of growth factor signal transduction pathways generates diverse developmental outcomes. The zinc finger protein Churchill (ChCh) is a key effector of fibroblast growth factor (FGF) signaling during gastrulation. ChCh is largely thought to act by inducing expression of the multifunctional Sip1 (Smad Interacting Protein 1). We investigated the function of ChCh and Sip1a during zebrafish somitogenesis. Knockdown of ChCh or Sip1a results in misshapen somites that are short and narrow. As in wild-type embryos, cycling gene expression occurs in the developing somites in ChCh and Sip1a compromised embryos, but expression of her1 and her7 is maintained in formed somites. In addition, tail bud fgf8 expression is expanded anteriorly in these embryos. Finally, we found that blocking FGF8 restores somite morphology in ChCh and Sip1a compromised embryos. These results demonstrate a novel role for ChCh and Sip1a in repression of FGF activity. Developmental Dynamics 239:548,558, 2010. © 2009 Wiley-Liss, Inc. [source]


    Cloning and characterization of voltage-gated calcium channel alpha1 subunits in Xenopus laevis during development

    DEVELOPMENTAL DYNAMICS, Issue 11 2009
    Brittany B. Lewis
    Abstract Voltage-gated calcium channels play a critical role in regulating the Ca2+ activity that mediates many aspects of neural development, including neural induction, neurotransmitter phenotype specification, and neurite outgrowth. Using Xenopus laevis embryos, we describe the spatial and temporal expression patterns during development of the 10 pore-forming alpha1 subunits that define the channels' kinetic properties. In situ hybridization indicates that CaV1.2, CaV2.1, CaV2.2, and CaV3.2 are expressed during neurula stages throughout the neural tube. These, along with CaV1.3 and CaV2.3, beginning at early tail bud stages, and CaV3.1 at late tail bud stages, are detected in complex patterns within the brain and spinal cord through swimming tadpole stages. Additional expression of various alpha1 subunits was observed in the cranial ganglia, retina, olfactory epithelium, pineal gland, and heart. The unique expression patterns for the different alpha1 subunits suggests they are under precise spatial and temporal regulation and are serving specific functions during embryonic development. Developmental Dynamics 238:2891,2902, 2009. © 2009 Wiley-Liss, Inc. [source]


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

    DEVELOPMENTAL DYNAMICS, Issue 3 2009
    Karen M. Downs
    Abstract The whereabouts and properties of the posterior end of the primitive streak have not been identified in any species. In the mouse, the streak's posterior terminus is assumed to be confined to the embryonic compartment, and to give rise to the allantois, which links the embryo to its mother during pregnancy. In this study, we have refined our understanding of the biology of the murine posterior primitive streak and its relation to the allantois. Through a combination of immunostaining and morphology, we demonstrate that the primitive streak spans the posterior extraembryonic and embryonic regions at the onset of the neural plate stage (,7.0 days postcoitum, dpc). Several hours later, the allantoic bud emerges from the extraembryonic component of the primitive streak (XPS). Then, possibly in collaboration with overlying allantois-associated extraembryonic visceral endoderm, the XPS establishes a germinal center within the allantois, named here the Allantoic Core Domain (ACD). Microsurgical removal of the ACD beyond headfold (HF) stages resulted in the formation of allantoic regenerates that lacked the ACD and failed to elongate; nevertheless, vasculogenesis and vascular patterning proceeded. In situ and transplantation fate mapping demonstrated that, from HF stages onward, the ACD's progenitor pool contributed to the allantois exclusive of the proximal flanks. By contrast, the posterior intraembryonic primitive streak (IPS) provided the flanks. Grafting the ACD into TC/TC hosts, whose allantoises are significantly foreshortened, restored allantoic elongation. These results revealed that the ACD is essential for allantoic elongation, but the cues required for vascularization lie outside of it. On the basis of these and previous findings, we conclude that the posterior primitive streak of the mouse conceptus is far more complex than was previously believed. Our results provide new directives for addressing the origin and development of the umbilical cord, and establish a novel paradigm for investigating the fetal/placental relationship. Developmental Dynamics 238:532,553, 2009. © 2009 Wiley-Liss, Inc. [source]


    Definition and spatial annotation of the dynamic secretome during early kidney development

    DEVELOPMENTAL DYNAMICS, Issue 6 2006
    Gemma Martinez
    Abstract The term "secretome" has been defined as a set of secreted proteins (Grimmond et al. [2003] Genome Res 13:1350,1359). The term "secreted protein" encompasses all proteins exported from the cell including growth factors, extracellular proteinases, morphogens, and extracellular matrix molecules. Defining the genes encoding secreted proteins that change in expression during organogenesis, the dynamic secretome, is likely to point to key drivers of morphogenesis. Such secreted proteins are involved in the reciprocal interactions between the ureteric bud (UB) and the metanephric mesenchyme (MM) that occur during organogenesis of the metanephros. Some key metanephric secreted proteins have been identified, but many remain to be determined. In this study, microarray expression profiling of E10.5, E11.5, and E13.5 kidney and consensus bioinformatic analysis were used to define a dynamic secretome of early metanephric development. In situ hybridisation was used to confirm microarray results and clarify spatial expression patterns for these genes. Forty-one secreted factors were dynamically expressed between the E10.5 and E13.5 timeframe profiled, and 25 of these factors had not previously been implicated in kidney development. A text-based anatomical ontology was used to spatially annotate the expression pattern of these genes in cultured metanephric explants. Developmental Dynamics 235:1709,1719, 2006. © 2006 Wiley-Liss, Inc. [source]


    Frontal nasal prominence expression driven by Tcfap2a relies on a conserved binding site for STAT proteins

    DEVELOPMENTAL DYNAMICS, Issue 5 2006
    Amy L. Donner
    Abstract The AP-2 transcription factor family is linked with development of the head and limbs in both vertebrate and invertebrate species. Recent evidence has also implicated this gene family in the evolution of the neural crest in chordates, a critical step that allowed the development and elaboration of the vertebrate craniofacial skeleton. In mice, the inappropriate embryonic expression of one particular AP-2 gene, Tcfap2a, encoding AP-2,, results in multiple developmental abnormalities, including craniofacial and limb defects. Thus, Tcfap2a provides a valuable genetic resource to analyze the regulatory hierarchy responsible for the evolution and development of the face and limbs. Previous studies have identified a 2-kilobase intronic region of both the mouse and human AP-2, locus that directs expression of a linked LacZ transgene to the facial processes and the distal mesenchyme of the limb bud in transgenic mice. Further analysis identified two highly conserved regions of ,200,400 bp within this tissue-specific enhancer. We have now initiated a transgenic and biochemical analysis of the most important of these highly conserved regions. Our analysis indicates that although the sequences regulating face and limb expression have been integrated into a single enhancer, different cis -acting sequences ultimately control these two expression domains. Moreover, these studies demonstrate that a conserved STAT binding site provides a major contribution to the expression of Tcfap2a in the facial prominences. Developmental Dynamics 235:1358,1370, 2006. © 2006 Wiley-Liss, Inc. [source]


    Chick limbs with mouse teeth: An effective in vivo culture system for tooth germ development and analysis

    DEVELOPMENTAL DYNAMICS, Issue 1 2003
    Eiki Koyama
    Abstract Mouse tooth germ development is currently studied by three main approaches: in wild-type and mutant mouse lines, after transplantation of tooth germs to ectopic sites, and in organ culture. The in vivo approaches are the most physiological but do not provide accessibility to tooth germs for further experimental manipulation. Organ cultures, although readily accessible, do not sustain full tooth germ development and are appropriate for short-term analysis. Thus, we sought to establish a new approach that would combine experimental accessibility with sustained development. We implanted fragments of embryonic day 12 mouse embryo first branchial arch containing early bud stage tooth germs into the lateral mesenchyme of day 4,5 chick embryo wing buds in ovo. Eggs were reincubated, and implanted tissues were examined by histochemistry and in situ hybridization over time. The tooth germs underwent seemingly normal growth, differentiation, and morphogenesis. They reached the cap, bell, and crown stages in approximately 3, 6, and 10 days, respectively, mimicking in a striking manner native temporal patterns. To examine mechanisms regulating tooth germ development, we first implanted tooth germ fragments, microinjected them with neutralizing antibodies to the key signaling molecule Sonic hedgehog (Shh), and examined them over time. Tooth germ development was markedly delayed, as revealed by poor morphogenesis and lack of mature ameloblasts and odontoblasts displaying characteristic traits such as an elongated cell shape, nuclear relocalization, and amelogenin gene expression. These phenotypic changes began to be reversed upon further incubation. The data show that the limb bud represents an effective, experimentally accessible as well as economical system for growth and analysis of developing tooth germs. The inhibitory effects of Shh neutralizing antibody treatment are discussed in relation to roles of this signaling pathway proposed by this and other groups previously. © 2002 Wiley-Liss, Inc. [source]


    Opposing effects on TSC-22 expression by BMP and receptor tyrosine kinase signals in the developing feather tract

    DEVELOPMENTAL DYNAMICS, Issue 1 2002
    Cord E. Dohrmann
    Abstract TSC-22 (transforming growth factor-,,stimulated clone 22) belongs to a family of leucine zipper transcription factors that includes sequences from invertebrates and vertebrates. The single Drosophila family member, encoded by the bunched gene, serves to integrate opposing bone morphogenic protein (BMP) and epidermal growth factor (EGF) signals during oogenesis. Similarly, mammalian TSC-22 expression is regulated by several families of secreted signaling molecules in cultured cells. Here, we show that chick TSC-22 is dynamically expressed in the condensing feather bud, as well as in many tissues of the chick embryo. BMP-2/4, previously shown to inhibit bud development, repress TSC-22 expression during feather bud formation in vivo. Noggin, a BMP antagonist, promotes TSC-22 expression. EGF, TGF-,, and fibroblast growth factor all promote both feather bud development and TSC-22 expression; each can promote ectopic feather buds that are regularly spaced between existing feather buds. Thus, TSC-22 is a candidate to integrate small imbalances in receptor tyrosine kinase and BMP signaling during feather tract development to generate stable and reproducible morphogenetic responses. © 2001 Wiley-Liss, Inc. [source]


    The apical ectodermal ridge in the pectoral fin of the Australian Lungfish (Neoceratodus forsteri): keeping the fin to limb transition in the fold

    ACTA ZOOLOGICA, Issue 2009
    Verity S. Hodgkinson
    Abstract The apical ectodermal ridge (AER) in Neoceratodus develops after an initial period of mesenchymal proliferation and outgrowth of the fin bud and persists until chondrogenesis of the stylopod and zeugopod is initiated. At this time, the lateral margins of the AER convert to the fin fold leading to subsequent development of the dermal fin skeleton. Thorogood's (1991) fin fold model predicts that the AER should persist longer in Neoceratodus than it does in actinopterygians because of the comparatively extensive endochondral skeleton in lungfish. While the AER does persist into early chondrogenesis and is extended compared to actinopterygians (lost before fin radial chondrogenesis) it does not persist into further stages of chondrogenesis, providing partial support for Thorogood's model. Fgf8 appears in the lungfish fin epithelium during the initial period of fin outgrowth before a physical AER forms, when Fgf8 is restricted to the AER plus the preaxial and postaxial epithelium immediately adjacent to the AER. Fgf8 is no longer detected after the AER is replaced by a fin fold. Neoceratodus appears to provide a halfway point between ray fins and limbs during very early development as Thorogood proposed, but not precisely for the reasons his model suggests. [source]


    Stem galls affect oak foliage with potential consequences for herbivory

    ECOLOGICAL ENTOMOLOGY, Issue 3 2004
    L. K. Foss
    Abstract., ,1. On two dates, foliar characteristics of pin oak, Quercus palustris, infested with stem galls caused by the horned oak gall, Callirhytis cornigera, were investigated, and the consequences for subsequent herbivory assessed. 2. Second-instar caterpillars of the gypsy moth, Lymantria dispar, preferred foliage from ungalled trees. 3. Ungalled trees broke bud earlier than their galled counterparts. 4. Galled trees produced denser leaves with higher nitrogen and tannin concentrations, but foliar carbohydrates did not differ among galled and ungalled trees. 5. Concentrations of foliar carbohydrates in both galled and ungalled trees increased uniformly between the two assay dates. Nitrogen concentrations were greater in leaves from galled trees, and decreased uniformly in galled and ungalled trees over time. Foliar tannins were also greater in foliage from galled trees early in the season; however, foliar tannins declined seasonally in galled tissue so that by the second assay date there was no difference in tannin concentrations between galled and ungalled foliage. 6. In spite of differences in foliar characteristics, performance of older, fourth instar gypsy moth caterpillars did not differ between galled and ungalled trees. [source]


    Early Distal-less expression in a developing crustacean limb bud becomes restricted to setal-forming cells

    EVOLUTION AND DEVELOPMENT, Issue 1 2008
    Terri A. Williams
    SUMMARY Distal-less (Dll) plays a well-known role in patterning the distal limb in arthropods. However, in some taxa, its expression even during early limb development is not always limited to the distal limb. Here, I trace the expression of Distal-less in a crustacean (Thamnocephalus platyurus) from the early limb bud to later stages of limb development, a period that includes differentiation of juvenile and adult morphology. During early development, I find two distinct types of DLL expression: one correlated with proximal distal leg patterning and the other restricted to setal-forming cells. Later in development, all the DLL expression is restricted to setal-forming cells. Based on the particular cells expressing DLL, I hypothesize an ancestral role for Dll function in the formation accessory cells of sensilla. [source]


    The amphioxus T-box gene, AmphiTbx15/18/22, illuminates the origins of chordate segmentation

    EVOLUTION AND DEVELOPMENT, Issue 2 2006
    Laura Beaster-Jones
    SUMMARY Amphioxus and vertebrates are the only deuterostomes to exhibit unequivocal somitic segmentation. The relative simplicity of the amphioxus genome makes it a favorable organism for elucidating the basic genetic network required for chordate somite development. Here we describe the developmental expression of the somite marker, AmphiTbx15/18/22, which is first expressed at the mid-gastrula stage in dorsolateral mesendoderm. At the early neurula stage, expression is detected in the first three pairs of developing somites. By the mid-neurula stage, expression is downregulated in anterior somites, and only detected in the penultimate somite primordia. In early larvae, the gene is expressed in nascent somites before they pinch off from the posterior archenteron (tail bud). Integrating functional, phylogenetic and expression data from a variety of triploblast organisms, we have reconstructed the evolutionary history of the Tbx15/18/22 subfamily. This analysis suggests that the Tbx15/18/22 gene may have played a role in patterning somites in the last common ancestor of all chordates, a role that was later conserved by its descendents following gene duplications within the vertebrate lineage. Furthermore, the comparison of expression domains within this gene subfamily reveals similarities in the genetic bases of trunk and cranial mesoderm segmentation. This lends support to the hypothesis that the vertebrate head evolved from an ancestor possessing segmented cranial mesoderm. [source]


    Expression of Hoxa-11 and Hoxa-13 in the pectoral fin of a basal ray-finned fish, Polyodon spathula: implications for the origin of tetrapod limbs

    EVOLUTION AND DEVELOPMENT, Issue 3 2005
    Brian D. Metscher
    Summary Paleontological and anatomical evidence suggests that the autopodium (hand or foot) is a novel feature that distinguishes limbs from fins, while the upper and lower limb (stylopod and zeugopod) are homologous to parts of the sarcopterygian paired fins. In tetrapod limb development Hoxa-11 plays a key role in differentiating the lower limb and Hoxa-13 plays a key role in differentiating the autopodium. It is thus important to determine the ancestral functions of these genes in order to understand the developmental genetic changes that led to the origin of the tetrapod autopodium. In particular it is important to understand which features of gene expression are derived in tetrapods and which are ancestral in bony fishes. To address these questions we cloned and sequenced the Hoxa-11 and Hoxa-13 genes from the North American paddlefish, Polyodon spathula, a basal ray-finned fish that has a pectoral fin morphology resembling that of primitive bony fishes ancestral to the tetrapod lineage. Sequence analysis of these genes shows that they are not orthologous to the duplicated zebrafish and fugu genes. This implies that the paddlefish has not duplicated its HoxA cluster, unlike zebrafish and fugu. The expression of Hoxa-11 and Hoxa-13 in the pectoral fins shows two main phases: an early phase in which Hoxa-11 is expressed proximally and Hoxa-13 is expressed distally, and a later phase in which Hoxa-11 and Hoxa-13 broadly overlap in the distal mesenchyme of the fin bud but are absent in the proximal fin bud. Hence the distal polarity of Hoxa-13 expression seen in tetrapods is likely to be an ancestral feature of paired appendage development. The main difference in HoxA gene expression between fin and limb development is that in tetrapods (with the exception of newts) Hoxa-11 expression is suppressed by Hoxa-13 in the distal limb bud mesenchyme. There is, however, a short period of limb bud development where Hoxa-11 and Hoxa-13 overlap similarly to the late expression seen in zebrafish and paddlefish. We conclude that the early expression pattern in tetrapods is similar to that seen in late fin development and that the local exclusion by Hoxa-13 of Hoxa-11 from the distal limb bud is a derived feature of limb developmental regulation. [source]


    Morphology and anatomy of anomalous short shoots in Pinus (Pinaceae) and their evolutionary meaning

    FEDDES REPERTORIUM, Issue 3-4 2010
    Veit Martin Dörken Dr.
    Abstract Recent Pinus -species are evergreen and have a typical long shoot/short shoot differentiation. For angiosperms we could show that this type of shoot differentiation is linked to deciduousness (Dörken & Stützel 2009). Evergreen angiosperms with prominent shoot differentiation are derived from deciduous ancestors. The primitive evergreen condition is however characterized by the absence of a shoot differentiation. Here it is therefore analysed if the shoot differentiation in Pinus could be regarded as a reminder of a deciduous ancestry. In such a context Pinus monophylla would be functionally closest to a primitive evergreen angiosperm and represent a nearly perfect secondary adaptation to the needs of an evergreen species. Morphology and anatomy of aberrant short shoots in Pinus -species have been analysed to test this hypothesis. We suppose that the ancestor of Pinus had several needle leaves inserted spirally on a well developed short shoot axis ending in a terminal bud, as it can be found in Larix today (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Lmx1b -expressing cells in the mouse limb bud define a dorsal mesenchymal lineage compartment

    GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 4 2009
    Qiong Qiu
    Lmx1b-lacZ expression (blue) highlights dorsal-restricted expression in limb bud mesenchyme of the mouse embryo. See the paper by Qiu and Johnson in this issue. [source]


    Identification of evolutionarily conserved regulatory elements in the mouse Fgf8 locus

    GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 1 2006
    Friedrich Beermann
    Abstract The secreted signaling molecule fibroblast growth factor 8 (Fgf8) is an essential component of certain embryonic signaling centers including the mid-hindbrain (isthmic) organizer, the first branchial arch (BA1), and the apical ectodermal ridge (AER). In these signaling centers Fgf8 transcripts are expressed in a dynamic and transient fashion, but the mechanism by which this highly specific expression pattern is established remains largely unknown. We used DNA sequence comparisons coupled to transgenic approaches to obtain insight into the structure and function of regulatory elements in the Fgf8 locus. First, a bacterial artificial chromosome (BAC) containing the mouse Fgf8 gene partially rescues the embryonic lethality of Fgf8- deficient mice and controls Fgf8 -specific gene expression of a coinjected lacZ reporter transgene. Second, sequence comparison of vertebrate Fgf8 loci revealed evolutionarily highly conserved noncoding sequences that were unexpectedly located mainly 3, of the Fgf8 coding region. Third, in transgenic mice some of these elements were sufficient to target expression to the AER, tail bud, and brain, including the isthmic organizer, indicating that they may represent Fgf8 cis-acting elements. Collectively, these data identify novel regulatory elements of the Fgf8 gene sufficient to drive expression to regions of known Fgf8 activity. genesis 44:1,6, 2006. © 2006 Wiley-Liss, Inc. [source]


    DPPH free-radical scavenging ability, total phenolic content, and chemical composition analysis of forty-five kinds of essential oils

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2009
    H.-F. Wang
    J. Cosmet. Sci., 59, 509,522 (November/December 2008) Synopsis Forty-five kinds of commonly used essential oils were employed to investigate the DPPH (1,1-diphenyl2-picrylhydrazyl) radical scavenging ability and total phenolic content of major chemical compositions. The free-radical scavenging ability and total phenolic content of cinnamon leaf and clove bud essential oils are the best among these essential oils. One-half milliliter of cinnamon leaf and clove bud essential oils (10 mg mL EtOH) are shown to be 96.74% and 96.12% of the DPPH (2.5ml, 1.52 × 10 -4 M) free-radical scavenging ability, respectively. Their EC50 (effective concentrations) are 53 and 36 (,g mL -1). One milligram per milliliter of cinnamon leaf, clove bud, and thyme red essential oils were shown to be 420, 480, and 270 (mg g -1 of GAE) of total phenolic content, respectively. Eugenol in cinnamon leaf and clove bud essential oils (82.87% and 82.32%, respectively) were analyzed by GC-MS. It is clear that the amounts of the phenol compounds in essential oils and the DPPH free-radical scavenging ability are in direct proportion. [source]


    Association of the sponge Tethya orphei (Porifera, Demospongiae) with filamentous cyanobacteria

    INVERTEBRATE BIOLOGY, Issue 4 2006
    Elda Gaino
    Abstract. Specimens of the sponge Tethya orphei, collected in February 2005 on the underside of coral stones on Arě Athol (Maldives), have been processed for histological and ultrastructural investigations. The cortical layer of the sponge was found to be permeated by filamentous cyanobacteria, the trichomes of which measured 45,63 ,m on average and were composed of 10,14 cells. The fine organization of the filaments was consistent with their taxonomic identification as Oscillatoria spongeliae. These filaments filled the cortical region of the sponge and penetrated inward into the upper choanosomal region, where they sometimes overlapped the siliceous spicule bundles. A budding specimen of T. orphei showed that the filaments were also present in the single bud protruding from the sponge surface, demonstrating that asexual reproduction can vertically transmit these symbionts from sponge to sponge. The occurrence of filaments in all the specimens studied is consistent with the assumption that filamentous cyanobacteria are not mere intruders but mutualistic symbionts with members of T. orphei. [source]


    The innervation of FGF-induced additional limbs in the chick embryo

    JOURNAL OF ANATOMY, Issue 1 2003
    B. W. Turney
    Abstract Motoneurones that supply the vertebrate limb innervate their muscle targets in a highly reproducible manner. As development proceeds, these limb-specific motoneurones send out axons, which grow towards the developing limb and then congregate at its base to form the plexus. In the plexus, in response to unknown positional cues, these axons rearrange, often changing their original spatial relationships, before sorting out to emerge in the defined nerve trunks that innervate the limb. Several proposals have been put forward to explain how this reproducible innervation pattern is achieved. These include (1) that early differences in the motoneurone identity dictate their future axonal trajectories, (2) that axons actively respond to attractive or repulsive positional cues provided by the limb bud itself, or (3) that motor axons are passively deployed, following pathways of least mechanical resistance. We have addressed the question of the relative roles of motoneurone identity and the signals that the axons encounter on their journey towards the limb bud. Using the developing chick embryo as our experimental model we tested the effect of providing an additional limb target for motor axons leaving the flank level of the spinal cord. To do this we placed FGF-soaked beads in the presumptive flank of 2-day-old chick embryos. This treatment induces an additional limb containing muscles. We investigated whether such additional limbs are innervated and by which neurones. We show that rather than the additional limbs being solely supplied by axons diverted from the two existing limb plexuses, motoneurones that normally supply the flank alter their trajectories to enter the induced limb. Once in the limb, axons respond to positional cues within the bud to generate the stereotypical innervation pattern. Our results show that the tendency of ,flank' motoneurones to innervate flank can be overcome by the presence of an additional limb. [source]