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Sample records for drosophila polar follicle

  1. Salvador-warts-hippo signaling promotes Drosophila posterior follicle cell maturation downstream of notch.

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    Polesello, Cédric; Tapon, Nicolas

    2007-11-06

    The Salvador Warts Hippo (SWH) network limits tissue size in Drosophila and vertebrates [1]. Decreased SWH pathway activity gives rise to excess proliferation and reduced apoptosis. The core of the SWH network is composed of two serine/threonine kinases Hippo (Hpo) and Warts (Wts), the scaffold proteins Salvador (Sav) and Mats, and the transcriptional coactivator Yorkie (Yki) [1]. Two band 4.1 related proteins, Merlin (Mer) and Expanded (Ex), have been proposed to act upstream of Hpo, which in turn activates Wts ([1] for review). Wts phosphorylates and inhibits Yki, repressing the expression of Yki target genes [2-4]. Recently, several planar cell polarity (PCP) genes have been implicated in the SWH network in growth control [5-8]. Here, we show that, during oogenesis, the core components of the SWH network are required in posterior follicle cells (PFCs) competent to receive the Gurken (Grk)/TGFalpha signal emitted by the oocyte to control body axis formation. Our results suggest that the SWH network controls the expression of Hindsight, the downstream effector of Notch, required for follicle cell mitotic cycle-endocycle switch. The PCP members of the SWH network are not involved in this process, indicating that signaling upstream of Hpo varies according to developmental context.

  2. Establishing and maintaining cell polarity with mRNA localization in Drosophila.

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    Barr, Justinn; Yakovlev, Konstantin V; Shidlovskii, Yulii; Schedl, Paul

    2016-03-01

    How cell polarity is established and maintained is an important question in diverse biological contexts. Molecular mechanisms used to localize polarity proteins to distinct domains are likely context-dependent and provide a feedback loop in order to maintain polarity. One such mechanism is the localized translation of mRNAs encoding polarity proteins, which will be the focus of this review and may play a more important role in the establishment and maintenance of polarity than is currently known. Localized translation of mRNAs encoding polarity proteins can be used to establish polarity in response to an external signal, and to maintain polarity by local production of polarity determinants. The importance of this mechanism is illustrated by recent findings, including orb2-dependent localized translation of aPKC mRNA at the apical end of elongating spermatid tails in the Drosophila testis, and the apical localization of stardust A mRNA in Drosophila follicle and embryonic epithelia.

  3. The cadherin Fat2 is required for planar cell polarity in the Drosophila ovary.

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    Viktorinová, Ivana; König, Tina; Schlichting, Karin; Dahmann, Christian

    2009-12-01

    Planar cell polarity is an important characteristic of many epithelia. In the Drosophila wing, eye and abdomen, establishment of planar cell polarity requires the core planar cell polarity genes and two cadherins, Fat and Dachsous. Drosophila Fat2 is a cadherin related to Fat; however, its role during planar cell polarity has not been studied. Here, we have generated mutations in fat2 and show that Fat2 is required for the planar polarity of actin filament orientation at the basal side of ovarian follicle cells. Defects in actin filament orientation correlate with a failure of egg chambers to elongate during oogenesis. Using a functional fosmid-based fat2-GFP transgene, we show that the distribution of Fat2 protein in follicle cells is planar polarized and that Fat2 localizes where basal actin filaments terminate. Mosaic analysis demonstrates that Fat2 acts non-autonomously in follicle cells, indicating that Fat2 is required for the transmission of polarity information. Our results suggest a principal role for Fat-like cadherins during the establishment of planar cell polarity.

  4. Modelling planar cell polarity in Drosophila melanogaster

    OpenAIRE

    2009-01-01

    During development, polarity is a common feature of many cell types. One example is the polarisation of whole fields of epithelial cells within the plane of the epithelium, a phenomenon called planar cell polarity (PCP). It is widespread in nature and plays important roles in development and physiology. Prominent examples include the epithelial cells of external structures of insects like the fruit fly Drosophila melanogaster, polarised tissue morphogenesis in vertebrates and sensory hair cel...

  5. Basolateral junction proteins regulate competition for the follicle stem cell niche in the Drosophila ovary.

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    Kronen, Maria R; Schoenfelder, Kevin P; Klein, Allon M; Nystul, Todd G

    2014-01-01

    Epithelial stem cells are routinely lost or damaged during adult life and must therefore be replaced to maintain homeostasis. Recent studies indicate that stem cell replacement occurs through neutral competition in many types of epithelial tissues, but little is known about the factors that determine competitive outcome. The epithelial follicle stem cells (FSCs) in the Drosophila ovary are regularly lost and replaced during normal homeostasis, and we show that FSC replacement conforms to a model of neutral competition. In addition, we found that FSCs mutant for the basolateral junction genes, lethal giant larvae (lgl) or discs large (dlg), undergo a biased competition for niche occupancy characterized by increased invasion of neighboring FSCs and reduced loss. Interestingly, FSCs mutant for a third basolateral junction gene, scribble (scrib), do not exhibit biased competition, suggesting that Lgl and Dlg regulate niche competition through a Scrib-independent process. Lastly, we found that FSCs have a unique cell polarity characterized by broadly distributed adherens junctions and the lack of a mature apical domain. Collectively, these observations indicate that Lgl and Dlg promote the differentiation of FSC progeny to a state in which they are less prone to invade the neighboring niche. In addition, we demonstrate that the neutral drift model can be adapted to quantify non-neutral behavior of mutant clones.

  6. Basolateral junction proteins regulate competition for the follicle stem cell niche in the Drosophila ovary.

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    Maria R Kronen

    Full Text Available Epithelial stem cells are routinely lost or damaged during adult life and must therefore be replaced to maintain homeostasis. Recent studies indicate that stem cell replacement occurs through neutral competition in many types of epithelial tissues, but little is known about the factors that determine competitive outcome. The epithelial follicle stem cells (FSCs in the Drosophila ovary are regularly lost and replaced during normal homeostasis, and we show that FSC replacement conforms to a model of neutral competition. In addition, we found that FSCs mutant for the basolateral junction genes, lethal giant larvae (lgl or discs large (dlg, undergo a biased competition for niche occupancy characterized by increased invasion of neighboring FSCs and reduced loss. Interestingly, FSCs mutant for a third basolateral junction gene, scribble (scrib, do not exhibit biased competition, suggesting that Lgl and Dlg regulate niche competition through a Scrib-independent process. Lastly, we found that FSCs have a unique cell polarity characterized by broadly distributed adherens junctions and the lack of a mature apical domain. Collectively, these observations indicate that Lgl and Dlg promote the differentiation of FSC progeny to a state in which they are less prone to invade the neighboring niche. In addition, we demonstrate that the neutral drift model can be adapted to quantify non-neutral behavior of mutant clones.

  7. Polarity and intracellular compartmentalization of Drosophila neurons

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    Henner Astra L

    2007-04-01

    Full Text Available Abstract Background Proper neuronal function depends on forming three primary subcellular compartments: axons, dendrites, and soma. Each compartment has a specialized function (the axon to send information, dendrites to receive information, and the soma is where most cellular components are produced. In mammalian neurons, each primary compartment has distinctive molecular and morphological features, as well as smaller domains, such as the axon initial segment, that have more specialized functions. How neuronal subcellular compartments are established and maintained is not well understood. Genetic studies in Drosophila have provided insight into other areas of neurobiology, but it is not known whether flies are a good system in which to study neuronal polarity as a comprehensive analysis of Drosophila neuronal subcellular organization has not been performed. Results Here we use new and previously characterized markers to examine Drosophila neuronal compartments. We find that: axons and dendrites can accumulate different microtubule-binding proteins; protein synthesis machinery is concentrated in the cell body; pre- and post-synaptic sites localize to distinct regions of the neuron; and specializations similar to the initial segment are present. In addition, we track EB1-GFP dynamics and determine microtubules in axons and dendrites have opposite polarity. Conclusion We conclude that Drosophila will be a powerful system to study the establishment and maintenance of neuronal compartments.

  8. Drosophila chem mutations disrupt epithelial polarity in Drosophila embryos

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    José M. Zamudio-Arroyo

    2016-12-01

    Full Text Available Drosophila embryogenesis has proven to be an extremely powerful system for developmental gene discovery and characterization. We isolated five new EMS-induced alleles that do not complement the l(3R5G83 lethal line isolated in the Nüsslein-Volhard and Wieschaus screens. We have named this locus chem. Lethality of the new alleles as homozygous zygotic mutants is not completely penetrant, and they have an extended phenocritical period. Like the original allele, a fraction of mutant embryos die with cuticular defects, notably head involution and dorsal closure defects. Embryonic defects are much more extreme in germline clones, where the majority of mutant embryos die during embryogenesis and do not form cuticle, implying a strong chem maternal contribution. chem mutations genetically interact with mutations in cytoskeletal genes (arm and with mutations in the epithelial polarity genes coracle, crumbs, and yurt. chem mutants dorsal open defects are similar to those present in yurt mutants, and, likewise, they have epithelial polarity defects. chem1 and chem3 mutations suppress yurt3, and chem3 mutants suppress crumbs1 mutations. In contrast, chem1 and coracle2 mutations enhance each other. Compared to controls, in chem mutants in embryonic lateral epithelia Crumbs expression is mislocalized and reduced, Coracle is increased and mislocalized basally at embryonic stages 13–14, then reduced at stage 16. Arm expression has a similar pattern but levels are reduced.

  9. Drosophila Boi limits Hedgehog levels to suppress follicle stem cell proliferation.

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    Hartman, Tiffiney R; Zinshteyn, Daniel; Schofield, Heather K; Nicolas, Emmanuelle; Okada, Ami; O'Reilly, Alana M

    2010-11-29

    Stem cells depend on signals from cells within their microenvironment, or niche, as well as factors secreted by distant cells to regulate their maintenance and function. Here we show that Boi, a Hedgehog (Hh)-binding protein, is a novel suppressor of proliferation of follicle stem cells (FSCs) in the Drosophila ovary. Hh is expressed in apical cells, distant from the FSC niche, and diffuses to reach FSCs, where it promotes FSC proliferation. We show that Boi is expressed in apical cells and exerts its suppressive effect on FSC proliferation by binding to and sequestering Hh on the apical cell surface, thereby inhibiting Hh diffusion. Our studies demonstrate that cells distant from the local niche can regulate stem cell function through ligand sequestration, a mechanism that likely is conserved in other epithelial tissues.

  10. Dystroglycan is required for polarizing the epithelial cells and the oocyte in Drosophila

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    Deng, Wu-Min; Schneider, Martina; Frock, Richard;

    2003-01-01

    The transmembrane protein Dystroglycan is a central element of the dystrophin-associated glycoprotein complex, which is involved in the pathogenesis of many forms of muscular dystrophy. Dystroglycan is a receptor for multiple extracellular matrix (ECM) molecules such as Laminin, agrin and perleca......, possibly by organizing the Laminin ECM. These data suggest that the primary function of Dystroglycan in oogenesis is to organize cellular polarity; and this study sets the stage for analyzing the Dystroglycan complex by using the power of Drosophila molecular genetics......., and plays a role in linking the ECM to the actin cytoskeleton; however, how these interactions are regulated and their basic cellular functions are poorly understood. Using mosaic analysis and RNAi in the model organism Drosophila melanogaster, we show that Dystroglycan is required cell......-autonomously for cellular polarity in two different cell types, the epithelial cells (apicobasal polarity) and the oocyte (anteroposterior polarity). Loss of Dystroglycan function in follicle and disc epithelia results in expansion of apical markers to the basal side of cells and overexpression results in a reduced apical...

  11. Mechanisms of planar cell polarity establishment in Drosophila.

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    Carvajal-Gonzalez, Jose Maria; Mlodzik, Marek

    2014-01-01

    Correct patterning and polarization of epithelial and mesenchymal cells are essential for morphogenesis and function of all organs and organisms. Epithelial cells are generally polarized in two axes: (a) the ubiquitous apical-basal axis and (b) polarity within the plane of the epithelium. The latter is generally referred to as planar cell polarity (PCP) and also is found in several contexts of mesenchymal cell patterning. In Drosophila, all adult structures display PCP features, and two conserved molecular systems (the Fat [Ft]/Dachsous [Ds] system and the Frizzled [Fz]/PCP pathway) that regulate this process have been identified. Although significant progress has been made in dissecting aspects of PCP signaling within cells, much remains to be discovered about the mechanisms of long-range and local PCP cell-cell interactions. Here, we discuss the current models based on Drosophila studies and incorporate recent insights into this long-standing cell and developmental biology problem.

  12. The spatio-temporal domains of Frizzled6 action in planar polarity control of hair follicle orientation.

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    Chang, Hao; Smallwood, Philip M; Williams, John; Nathans, Jeremy

    2016-01-01

    In mammals, hair follicles cover most of the body surface and exhibit precise and stereotyped orientations relative to the body axes. Follicle orientation is controlled by the planar cell polarity (PCP; or, more generally, tissue polarity) system, as determined by the follicle mis-orientation phenotypes observed in mice with PCP gene mutations. The present study uses conditional knockout alleles of the PCP genes Frizzled6 (Fz6), Vangl1, and Vangl2, together with a series of Cre drivers to interrogate the spatio-temporal domains of PCP gene action in the developing mouse epidermis required for follicle orientation. Fz6 is required starting between embryonic day (E)11.5 and E12.5. Eliminating Fz6 in either the anterior or the posterior halves of the embryo or in either the feet or the torso leads to follicle mis-orientation phenotypes that are limited to the territories associated with Fz6 loss, implying either that PCP signaling is required for communicating polarity information on a local but not a global scale, or that there are multiple independent sources of global polarity information. Eliminating Fz6 in most hair follicle cells or in the inter-follicular epidermis at E15.5 suggests that PCP signaling in developing follicles is not required to maintain their orientation. The asymmetric arrangement of Merkel cells around the base of each guard hair follicle dependents on Fz6 expression in the epidermis but not in differentiating Merkel cells. These experiments constrain current models of PCP signaling and the flow of polarity information in mammalian skin.

  13. Polarization of the epithelial layer and apical localization of integrins are required for engulfment of apoptotic cells in the Drosophila ovary

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    Tracy L. Meehan

    2015-12-01

    Full Text Available Inefficient clearance of dead cells or debris by epithelial cells can lead to or exacerbate debilitating conditions such as retinitis pigmentosa, macular degeneration, chronic obstructive pulmonary disease and asthma. Despite the importance of engulfment by epithelial cells, little is known about the molecular changes that are required within these cells. The misregulation of integrins has previously been associated with disease states, suggesting that a better understanding of the regulation of receptor trafficking could be key to treating diseases caused by defects in phagocytosis. Here, we demonstrate that the integrin heterodimer αPS3/βPS becomes apically enriched and is required for engulfment by the epithelial follicle cells of the Drosophila ovary. We found that integrin heterodimer localization and function is largely directed by the α-subunit. Moreover, proper cell polarity promotes asymmetric integrin enrichment, suggesting that αPS3/βPS trafficking occurs in a polarized fashion. We show that several genes previously known for their roles in trafficking and cell migration are also required for engulfment. Moreover, as in mammals, the same α-integrin subunit is required by professional and non-professional phagocytes and migrating cells in Drosophila. Our findings suggest that migrating and engulfing cells use common machinery, and demonstrate a crucial role for integrin function and polarized trafficking of integrin subunits during engulfment. This study also establishes the epithelial follicle cells of the Drosophila ovary as a powerful model for understanding the molecular changes required for engulfment by a polarized epithelium.

  14. Immunohistochemical Analysis of Human Homologue of Drosophila Patched (PTCH) in Dental Follicles of Impacted Third Molars

    OpenAIRE

    de OLIVEIRA, David Moraes; Ferreira da Silveira, Marcia Maria; de Souza Andrade, Emanuel Savio; Veras Sobral, Ana Paula; Saquete Martins-Filho, Paulo Ricardo; SANTOS, Thiago de Santana; Amorim de Oliveira, Patricia Leimig; Peixoto, Aline Carvalho; Santana de Souza Santos, Jadson Alipio; PIVA, MARTA RABELLO

    2012-01-01

    This study investigated the immunodetection of PTCH in epithelial components of dental follicles associated with impacted third molars without radiographic signs of pathosis. One hundred and five specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla's stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferation was determined by using immunohistochemical labeling. Statistical analysis was performed using Fishe...

  15. The transcriptional response to tumorigenic polarity loss in Drosophila.

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    Bunker, Brandon D; Nellimoottil, Tittu T; Boileau, Ryan M; Classen, Anne K; Bilder, David

    2015-02-26

    Loss of polarity correlates with progression of epithelial cancers, but how plasma membrane misorganization drives oncogenic transcriptional events remains unclear. The polarity regulators of the Drosophila Scribble (Scrib) module are potent tumor suppressors and provide a model for mechanistic investigation. RNA profiling of Scrib mutant tumors reveals multiple signatures of neoplasia, including altered metabolism and dedifferentiation. Prominent among these is upregulation of cytokine-like Unpaired (Upd) ligands, which drive tumor overgrowth. We identified a polarity-responsive enhancer in upd3, which is activated in a coincident manner by both JNK-dependent Fos and aPKC-mediated Yki transcription. This enhancer, and Scrib mutant overgrowth in general, are also sensitive to activity of the Polycomb Group (PcG), suggesting that PcG attenuation upon polarity loss potentiates select targets for activation by JNK and Yki. Our results link epithelial organization to signaling and epigenetic regulators that control tissue repair programs, and provide insight into why epithelial polarity is tumor-suppressive.

  16. Order and stochastic dynamics in Drosophila planar cell polarity.

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    Yoram Burak

    2009-12-01

    Full Text Available Cells in the wing blade of Drosophila melanogaster exhibit an in-plane polarization causing distal orientation of hairs. Establishment of the Planar Cell Polarity (PCP involves intercellular interactions as well as a global orienting signal. Many of the genetic and molecular components underlying this process have been experimentally identified and a recently advanced system-level model has suggested that the observed mutant phenotypes can be understood in terms of intercellular interactions involving asymmetric localization of membrane bound proteins. Among key open questions in understanding the emergence of ordered polarization is the effect of stochasticity and the role of the global orienting signal. These issues relate closely to our understanding of ferromagnetism in physical systems. Here we pursue this analogy to understand the emergence of PCP order. To this end we develop a semi-phenomenological representation of the underlying molecular processes and define a "phase diagram" of the model which provides a global view of the dependence of the phenotype on parameters. We show that the dynamics of PCP has two regimes: rapid growth in the amplitude of local polarization followed by a slower process of alignment which progresses from small to large scales. We discuss the response of the tissue to various types of orienting signals and show that global PCP order can be achieved with a weak orienting signal provided that it acts during the early phase of the process. Finally we define and discuss some of the experimental predictions of the model.

  17. Tissue growth and tumorigenesis in Drosophila: cell polarity and the Hippo pathway.

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    Richardson, Helena E; Portela, Marta

    2017-03-28

    Cell polarity regulation is critical for defining membrane domains required for the establishment and maintenance of the apical-basal axis in epithelial cells (apico-basal polarity), asymmetric cell divisions, planar organization of tissues (planar cell polarity), and the formation of the front-rear axis in cell migration (front-rear polarity). In the vinegar fly, Drosophila melanogaster, cell polarity regulators also interact with the Hippo tissue growth control signaling pathway. In this review we survey the recent Drosophila literature linking cell polarity regulators with the Hippo pathway in epithelial tissue growth, neural stem cell asymmetric divisions and in cell migration in physiological and tumorigenic settings.

  18. Localized serine protease activity and the establishment of Drosophila embryonic dorsoventral polarity.

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    Stein, David; Cho, Yong Suk; Stevens, Leslie M

    2013-01-01

    Drosophila embryo dorsoventral polarity is established by a maternally encoded signal transduction pathway in which three sequentially acting serine proteases, Gastrulation Defective, Snake and Easter, generate the ligand that activates the Toll receptor on the ventral side of the embryo. The spatial regulation of this pathway depends upon ventrally restricted expression of the Pipe sulfotransferase in the ovarian follicle during egg formation. Several recent observations have advanced our understanding of the mechanism regulating the spatially restricted activation of Toll. First, several protein components of the vitelline membrane layer of the eggshell have been determined to be targets of Pipe-mediated sulfation. Second, the processing of Easter by Snake has been identified as the first Pipe-dependent, ventrally-restricted processing event in the pathway. Finally, Gastrulation Defective has been shown to undergo Pipe-dependent, ventral localization within the perivitelline space and to facilitate Snake-mediated processing of Easter. Together, these observations suggest that Gastrulation Defective, localized on the interior ventral surface of the eggshell in association with Pipe-sulfated eggshell proteins, recruits and mediates an interaction between Snake and Easter. This event leads to ventrally-restricted processing and activation of Easter and consequently, localized formation of the Toll ligand, and Toll activation.

  19. MicroRNA-Dependent Transcriptional Silencing of Transposable Elements in Drosophila Follicle Cells.

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    Mugat, Bruno; Akkouche, Abdou; Serrano, Vincent; Armenise, Claudia; Li, Blaise; Brun, Christine; Fulga, Tudor A; Van Vactor, David; Pélisson, Alain; Chambeyron, Séverine

    2015-05-01

    RNA interference-related silencing mechanisms concern very diverse and distinct biological processes, from gene regulation (via the microRNA pathway) to defense against molecular parasites (through the small interfering RNA and the Piwi-interacting RNA pathways). Small non-coding RNAs serve as specificity factors that guide effector proteins to ribonucleic acid targets via base-pairing interactions, to achieve transcriptional or post-transcriptional regulation. Because of the small sequence complementarity required for microRNA-dependent post-transcriptional regulation, thousands of microRNA (miRNA) putative targets have been annotated in Drosophila. In Drosophila somatic ovarian cells, genomic parasites, such as transposable elements (TEs), are transcriptionally repressed by chromatin changes induced by Piwi-interacting RNAs (piRNAs) that prevent them from invading the germinal genome. Here we show, for the first time, that a functional miRNA pathway is required for the piRNA-mediated transcriptional silencing of TEs in this tissue. Global miRNA depletion, caused by tissue- and stage-specific knock down of drosha (involved in miRNA biogenesis), AGO1 or gawky (both responsible for miRNA activity), resulted in loss of TE-derived piRNAs and chromatin-mediated transcriptional de-silencing of TEs. This specific TE de-repression was also observed upon individual titration (by expression of the complementary miRNA sponge) of two miRNAs (miR-14 and miR-34) as well as in a miR-14 loss-of-function mutant background. Interestingly, the miRNA defects differentially affected TE- and 3' UTR-derived piRNAs. To our knowledge, this is the first indication of possible differences in the biogenesis or stability of TE- and 3' UTR-derived piRNAs. This work is one of the examples of detectable phenotypes caused by loss of individual miRNAs in Drosophila and the first genetic evidence that miRNAs have a role in the maintenance of genome stability via piRNA-mediated TE repression.

  20. Temporal regulation of planar cell polarity: insights from the Drosophila eye.

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    Schweisguth, François

    2005-05-20

    In this issue of Cell, identify a first regulatory link between planar cell polarity (PCP) signaling and apical-basal polarity. The authors propose that a component of the apical Crumbs complex regulates the phosphorylation of the Frizzled (Fz) PCP receptor, thus modulating PCP in the Drosophila eye.

  1. Infection of the germ line by retroviral particles produced in the follicle cells: a possible mechanism for the mobilization of the gypsy retroelement of Drosophila.

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    Song, S U; Kurkulos, M; Boeke, J D; Corces, V G

    1997-07-01

    The gypsy retroelement of Drosophila moves at high frequency in the germ line of the progeny of females carrying a mutation in the flamenco (flam) gene. This high rate of de novo insertion correlates with elevated accumulation of full-length gypsy RNA in the ovaries of these females, as well as the presence of an env-specific RNA. We have prepared monoclonal antibodies against the gypsy Pol and Env products and found that these proteins are expressed in the ovaries of flam females and processed in the manner characteristic of vertebrate retroviruses. The Pol proteins are expressed in both follicle and nurse cells, but they do not accumulate at detectable levels in the oocyte. The Env proteins are expressed exclusively in the follicle cells starting at stage 9 of oogenesis, where they accumulate in the secretory apparatus of the endoplasmic reticulum. They then migrate to the inner side of the cytoplasmic membrane where they assemble into viral particles. These particles can be observed in the perivitelline space starting at stage 10 by immunoelectron microscopy using anti-Env antibodies. We propose a model to explain flamenco-mediated induction of gypsy mobilization that involves the synthesis of gypsy viral particles in the follicle cells, from where they leave and infect the oocyte, thus explaining gypsy insertion into the germ line of the subsequent generation.

  2. Tsp66E, the Drosophila KAI1 homologue, and Tsp74F function to regulate ovarian follicle cell and wing development by stabilizing integrin localization.

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    Han, Seung Yeop; Lee, Minjung; Hong, Yoon Ki; Hwang, Soojin; Choi, Gahee; Suh, Yoon Seok; Park, Seung Hwan; Lee, Soojin; Lee, Sang-Hee; Chung, Jongkyeong; Baek, Sung Hee; Cho, Kyoung Sang

    2012-11-16

    The metastasis suppressor KAI1/CD82 has been implicated in various cellular processes; however, its function in development is not fully understood. Here, we generated and characterized mutants of Tsp66E and Tsp74F, which are Drosophila homologues of KAI1/CD82 and Tspan11, respectively. These mutants exhibited egg elongation defects along with disturbed integrin localization and actin polarity. Moreover, the defects were enhanced by mutation of inflated, an αPS2 integrin gene. Mutant ovaries had elevated αPS2 integrin levels and reduced endocytic trafficking. These results suggest that Drosophila KAI1/CD82 affects the polarized localization and the level of integrin, which may contribute to epithelial cell polarity.

  3. Cytoskeletal dynamics and cell signaling during planar polarity establishment in the Drosophila embryonic denticle.

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    Price, Meredith H; Roberts, David M; McCartney, Brooke M; Jezuit, Erin; Peifer, Mark

    2006-02-01

    Many epithelial cells are polarized along the plane of the epithelium, a property termed planar cell polarity. The Drosophila wing and eye imaginal discs are the premier models of this process. Many proteins required for polarity establishment and its translation into cytoskeletal polarity were identified from studies of those tissues. More recently, several vertebrate tissues have been shown to exhibit planar cell polarity. Striking similarities and differences have been observed when different tissues exhibiting planar cell polarity are compared. Here we describe a new tissue exhibiting planar cell polarity - the denticles, hair-like projections of the Drosophila embryonic epidermis. We describe in real time the changes in the actin cytoskeleton that underlie denticle development, and compare this with the localization of microtubules, revealing new aspects of cytoskeletal dynamics that may have more general applicability. We present an initial characterization of the localization of several actin regulators during denticle development. We find that several core planar cell polarity proteins are asymmetrically localized during the process. Finally, we define roles for the canonical Wingless and Hedgehog pathways and for core planar cell polarity proteins in denticle polarity.

  4. A role for Drosophila LKB1 in anterior-posterior axis formation and epithelial polarity

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    Martin, Sophie G.; St Johnston, Daniel

    2003-01-01

    The PAR-4 and PAR-1 kinases are necessary for the formation of the anterior-posterior (A-P) axis in Caenorhabditis elegans. PAR-1 is also required for A-P axis determination in Drosophila. Here we show that the Drosophila par-4 homologue, lkb1, is required for the early A-P polarity of the oocyte, and for the repolarization of the oocyte cytoskeleton that defines the embryonic A-P axis. LKB1 is phosphorylated by PAR-1 in vitro, and overexpression of LKB1 partially rescues the par-1 phenotype. These two kinases therefore function in a conserved pathway for axis formation in flies and worms. lkb1 mutant clones also disrupt apical-basal epithelial polarity, suggesting a general role in cell polarization. The human homologue, LKB1, is mutated in Peutz-Jeghers syndrome and is regulated by prenylation and by phosphorylation by protein kinase A. We show that protein kinase A phosphorylates Drosophila LKB1 on a conserved site that is important for its activity. Thus, Drosophila and human LKB1 may be functional homologues, suggesting that loss of cell polarity may contribute to tumour formation in individuals with Peutz-Jeghers syndrome.

  5. Dynamics of cell polarity in tissue morphogenesis: a comparative view from Drosophila and Ciona.

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    Veeman, Michael T; McDonald, Jocelyn A

    2016-01-01

    Tissues in developing embryos exhibit complex and dynamic rearrangements that shape forming organs, limbs, and body axes. Directed migration, mediolateral intercalation, lumen formation, and other rearrangements influence the topology and topography of developing tissues. These collective cell behaviors are distinct phenomena but all involve the fine-grained control of cell polarity. Here we review recent findings in the dynamics of polarized cell behavior in both the Drosophila ovarian border cells and the Ciona notochord. These studies reveal the remarkable reorganization of cell polarity during organ formation and underscore conserved mechanisms of developmental cell polarity including the Par/atypical protein kinase C (aPKC) and planar cell polarity pathways. These two very different model systems demonstrate important commonalities but also key differences in how cell polarity is controlled in tissue morphogenesis. Together, these systems raise important, broader questions on how the developmental control of cell polarity contributes to morphogenesis of diverse tissues across the metazoa.

  6. Role of Securin, Separase and Cohesins in female meiosis and polar body formation in Drosophila.

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    Guo, Zhihao; Batiha, Osamah; Bourouh, Mohammed; Fifield, Eric; Swan, Andrew

    2016-02-01

    Chromosome segregation in meiosis is controlled by a conserved pathway that culminates in Separase-mediated cleavage of the α-kleisin Rec8, leading to dissolution of cohesin rings. Drosophila has no gene encoding Rec8, and the absence of a known Separase target raises the question of whether Separase and its regulator Securin (Pim in Drosophila) are important in Drosophila meiosis. Here, we investigate the role of Securin, Separase and the cohesin complex in female meiosis using fluorescence in situ hybridization against centromeric and arm-specific sequences to monitor cohesion. We show that Securin destruction and Separase activity are required for timely release of arm cohesion in anaphase I and centromere-proximal cohesion in anaphase II. They are also required for release of arm cohesion on polar body chromosomes. Cohesion on polar body chromosomes depends on the cohesin components SMC3 and the mitotic α-kleisin Rad21 (also called Vtd in Drosophila). We provide cytological evidence that SMC3 is required for arm cohesion in female meiosis, whereas Rad21, in agreement with recent findings, is not. We conclude that in Drosophila meiosis, cohesion is regulated by a conserved Securin-Separase pathway that targets a diverged Separase target, possibly within the cohesin complex. © 2016. Published by The Company of Biologists Ltd.

  7. Expression of the Idefix retrotransposon in early follicle cells in the germarium of Drosophila melanogaster is determined by its LTR sequences and a specific genomic context.

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    Tcheressiz, S; Calco, V; Arnaud, F; Arthaud, L; Dastugue, B; Vaury, C

    2002-04-01

    Retrotransposons are transcriptionally activated in different tissues and cell types by a variety of genomic and environmental factors. Transcription of LTR retrotransposons is controlled by cis-acting regulatory sequences in the 5' LTR. Mobilization of two LTR retroelements, Idefix and ZAM, occurs in the unstable RevI line of Drosophila melanogaster, in which their copy numbers are high, while they are low in all other stocks tested. Here we show that both a full-length and a subgenomic Idefix transcript that are necessary for its mobilization are present in the Rev1 line, but not in the other lines. Studies on transgenic strains demonstrate that the 5' LTR of Idefix contains sequences that direct the tissue-specific expression of the retroelement in testes and ovaries of adult flies. In ovaries, expression occurs in the early follicle and in other somatic cells of the germarium, and is strictly associated with the unstable genetic context conferred by the RevI line. Control of tissue-specific Idefix expression by interactions between cis-acting sequences of its LTR and trans-acting genomic factors provides an opportunity to use this retroelement as a tool for the study of the early follicle cell lineage in the germarium.

  8. Spermatid cyst polarization in Drosophila depends upon apkc and the CPEB family translational regulator orb2.

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    Shuwa Xu

    2014-05-01

    Full Text Available Mature Drosophila sperm are highly polarized cells--on one side is a nearly 2 mm long flagellar tail that comprises most of the cell, while on the other is the sperm head, which carries the gamete's genetic information. The polarization of the sperm cells commences after meiosis is complete and the 64-cell spermatid cyst begins the process of differentiation. The spermatid nuclei cluster to one side of the cyst, while the flagellar axonemes grows from the other. The elongating spermatid bundles are also polarized with respect to the main axis of the testis; the sperm heads are always oriented basally, while the growing tails extend apically. This orientation within the testes is important for transferring the mature sperm into the seminal vesicles. We show here that orienting cyst polarization with respect to the main axis of the testis depends upon atypical Protein Kinase C (aPKC, a factor implicated in polarity decisions in many different biological contexts. When apkc activity is compromised in the male germline, the direction of cyst polarization within this organ is randomized. Significantly, the mechanisms used to spatially restrict apkc activity to the apical side of the spermatid cyst are different from the canonical cross-regulatory interactions between this kinase and other cell polarity proteins that normally orchestrate polarization. We show that the asymmetric accumulation of aPKC protein in the cyst depends on an mRNA localization pathway that is regulated by the Drosophila CPEB protein Orb2. orb2 is required to properly localize and activate the translation of apkc mRNAs in polarizing spermatid cysts. We also show that orb2 functions not only in orienting cyst polarization with respect to the apical-basal axis of the testis, but also in the process of polarization itself. One of the orb2 targets in this process is its own mRNA. Moreover, the proper execution of this orb2 autoregulatory pathway depends upon apkc.

  9. Rho1-Wnd signaling regulates loss-of-cell polarity-induced cell invasion in Drosophila.

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    Ma, X; Chen, Y; Zhang, S; Xu, W; Shao, Y; Yang, Y; Li, W; Li, M; Xue, L

    2016-02-18

    Both cell polarity and c-Jun N-terminal kinase (JNK) activity are essential to the maintenance of tissue homeostasis, and disruption of either is commonly seen in cancer progression. Despite the established connection between loss-of-cell polarity and JNK activation, much less is known about the molecular mechanism by which aberrant cell polarity induces JNK-mediated cell migration and tumor invasion. Here we show results from a genetic screen using an in vivo invasion model via knocking down cell polarity gene in Drosophila wing discs, and identify Rho1-Wnd signaling as an important molecular link that mediates loss-of-cell polarity-triggered JNK activation and cell invasion. We show that Wallenda (Wnd), a protein kinase of the mitogen-activated protein kinase kinase kinase family, by forming a complex with the GTPase Rho1, is both necessary and sufficient for Rho1-induced JNK-dependent cell invasion, MMP1 activation and epithelial-mesenchymal transition. Furthermore, Wnd promotes cell proliferation and tissue growth through wingless production when apoptosis is inhibited by p35. Finally, Wnd shows oncogenic cooperation with Ras(V12) to trigger tumor growth in eye discs and causes invasion into the ventral nerve cord. Together, our data not only provides a novel mechanistic insight on how cell polarity loss contributes to cell invasion, but also highlights the value of the Drosophila model system to explore human cancer biology.

  10. Wnt, Hedgehog and junctional Armadillo/beta-catenin establish planar polarity in the Drosophila embryo.

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    Pamela F Colosimo

    Full Text Available To generate specialized structures, cells must obtain positional and directional information. In multi-cellular organisms, cells use the non-canonical Wnt or planar cell polarity (PCP signaling pathway to establish directionality within a cell. In vertebrates, several Wnt molecules have been proposed as permissible polarity signals, but none has been shown to provide a directional cue. While PCP signaling components are conserved from human to fly, no PCP ligands have been reported in Drosophila. Here we report that in the epidermis of the Drosophila embryo two signaling molecules, Hedgehog (Hh and Wingless (Wg or Wnt1, provide directional cues that induce the proper orientation of Actin-rich structures in the larval cuticle. We further find that proper polarity in the late embryo also involves the asymmetric distribution and phosphorylation of Armadillo (Arm or beta-catenin at the membrane and that interference with this Arm phosphorylation leads to polarity defects. Our results suggest new roles for Hh and Wg as instructive polarizing cues that help establish directionality within a cell sheet, and a new polarity-signaling role for the membrane fraction of the oncoprotein Arm.

  11. Regulation of the formin Cappuccino is critical for polarity of Drosophila oocytes

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    Bor, Batbileg; Bois, Justin S.; Quinlan, Margot E.

    2015-01-01

    The Drosophila formin Cappuccino (Capu) creates an actin mesh-like structure that traverses the oocyte during mid-oogenesis. This mesh is thought to prevent premature onset of fast cytoplasmic streaming which normally happens during late-oogenesis. Proper cytoskeletal organization and cytoplasmic streaming are crucial for localization of polarity determinants such as osk, grk, bcd and nanos mRNAs. Capu mutants disrupt these events, leading to female sterility. Capu is regulated by another nuc...

  12. Trafficking through COPII stabilises cell polarity and drives secretion during Drosophila epidermal differentiation.

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    Michaela Norum

    Full Text Available BACKGROUND: The differentiation of an extracellular matrix (ECM at the apical side of epithelial cells implies massive polarised secretion and membrane trafficking. An epithelial cell is hence engaged in coordinating secretion and cell polarity for a correct and efficient ECM formation. PRINCIPAL FINDINGS: We are studying the molecular mechanisms that Drosophila tracheal and epidermal cells deploy to form their specific apical ECM during differentiation. In this work we demonstrate that the two genetically identified factors haunted and ghost are essential for polarity maintenance, membrane topology as well as for secretion of the tracheal luminal matrix and the cuticle. We show that they code for the Drosophila COPII vesicle-coating components Sec23 and Sec24, respectively, that organise vesicle transport from the ER to the Golgi apparatus. CONCLUSION: Taken together, epithelial differentiation during Drosophila embryogenesis is a concerted action of ECM formation, plasma membrane remodelling and maintenance of cell polarity that all three rely mainly, if not absolutely, on the canonical secretory pathway from the ER over the Golgi apparatus to the plasma membrane. Our results indicate that COPII vesicles constitute a central hub for these processes.

  13. Trafficking through COPII Stabilises Cell Polarity and Drives Secretion during Drosophila Epidermal Differentiation

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    Norum, Michaela; Tång, Erika; Chavoshi, Tina; Schwarz, Heinz; Linke, Dirk; Uv, Anne; Moussian, Bernard

    2010-01-01

    Background The differentiation of an extracellular matrix (ECM) at the apical side of epithelial cells implies massive polarised secretion and membrane trafficking. An epithelial cell is hence engaged in coordinating secretion and cell polarity for a correct and efficient ECM formation. Principal Findings We are studying the molecular mechanisms that Drosophila tracheal and epidermal cells deploy to form their specific apical ECM during differentiation. In this work we demonstrate that the two genetically identified factors haunted and ghost are essential for polarity maintenance, membrane topology as well as for secretion of the tracheal luminal matrix and the cuticle. We show that they code for the Drosophila COPII vesicle-coating components Sec23 and Sec24, respectively, that organise vesicle transport from the ER to the Golgi apparatus. Conclusion Taken together, epithelial differentiation during Drosophila embryogenesis is a concerted action of ECM formation, plasma membrane remodelling and maintenance of cell polarity that all three rely mainly, if not absolutely, on the canonical secretory pathway from the ER over the Golgi apparatus to the plasma membrane. Our results indicate that COPII vesicles constitute a central hub for these processes. PMID:20520821

  14. Hexagonal packing of Drosophila wing epithelial cells by the planar cell polarity pathway.

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    Classen, Anne-Kathrin; Anderson, Kurt I; Marois, Eric; Eaton, Suzanne

    2005-12-01

    The mechanisms that order cellular packing geometry are critical for the functioning of many tissues, but they are poorly understood. Here, we investigate this problem in the developing wing of Drosophila. The surface of the wing is decorated by hexagonally packed hairs that are uniformly oriented by the planar cell polarity pathway. They are constructed by a hexagonal array of wing epithelial cells. Wing epithelial cells are irregularly arranged throughout most of development, but they become hexagonally packed shortly before hair formation. During the process, individual cell boundaries grow and shrink, resulting in local neighbor exchanges, and Cadherin is actively endocytosed and recycled through Rab11 endosomes. Hexagonal packing depends on the activity of the planar cell polarity proteins. We propose that these proteins polarize trafficking of Cadherin-containing exocyst vesicles during junction remodeling. This may be a common mechanism for the action of planar cell polarity proteins in diverse systems.

  15. Drosophila Stardust interacts with Crumbs to control polarity of epithelia but not neuroblasts.

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    Hong, Y; Stronach, B; Perrimon, N; Jan, L Y; Jan, Y N

    2001-12-01

    Establishing cellular polarity is critical for tissue organization and function. Initially discovered in the landmark genetic screen for Drosophila developmental mutants, bazooka, crumbs, shotgun and stardust mutants exhibit severe disruption in apicobasal polarity in embryonic epithelia, resulting in multilayered epithelia, tissue disintegration, and defects in cuticle formation. Here we report that stardust encodes single PDZ domain MAGUK (membrane-associated guanylate kinase) proteins that are expressed in all primary embryonic epithelia from the onset of gastrulation. Stardust colocalizes with Crumbs at the apicolateral boundary, although their expression patterns in sensory organs differ. Stardust binds to the carboxy terminus of Crumbs in vitro, and Stardust and Crumbs are mutually dependent in their stability, localization and function in controlling the apicobasal polarity of epithelial cells. However, for the subset of ectodermal cells that delaminate and form neuroblasts, their polarity requires the function of Bazooka, but not of Stardust or Crumbs.

  16. Bazooka/PAR3 is dispensable for polarity in Drosophila follicular epithelial cells.

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    Shahab, Jaffer; Tiwari, Manu D; Honemann-Capito, Mona; Krahn, Michael P; Wodarz, Andreas

    2015-03-13

    Apico-basal polarity is the defining characteristic of epithelial cells. In Drosophila, apical membrane identity is established and regulated through interactions between the highly conserved Par complex (Bazooka/Par3, atypical protein kinase C and Par6), and the Crumbs complex (Crumbs, Stardust and PATJ). It has been proposed that Bazooka operates at the top of a genetic hierarchy in the establishment and maintenance of apico-basal polarity. However, there is still ambiguity over the correct sequence of events and cross-talk with other pathways during this process. In this study, we reassess this issue by comparing the phenotypes of the commonly used baz(4) and baz(815-8) alleles with those of the so far uncharacterized baz(XR11) and baz(EH747) null alleles in different Drosophila epithelia. While all these baz alleles display identical phenotypes during embryonic epithelial development, we observe strong discrepancies in the severity and penetrance of polarity defects in the follicular epithelium: polarity is mostly normal in baz(EH747) and baz(XR11) while baz(4) and baz(815) (-8) show loss of polarity, severe multilayering and loss of epithelial integrity throughout the clones. Further analysis reveals that the chromosomes carrying the baz(4) and baz(815-8) alleles may contain additional mutations that enhance the true baz loss-of-function phenotype in the follicular epithelium. This study clearly shows that Baz is dispensable for the regulation of polarity in the follicular epithelium, and that the requirement for key regulators of cell polarity is highly dependent on developmental context and cell type.

  17. Bazooka/PAR3 is dispensable for polarity in Drosophila follicular epithelial cells

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    Jaffer Shahab

    2015-03-01

    Full Text Available Apico-basal polarity is the defining characteristic of epithelial cells. In Drosophila, apical membrane identity is established and regulated through interactions between the highly conserved Par complex (Bazooka/Par3, atypical protein kinase C and Par6, and the Crumbs complex (Crumbs, Stardust and PATJ. It has been proposed that Bazooka operates at the top of a genetic hierarchy in the establishment and maintenance of apico-basal polarity. However, there is still ambiguity over the correct sequence of events and cross-talk with other pathways during this process. In this study, we reassess this issue by comparing the phenotypes of the commonly used baz4 and baz815-8 alleles with those of the so far uncharacterized bazXR11 and bazEH747 null alleles in different Drosophila epithelia. While all these baz alleles display identical phenotypes during embryonic epithelial development, we observe strong discrepancies in the severity and penetrance of polarity defects in the follicular epithelium: polarity is mostly normal in bazEH747 and bazXR11 while baz4 and baz815-8 show loss of polarity, severe multilayering and loss of epithelial integrity throughout the clones. Further analysis reveals that the chromosomes carrying the baz4 and baz815-8 alleles may contain additional mutations that enhance the true baz loss-of-function phenotype in the follicular epithelium. This study clearly shows that Baz is dispensable for the regulation of polarity in the follicular epithelium, and that the requirement for key regulators of cell polarity is highly dependent on developmental context and cell type.

  18. A Kinome RNAi Screen in Drosophila Identifies Novel Genes Interacting with Lgl, aPKC, and Crb Cell Polarity Genes in Epithelial Tissues

    NARCIS (Netherlands)

    Parsons, Linda M.; Grzeschik, Nicola A; Amaratunga, Kasun; Burke, Peter; Quinn, Leonie M; Richardson, Helena E

    2017-01-01

    In both Drosophila melanogaster and mammalian systems, epithelial structure and underlying cell polarity are essential for proper tissue morphogenesis and organ growth. Cell polarity interfaces with multiple cellular processes that are regulated by the phosphorylation status of large protein

  19. Cloning and expression of Xenopus Prickle, an orthologue of a Drosophila planar cell polarity gene.

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    Wallingford, John B; Goto, Toshiyasu; Keller, Ray; Harland, Richard M

    2002-08-01

    We have cloned Xenopus orthologues of the Drosophila planar cell polarity (PCP) gene Prickle. Xenopus Prickle (XPk) is expressed in tissues at the dorsal midline during gastrulation and early neurulation. XPk is later expressed in a segmental pattern in the presomitic mesoderm and then in recently formed somites. XPk is also expressed in the tailbud, pronephric duct, retina, and the otic vesicle. The complex expression pattern of XPk suggests that PCP signaling is used in a diverse array of developmental processes in vertebrate embryos.

  20. Pak3 regulates apical-basal polarity in migrating border cells during Drosophila oogenesis.

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    Felix, Martina; Chayengia, Mrinal; Ghosh, Ritabrata; Sharma, Aditi; Prasad, Mohit

    2015-11-01

    Group cell migration is a highly coordinated process that is involved in a number of physiological events such as morphogenesis, wound healing and tumor metastasis. Unlike single cells, collectively moving cells are physically attached to each other and retain some degree of apical-basal polarity during the migratory phase. Although much is known about direction sensing, how polarity is regulated in multicellular movement remains unclear. Here we report the role of the protein kinase Pak3 in maintaining apical-basal polarity in migrating border cell clusters during Drosophila oogenesis. Pak3 is enriched in border cells and downregulation of its function impedes border cell movement. Time-lapse imaging suggests that Pak3 affects protrusive behavior of the border cell cluster, specifically regulating the stability and directionality of protrusions. Pak3 functions downstream of guidance receptor signaling to regulate the level and distribution of F-actin in migrating border cells. We also provide evidence that Pak3 genetically interacts with the lateral polarity marker Scribble and that it regulates JNK signaling in the moving border cells. Since Pak3 depletion results in mislocalization of several apical-basal polarity markers and overexpression of Jra rescues the polarity of the Pak3-depleted cluster, we propose that Pak3 functions through JNK signaling to modulate apical-basal polarity of the migrating border cell cluster. We also observe loss of apical-basal polarity in Rac1-depleted border cell clusters, suggesting that guidance receptor signaling functions through Rac GTPase and Pak3 to regulate the overall polarity of the cluster and mediate efficient collective movement of the border cells to the oocyte boundary.

  1. The Hippo pathway polarizes the actin cytoskeleton during collective migration of Drosophila border cells.

    Science.gov (United States)

    Lucas, Eliana P; Khanal, Ichha; Gaspar, Pedro; Fletcher, Georgina C; Polesello, Cedric; Tapon, Nicolas; Thompson, Barry J

    2013-06-10

    Collective migration of Drosophila border cells depends on a dynamic actin cytoskeleton that is highly polarized such that it concentrates around the outer rim of the migrating cluster of cells. How the actin cytoskeleton becomes polarized in these cells to enable collective movement remains unknown. Here we show that the Hippo signaling pathway links determinants of cell polarity to polarization of the actin cytoskeleton in border cells. Upstream Hippo pathway components localize to contacts between border cells inside the cluster and signal through the Hippo and Warts kinases to polarize actin and promote border cell migration. Phosphorylation of the transcriptional coactivator Yorkie (Yki)/YAP by Warts does not mediate the function of this pathway in promoting border cell migration, but rather provides negative feedback to limit the speed of migration. Instead, Warts phosphorylates and inhibits the actin regulator Ena to activate F-actin Capping protein activity on inner membranes and thereby restricts F-actin polymerization mainly to the outer rim of the migrating cluster.

  2. Mathematical modeling of planar cell polarity signaling in the Drosophila melanogaster wing

    Science.gov (United States)

    Amonlirdviman, Keith

    Planar cell polarity (PCP) signaling refers to the coordinated polarization of cells within the plane of various epithelial tissues to generate sub-cellular asymmetry along an axis orthogonal to their apical-basal axes. For example, in the Drosophila wing, PCP is seen in the parallel orientation of hairs that protrude from each of the approximately 30,000 epithelial cells to robustly point toward the wing tip. Through a poorly understood mechanism, cell clones mutant for some PCP signaling components, including some, but not all alleles of the receptor frizzled, cause polarity disruptions of neighboring, wild-type cells, a phenomenon referred to as domineering nonautonomy. Previous models have proposed diffusible factors to explain nonautonomy, but no such factors have yet been found. This dissertation describes the mathematical modeling of PCP in the Drosophila wing, based on a contact dependent signaling hypothesis derived from experimental results. Intuition alone is insufficient to deduce that this hypothesis, which relies on a local feedback loop acting at the cell membrane, underlies the complex patterns observed in large fields of cells containing mutant clones, and others have argued that it cannot account for observed phenotypes. Through reaction-diffusion, partial differential equation modeling and simulation, the feedback loop is shown to fully reproduce PCP phenotypes, including domineering nonautonomy. The sufficiency of this model and the experimental validation of model predictions argue that previously proposed diffusible factors need not be invoked to explain PCP signaling and reveal how specific protein-protein interactions lead to autonomy or domineering nonautonomy. Based on these results, an ordinary differential equation model is derived to study the relationship of the feedback loop with upstream signaling components. The cadherin Fat transduces a cue to the local feedback loop, biasing the polarity direction of each cell toward the wing tip

  3. Dynamics of cell polarity in tissue morphogenesis: a comparative view from Drosophila and Ciona [version 1; referees: 2 approved

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    Michael T. Veeman

    2016-06-01

    Full Text Available Tissues in developing embryos exhibit complex and dynamic rearrangements that shape forming organs, limbs, and body axes. Directed migration, mediolateral intercalation, lumen formation, and other rearrangements influence the topology and topography of developing tissues. These collective cell behaviors are distinct phenomena but all involve the fine-grained control of cell polarity. Here we review recent findings in the dynamics of polarized cell behavior in both the Drosophila ovarian border cells and the Ciona notochord. These studies reveal the remarkable reorganization of cell polarity during organ formation and underscore conserved mechanisms of developmental cell polarity including the Par/atypical protein kinase C (aPKC and planar cell polarity pathways. These two very different model systems demonstrate important commonalities but also key differences in how cell polarity is controlled in tissue morphogenesis. Together, these systems raise important, broader questions on how the developmental control of cell polarity contributes to morphogenesis of diverse tissues across the metazoa.

  4. Regulation of the formin Cappuccino is critical for polarity of Drosophila oocytes.

    Science.gov (United States)

    Bor, Batbileg; Bois, Justin S; Quinlan, Margot E

    2015-01-01

    The Drosophila formin Cappuccino (Capu) creates an actin mesh-like structure that traverses the oocyte during midoogenesis. This mesh is thought to prevent premature onset of fast cytoplasmic streaming which normally happens during late-oogenesis. Proper cytoskeletal organization and cytoplasmic streaming are crucial for localization of polarity determinants such as osk, grk, bcd, and nanos mRNAs. Capu mutants disrupt these events, leading to female sterility. Capu is regulated by another nucleator, Spire, as well as by autoinhibition in vitro. Studies in vivo confirm that Spire modulates Capu's function in oocytes; however, how autoinhibition contributes is still unclear. To study the role of autoinhibition in flies, we expressed a Capu construct that is missing the Capu Inhibitory Domain, CapuΔN. Consistent with a gain of activity due to loss of autoinhibition, the actin mesh was denser in CapuΔN oocytes. Further, cytoplasmic streaming was delayed and fertility levels decreased. Localization of osk mRNA in early stages, and bcd and nanos in late stages, were disrupted in CapuΔN-expressing oocytes. Finally, evidence that these phenotypes were due to a loss of autoinhibition comes from coexpression of the N-terminal half of Capu with CapuΔN, which suppressed the defects in actin, cytoplasmic streaming and fertility. From these results, we conclude that Capu can be autoinhibited during Drosophila oocyte development.

  5. A biomechanical model for cell polarization and intercalation during Drosophila germband extension

    Science.gov (United States)

    Lan, Haihan; Wang, Qiming; Fernandez-Gonzalez, Rodrigo; Feng, James J.

    2015-10-01

    Germband extension during Drosophila development features the merging of cells along the dorsal-ventral (DV) axis and their separation along the anterior-posterior (AP) axis. This intercalation process involves planar cell polarity, anisotropic contractile forces along cell edges, and concerted cell deformation and movement. Although prior experiments have probed each of these factors separately, the connection among them remains unclear. This paper presents a chemo-mechanical model that integrates the three factors into a coherent framework. The model predicts the polarization of Rho-kinase, myosin and Bazooka downstream of an anisotropic Shroom distribution. In particular, myosin accumulates on cell edges along the DV axis, causing them to contract into a vertex. Subsequently, medial myosin in the cells anterior and posterior to the vertex helps to elongate it into a new edge parallel to the body axis. Thus, the tissue extends along the AP axis and narrows in the transverse direction through neighbor exchange. Model predictions of the polarity of the proteins and cell and tissue deformation are in good agreement with experimental observations.

  6. Kermit interacts with Gαo, Vang, and motor proteins in Drosophila planar cell polarity.

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    Chen Lin

    Full Text Available In addition to the ubiquitous apical-basal polarity, epithelial cells are often polarized within the plane of the tissue--the phenomenon known as planar cell polarity (PCP. In Drosophila, manifestations of PCP are visible in the eye, wing, and cuticle. Several components of the PCP signaling have been characterized in flies and vertebrates, including the heterotrimeric Go protein. However, Go signaling partners in PCP remain largely unknown. Using a genetic screen we uncover Kermit, previously implicated in G protein and PCP signaling, as a novel binding partner of Go. Through pull-down and genetic interaction studies, we find that Kermit interacts with Go and another PCP component Vang, known to undergo intracellular relocalization during PCP establishment. We further demonstrate that the activity of Kermit in PCP differentially relies on the motor proteins: the microtubule-based dynein and kinesin motors and the actin-based myosin VI. Our results place Kermit as a potential transducer of Go, linking Vang with motor proteins for its delivery to dedicated cellular compartments during PCP establishment.

  7. Drosophila Stardust is a partner of Crumbs in the control of epithelial cell polarity.

    Science.gov (United States)

    Bachmann, A; Schneider, M; Theilenberg, E; Grawe, F; Knust, E

    2001-12-01

    The polarized architecture of epithelial cells depends on the highly stereotypic distribution of cellular junctions and other membrane-associated protein complexes. In epithelial cells of the Drosophila embryo, three distinct domains subdivide the lateral plasma membrane. The most apical one comprises the subapical complex (SAC). It is followed by the zonula adherens (ZA) and, further basally, by the septate junction. A core component of the SAC is the transmembrane protein Crumbs, the cytoplasmic domain of which recruits the PDZ-protein Discs Lost into the complex. Cells lacking crumbs or the functionally related gene stardust fail to organize a continuous ZA and to maintain cell polarity. Here we show that stardust provides an essential component of the SAC. Stardust proteins colocalize with Crumbs and bind to the carboxy-terminal amino acids of its cytoplasmic tail. We introduce two different Stardust proteins here: one MAGUK protein, characterized by a PDZ domain, an SH3 domain and a guanylate kinase domain; and a second isoform comprising only the guanylate kinase domain. The Stardust proteins represent versatile candidates as structural and possibly regulatory constituents of the SAC, a crucial element in the control of epithelial cell polarity.

  8. Dachsous-Dependent Asymmetric Localization of Spiny-Legs Determines Planar Cell Polarity Orientation in Drosophila

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    Tomonori Ayukawa

    2014-07-01

    Full Text Available In Drosophila, planar cell polarity (PCP molecules such as Dachsous (Ds may function as global directional cues directing the asymmetrical localization of PCP core proteins such as Frizzled (Fz. However, the relationship between Ds asymmetry and Fz localization in the eye is opposite to that in the wing, thereby causing controversy regarding how these two systems are connected. Here, we show that this relationship is determined by the ratio of two Prickle (Pk isoforms, Pk and Spiny-legs (Sple. Pk and Sple form different complexes with distinct subcellular localizations. When the amount of Sple is increased in the wing, Sple induces a reversal of PCP using the Ds-Ft system. A mathematical model demonstrates that Sple is the key regulator connecting Ds and the core proteins. Our model explains the previously noted discrepancies in terms of the differing relative amounts of Sple in the eye and wing.

  9. The Drosophila Cadherin Fat regulates tissue size and planar cell polarity through different domains.

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    Xuesong Zhao

    Full Text Available The Drosophila Cadherin Fat (Ft has been identified as a crucial regulator of tissue size and Planar Cell Polarity (PCP. However, the precise mechanism by which Ft regulates these processes remains unclear. In order to advance our understanding of the action of Ft, we have sought to identify the crucial Ft effector domains. Here we report that a small region of the Ft cytoplasmic domain (H2 region is both necessary and sufficient, when membrane localized, to support viability and prevent tissue overgrowth. Interestingly, the H2 region is dispensable for regulating PCP signaling, whereas the mutant Ft lacking the H2 region is fully capable of directing PCP. This result suggests that Ft's roles in PCP signaling and tissue size control are separable, and each can be carried out independently. Surprisingly, the crucial regions of Ft identified in our structure-function study do not overlap with the previously reported interaction regions with Atrophin, Dco, or Lowfat.

  10. Drosophila Rho-associated kinase (Drok) links Frizzled-mediated planar cell polarity signaling to the actin cytoskeleton.

    Science.gov (United States)

    Winter, C G; Wang, B; Ballew, A; Royou, A; Karess, R; Axelrod, J D; Luo, L

    2001-04-06

    Frizzled (Fz) and Dishevelled (Dsh) are components of an evolutionarily conserved signaling pathway that regulates planar cell polarity. How this signaling pathway directs asymmetric cytoskeletal reorganization and polarized cell morphology remains unknown. Here, we show that Drosophila Rho-associated kinase (Drok) works downstream of Fz/Dsh to mediate a branch of the planar polarity pathway involved in ommatidial rotation in the eye and in restricting actin bundle formation to a single site in developing wing cells. The primary output of Drok signaling is regulating the phosphorylation of nonmuscle myosin regulatory light chain, and hence the activity of myosin II. Drosophila myosin VIIA, the homolog of the human Usher Syndrome 1B gene, also functions in conjunction with this newly defined portion of the Fz/Dsh signaling pathway to regulate the actin cytoskeleton.

  11. Plasticity of both planar cell polarity and cell identity during the development of Drosophila.

    Science.gov (United States)

    Saavedra, Pedro; Vincent, Jean-Paul; Palacios, Isabel M; Lawrence, Peter A; Casal, José

    2014-02-11

    Drosophila has helped us understand the genetic mechanisms of pattern formation. Particularly useful have been those organs in which different cell identities and polarities are displayed cell by cell in the cuticle and epidermis (Lawrence, 1992; Bejsovec and Wieschaus, 1993; Freeman, 1997). Here we use the pattern of larval denticles and muscle attachments and ask how this pattern is maintained and renewed over the larval moult cycles. During larval growth each epidermal cell increases manyfold in size but neither divides nor dies. We follow individuals from moult to moult, tracking marked cells and find that, as cells are repositioned and alter their neighbours, their identities change to compensate and the pattern is conserved. Single cells adopting a new fate may even acquire a new polarity: an identified cell that makes a forward-pointing denticle in the first larval stage may make a backward-pointing denticle in the second and third larval stages. DOI: http://dx.doi.org/10.7554/eLife.01569.001.

  12. Twinstar, the Drosophila homolog of cofilin/ADF, is required for planar cell polarity patterning.

    Science.gov (United States)

    Blair, Adrienne; Tomlinson, Andrew; Pham, Hung; Gunsalus, Kristin C; Goldberg, Michael L; Laski, Frank A

    2006-05-01

    Planar cell polarity (PCP) is a level of tissue organization in which cells adopt a uniform orientation within the plane of an epithelium. The process of tissue polarization is likely to be initiated by an extracellular gradient. Thus, determining how cells decode and convert this graded information into subcellular asymmetries is key to determining how cells direct the reorganization of the cytoskeleton to produce uniformly oriented structures. Twinstar (Tsr), the Drosophila homolog of Cofilin/ADF (actin depolymerization factor), is a component of the cytoskeleton that regulates actin dynamics. We show here that various alleles of tsr produce PCP defects in the wing, eye and several other epithelia. In wings mutant for tsr, Frizzled (Fz) and Flamingo (Fmi) proteins do not properly localize to the proximodistal boundaries of cells. The correct asymmetric localization of these proteins instructs the actin cytoskeleton to produce one actin-rich wing hair at the distal-most vertex of each cell. These results argue that actin remodeling is not only required in the manufacture of wing hairs, but also in the PCP read-out that directs where a wing hair will be secreted.

  13. FoxO regulates microtubule dynamics and polarity to promote dendrite branching in Drosophila sensory neurons.

    Science.gov (United States)

    Sears, James C; Broihier, Heather T

    2016-10-01

    The size and shape of dendrite arbors are defining features of neurons and critical determinants of neuronal function. The molecular mechanisms establishing arborization patterns during development are not well understood, though properly regulated microtubule (MT) dynamics and polarity are essential. We previously found that FoxO regulates axonal MTs, raising the question of whether it also regulates dendritic MTs and morphology. Here we demonstrate that FoxO promotes dendrite branching in all classes of Drosophila dendritic arborization (da) neurons. FoxO is required both for initiating growth of new branches and for maintaining existing branches. To elucidate FoxO function, we characterized MT organization in both foxO null and overexpressing neurons. We find that FoxO directs MT organization and dynamics in dendrites. Moreover, it is both necessary and sufficient for anterograde MT polymerization, which is known to promote dendrite branching. Lastly, FoxO promotes proper larval nociception, indicating a functional consequence of impaired da neuron morphology in foxO mutants. Together, our results indicate that FoxO regulates dendrite structure and function and suggest that FoxO-mediated pathways control MT dynamics and polarity.

  14. The Fz-Dsh Planar Cell Polarity Pathway Induces Oriented Cell Division via Mud/NuMA in Drosophila and Zebrafish

    OpenAIRE

    2010-01-01

    The Frizzled receptor and Dishevelled effector regulate mitotic spindle orientation in both vertebrates and invertebrates, but how Dishevelled orients the mitotic spindle is unknown. Using the Drosophila S2 cell "induced polarity" system, we find that Dishevelled cortical polarity is sufficient to orient the spindle, and that Dishevelled's DEP domain mediates this function. This domain binds a C-terminal domain of Mud (the Drosophila NuMA ortholog), and Mud is required for Dishevelled-mediate...

  15. Drosophila Dachsous and Fat polarize actin-based protrusions over a restricted domain of the embryonic denticle field.

    Science.gov (United States)

    Lawlor, Kynan T; Ly, Daniel C; DiNardo, Stephen

    2013-11-15

    Atypical cadherins Dachsous (Ds) and Fat coordinate the establishment of planar polarity, essential for the patterning of complex tissues and organs. The precise mechanisms by which this system acts, particularly in cases where Ds and Fat act independently of the 'core' frizzled system, are still the subject of investigation. Examining the deployment of the Ds-Fat system in different tissues of the model organism Drosophila, has provided insights into the general mechanisms by which polarity is established and propagated to coordinate outcomes across a field of cells. The Drosophila embryonic epidermis provides a simple model epithelia where the establishment of polarity can be observed from start to finish, and in the absence of proliferation, over a fixed number of cells. Using the asymmetric placement of f-actin during denticle assembly as a read-out of polarity, we examine the requirement for Ds and Fat in establishing polarity across the denticle field. Comparing detailed phenotypic analysis with steady state protein enrichment revealed a spatially restricted requirement for the Ds-Fat system within the posterior denticle field. Ectopic Ds signaling provides evidence for a model whereby Ds acts to asymmetrically enrich Fat in a neighboring cell, in turn polarizing the cell to specify the position of the actin-based protrusions at the cell cortex.

  16. The Drosophila planar polarity gene multiple wing hairs directly regulates the actin cytoskeleton.

    Science.gov (United States)

    Lu, Qiuheng; Schafer, Dorothy A; Adler, Paul N

    2015-07-15

    The evolutionarily conserved frizzled/starry night (fz/stan) pathway regulates planar cell polarity (PCP) in vertebrates and invertebrates. This pathway has been extensively studied in the Drosophila wing, where it is manifested by an array of distally pointing cuticular hairs. Using in vivo imaging we found that, early in hair growth, cells have multiple actin bundles and hairs that subsequently fuse into a single growing hair. The downstream PCP gene multiple wing hairs (mwh) plays a key role in this process and acts to antagonize the actin cytoskeleton. In mwh mutants hair initiation is not limited to a small region at the distal edge of pupal wing cells as in wild type, resulting in multiple hairs with aberrant polarity. Extra actin bundles/hairs are formed and do not completely fuse, in contrast to wild type. As development proceeded additional hairs continued to form, further increasing hair number. We identified a fragment of Mwh with in vivo rescue activity and that bound and bundled F-actin filaments and inhibited actin polymerization in in vitro actin assays. The loss of these activities can explain the mwh mutant phenotype. Our data suggest a model whereby, prior to hair initiation, proximally localized Mwh inhibits actin polymerization resulting in polarized activation of the cytoskeleton and hair formation on the distal side of wing cells. During hair growth Mwh is found in growing hairs, where we suggest it functions to promote the fusion of actin bundles and inhibit the formation of additional actin bundles that could lead to extra hairs.

  17. Study of bantam miRNA expression in brain tumour resulted due to loss of polarity modules in Drosophila melanogaster

    Indian Academy of Sciences (India)

    ANIMESH BANERJEE; JAGAT K. ROY

    2017-06-01

    Disturbance of delicate concordance between stem cell proliferation, specification and differentiation during brain development leads to several neural disorders including tumours. Accumulating evidences have demonstratedinvolvement of short noncoding microRNAs (miRNAs) in governing several biological as well as pathological processes, including tumourigenesis across various species. Drosophila bantam miRNA, known to regulate critical physiological functions is reported to have elevated expression in ovarian tumour. Here, we provide an update on the expression of bantam miRNA in Drosophila brain tumour background resulting due to loss of well characterized polarity proteins, Brat, Lgl and Scrib. Since, both miRNA TaqMan assay and bantam sensor assay showed elevated expression of bantam in brain tumour background, it clearly reflects presence of an antagonistic relationship between polarity proteins and bantam miRNA indicating of its involvement in tumour progression.

  18. The balance between the novel protein target of wingless and the Drosophila Rho-associated kinase pathway regulates planar cell polarity in the Drosophila wing.

    Science.gov (United States)

    Chung, Seyeon; Kim, Sangjoon; Yoon, Jeongsook; Adler, Paul N; Yim, Jeongbin

    2007-06-01

    Planar cell polarity (PCP) signaling is mediated by the serpentine receptor Frizzled (Fz) and transduced by Dishevelled (Dsh). Wingless (Wg) signaling utilizes Drosophila Frizzled 2 (DFz2) as a receptor and also requires Dsh for transducing signals to regulate cell proliferation and differentiation in many developmental contexts. Distinct pathways are activated downstream of Dsh in Wg- and Fz-signaling pathways. Recently, a number of genes, which have essential roles as downstream components of PCP signaling, have been identified in Drosophila. They include the small GTPase RhoA/Rho1, its downstream effector Drosophila rho-associated kinase (Drok), and a number of genes such as inturned (in) and fuzzy (fy), whose biochemical functions are unclear. RhoA and Drok provide a link from Fz/Dsh signaling to the modulation of actin cytoskeleton. Here we report the identification of the novel gene target of wingless (tow) by enhancer trap screening. tow expression is negatively regulated by Wg signaling in wing imaginal discs, and the balance between tow and the Drok pathway regulates wing-hair morphogenesis. A loss-of-function mutation in tow does not result in a distinct phenotype. Genetic interaction and gain-of-function studies provide evidence that Tow acts downstream of Fz/Dsh and plays a role in restricting the number of hairs that wing cells form.

  19. The core planar cell polarity gene prickle interacts with flamingo to promote sensory axon advance in the Drosophila embryo.

    Science.gov (United States)

    Mrkusich, Eli M; Flanagan, Dustin J; Whitington, Paul M

    2011-10-01

    The atypical cadherin Drosophila protein Flamingo and its vertebrate homologues play widespread roles in the regulation of both dendrite and axon growth. However, little is understood about the molecular mechanisms that underpin these functions. Whereas flamingo interacts with a well-defined group of genes in regulating planar cell polarity, previous studies have uncovered little evidence that the other core planar cell polarity genes are involved in regulation of neurite growth. We present data in this study showing that the planar cell polarity gene prickle interacts with flamingo in regulating sensory axon advance at a key choice point - the transition between the peripheral nervous system and the central nervous system. The cytoplasmic tail of the Flamingo protein is not required for this interaction. Overexpression of another core planar cell polarity gene dishevelled produces a similar phenotype to prickle mutants, suggesting that this gene may also play a role in regulation of sensory axon advance.

  20. Genetic evidence that Drosophila frizzled controls planar cell polarity and Armadillo signaling by a common mechanism.

    Science.gov (United States)

    Povelones, Michael; Howes, Rob; Fish, Matt; Nusse, Roel

    2005-12-01

    The frizzled (fz) gene in Drosophila controls two distinct signaling pathways: it directs the planar cell polarization (PCP) of epithelia and it regulates cell fate decisions through Armadillo (Arm) by acting as a receptor for the Wnt protein Wingless (Wg). With the exception of dishevelled (dsh), the genes functioning in these two pathways are distinct. We have taken a genetic approach, based on a series of new and existing fz alleles, for identifying individual amino acids required for PCP or Arm signaling. For each allele, we have attempted to quantify the strength of signaling by phenotypic measurements. For PCP signaling, the defect was measured by counting the number of cells secreting multiple hairs in the wing. We then examined each allele for its ability to participate in Arm signaling by the rescue of fz mutant embryos with maternally provided fz function. For both PCP and Arm signaling we observed a broad range of phenotypes, but for every allele there is a strong correlation between its phenotypic strength in each pathway. Therefore, even though the PCP and Arm signaling pathways are genetically distinct, the set of signaling-defective fz alleles affected both pathways to a similar extent. This suggests that fz controls these two different signaling activities by a common mechanism. In addition, this screen yielded a set of missense mutations that identify amino acids specifically required for fz signaling function.

  1. Perlecan and Dystroglycan act at the basal side of the Drosophila follicular epithelium to maintain epithelial organization

    DEFF Research Database (Denmark)

    Schneider, Martina; Khalil, Ashraf A; Poulton, John

    2006-01-01

    , but the mechanisms of this polarizing activity and upstream/downstream components are largely unknown. Using the Drosophila follicle-cell epithelium (FCE) as a model system, we show that the ECM molecule Perlecan (Pcan) is required for maintenance of epithelial-cell polarity. Follicle cells that lack Pcan develop...... to be essential for Dg ligand binding activity. Finally, we describe two examples of how Dg promotes the differentiation of the basal membrane domain: (1) by recruiting/anchoring the cytoplasmic protein Dystrophin; and (2) by excluding the transmembrane protein Neurexin. We suggest that the interaction of Pcan...

  2. The Drosophila GIPC homologue can modulate myosin based processes and planar cell polarity but is not essential for development.

    Directory of Open Access Journals (Sweden)

    Alexandre Djiane

    Full Text Available Epithelia often show, in addition to the ubiquitous apico-basal (A/B axis, a polarization within the plane of the epithelium, perpendicular to the A/B axis. Such planar cell polarity (PCP is for example evident in the regular arrangement of the stereocilia in the cochlea of the mammalian inner ear or in (almost all Drosophila adult external structures. GIPCs (GAIP interacting protein, C terminus were first identified in mammals and bind to the Galphai GTPase activating protein RGS-GAIP. They have been proposed to act in a G-protein coupled complex controlling vesicular trafficking. Although GIPCs have been found to bind to numerous proteins including Frizzled receptors, which participate in PCP establishment, there is little in vivo evidence for the functional role(s of GIPCs. We show here that overexpressed Drosophila dGIPC alters PCP generation in the wing. We were however unable to find any binding between dGIPC and the Drosophila receptors Fz1 and Fz2. The effect of overexpressed dGIPC is likely due to an effect on the actin cytoskeleton via myosins, since it is almost entirely suppressed by removing a genomic copy of the Myosin VI/jaguar gene. Surprisingly, although dGIPC can interfere with PCP generation and myosin based processes, the complete loss-of-function of dGIPC gives viable adults with no PCP or other detectable defects arguing for a non-essential role of dGIPC in viability and normal Drosophila development.

  3. Activation of JNK signaling links IgI mutations to disruption of the cell polarity and epithelial organization in Drosophila imaginal discs

    Institute of Scientific and Technical Information of China (English)

    Ming-wei Zhu; Tian-chi Xin; Shun-yan Weng; Yin Gao; Ying-jie Zhang; Qi Li; Ming-fa Li

    2010-01-01

    Dear Editor, Identification of Drosophila melanogaster as a model organism for cancer research has facilitated the exploration of human tumor malignancy. In Drosophila, lossof-function mutations in the neoplastic tumor suppressor genes (nTSGs) lethal(2)giant larvae (lgl), discs large (dlg) or scribble (scrib) cause a malignant tumor-like phenotype characteristic of disrupted cell polarity and overgrowth in epithelial tissues such as imaginal discs [1].

  4. Interactions between Fat and Dachsous and the regulation of planar cell polarity in the Drosophila wing.

    Science.gov (United States)

    Matakatsu, Hitoshi; Blair, Seth S

    2004-08-01

    It was recently suggested that a proximal to distal gradient of the protocadherin Dachsous (Ds) acts as a cue for planar cell polarity (PCP) in the Drosophila wing, orienting cell-cell interactions by inhibiting the activity of the protocadherin Fat (Ft). This Ft-Ds signaling model is based on mutant loss-of-function phenotypes, leaving open the question of whether Ds is instructive or permissive for PCP. We developed tools for misexpressing ds and ft in vitro and in vivo, and have used these to test aspects of the model. First, this model predicts that Ds and Ft can bind. We show that Ft and Ds mediate preferentially heterophilic cell adhesion in vitro, and that each stabilizes the other on the cell surface. Second, the model predicts that artificial gradients of Ds are sufficient to reorient PCP in the wing; our data confirms this prediction. Finally, loss-of-function phenotypes suggest that the gradient of ds expression is necessary for correct PCP throughout the wing. Surprisingly, this is not the case. Uniform levels of ds drive normally oriented PCP and, in all but the most proximal regions of the wing, uniform ds rescues the ds mutant PCP phenotype. Nor are distal PCP defects increased by the loss of spatial information from the distally expressed four-jointed (fj) gene, which encodes putative modulator of Ft-Ds signaling. Thus, while our results support the existence of Ft-Ds binding and show that it is sufficient to alter PCP, ds expression is permissive or redundant with other PCP cues in much of the wing.

  5. The abdomen of Drosophila: does planar cell polarity orient the neurons of mechanosensory bristles?

    Directory of Open Access Journals (Sweden)

    Fabre Caroline CG

    2008-04-01

    Full Text Available Abstract Background In the adult abdomen of Drosophila, the shafts of mechanosensory bristles point consistently from anterior to posterior. This is an example of planar cell polarity (PCP; some genes responsible for PCP have been identified. Each adult bristle is made by a clone of four cells, including the neuron that innervates it, but little is known as to how far the formation or positions of these cells depends on PCP. The neurons include a single dendrite and an axon; it is not known whether the orientation of these processes is influenced by PCP. Results We describe the development of the abdominal mechanosensory bristles in detail. The division of the precursor cell gives two daughters, one (pIIa divides to give rise to the bristle shaft and socket cell and the other (pIIb generates the neuron, the sheath and the fifth cell. Although the bristles and their associated shaft and socket cells are consistently oriented, the positioning and behaviour of the neuron, the sheath and the fifth cell, as well as the orientation of the axons and the dendritic paths, depend on location. For example, in the anterior zone of the segment, the axons grow posteriorly, while in the posterior zone, they grow anteriorly. Manipulating the PCP genes can reverse bristle orientation, change the path taken by the dendrite and the position of the cell body of the neuron. However, the paths taken by the axon are not affected. Conclusion PCP genes, such as starry night and dachsous orient the bristles and position the neuronal cell body and affect the shape of the dendrites. However, these PCP genes do not appear to change the paths followed by the sensory axons, which must, therefore, be polarised by other factors.

  6. Walking Drosophila align with the e-vector of linearly polarized light through directed modulation of angular acceleration.

    Science.gov (United States)

    Velez, Mariel M; Wernet, Mathias F; Clark, Damon A; Clandinin, Thomas R

    2014-06-01

    Understanding the mechanisms that link sensory stimuli to animal behavior is a central challenge in neuroscience. The quantitative description of behavioral responses to defined stimuli has led to a rich understanding of different behavioral strategies in many species. One important navigational cue perceived by many vertebrates and insects is the e-vector orientation of linearly polarized light. Drosophila manifests an innate orientation response to this cue ('polarotaxis'), aligning its body axis with the e-vector field. We have established a population-based behavioral paradigm for the genetic dissection of neural circuits guiding polarotaxis to both celestial as well as reflected polarized stimuli. However, the behavioral mechanisms by which flies align with a linearly polarized stimulus remain unknown. Here, we present a detailed quantitative description of Drosophila polarotaxis, systematically measuring behavioral parameters that are modulated by the stimulus. We show that angular acceleration is modulated during alignment, and this single parameter may be sufficient for alignment. Furthermore, using monocular deprivation, we show that each eye is necessary for modulating turns in the ipsilateral direction. This analysis lays the foundation for understanding how neural circuits guide these important visual behaviors.

  7. Isoform-specific interaction of Flamingo/Starry Night with excess Bazooka affects planar cell polarity in the Drosophila wing.

    Science.gov (United States)

    Wasserscheid, Isabel; Thomas, Ulrich; Knust, Elisabeth

    2007-04-01

    Epithelia display two types of polarity, apical-basal and planar cell polarity (PCP), and both are crucial for morphogenesis and organogenesis. PCP signaling pathways comprise transmembrane proteins, such as Flamingo/Starry Night, and cytoplasmic, membrane-associated proteins such as Dishevelled. During establishment of PCP in the Drosophila wing, PCP proteins accumulate apically in distinct "cortical domains" on proximal and distal plasma membranes. This finding suggests that their localized function depends on prior definition of apicobasal polarity. Here, we show that overexpression of Bazooka, a PDZ-domain protein essential for apicobasal polarity in the embryo, perturbs development of PCP, but has no effect on apicobasal polarity. The PCP phenotype is associated with a failure to restrict Flamingo/Starry night to the proximal and distal plasma membranes of the wing epithelium. We further demonstrate that flamingo expresses two differentially spliced RNAs in wing imaginal discs, which encode two isoforms of the atypical cadherin Flamingo. The predominant Starry night-type form contains a PDZ-binding motif, which mediates binding to Bazooka in vitro. Pull-down assays support the occurrence of such an interaction in wing imaginal discs. The results suggest that interaction between the apicobasal and planar cell polarity systems has to be tightly coordinated to ensure proper morphogenesis of the wing disc epithelium.

  8. Planar cell polarity in the Drosophila eye is directed by graded Four-jointed and Dachsous expression.

    Science.gov (United States)

    Simon, Michael A

    2004-12-01

    Planar cell polarity (PCP) occurs when the cells of an epithelium are polarized along a common axis lying in the epithelial plane. During the development of PCP, cells respond to long-range directional signals that specify the axis of polarization. In previous work on the Drosophila eye, we proposed that a crucial step in this process is the establishment of graded expression of the cadherin Dachsous (Ds) and the Golgi-associated protein Four-jointed (Fj). These gradients were proposed to specify the direction of polarization by producing an activity gradient of the cadherin Fat within each ommatidium. In this report, I test and confirm the key predictions of this model by altering the patterns of Fj, Ds and Fat expression. It is shown that the gradients of Fj and Ds expression provide partially redundant positional information essential for specifying the polarization axis. I further demonstrate that reversing the Fj and Ds gradients can lead to reversal of the axis of polarization. Finally, it is shown that an ectopic gradient of Fat expression can re-orient PCP in the eye. In contrast to the eye, the endogenous gradients of Fj and Ds expression do not play a major role in directing PCP in the wing. Thus, this study reveals that the two tissues use different strategies to orient their PCP.

  9. Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear.

    Science.gov (United States)

    Jones, Chonnettia; Qian, Dong; Kim, Sun Myoung; Li, Shuangding; Ren, Dongdong; Knapp, Lindsey; Sprinzak, David; Avraham, Karen B; Matsuzaki, Fumio; Chi, Fanglu; Chen, Ping

    2014-11-01

    The coordinated polarization of neighboring cells within the plane of the tissue, known as planar cell polarity (PCP), is a recurring theme in biology. It is required for numerous developmental processes for the form and function of many tissues and organs across species. The genetic pathway regulating PCP was first discovered in Drosophila, and an analogous but distinct pathway is emerging in vertebrates. It consists of membrane protein complexes known as core PCP proteins that are conserved across species. Here we report that the over-expression of the murine Ankrd6 (mAnkrd6) gene that shares homology with Drosophila core PCP gene diego causes a typical PCP phenotype in Drosophila, and mAnkrd6 can rescue the loss of function of diego in Drosophila. In mice, mAnkrd6 protein is asymmetrically localized in cells of the inner ear sensory organs, characteristic of components of conserved core PCP complexes. The loss of mAnkrd6 causes PCP defects in the inner ear sensory organs. Moreover, canonical Wnt signaling is significantly increased in mouse embryonic fibroblasts from mAnkrd6 knockout mice in comparison to wild type controls. Together, these results indicated that mAnkrd6 is a functional homolog of the Drosophila diego gene for mammalian PCP regulation and act to suppress canonical Wnt signaling.

  10. A Novel Frizzled-Based Screening Tool Identifies Genetic Modifiers of Planar Cell Polarity in Drosophila Wings

    Directory of Open Access Journals (Sweden)

    Jose Maria Carvajal-Gonzalez

    2016-12-01

    Full Text Available Most mutant alleles in the Fz-PCP pathway genes were discovered in classic Drosophila screens looking for recessive loss-of-function (LOF mutations. Nonetheless, although Fz-PCP signaling is sensitive to increased doses of PCP gene products, not many screens have been performed in the wing under genetically engineered Fz overexpression conditions, mostly because the Fz phenotypes were strong and/or not easy to score and quantify. Here, we present a screen based on an unexpected mild Frizzled gain-of-function (GOF phenotype. The leakiness of a chimeric Frizzled protein designed to be accumulated in the endoplasmic reticulum (ER generated a reproducible Frizzled GOF phenotype in Drosophila wings. Using this genotype, we first screened a genome-wide collection of large deficiencies and found 16 strongly interacting genomic regions. Next, we narrowed down seven of those regions to finally test 116 candidate genes. We were, thus, able to identify eight new loci with a potential function in the PCP context. We further analyzed and confirmed krasavietz and its interactor short-stop as new genes acting during planar cell polarity establishment with a function related to actin and microtubule dynamics.

  11. The hippo pathway promotes Notch signaling in regulation of cell differentiation, proliferation, and oocyte polarity.

    Directory of Open Access Journals (Sweden)

    Jianzhong Yu

    Full Text Available Specification of the anterior-posterior axis in Drosophila oocytes requires proper communication between the germ-line cells and the somatically derived follicular epithelial cells. Multiple signaling pathways, including Notch, contribute to oocyte polarity formation by controlling the temporal and spatial pattern of follicle cell differentiation and proliferation. Here we show that the newly identified Hippo tumor-suppressor pathway plays a crucial role in the posterior follicle cells in the regulation of oocyte polarity. Disruption of the Hippo pathway, including major components Hippo, Salvador, and Warts, results in aberrant follicle-cell differentiation and proliferation and dramatic disruption of the oocyte anterior-posterior axis. These phenotypes are related to defective Notch signaling in follicle cells, because misexpression of a constitutively active form of Notch alleviates the oocyte polarity defects. We also find that follicle cells defective in Hippo signaling accumulate the Notch receptor and display defects in endocytosis markers. Our findings suggest that the interaction between Hippo and classic developmental pathways such as Notch is critical to spatial and temporal regulation of differentiation and proliferation and is essential for development of the body axes in Drosophila.

  12. The planar cell polarity protein Strabismus promotes Pins anterior localization during asymmetric division of sensory organ precursor cells in Drosophila.

    Science.gov (United States)

    Bellaïche, Yohanns; Beaudoin-Massiani, Olivia; Stuttem, Isabella; Schweisguth, François

    2004-01-01

    Cell fate diversity is generated in part by the unequal segregation of cell-fate determinants during asymmetric cell division. In the Drosophila bristle lineage, the sensory organ precursor (pI) cell is polarized along the anteroposterior (AP) axis by Frizzled (Fz) receptor signaling. We show here that Fz localizes at the posterior apical cortex of the pI cell prior to mitosis, whereas Strabismus (Stbm) and Prickle (Pk), which are also required for AP polarization of the pI cell, co-localize at the anterior apical cortex. Thus, asymmetric localization of Fz, Stbm and Pk define two opposite cortical domains prior to mitosis of the pI cell. At mitosis, Stbm forms an anterior crescent that overlaps with the distribution of Partner of Inscuteable (Pins) and Discs-large (Dlg), two components of the anterior Dlg-Pins-Galphai complex that regulates the localization of cell-fate determinants. At prophase, Stbm promotes the anterior localization of Pins. By contrast, Dishevelled (Dsh) acts antagonistically to Stbm by excluding Pins from the posterior cortex. We propose that the Stbm-dependent recruitment of Pins at the anterior cortex of the pI cell is a novel read-out of planar cell polarity.

  13. Maternal control of the Drosophila dorsal-ventral body axis.

    Science.gov (United States)

    Stein, David S; Stevens, Leslie M

    2014-01-01

    The pathway that generates the dorsal-ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. For further resources related to this article, please visit the WIREs website. The authors have declared no conflicts of interest for this article. © 2014 Wiley Periodicals, Inc.

  14. Maternal control of the Drosophila dorsal–ventral body axis

    Science.gov (United States)

    Stein, David S.; Stevens, Leslie M.

    2016-01-01

    The pathway that generates the dorsal–ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. PMID:25124754

  15. Differences in neural circuitry guiding behavioral responses to polarized light presented to either the dorsal or ventral retina in Drosophila.

    Science.gov (United States)

    Velez, Mariel M; Gohl, Daryl; Clandinin, Thomas R; Wernet, Mathias F

    2014-01-01

    Linearly polarized light (POL) serves as an important cue for many animals, providing navigational information, as well as directing them toward food sources and reproduction sites. Many insects detect the celestial polarization pattern, or the linearly polarized reflections off of surfaces, such as water. Much progress has been made toward characterizing both retinal detectors and downstream circuit elements responsible for celestial POL vision in different insect species, yet much less is known about the neural basis of how polarized reflections are detected. We previously established a novel, fully automated behavioral assay for studying the spontaneous orientation response of Drosophila melanogaster populations to POL stimuli presented to either the dorsal, or the ventral halves of the retina. We identified separate retinal detectors mediating these responses: the 'Dorsal Rim Area' (DRA), which had long been implicated in celestial POL vision, as well as a previously uncharacterized 'ventral polarization area' (VPA). In this study, we investigate whether DRA and VPA use the same or different downstream circuitry, for mediating spontaneous behavioral responses. We use homozygous mutants, or molecular genetic circuit-breaking tools (silencing, as well as rescue of synaptic activity), in combination with our behavioral paradigm. We show that responses to dorsal versus ventral stimulation involve previously characterized optic lobe neurons, like lamina monopolar cell L2 and medulla cell types Dm8/Tm5c. However, using different experimental conditions, we show that important differences exist between the requirement of these cell types downstream of DRA versus VPA. Therefore, while the neural circuits underlying behavioral responses to celestial and reflected POL cues share important building blocks, these elements play different functional roles within the network.

  16. Avalanches, branching ratios, and clustering of attractors in random Boolean networks and in the segment polarity network of Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Berdahl, Andrew; Shreim, Amer; Sood, Vishal; Davidsen, Joern; Paczuski, Maya [Complexity Science Group, Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)], E-mail: aberdahl@phas.ucalgary.ca

    2008-06-15

    We discuss basic features of emergent complexity in dynamical systems far from equilibrium by focusing on the network structure of their state space. We start by measuring the distributions of avalanche and transient times in random Boolean networks (RBNs) and in the Drosophila polarity network by exact enumeration. A transient time is the duration of the transient from a starting state to an attractor. An avalanche is a special transient which starts as a single Boolean element perturbation of an attractor state. Significant differences at short times between the avalanche and the transient times for RBNs with small connectivity K-compared to the number of elements N-indicate that attractors tend to cluster in configuration space. In addition, one bit flip has a non-negligible chance to put an attractor state directly onto another attractor. This clustering is also present in the segment polarity gene network of Drosophila melanogaster, suggesting that this may be a robust feature of biological regulatory networks. We also define and measure a branching ratio for the state space networks and find evidence for a new timescale that diverges roughly linearly with N for 2{<=}K<

  17. Drosophila tensin plays an essential role in cell migration and planar polarity formation during oogenesis by mediating integrin-dependent extracellular signals to actin organization.

    Science.gov (United States)

    Cha, In Jun; Lee, Jang Ho; Cho, Kyoung Sang; Lee, Sung Bae

    2017-03-11

    Oogenesis in Drosophila involves very dynamic cellular changes such as cell migration and polarity formation inside an ovary during short period. Previous studies identified a number of membrane-bound receptors directly receiving certain types of extracellular inputs as well as intracellular signalings to be involved in the regulation of these dynamic cellular changes. However, yet our understanding on exactly how these receptor-mediated extracellular inputs lead to dynamic cellular changes remains largely unclear. Here, we identified Drosophila tensin encoded by blistery (by) as a novel regulator of cell migration and planar polarity formation and characterized the genetic interaction between tensin and integrin during oogenesis. Eggs from by mutant showed decreased hatching rate and morphological abnormality, a round-shape, compared to the wild-type eggs. Further analyses revealed that obvious cellular defects such as defective border cell migration and planar polarity formation might be primarily associated with the decreased hatching rate and the round-shape phenotype of by mutant eggs, respectively. Moreover, by mutation also induced marked defects in F-actin organization closely associated with both cell migration and planar polarity formation during oogenesis of Drosophila. Notably, all these defective phenotypes observed in by mutant eggs became much severer by reduced level of integrin, indicative of a close functional association between integrin and tensin during oogenesis. Collectively, our findings suggest that tensin acts as a crucial regulator of dynamic cellular changes during oogenesis by bridging integrin-dependent extracellular signals to intracellular cytoskeletal organization.

  18. Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila

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    Pedro Saavedra

    2016-04-01

    Full Text Available The epidermal patterns of all three larval instars (L1–L3 of Drosophila are made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults.

  19. Symmetry Breaking in an Edgeless Epithelium by Fat2-Regulated Microtubule Polarity

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    Dong-Yuan Chen

    2016-05-01

    Full Text Available Planar cell polarity (PCP information is a critical determinant of organ morphogenesis. While PCP in bounded epithelial sheets is increasingly well understood, how PCP is organized in tubular and acinar tissues is not. Drosophila egg chambers (follicles are an acinus-like “edgeless epithelium” and exhibit a continuous, circumferential PCP that does not depend on pathways active in bounded epithelia; this follicle PCP directs formation of an ellipsoid rather than a spherical egg. Here, we apply an imaging algorithm to “unroll” the entire 3D tissue surface and comprehensively analyze PCP onset. This approach traces chiral symmetry breaking to plus-end polarity of microtubules in the germarium, well before follicles form and rotate. PCP germarial microtubules provide chiral information that predicts the direction of whole-tissue rotation as soon as independent follicles form. Concordant microtubule polarity, but not microtubule alignment, requires the atypical cadherin Fat2, which acts at an early stage to translate plus-end bias into coordinated actin-mediated collective cell migration. Because microtubules are not required for PCP or migration after follicle rotation initiates, while dynamic actin and extracellular matrix are, polarized microtubules lie at the beginning of a handoff mechanism that passes early chiral PCP of the cytoskeleton to a supracellular planar polarized extracellular matrix and elongates the organ.

  20. AP-2-complex-mediated endocytosis of Drosophila Crumbs regulates polarity by antagonizing Stardust.

    Science.gov (United States)

    Lin, Ya-Huei; Currinn, Heather; Pocha, Shirin Meher; Rothnie, Alice; Wassmer, Thomas; Knust, Elisabeth

    2015-12-15

    Maintenance of epithelial polarity depends on the correct localization and levels of polarity determinants. The evolutionarily conserved transmembrane protein Crumbs is crucial for the size and identity of the apical membrane, yet little is known about the molecular mechanisms controlling the amount of Crumbs at the surface. Here, we show that Crumbs levels on the apical membrane depend on a well-balanced state of endocytosis and stabilization. The adaptor protein 2 (AP-2) complex binds to a motif in the cytoplasmic tail of Crumbs that overlaps with the binding site of Stardust, a protein known to stabilize Crumbs on the surface. Preventing endocytosis by mutation of AP-2 causes expansion of the Crumbs-positive plasma membrane domain and polarity defects, which can be partially rescued by removing one copy of crumbs. Strikingly, knocking down both AP-2 and Stardust leads to the retention of Crumbs on the membrane. This study provides evidence for a molecular mechanism, based on stabilization and endocytosis, to adjust surface levels of Crumbs, which are essential for maintaining epithelial polarity.

  1. crumbs and stardust, two genes of Drosophila required for the development of epithelial cell polarity.

    Science.gov (United States)

    Knust, E; Tepass, U; Wodarz, A

    1993-01-01

    Loss-of-function mutations in the Drosophila genes crumbs and stardust are embryonic lethal and cause a breakdown of ectodermally derived epithelia during organogenesis, leading to formation of irregular cell clusters and extensive cell death in some epithelia. The mutant phenotype develops gradually and affects the various epithelia to different extents. crumbs encodes a large transmembrane protein with 30 EGF-like repeats and four laminin A G-domain-like repeats in its extracellular domain, suggesting its participation in protein-protein interactions. The CRUMBS protein is exclusively expressed on the apical membrane of all ectodermally derived epithelia, the tissues affected in crumbs and stardust mutant embryos. The gene function is completely abolished by a crumbs mutation that causes production of a protein with a truncated cytoplasmic domain. Instead of being apically localized as in wild-type, the mutant CRUMBS protein is diffusely distributed in the cytoplasm; this occurs before any morphologically detectable cellular phenotype is visible, suggesting that targeting of proteins is affected in crumbs mutant embryos. Later, the protein can be detected on the apical and basolateral membranes. Mutations in stardust produce a phenotype nearly identical to that associated with crumbs mutations, suggesting that both genes are functionally related. Double mutant combinations and gene dosage studies suggest that both genes are part of a common genetic pathway, in which stardust acts downstream of crumbs.

  2. The Formin DAAM Functions as Molecular Effector of the Planar Cell Polarity Pathway during Axonal Development in Drosophila.

    Science.gov (United States)

    Gombos, Rita; Migh, Ede; Antal, Otilia; Mukherjee, Anindita; Jenny, Andreas; Mihály, József

    2015-07-15

    Recent studies established that the planar cell polarity (PCP) pathway is critical for various aspects of nervous system development and function, including axonal guidance. Although it seems clear that PCP signaling regulates actin dynamics, the mechanisms through which this occurs remain elusive. Here, we establish a functional link between the PCP system and one specific actin regulator, the formin DAAM, which has previously been shown to be required for embryonic axonal morphogenesis and filopodia formation in the growth cone. We show that dDAAM also plays a pivotal role during axonal growth and guidance in the adult Drosophila mushroom body, a brain center for learning and memory. By using a combination of genetic and biochemical assays, we demonstrate that Wnt5 and the PCP signaling proteins Frizzled, Strabismus, and Dishevelled act in concert with the small GTPase Rac1 to activate the actin assembly functions of dDAAM essential for correct targeting of mushroom body axons. Collectively, these data suggest that dDAAM is used as a major molecular effector of the PCP guidance pathway. By uncovering a signaling system from the Wnt5 guidance cue to an actin assembly factor, we propose that the Wnt5/PCP navigation system is linked by dDAAM to the regulation of the growth cone actin cytoskeleton, and thereby growth cone behavior, in a direct way.

  3. Expression of mouse dchs1, fjx1, and fat-j suggests conservation of the planar cell polarity pathway identified in Drosophila.

    Science.gov (United States)

    Rock, Rebecca; Schrauth, Sabrina; Gessler, Manfred

    2005-11-01

    The dachsous (ds), fat (ft), and four-jointed (fj) genes have been identified in Drosophila as part of a signaling pathway that regulates planar cell polarity (PCP). A homologous PCP signaling pathway has also been identified in vertebrates, but nothing is known thus far about the conservation of Ds/Ft/Fj signaling. Here we analyzed and compared for the first time the expression patterns of all ds, ft and fj homologs in the mouse. During embryogenesis, expression analysis was performed by RNA in situ hybridization and in adult organs by real time PCR. As in Drosophila, we detected a complementary expression of fjx1 and dchs1 in organs like kidney, lung, and intestine. The ubiquitous expression of ft in several tissues in Drosophila appears to be split into an epithelial expression of fat1/fat3 and a mesenchymal expression of fat-j. These data are compatible with a conservation and sub-functionalization of the Drosophila Ds, Fj, and Fat signaling in higher vertebrates.

  4. The polarity protein Baz forms a platform for the centrosome orientation during asymmetric stem cell division in the Drosophila male germline.

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    Inaba, Mayu; Venkei, Zsolt G; Yamashita, Yukiko M

    2015-03-20

    Many stem cells divide asymmetrically in order to balance self-renewal with differentiation. The essence of asymmetric cell division (ACD) is the polarization of cells and subsequent division, leading to unequal compartmentalization of cellular/extracellular components that confer distinct cell fates to daughter cells. Because precocious cell division before establishing cell polarity would lead to failure in ACD, these two processes must be tightly coupled; however, the underlying mechanism is poorly understood. In Drosophila male germline stem cells, ACD is prepared by stereotypical centrosome positioning. The centrosome orientation checkpoint (COC) further serves to ensure ACD by preventing mitosis upon centrosome misorientation. In this study, we show that Bazooka (Baz) provides a platform for the correct centrosome orientation and that Baz-centrosome association is the key event that is monitored by the COC. Our work provides a foundation for understanding how the correct cell polarity may be recognized by the cell to ensure productive ACD.

  5. Two frizzled planar cell polarity signals in the Drosophila wing are differentially organized by the Fat/Dachsous pathway.

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    Justin Hogan

    2011-02-01

    Full Text Available The regular array of distally pointing hairs on the mature Drosophila wing is evidence for the fine control of Planar Cell Polarity (PCP during wing development. Normal wing PCP requires both the Frizzled (Fz PCP pathway and the Fat/Dachsous (Ft/Ds pathway, although the functional relationship between these pathways remains under debate. There is strong evidence that the Fz PCP pathway signals twice during wing development, and we have previously presented a Bidirectional-Biphasic Fz PCP signaling model which proposes that the Early and Late Fz PCP signals are in different directions and employ different isoforms of the Prickle protein. The goal of this study was to investigate the role of the Ft/Ds pathway in the context of our Fz PCP signaling model. Our results allow us to draw the following conclusions: (1 The Early Fz PCP signals are in opposing directions in the anterior and posterior wing and converge precisely at the site of the L3 wing vein. (2 Increased or decreased expression of Ft/Ds pathway genes can alter the direction of the Early Fz PCP signal without affecting the Late Fz PCP signal. (3 Lowfat, a Ft/Ds pathway regulator, is required for the normal orientation of the Early Fz PCP signal but not the Late Fz PCP signal. (4 At the time of the Early Fz PCP signal there are symmetric gradients of dachsous (ds expression centered on the L3 wing vein, suggesting Ds activity gradients may orient the Fz signal. (5 Localized knockdown or over-expression of Ft/Ds pathway genes shows that boundaries/gradients of Ft/Ds pathway gene expression can redirect the Early Fz PCP signal specifically. (6 Altering the timing of ds knockdown during wing development can separate the role of the Ft/Ds pathway in wing morphogenesis from its role in Early Fz PCP signaling.

  6. Analysis of the role of the Rac/Cdc42 GTPases during planar cell polarity generation in Drosophila.

    Science.gov (United States)

    Muñoz-Descalzo, Silvia; Gómez-Cabrero, Azucena; Mlodzik, Marek; Paricio, Nuria

    2007-01-01

    Initial genetic studies in Drosophila suggested that several members of the Rho subfamily (RhoA, Rac1 and Cdc42) are involved in planar cell polarity (PCP) establishment. However, analyses of Rac1, Rac2 and Mtl loss-of-function (LOF) mutants have argued against their role in this process. Here, we investigate in detail the role of the Rho GTPases Mtl, Cdc42, Rac1 and Rac2 in PCP generation. These functional analyses were performed by overexpressing Mtl in eyes and wings, by performing genetic interaction assays and by using a combination of triple and quadruple mutant LOF clones. We found that Mtl overexpression caused PCP phenotypes and that it interacted genetically with other Rho GTPases, such as Rac1 and Cdc42 as well as with several PCP genes, such as stbm, pk and aos. However, Mtl was not found to interact with Rac2, RhoA and other members of the Fz/PCP pathway. Triple mutant clones of Rac1, Rac2 and Mtl were found to exhibit mild PCP defects which were enhanced by reduction of Cdc42 function with a hypomorphic Cdc42 allele. Taken together, these and previous results suggest that Rho GTPases may have partially overlapping functions during PCP generation. Alternatively, it is also possible that the mild PCP phenotypes observed could indicate that they are required at low levels in that process. However, since not all of them function upstream of a JNK cassette, we propose that they may act in at least two parallel pathways.

  7. The apical determinants aPKC and dPatj regulate Frizzled-dependent planar cell polarity in the Drosophila eye.

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    Djiane, Alexandre; Yogev, Shaul; Mlodzik, Marek

    2005-05-20

    Planar cell polarity (PCP) is a common feature of many vertebrate and invertebrate epithelia and is perpendicular to their apical/basal (A/B) polarity axis. While apical localization of PCP determinants such as Frizzled (Fz1) is critical for their function, the link between A/B polarity and PCP is poorly understood. Here, we describe a direct molecular link between A/B determinants and Fz1-mediated PCP establishment in the Drosophila eye. We demonstrate that dPatj binds the cytoplasmic tail of Fz1 and propose that it recruits aPKC, which in turn phosphorylates and inhibits Fz1. Accordingly, components of the aPKC complex and dPatj produce PCP defects in the eye. We also show that during PCP signaling, aPKC and dPatj are downregulated, while Bazooka is upregulated, suggesting an antagonistic effect of Bazooka on dPatj/aPKC. We propose a model whereby the dPatj/aPKC complex regulates PCP by inhibiting Fz1 in cells where it should not be active.

  8. Atg6/UVRAG/Vps34-Containing Lipid Kinase Complex Is Required for Receptor Downregulation through Endolysosomal Degradation and Epithelial Polarity during Drosophila Wing Development

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    Péter Lőrincz

    2014-01-01

    Full Text Available Atg6 (Beclin 1 in mammals is a core component of the Vps34 PI3K (III complex, which promotes multiple vesicle trafficking pathways. Atg6 and Vps34 form two distinct PI3K (III complexes in yeast and mammalian cells, either with Atg14 or with UVRAG. The functions of these two complexes are not entirely clear, as both Atg14 and UVRAG have been suggested to regulate both endocytosis and autophagy. In this study, we performed a microscopic analysis of UVRAG, Atg14, or Atg6 loss-of-function cells in the developing Drosophila wing. Both autophagy and endocytosis are seriously impaired and defective endolysosomes accumulate upon loss of Atg6. We show that Atg6 is required for the downregulation of Notch and Wingless signaling pathways; thus it is essential for normal wing development. Moreover, the loss of Atg6 impairs cell polarity. Atg14 depletion results in autophagy defects with no effect on endocytosis or cell polarity, while the silencing of UVRAG phenocopies all but the autophagy defect of Atg6 depleted cells. Thus, our results indicate that the UVRAG-containing PI3K (III complex is required for receptor downregulation through endolysosomal degradation and for the establishment of proper cell polarity in the developing wing, while the Atg14-containing complex is involved in autophagosome formation.

  9. Spalt transcription factors are required for R3/R4 specification and establishment of planar cell polarity in the Drosophila eye.

    Science.gov (United States)

    Domingos, Pedro M; Mlodzik, Marek; Mendes, César S; Brown, Samara; Steller, Hermann; Mollereau, Bertrand

    2004-11-01

    The establishment of planar cell polarity in the Drosophila eye requires correct specification of the R3/R4 pair of photoreceptor cells. In response to a polarizing factor, Frizzled signaling specifies R3 and induces Delta, which activates Notch in the neighboring cell, specifying it as R4. Here, we show that the spalt zinc-finger transcription factors (spalt major and spalt-related) are part of the molecular mechanisms regulating R3/R4 specification and planar cell polarity establishment. In mosaic analysis, we find that the spalt genes are specifically required in R3 for the establishment of correct ommatidial polarity. In addition, we show that spalt genes are required for proper localization of Flamingo in the equatorial side of R3 and R4, and for the upregulation of Delta in R3. These requirements are very similar to those of frizzled during R3/R4 specification. We show that spalt genes are required cell-autonomously for the expression of seven-up in R3 and R4, and that seven-up is downstream of spalt genes in the genetic hierarchy of R3/R4 specification. Thus, spalt and seven-up are necessary for the correct interpretation of the Frizzled-mediated polarity signal in R3. Finally, we show that, posterior to row seven, seven-up represses spalt in R3/R4 in order to maintain the R3/R4 identity and to inhibit the transformation of these cells to the R7 cell fate.

  10. Loss of the Drosophila cell polarity regulator Scribbled promotes epithelial tissue overgrowth and cooperation with oncogenic Ras-Raf through impaired Hippo pathway signaling

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    Grusche Felix A

    2011-09-01

    Full Text Available Abstract Background Epithelial neoplasias are associated with alterations in cell polarity and excessive cell proliferation, yet how these neoplastic properties are related to one another is still poorly understood. The study of Drosophila genes that function as neoplastic tumor suppressors by regulating both of these properties has significant potential to clarify this relationship. Results Here we show in Drosophila that loss of Scribbled (Scrib, a cell polarity regulator and neoplastic tumor suppressor, results in impaired Hippo pathway signaling in the epithelial tissues of both the eye and wing imaginal disc. scrib mutant tissue overgrowth, but not the loss of cell polarity, is dependent upon defective Hippo signaling and can be rescued by knockdown of either the TEAD/TEF family transcription factor Scalloped or the transcriptional coactivator Yorkie in the eye disc, or reducing levels of Yorkie in the wing disc. Furthermore, loss of Scrib sensitizes tissue to transformation by oncogenic Ras-Raf signaling, and Yorkie-Scalloped activity is required to promote this cooperative tumor overgrowth. The inhibition of Hippo signaling in scrib mutant eye disc clones is not dependent upon JNK activity, but can be significantly rescued by reducing aPKC kinase activity, and ectopic aPKC activity is sufficient to impair Hippo signaling in the eye disc, even when JNK signaling is blocked. In contrast, warts mutant overgrowth does not require aPKC activity. Moreover, reducing endogenous levels of aPKC or increasing Scrib or Lethal giant larvae levels does not promote increased Hippo signaling, suggesting that aPKC activity is not normally rate limiting for Hippo pathway activity. Epistasis experiments suggest that Hippo pathway inhibition in scrib mutants occurs, at least in part, downstream or in parallel to both the Expanded and Fat arms of Hippo pathway regulation. Conclusions Loss of Scrib promotes Yorkie/Scalloped-dependent epithelial tissue

  11. armadillo, bazooka, and stardust are critical for early stages in formation of the zonula adherens and maintenance of the polarized blastoderm epithelium in Drosophila.

    Science.gov (United States)

    Müller, H A; Wieschaus, E

    1996-07-01

    Cellularization of the Drosophila embryo results in the formation of a cell monolayer with many characteristics of a polarized epithelium. We have used antibodies specific to cellular junctions and nascent plasma membranes to study the formation of the zonula adherens (ZA) in relation to the establishment of basolateral membrane polarity. The same approach was then used as a test system to identify X-linked zygotically active genes required for ZA formation. We show that ZA formation begins during cellularization and that the basolateral membrane domain is established at mid-gastrulation. By creating deficiencies for defined regions of the X chromosome, we have identified genes that are required for the formation of the ZA and the generation of basolateral membrane polarity. We show that embryos mutant for both stardust (sdt) and bazooka (baz) fail to form a ZA. In addition to the failure to establish the ZA, the formation of the monolayered epithelium is disrupted after cellularization, resulting in formation of a multilayered cell sheet by mid-gastrulation. SEM analysis of mutant embryos revealed a conversion of cells exhibiting epithelial characteristics into cells exhibiting mesenchymal characteristics. To investigate how mutations that affect an integral component of the ZA itself influence ZA formation, we examined embryos with reduced maternal and zygotic supply of wild-type Arm protein. These embryos, like embryos mutant for both sdt and baz, exhibit an early disruption of ZA formation. These results suggest that early stages in the assembly of the ZA are critical for the stability of the polarized blastoderm epithelium.

  12. Signaling through the G-protein-coupled receptor Rickets is important for polarity, detachment, and migration of the border cells in Drosophila.

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    Anllo, Lauren; Schüpbach, Trudi

    2016-06-15

    Cell migration plays crucial roles during development. An excellent model to study coordinated cell movements is provided by the migration of border cell clusters within a developing Drosophila egg chamber. In a mutagenesis screen, we isolated two alleles of the gene rickets (rk) encoding a G-protein-coupled receptor. The rk alleles result in border cell migration defects in a significant fraction of egg chambers. In rk mutants, border cells are properly specified and express the marker Slbo. Yet, analysis of both fixed as well as live samples revealed that some single border cells lag behind the main border cell cluster during migration, or, in other cases, the entire border cell cluster can remain tethered to the anterior epithelium as it migrates. These defects are observed significantly more often in mosaic border cell clusters, than in full mutant clusters. Reduction of the Rk ligand, Bursicon, in the border cell cluster also resulted in migration defects, strongly suggesting that Rk signaling is utilized for communication within the border cell cluster itself. The mutant border cell clusters show defects in localization of the adhesion protein E-cadherin, and apical polarity proteins during migration. E-cadherin mislocalization occurs in mosaic clusters, but not in full mutant clusters, correlating well with the rk border cell migration phenotype. Our work has identified a receptor with a previously unknown role in border cell migration that appears to regulate detachment and polarity of the border cell cluster coordinating processes within the cells of the cluster themselves.

  13. Hair follicle proteoglycans

    DEFF Research Database (Denmark)

    Couchman, J R

    1993-01-01

    structure. These classes include cell surface proteoglycans, basement membrane proteoglycans, small leucine-rich proteoglycans, large proteoglycans aggregating with hyaluronan, and intracellular granule proteoglycans. They have a wide range of functions, but little is known of the proteoglycans...... that are present in the epithelial and stromal compartments of hair follicles. However, the transmembrane proteoglycan syndecan may be important in follicle morphogenesis, both with respect to the epithelium and dermal papilla cells. Syndecan may possess both heparan and chondroitin sulfate chains, interacts...... basement membranes, including those surrounding the epithelial compartment of hair follicles. Additionally, and quite unlike the dermis, the dermal papilla is enriched in basement-membrane components, especially a chondroitin 6-sulfate-containing proteoglycan, BM-CSPG. The function of this proteoglycan...

  14. Molecular cloning, genomic organization, and developmental regulation of a novel receptor from Drosophila melanogaster structurally related to members of the thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone/choriogonadotropin receptor family from mammals

    DEFF Research Database (Denmark)

    Hauser, F; Nothacker, H P; Grimmelikhuijzen, C J

    1997-01-01

    Using oligonucleotide probes derived from consensus sequences for glycoprotein hormone receptors, we have cloned an 831-amino acid residue-long receptor from Drosophila melanogaster that shows a striking structural homology with members of the glycoprotein hormone (thyroid-stimulating hormone (TSH...... until after pupation. Adult male flies express high levels of receptor mRNA, but female flies express about 6 times less. The expression pattern in embryos and larvae suggests that the receptor is involved in insect development. This is the first report on the molecular cloning of a glycoprotein hormone...

  15. Planar Cell Polarity Breaks the Symmetry of PAR Protein Distribution prior to Mitosis in Drosophila Sensory Organ Precursor Cells.

    Science.gov (United States)

    Besson, Charlotte; Bernard, Fred; Corson, Francis; Rouault, Hervé; Reynaud, Elodie; Keder, Alyona; Mazouni, Khalil; Schweisguth, François

    2015-04-20

    During development, cell-fate diversity can result from the unequal segregation of fate determinants at mitosis. Polarization of the mother cell is essential for asymmetric cell division (ACD). It often involves the formation of a cortical domain containing the PAR complex proteins Par3, Par6, and atypical protein kinase C (aPKC). In the fly notum, sensory organ precursor cells (SOPs) divide asymmetrically within the plane of the epithelium and along the body axis to generate two distinct cells. Fate asymmetry depends on the asymmetric localization of the PAR complex. In the absence of planar cell polarity (PCP), SOPs divide with a random planar orientation but still asymmetrically, showing that PCP is dispensable for PAR asymmetry at mitosis. To study when and how the PAR complex localizes asymmetrically, we have used a quantitative imaging approach to measure the planar polarization of the proteins Bazooka (Baz, fly Par3), Par6, and aPKC in living pupae. By using imaging of functional GFP-tagged proteins with image processing and computational modeling, we find that Baz, Par6, and aPKC become planar polarized prior to mitosis in a manner independent of the AuroraA kinase and that PCP is required for the planar polarization of Baz, Par6, and aPKC during interphase. This indicates that a "mitosis rescue" mechanism establishes asymmetry at mitosis in PCP mutants. This study therefore identifies PCP as the initial symmetry-breaking signal for the planar polarization of PAR proteins in asymmetrically dividing SOPs.

  16. Epithelial rotation promotes the global alignment of contractile actin bundles during Drosophila egg chamber elongation.

    Science.gov (United States)

    Cetera, Maureen; Ramirez-San Juan, Guillermina R; Oakes, Patrick W; Lewellyn, Lindsay; Fairchild, Michael J; Tanentzapf, Guy; Gardel, Margaret L; Horne-Badovinac, Sally

    2014-01-01

    Tissues use numerous mechanisms to change shape during development. The Drosophila egg chamber is an organ-like structure that elongates to form an elliptical egg. During elongation the follicular epithelial cells undergo a collective migration that causes the egg chamber to rotate within its surrounding basement membrane. Rotation coincides with the formation of a 'molecular corset', in which actin bundles in the epithelium and fibrils in the basement membrane are all aligned perpendicular to the elongation axis. Here we show that rotation plays a critical role in building the actin-based component of the corset. Rotation begins shortly after egg chamber formation and requires lamellipodial protrusions at each follicle cell's leading edge. During early stages, rotation is necessary for tissue-level actin bundle alignment, but it becomes dispensable after the basement membrane is polarized. This work highlights how collective cell migration can be used to build a polarized tissue organization for organ morphogenesis.

  17. The proteins encoded by the Drosophila Planar Polarity Effector genes inturned, fuzzy and fritz interact physically and can re-pattern the accumulation of "upstream" Planar Cell Polarity proteins.

    Science.gov (United States)

    Wang, Ying; Yan, Jie; Lee, Haeryun; Lu, Qiuheng; Adler, Paul N

    2014-10-01

    The frizzled/starry night pathway regulates planar cell polarity in a wide variety of tissues in many types of animals. It was discovered and has been most intensively studied in the Drosophila wing where it controls the formation of the array of distally pointing hairs that cover the wing. The pathway does this by restricting the activation of the cytoskeleton to the distal edge of wing cells. This results in hairs initiating at the distal edge and growing in the distal direction. All of the proteins encoded by genes in the pathway accumulate asymmetrically in wing cells. The pathway is a hierarchy with the Planar Cell Polarity (PCP) genes (aka the core genes) functioning as a group upstream of the Planar Polarity Effector (PPE) genes which in turn function as a group upstream of multiple wing hairs. Upstream proteins, such as Frizzled accumulate on either the distal and/or proximal edges of wing cells. Downstream PPE proteins accumulate on the proximal edge under the instruction of the upstream proteins. A variety of types of data support this hierarchy, however, we have found that when over expressed the PPE proteins can alter both the subcellular location and level of accumulation of the upstream proteins. Thus, the epistatic relationship is context dependent. We further show that the PPE proteins interact physically and can modulate the accumulation of each other in wing cells. We also find that over expression of Frtz results in a marked delay in hair initiation suggesting that it has a separate role/activity in regulating the cytoskeleton that is not shared by other members of the group.

  18. Sds22, a PP1 phosphatase regulatory subunit, regulates epithelial cell polarity and shape [Sds22 in epithelial morphology

    Directory of Open Access Journals (Sweden)

    Sung Hsin-Ho

    2009-02-01

    Full Text Available Abstract Background How epithelial cells adopt their particular polarised forms is poorly understood. In a screen for genes regulating epithelial morphology in Drosophila, we identified sds22, a conserved gene previously characterised in yeast. Results In the columnar epithelia of imaginal discs or follicle cells, mutation of sds22 causes contraction of cells along their apical-basal axis, resulting in a more cuboidal morphology. In addition, the mutant cells can also display altered cell polarity, forming multiple layers in follicle cells and leaving the epithelium in imaginal discs. In yeast, sds22 encodes a PP1 phosphatase regulatory subunit. Consistent with this, we show that Drosophila Sds22 binds to all four Drosophila PP1s and shares an overlapping phenotype with PP1beta9c. We also show that two previously postulated PP1 targets, Spaghetti Squash and Moesin are hyper-phosphorylated in sds22 mutants. This function is shared by the human homologue of Sds22, PPP1R7. Conclusion Sds22 is a conserved PP1 phosphatase regulatory subunit that controls cell shape and polarity.

  19. dusky-like is required to maintain the integrity and planar cell polarity of hairs during the development of the Drosophila wing.

    Science.gov (United States)

    Adler, Paul N; Sobala, Lukasz F; Thom, Desean; Nagaraj, Ranganayaki

    2013-07-01

    The cuticular hairs and sensory bristles that decorate the adult Drosophila epidermis and the denticles found on the embryo have been used in studies on planar cell polarity and as models for the cytoskeletal mediated morphogenesis of cellular extensions. ZP domain proteins have recently been found to be important for the morphogenesis of both denticles and bristles. Here we show that the ZP domain protein Dusky-like is a key player in hair morphogenesis. As is the case in bristles, in hairs dyl mutants display a dramatic phenotype that is the consequence of a failure to maintain the integrity of the extension after outgrowth. Hairs lacking dyl function are split, thinned, multipled and often very short. dyl is required for normal chitin deposition in hairs, but chitin is not required for the normal accumulation of Dyl, hence dyl acts upstream of chitin. A lack of chitin however, does not mimic the dyl hair phenotype, thus Dyl must have other targets in hair morphogenesis. One of these appears to be the actin cytoskeleton. Interestingly, dyl mutants also display a unique planar cell polarity phenotype that is distinct from that seen with mutations in the frizzled/starry night or dachsous/fat pathway genes. Rab11 was previously found to be essential for Dyl plasma membrane localization in bristles. Here we found that the expression of a dominant negative Rab11 can mimic the dyl hair morphology phenotype consistent with Rab11 also being required for Dyl function in hairs. We carried out a small directed screen to identify genes that might function with dyl and identified Chitinase 6 (Cht6) as a strong candidate, as knocking down Cht6 function led to weak versions of all of the dyl hair phenotypes.

  20. Parental exposure to low-dose X-rays in Drosophila melanogaster induces early emergence offspring, which can be modulated by transplantation of polar cytoplasm

    Energy Technology Data Exchange (ETDEWEB)

    Kanao, T.; Okamoto, T.; Miyachi, Y.

    2004-07-01

    In recent years there has been growing concern over the biological effects of low-dose X-rays, but few studies have addressed this issue. Our laboratory had observed files (Drosophila melanogaster) irradiated with low dose X-rays tend to emerge earlier than normal flies. This observation led us to quantitatively examine the effects of low dose X-irradiation on development in the fly Following exposure of prepupal (day 5) flies to 0.5 Gy X-rays, the time to emergence was slightly shorter than in the sham controls. This tendency was increased when the X-ray exposure came during the pupal stage (day 7). In these flies, the time to eclosion decreased significantly, by an average of thirty hours sooner than sham controls. Exposure of pre pupa to 0.5 Gy results in marked changes in the puffing patterns of salivary gland chromosomes. A 0.5 Gy exposure induces puffing at 75B specific loci; this pattern of induced puffs shows little developmental specificity. A further experiment examined whether such radiation effects could be observed in the unexposed F1 generation of exposed individuals Greater radiation effects on early Fi emergence were seen when the time between exposure and mating was 3 days, indicating an effect on early spermatid development. Early F1 emergence was also observed after exposure of female flies to X-rays during late previtellogeny. furthermore, rapid emergence could be induced in the F1 embryos of unexposed parents by transferring the polar cytoplasm (precursor cells of the germ cell line) from F1 embryos of exposed flies. furthermore pumilio mutant arrested the assembly of polar cytoplasm did not induce the early emergency even after 0.5 Gy exposure. These results show that radiation-induced effects can be transmitted to the next generation through the germ cell line. (Author)

  1. Cappuccino, a Drosophila maternal effect gene required for polarity of the egg and embryo, is related to the vertebrate limb deformity locus.

    Science.gov (United States)

    Emmons, S; Phan, H; Calley, J; Chen, W; James, B; Manseau, L

    1995-10-15

    We report the molecular isolation of cappuccino (capu), a gene required for localization of molecular determinants within the developing Drosophila oocyte. The carboxy-terminal half of the capu protein is closely related to that of the vertebrate limb deformity locus, which is known to function in polarity determination in the developing vertebrate limb. In addition, capu shares both a proline-rich region and a 70-amino-acid domain with a number of other genes, two of which also function in pattern formation, the Saccharomyes cerevisiae BNI1 gene and the Aspergillus FigA gene. We also show that capu mutant oocytes have abnormal microtubule distributions and premature microtubule-based cytoplasmic streaming within the oocyte, but that neither the speed nor the timing of the cytoplasmic streaming correlates with the strength of the mutant allele. This suggests that the premature cytoplasmic streaming in capu mutant oocytes does not suffice to explain the patterning defects. By inducing cytoplasmic streaming in wild-type oocytes during mid-oogenesis, we show that premature cytoplasmic streaming can displace staufen protein from the posterior pole, but not gurken mRNA from around the oocyte nucleus.

  2. Parental exposure to low-dose X-rays in Drosophila melanogaster induces early emergence in offspring, which can be modulated by transplantation of polar cytoplasm

    Energy Technology Data Exchange (ETDEWEB)

    Kanao, Tomoko; Okamoto, Takehito; Miyachi, Yukihisa; Nohara, Norimasa

    2003-06-19

    In recent years there has been growing concern over the biological effects of low-dose X-rays, but few studies have addressed this issue. Our laboratory had observed flies (Drosophila melanogaster) irradiated with low-dose X-rays tend to emerge earlier than normal flies. This observation led us to quantitatively examine the effects of low-dose X-irradiation on development in the fly. Following exposure of prepupal (day 5) flies to 0.5 Gy X-rays, the time to emergence was slightly shorter than in the sham controls. This tendency was increased when the X-ray exposure came during the pupal stage (day 7). In these flies, the time to eclosion decreased significantly, by an average of 30 h sooner than sham controls. A further experiment examined whether such radiation effects could be observed in the unexposed F1 generation of exposed individuals. Greater radiation effects on early F1 emergence were seen when the time between exposure and mating was 3 days, indicating an effect on early spermatid development. Early F1 emergence was also observed after exposure of female flies to X-rays during late previtellogeny. Furthermore, rapid emergence could be induced in the F1 embryos of unexposed parents by transferring the polar cytoplasm (precursor cells of the germ cell line) from F1 embryos of exposed flies. These results show that radiation-induced effects can be transmitted to the next generation through the germ cell line.

  3. Distinct functional specificities are associated with protein isoforms encoded by the Drosophila dorsal-ventral patterning gene pipe.

    Science.gov (United States)

    Zhang, Zhenyu; Zhu, Xianjun; Stevens, Leslie M; Stein, David

    2009-08-01

    Spatially regulated transcription of the pipe gene in ventral cells of the Drosophila ovary follicle cell epithelium is a key event that specifies progeny embryo dorsal-ventral (DV) polarity. pipe encodes ten putative protein isoforms, all of which exhibit similarity to vertebrate glycosaminoglycan-modifying enzymes. Expression of one of the isoforms, Pipe-ST2, in follicle cells has previously been shown to be essential for DV patterning. pipe is also expressed in the embryonic salivary gland and its expression there is required for normal viability. Here, we show that in addition to Pipe-ST2, seven of the other Pipe isoforms are expressed in the ovary, whereas all Pipe isoforms are abundantly expressed in the embryo. Of the ten isoforms, only Pipe-ST2 can restore ventral and lateral pattern elements to the progeny of otherwise pipe-null mutant females. By contrast, three Pipe isoforms, but not Pipe-ST2, support the production of a novel pipe-dependent epitope present in the embryonic salivary gland. These data indicate that differences in functional specificity, and presumably enzymatic specificity, are associated with several of the Pipe isoforms. In addition, we show that uniform expression of the Pipe-ST2 isoform in the follicle cell layer of females otherwise lacking pipe expression leads to the formation of embryos with a DV axis that is appropriately oriented with respect to the intrinsic polarity of the eggshell. This suggests the existence of a second mechanism that polarizes the Drosophila embryo, in addition to the ventrally restricted transcription of the pipe gene.

  4. Partial interchangeability of Fz3 and Fz6 in tissue polarity signaling for epithelial orientation and axon growth and guidance.

    Science.gov (United States)

    Hua, Zhong L; Chang, Hao; Wang, Yanshu; Smallwood, Philip M; Nathans, Jeremy

    2014-10-01

    In mammals, a set of anatomically diverse polarity processes - including axon growth and guidance, hair follicle orientation, and stereociliary bundle orientation in inner ear sensory hair cells - appear to be mechanistically related, as judged by their dependence on vertebrate homologues of core tissue polarity/planar cell polarity (PCP) genes in Drosophila. To explore more deeply the mechanistic similarities between different polarity processes, we have determined the extent to which frizzled 3 (Fz3) can rescue the hair follicle and Merkel cell polarity defects in frizzled 6-null (Fz6(-/-)) mice, and, reciprocally, the extent to which Fz6 can rescue the axon growth and guidance defects in Fz3(-/-) mice. These experiments reveal full rescue of the Fz6(-/-) phenotype by Fz3 and partial rescue of the Fz3(-/-) phenotype by Fz6, implying that these two proteins are likely to act in a conserved manner in these two contexts. Stimulated by these observations, we searched for additional anatomical structures that exhibit macroscopic polarity and that might plausibly use Fz3 and/or Fz6 signaling. This search has revealed a hitherto unappreciated pattern of papillae on the dorsal surface of the tongue that depends, at least in part, on redundant signaling by Fz3 and Fz6. Taken together, these experiments provide compelling evidence for a close mechanistic relationship between multiple anatomically diverse polarity processes.

  5. Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis

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    Yu Lingzhu

    2009-12-01

    Full Text Available Abstract Background Proper patterning of the follicle cell epithelium over the egg chamber is essential for the Drosophila egg development. Differentiation of the epithelium into several distinct cell types along the anterior-posterior axis requires coordinated activities of multiple signaling pathways. Previously, we reported that lethal(2giant larvae (lgl, a Drosophila tumor suppressor gene, is required in the follicle cells for the posterior follicle cell (PFC fate induction at mid-oogenesis. Here we explore the role of another two tumor suppressor genes, scribble (scrib and discs large (dlg, in the epithelial patterning. Results We found that removal of scrib or dlg function from the follicle cells at posterior terminal of the egg chamber causes a complete loss of the PFC fate. Aberrant specification and differentiation of the PFCs in the mosaic clones can be ascribed to defects in coordinated activation of the EGFR, JAK and Notch signaling pathways in the multilayered cells. Meanwhile, the clonal analysis revealed that loss-of-function mutations in scrib/dlg at the anterior domains result in a partially penetrant phenotype of defective induction of the stretched and centripetal cell fate, whereas specification of the border cell fate can still occur in the most anterior region of the mutant clones. Further, we showed that scrib genetically interacts with dlg in regulating posterior patterning of the epithelium. Conclusion In this study we provide evidence that scrib and dlg function differentially in anterior and posterior patterning of the follicular epithelium at oogenesis. Further genetic analysis indicates that scrib and dlg act in a common pathway to regulate PFC fate induction. This study may open another window for elucidating role of scrib/dlg in controlling epithelial polarity and cell proliferation during development.

  6. Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila.

    Science.gov (United States)

    Saavedra, Pedro; Brittle, Amy; Palacios, Isabel M; Strutt, David; Casal, José; Lawrence, Peter A

    2016-04-15

    The epidermal patterns of all three larval instars (L1-L3) ofDrosophilaare made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults.

  7. Slmb antagonises the aPKC/Par-6 complex to control oocyte and epithelial polarity.

    Science.gov (United States)

    Morais-de-Sá, Eurico; Mukherjee, Avik; Lowe, Nick; St Johnston, Daniel

    2014-08-01

    The Drosophila anterior-posterior axis is specified when the posterior follicle cells signal to polarise the oocyte, leading to the anterior/lateral localisation of the Par-6/aPKC complex and the posterior recruitment of Par-1, which induces a microtubule reorganisation that localises bicoid and oskar mRNAs. Here we show that oocyte polarity requires Slmb, the substrate specificity subunit of the SCF E3 ubiquitin ligase that targets proteins for degradation. The Par-6/aPKC complex is ectopically localised to the posterior of slmb mutant oocytes, and Par-1 and oskar mRNA are mislocalised. Slmb appears to play a related role in epithelial follicle cells, as large slmb mutant clones disrupt epithelial organisation, whereas small clones show an expansion of the apical domain, with increased accumulation of apical polarity factors at the apical cortex. The levels of aPKC and Par-6 are significantly increased in slmb mutants, whereas Baz is slightly reduced. Thus, Slmb may induce the polarisation of the anterior-posterior axis of the oocyte by targeting the Par-6/aPKC complex for degradation at the oocyte posterior. Consistent with this, overexpression of the aPKC antagonist Lgl strongly rescues the polarity defects of slmb mutant germline clones. The role of Slmb in oocyte polarity raises an intriguing parallel with C. elegans axis formation, in which PAR-2 excludes the anterior PAR complex from the posterior cortex to induce polarity, but its function can be substituted by overexpressing Lgl.

  8. Human hair follicle: reservoir function and selective targeting.

    Science.gov (United States)

    Blume-Peytavi, U; Vogt, A

    2011-10-01

    Penetration of topically applied compounds may occur via the stratum corneum, skin appendages and hair follicles. The follicular infundibulum increases the surface area, disrupts the epidermal barrier towards the lower parts of the follicle, and serves as a reservoir. Topical delivery of active compounds to specific targets within the skin, especially to distinct hair follicle compartments or cell populations, may help to treat local inflammatory reactions selectively, with reduced systemic side-effects. Various in vitro and in vivo methods exist for studying the hair follicle structure and follicular penetration pathways. These include cyanoacrylate skin surface stripping, confocal microscopy and cyanoacrylate scalp follicle biopsy. The complex anatomical structure as well as the cyclical activity of the hair follicle must be taken into consideration when designing delivery systems. In addition, delivery into and retention inside the infundibular reservoir are controlled by, for example, molecule or particle size, their polarity and the type of preparation. Preferred penetration depth and storage time must also be considered. Particles with release mechanisms should be preferred; however, the release of drugs from nanoparticles still requires further investigations.

  9. Discs large 5, an Essential Gene in Drosophila, Regulates Egg Chamber Organization.

    Science.gov (United States)

    Reilly, Eve; Changela, Neha; Naryshkina, Tatyana; Deshpande, Girish; Steward, Ruth

    2015-03-19

    Discs large 5 (Dlg5) is a member of the MAGUK family of proteins that typically serve as molecular scaffolds and mediate signaling complex formation and localization. In vertebrates, Dlg5 has been shown to be responsible for polarization of neural progenitors and to associate with Rab11-positive vesicles in epithelial cells. In Drosophila, however, the function of Dlg5 is not well-documented. We have identified dlg5 as an essential gene that shows embryonic lethality. dlg5 embryos display partial loss of primordial germ cells (PGCs) during gonad coalescence between stages 12 and 15 of embryogenesis. Loss of Dlg5 in germline and somatic stem cells in the ovary results in the depletion of both cell lineages. Reduced expression of Dlg5 in the follicle cells of the ovary leads to a number of distinct phenotypes, including defects in egg chamber budding, stalk cell overgrowth, and ectopic polar cell induction. Interestingly, loss of Dlg5 in follicle cells results in abnormal distribution of a critical component of cell adhesion, E-cadherin, shown to be essential for proper organization of egg chambers.

  10. Combover/CG10732, a novel PCP effector for Drosophila wing hair formation.

    Science.gov (United States)

    Fagan, Jeremy K; Dollar, Gretchen; Lu, Qiuheng; Barnett, Austen; Pechuan Jorge, Joaquin; Schlosser, Andreas; Pfleger, Cathie; Adler, Paul; Jenny, Andreas

    2014-01-01

    The polarization of cells is essential for the proper functioning of most organs. Planar Cell Polarity (PCP), the polarization within the plane of an epithelium, is perpendicular to apical-basal polarity and established by the non-canonical Wnt/Fz-PCP signaling pathway. Within each tissue, downstream PCP effectors link the signal to tissue specific readouts such as stereocilia orientation in the inner ear and hair follicle orientation in vertebrates or the polarization of ommatidia and wing hairs in Drosophila melanogaster. Specific PCP effectors in the wing such as Multiple wing hairs (Mwh) and Rho Kinase (Rok) are required to position the hair at the correct position and to prevent ectopic actin hairs. In a genome-wide screen in vitro, we identified Combover (Cmb)/CG10732 as a novel Rho kinase substrate. Overexpression of Cmb causes the formation of a multiple hair cell phenotype (MHC), similar to loss of rok and mwh. This MHC phenotype is dominantly enhanced by removal of rok or of other members of the PCP effector gene family. Furthermore, we show that Cmb physically interacts with Mwh, and cmb null mutants suppress the MHC phenotype of mwh alleles. Our data indicate that Cmb is a novel PCP effector that promotes to wing hair formation, a function that is antagonized by Mwh.

  11. Combover/CG10732, a novel PCP effector for Drosophila wing hair formation.

    Directory of Open Access Journals (Sweden)

    Jeremy K Fagan

    Full Text Available The polarization of cells is essential for the proper functioning of most organs. Planar Cell Polarity (PCP, the polarization within the plane of an epithelium, is perpendicular to apical-basal polarity and established by the non-canonical Wnt/Fz-PCP signaling pathway. Within each tissue, downstream PCP effectors link the signal to tissue specific readouts such as stereocilia orientation in the inner ear and hair follicle orientation in vertebrates or the polarization of ommatidia and wing hairs in Drosophila melanogaster. Specific PCP effectors in the wing such as Multiple wing hairs (Mwh and Rho Kinase (Rok are required to position the hair at the correct position and to prevent ectopic actin hairs. In a genome-wide screen in vitro, we identified Combover (Cmb/CG10732 as a novel Rho kinase substrate. Overexpression of Cmb causes the formation of a multiple hair cell phenotype (MHC, similar to loss of rok and mwh. This MHC phenotype is dominantly enhanced by removal of rok or of other members of the PCP effector gene family. Furthermore, we show that Cmb physically interacts with Mwh, and cmb null mutants suppress the MHC phenotype of mwh alleles. Our data indicate that Cmb is a novel PCP effector that promotes to wing hair formation, a function that is antagonized by Mwh.

  12. The amazing miniorgan: Hair follicle

    Directory of Open Access Journals (Sweden)

    Çiler Çelik Özenci

    2014-06-01

    Full Text Available Hair is a primary characteristic of mammals, and exerts a wide range of functions including thermoregulation, physical protection, sensory activity, and social interactions. The hair shaft consists of terminally differentiated keratinocytes that are produced by the hair follicle. Hair follicle development takes place during fetal skin development and relies on tightly regulated ectodermal–mesodermal interactions. Hair follicles form during embryonic development and, after birth, undergo recurrent cycling of growth (anagen, apoptosis-driven regression (catagen, and relative quiescence (telogen. As a functional mini-organ, the hair follicle develops in an environment with dynamic and alternating changes of diverse molecular signals. Our molecular understanding of hair follicle biology relies heavily on genetically engineered mouse models with abnormalities in hair structure, growth, and/or pigmentation and significant advances have been made toward the identification of key signaling pathways and the regulatory genes involved. In this review, the basic concepts of hair follicle, a mini-complex organ, biology will be presented and its importance in clinical applications will be summarized.

  13. Conception rate in Holstein dairy cows having both normal sized follicles and cystic follicles at estrus

    Directory of Open Access Journals (Sweden)

    K. Kaneko

    2016-09-01

    Conclusion: These results support artificially inseminated of cows that show clear signs of estrus even if they have both cystic follicles and normal sized follicles, and especially when the cows have only one cystic follicle.

  14. Polycomb group genes Psc and Su(z)2 restrict follicle stem cell self-renewal and extrusion by controlling canonical and noncanonical Wnt signaling.

    Science.gov (United States)

    Li, Xinghua; Han, Yue; Xi, Rongwen

    2010-05-01

    Stem cells are critical for maintaining tissue homeostasis and are commonly governed by their niche microenvironment, although the intrinsic mechanisms controlling their multipotency are poorly understood. Polycomb group (PcG) genes are epigenetic silencers, and have emerged recently as important players in maintaining stem cell multipotency by preventing the initiation of differentiation programs. Here we describe an unexpected role of specific PcG genes in allowing adult stem cell differentiation and preventing stem cell-derived tumor development. We show that Posterior sex combs (Psc), which encodes a core Polycomb-repressive complex 1 (PRC1) component, functions redundantly with a similar gene, Suppressor of zeste two [Su(z)2], to restrict follicle stem cell (FSC) self-renewal in the Drosophila ovary. FSCs carrying deletion mutations of both genes extrude basally from the epithelium and continue to self-propagate at ectopic sites, leading to the development of FSC-like tumors. Furthermore, we show that the propagation of the mutant cells is driven by sustained activation of the canonical Wnt signaling pathway, which is essential for FSC self-renewal, whereas the epithelial extrusion is mediated through the planar cell polarity pathway. This study reveals a novel mechanism of epithelial extrusion, and indicates a novel role of polycomb function in allowing adult stem cell differentiation by antagonizing self-renewal programs. Given evolutionary conservation of PcG genes from Drosophila to mammals, they could have similar functions in mammalian stem cells and cancer.

  15. Planar cell polarity signaling: a common mechanism for cellular polarization.

    Science.gov (United States)

    Jenny, Andreas; Mlodzik, Marek

    2006-09-01

    Epithelial cells frequently display--in addition to the common apical-basolateral polarity--a polarization within the plane of the epithelium. This is commonly referred to as planar cell polarity (PCP) or tissue polarity. Examples of vertebrate PCP include epithelial patterning in the skin and inner ear, and also the morphogenetic movements of mesenchymal cells during convergent extension at gastrulation. In Drosophila, all adult epithelial structures of the cuticle are polarized within the plane. This review presents recent results and new insights into the molecular mechanisms underlying the establishment of PCP, and compares and contrasts the intriguing similarities between PCP signaling in Drosophila and vertebrates.

  16. Asymmetric cell division in the Drosophila bristle lineage: from the polarization of sensory organ precursor cells to Notch-mediated binary fate decision.

    Science.gov (United States)

    Schweisguth, François

    2015-01-01

    Asymmetric cell division (ACD) is a simple and evolutionary conserved process whereby a mother divides to generate two daughter cells with distinct developmental potentials. This process can generate cell fate diversity during development. Fate asymmetry may result from the unequal segregation of molecules and/or organelles between the two daughter cells. Here, I will review how fate asymmetry is regulated in the sensory bristle lineage in Drosophila and focus on the molecular mechanisms underlying ACD of the sensory organ precursor cells (SOPs). For further resources related to this article, please visit the WIREs website. © 2015 The Authors. WIREs Developmental Biology published by Wiley Periodicals, Inc.

  17. Xenobiotic effects on ovarian preantral follicles.

    Science.gov (United States)

    Mark-Kappeler, Connie J; Hoyer, Patricia B; Devine, Patrick J

    2011-11-01

    Women are born with a finite population of ovarian follicles, which are slowly depleted during their reproductive years until reproductive failure (menopause) occurs. The rate of loss of primordial follicles is determined by genetic and environmental influences, but certain toxic exposures can accelerate this process. Ionizing radiation reduces preantral follicle numbers in rodents and humans in a dose-dependent manner. Cigarette smoking is linked to menopause occurring 1-4 yr earlier than with nonsmokers, and components of smoke, polycyclic aromatic hydrocarbons, can cause follicle depletion in rodents or in ovaries in vitro. Chemotherapeutic agents, such as alkylating drugs and cisplatin, also cause loss of preantral ovarian follicles. Effects depend on dose, type, and reactivity of the drug, and the age of the individual. Evidence suggests DNA damage may underlie follicle loss induced by one common alkylating drug, cyclophosphamide. Occupational exposures have also been linked to ovarian damage. In an industrial setting, 2-bromopropane caused infertility in men and women, and it can induce ovarian follicle depletion in rats. Solvents, such as butadiene, 4-vinylcyclohexene, and their diepoxides, can also cause specific preantral follicle depletion. The mechanism(s) underlying effects of the latter compound may involve alterations in apoptosis, survival factors such as KIT/Kit Ligand, and/or the cellular signaling that maintains primordial follicle dormancy. Estrogenic endocrine disruptors may alter follicle formation/development and impair fertility or normal development of offspring. Thus, specific exposures are known or suspected of detrimentally impacting preantral ovarian follicles, leading to early ovarian failure.

  18. Drosophila Lin-7 is a component of the Crumbs complex in epithelia and photoreceptor cells and prevents light-induced retinal degeneration.

    Science.gov (United States)

    Bachmann, André; Grawe, Ferdi; Johnson, Kevin; Knust, Elisabeth

    2008-03-01

    The Drosophila Crumbs protein complex is required to maintain epithelial cell polarity in the embryo, to ensure proper morphogenesis of photoreceptor cells and to prevent light-dependent retinal degeneration. In Drosophila, the core components of the complex are the transmembrane protein Crumbs, the membrane-associated guanylate kinase (MAGUK) Stardust and the scaffolding protein DPATJ. The composition of the complex and some of its functions are conserved in mammalian epithelial and photoreceptor cells. Here, we report that Drosophila Lin-7, a scaffolding protein with one Lin-2/Lin-7 (L27) domain and one PSD-95/Dlg/ZO-1 (PDZ) domain, is associated with the Crumbs complex in the subapical region of embryonic and follicle epithelia and at the stalk membrane of adult photoreceptor cells. DLin-7 loss-of-function mutants are viable and fertile. While DLin-7 localization depends on Crumbs, neither Crumbs, Stardust nor DPATJ require DLin-7 for proper accumulation in the subapical region. Unlike other components of the Crumbs complex, DLin-7 is also enriched in the first optic ganglion, the lamina, where it co-localizes with Discs large, another member of the MAGUK family. In contrast to crumbs mutant photoreceptor cells, those mutant for DLin-7 do not display any morphogenetic abnormalities. Similar to crumbs mutant eyes, however, DLin-7 mutant photoreceptors undergo progressive, light-dependent degeneration. These results support the previous conclusions that the function of the Crumbs complex in cell survival is independent from its function in photoreceptor morphogenesis.

  19. Tissue/planar cell polarity in vertebrates: new insights and new questions.

    Science.gov (United States)

    Wang, Yanshu; Nathans, Jeremy

    2007-02-01

    This review focuses on the tissue/planar cell polarity (PCP) pathway and its role in generating spatial patterns in vertebrates. Current evidence suggests that PCP integrates both global and local signals to orient diverse structures with respect to the body axes. Interestingly, the system acts on both subcellular structures, such as hair bundles in auditory and vestibular sensory neurons, and multicellular structures, such as hair follicles. Recent work has shown that intriguing connections exist between the PCP-based orienting system and left-right asymmetry, as well as between the oriented cell movements required for neural tube closure and tubulogenesis. Studies in mice, frogs and zebrafish have revealed that similarities, as well as differences, exist between PCP in Drosophila and vertebrates.

  20. Immunohistochemical study of hair follicle stem cells in regenerated hair follicles induced by Wnt10b

    Science.gov (United States)

    Zhang, Yiming; Xing, Yizhan; Guo, Haiying; Ma, Xiaogen; Li, Yuhong

    2016-01-01

    The regulation of the periodic regeneration of hair follicles is complicated. Although Wnt10b has been reported to induce hair follicle regeneration, the characteristics of induced hair follicles, especially the target cells of Wnt10b, have not yet been clearly elucidated. Thus, we systematically evaluated the expression and proliferation patterns of Wnt10b-induced hair follicles. We found that Wnt10b promoted the proliferation of hair follicle stem cells from 24 hours after AdWnt10b injection. Seventy-two hours after AdWnt10b injection, cells outside of bulge area began to proliferate. When the induced hair follicle entered full anagen, although the hair follicle stem cells were normal, canonical Wnt signaling was maintained in the hair precortex cells. Our results reveal that the target cells that overexpressed Wnt10b included hair follicle stem cells, hair precortex cells, and matrix cells.

  1. Xenobiotic Effects on Ovarian Preantral Follicles1

    OpenAIRE

    2011-01-01

    Women are born with a finite population of ovarian follicles, which are slowly depleted during their reproductive years until reproductive failure (menopause) occurs. The rate of loss of primordial follicles is determined by genetic and environmental influences, but certain toxic exposures can accelerate this process. Ionizing radiation reduces preantral follicle numbers in rodents and humans in a dose-dependent manner. Cigarette smoking is linked to menopause occurring 1–4 yr earlier than wi...

  2. Diverse in- and output polarities and high complexity of local synaptic and nonsynaptic signalling within a chemically defined class of peptidergic Drosophila neurons

    Science.gov (United States)

    Peptidergic neurons are not easily integrated into current connectomics concepts, since their peptide messages can be distributed via non-synaptic paracrine signaling or even via volume transmission. Moreover, and especially in insects, the polarity of peptidergic interneurons in terms of in- and o...

  3. Isolation of Drosophila egg chambers for imaging.

    Science.gov (United States)

    Parton, Richard M; Vallés, Ana Maria; Dobbie, Ian M; Davis, Ilan

    2010-04-01

    The fruit fly Drosophila melanogaster is an important model for basic research into the molecular mechanisms underlying cell function and development, as well as a major biomedical research tool. A significant advantage of Drosophila is the ability to apply live cell imaging to a variety of living tissues that can be dissected and imaged in vivo, ex vivo, or in vitro. Drosophila egg chambers, for example, have proven to be a useful model system for studying border cell migration, Golgi unit transport, the rapid movement of mRNA and protein particles, and the role of microtubules in meiosis and oocyte differentiation. A crucial first step before imaging is preparation of the experimental material to ensure physiological relevance and to achieve the best conditions for image quality. Early- to mid-stage egg chambers cannot be mounted in an aqueous-based medium, because this causes a change in microtubule organization and follicle cell morphology. Such egg chambers survive better in Halocarbon oil, which allows free diffusion of oxygen, has low viscosity, and thus prevents dehydration and hypoxia. With a refractive index similar to glycerol, Halocarbon oil also has good optical properties for imaging. It also provides a good environment for injection and is particularly useful for long-term imaging of embryos. However, unlike with aqueous solutions, changes in the medium are not possible. This protocol describes the isolation of Drosophila egg chambers.

  4. Drosophila eggshell production: identification of new genes and coordination by Pxt.

    Directory of Open Access Journals (Sweden)

    Tina L Tootle

    Full Text Available Drosophila ovarian follicles complete development using a spatially and temporally controlled maturation process in which they resume meiosis and secrete a multi-layered, protective eggshell before undergoing arrest and/or ovulation. Microarray analysis revealed more than 150 genes that are expressed in a stage-specific manner during the last 24 hours of follicle development. These include all 30 previously known eggshell genes, as well as 19 new candidate chorion genes and 100 other genes likely to participate in maturation. Mutations in pxt, encoding a putative Drosophila cyclooxygenase, cause many transcripts to begin expression prematurely, and are associated with eggshell defects. Somatic activity of Pxt is required, as RNAi knockdown of pxt in the follicle cells recapitulates both the temporal expression and eggshell defects. One of the temporally regulated genes, cyp18a1, which encodes a cytochromome P450 protein mediating ecdysone turnover, is downregulated in pxt mutant follicles, and cyp18a1 mutation itself alters eggshell gene expression. These studies further define the molecular program of Drosophila follicle maturation and support the idea that it is coordinated by lipid and steroid hormonal signals.

  5. Isolation and culture of chicken primordial follicles.

    Science.gov (United States)

    Leghari, Imdad Hussain; Zhao, Dan; Mi, Yuling; Zhang, Caiqiao

    2015-10-01

    The establishment of a primordial follicle culture system is important for the study of follicular development. Hence, the objective of this study was to isolate chicken primordial follicles and establish culture methods. Ovaries from 2-wk-old chickens were treated with trypsin-EDTA, collagenase II, or collagenase type IA, along with a mechanical isolation technique. Isolated follicles were cultured under different conditions. Results showed a significant difference in the follicular recovery and survival rates among different enzymes and methods used. The maximal follicular yield was obtained by trypsin+EDTA and collagenase II digestion, followed by collagenase type IA digestion. However, the highest follicular viability rate was observed in groups of collagenase type IA digestion and the mechanical isolation method. Enzymatic treatment resulted in higher misshapen oocytes or follicles, though the diameters of the follicles were not significantly changed. In addition, our follicle culture results for different conditions showed maximal survival rates of primordial follicles in alginate hydrogel beads after 12 d of culture. Thus, we successfully established methods for isolating and culturing chicken primordial follicles. The present method will greatly facilitate investigation of the regulation of follicular development. © 2015 Poultry Science Association Inc.

  6. Ovarian follicle vascularization in fasted pig.

    Science.gov (United States)

    Barboni, Barbara; Barbara, Barboni; Martelli, Alessandra; Alessandra, Martelli; Berardinelli, Paolo; Paolo, Berardinelli; Russo, Valentina; Valentina, Russo; Turriani, Maura; Maura, Turriani; Bernabò, Nicola; Nicola, Bernabò; Lucidi, Pia; Pia, Lucidi; Mattioli, Mauro; Mauro, Mattioli

    2004-09-01

    The authors have investigated in the different classes of ovarian follicles the vascular area, the blood vessel distribution, the vascular endothelial growth factor (VEGF) mRNA expression and the VEGF secretion during equine chorionic gonadotropin (eCG) induced follicle growth in prepubertal gilts fed ad libitum or fasted. Immunohistochemistry staining of Von Willebrand factor showed that fasting caused a dramatic increase in the vascular area of medium-large tertiary follicles. The increase involved the two concentric vessel networks and the area between them that, becoming crossed by several anastomosis, modified the whole vessel architecture. Both in situ hybridization and in vitro culture experiments demonstrate that granulosa cells from medium-large follicles are engaged in a copious VEGF production upon eCG stimulation both in gilts fed ad libitum or fasted. More surprisingly, the production of VEGF becomes diffuse amongst theca cells of fasted animals thus recruiting a compartment that in condition of normal feeding regimen appears nearly quiescent. In conclusion, the data presented describe a local angiogenic process that develops in the follicle wall of growing antral follicle in case of acute severe food restriction. The mechanism, essentially confined to follicles that potentially approach ovulation, appears to assume the meaning of a local compensatory mechanism that may help maintaining adequate nutrient delivery to follicles that undergo ovulation.

  7. Ion beam microanalysis of human hair follicles

    Energy Technology Data Exchange (ETDEWEB)

    Kertesz, Zs. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, P.O. Box 51 (Hungary)]. E-mail: zsofi@atomki.hu; Szikszai, Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, P.O. Box 51 (Hungary); Pelicon, P. [Jozef Stefan Institute, Jamova 39, P.O. Box 3000, Ljubljana (Slovenia); Simcic, J. [Jozef Stefan Institute, Jamova 39, P.O. Box 3000, Ljubljana (Slovenia); Telek, A. [Department of Physiology and Cell Physiology Research Group of the Hungarian Academy of Sciences, University of Debrecen, Medical and Health Science Center, Research Center for Molecular Medicine, H-4012, Debrecen, Nagyerdei krt. 98 (Hungary); Biro, T. [Department of Physiology and Cell Physiology Research Group of the Hungarian Academy of Sciences, University of Debrecen, Medical and Health Science Center, Research Center for Molecular Medicine, H-4012, Debrecen, Nagyerdei krt. 98 (Hungary)

    2007-07-15

    Hair follicle is an appendage organ of the skin which is of importance to the survival of mammals and still maintains significance for the human race - not just biologically, but also through cosmetic and commercial considerations. However data on composition of hair follicles are scarce and mostly limited to the hair shaft. In this study we provide detailed information on the elemental distribution in human hair follicles in different growth phases (anagen and catagen) using a scanning proton microprobe. The analysis of skin samples obtained from human adults undergoing plastic surgery and of organ-cultured human hair follicles may yield a new insight into the function, development and cyclic activity of the hair follicle.

  8. Ion beam microanalysis of human hair follicles

    Science.gov (United States)

    Kertész, Zs.; Szikszai, Z.; Pelicon, P.; Simčič, J.; Telek, A.; Bíró, T.

    2007-07-01

    Hair follicle is an appendage organ of the skin which is of importance to the survival of mammals and still maintains significance for the human race - not just biologically, but also through cosmetic and commercial considerations. However data on composition of hair follicles are scarce and mostly limited to the hair shaft. In this study we provide detailed information on the elemental distribution in human hair follicles in different growth phases (anagen and catagen) using a scanning proton microprobe. The analysis of skin samples obtained from human adults undergoing plastic surgery and of organ-cultured human hair follicles may yield a new insight into the function, development and cyclic activity of the hair follicle.

  9. Fluorescently labeled inhibitors detect localized serine protease activities in Drosophila melanogaster pole cells, embryos, and ovarian egg chambers

    DEFF Research Database (Denmark)

    Jakobsen, Rasmus Kragh; Ono, S.; Powers, J. C.

    2005-01-01

    processes that they mediate. Until only recently, the tools to conveniently address the question of where and when serine proteases are active within complex tissues have been lacking. In order to detect spatially restricted serine protease activities in Drosophila embryos and ovaries we introduce...... activity localized to the oocyte-somatic follicle cell interface of the developing egg chamber. Our results suggest that this technique holds promise to identify new spatially restricted activities in adult Drosophila tissues and developing embryos....

  10. Control of ovarian primordial follicle activation

    Science.gov (United States)

    2012-01-01

    The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation. PMID:22563545

  11. PREOVULATORY FOLLICLE DEVELOPMENT IN HIGH YIELDING COWS

    Directory of Open Access Journals (Sweden)

    Radovan Tomášek

    2013-06-01

    Full Text Available The aim of the study was to examine the development of preovulatory follicles in pregnant and non-pregnant high yielding cows. The treatment by supergestran and oestrophan was used to synchronize the estrous cycle. Ovaries were monitored by transrectal ultrasonography. The linear increase of preovulatory follicles was observed in pregnant (P < 0,001 and non-pregnant (P < 0,001 cows during 8 days before ovulation. In conclusion, preovulatory follicles in pregnant and non-pregnant high yielding cows developed similarly.

  12. Aging of the hair follicle pigmentation system

    National Research Council Canada - National Science Library

    Tobin, Desmond J

    2009-01-01

    .... The hair follicle pigmentary unit is perhaps one of our most visible, accessible and potent aging sensors, with marked dilution of pigment intensity occurring long before even subtle changes are seen in the epidermis...

  13. Asymmetric stem cell division: lessons from Drosophila.

    Science.gov (United States)

    Wu, Pao-Shu; Egger, Boris; Brand, Andrea H

    2008-06-01

    Asymmetric cell division is an important and conserved strategy in the generation of cellular diversity during animal development. Many of our insights into the underlying mechanisms of asymmetric cell division have been gained from Drosophila, including the establishment of polarity, orientation of mitotic spindles and segregation of cell fate determinants. Recent studies are also beginning to reveal the connection between the misregulation of asymmetric cell division and cancer. What we are learning from Drosophila as a model system has implication both for stem cell biology and also cancer research.

  14. Developing a Drosophila Model of Schwannomatosis

    Science.gov (United States)

    2012-08-01

    found to associate with RasV12;scrib–/– tumors and to reduce tumor growth in scrib–/– animals (Pastor- Pareja et al., 2008). The Drosophila genome...2006). Loss of cell polarity drives tumor growth and invasion through JNK activation in Drosophila. Curr. Biol. 16, 1139-1146. Igaki, T., Pastor- Pareja ...genome. Nat. Genet. 36, 288-292. Pastor- Pareja , J. C., Wu, M. and Xu. T. (2008). An innate immune response of blood cells to tumors and tissue damage in

  15. Wdr1-mediated cell shape dynamics and cortical tension are essential for epidermal planar cell polarity.

    Science.gov (United States)

    Luxenburg, Chen; Heller, Evan; Pasolli, H Amalia; Chai, Sophia; Nikolova, Maria; Stokes, Nicole; Fuchs, Elaine

    2015-05-01

    During mouse development, core planar cell polarity (PCP) proteins become polarized in the epidermal plane to guide angling/morphogenesis of hair follicles. How PCP is established is poorly understood. Here, we identify a key role for Wdr1 (also known as Aip1), an F-actin-binding protein that enhances cofilin/destrin-mediated F-actin disassembly. We show that cofilin and destrin function redundantly in developing epidermis, but their combined depletion perturbs cell adhesion, cytokinesis, apicobasal polarity and PCP. Although Wdr1 depletion accentuates single-loss-of-cofilin/destrin phenotypes, alone it resembles core PCP mutations. Seeking a mechanism, we find that Wdr1 and cofilin/destrin-mediated actomyosin remodelling are essential for generating or maintaining cortical tension within the developing epidermal sheet and driving the cell shape and planar orientation changes that accompany establishment of PCP in mammalian epidermis. Our findings suggest intriguing evolutionary parallels but mechanistic modifications to the distal wing hinge-mediated mechanical forces that drive cell shape change and orient PCP in the Drosophila wing disc.

  16. Dynein regulates epithelial polarity and the apical localization of stardust A mRNA.

    Science.gov (United States)

    Horne-Badovinac, Sally; Bilder, David

    2008-01-01

    Intense investigation has identified an elaborate protein network controlling epithelial polarity. Although precise subcellular targeting of apical and basolateral determinants is required for epithelial architecture, little is known about how the individual determinant proteins become localized within the cell. Through a genetic screen for epithelial defects in the Drosophila follicle cells, we have found that the cytoplasmic Dynein motor is an essential regulator of apico-basal polarity. Our data suggest that Dynein acts through the cytoplasmic scaffolding protein Stardust (Sdt) to localize the transmembrane protein Crumbs, in part through the apical targeting of specific sdt mRNA isoforms. We have mapped the sdt mRNA localization signal to an alternatively spliced coding exon. Intriguingly, the presence or absence of this exon corresponds to a developmental switch in sdt mRNA localization in which apical transcripts are only found during early stages of epithelial development, while unlocalized transcripts predominate in mature epithelia. This work represents the first demonstration that Dynein is required for epithelial polarity and suggests that mRNA localization may have a functional role in the regulation of apico-basal organization. Moreover, we introduce a unique mechanism in which alternative splicing of a coding exon is used to control mRNA localization during development.

  17. Dynein regulates epithelial polarity and the apical localization of stardust A mRNA.

    Directory of Open Access Journals (Sweden)

    Sally Horne-Badovinac

    2008-01-01

    Full Text Available Intense investigation has identified an elaborate protein network controlling epithelial polarity. Although precise subcellular targeting of apical and basolateral determinants is required for epithelial architecture, little is known about how the individual determinant proteins become localized within the cell. Through a genetic screen for epithelial defects in the Drosophila follicle cells, we have found that the cytoplasmic Dynein motor is an essential regulator of apico-basal polarity. Our data suggest that Dynein acts through the cytoplasmic scaffolding protein Stardust (Sdt to localize the transmembrane protein Crumbs, in part through the apical targeting of specific sdt mRNA isoforms. We have mapped the sdt mRNA localization signal to an alternatively spliced coding exon. Intriguingly, the presence or absence of this exon corresponds to a developmental switch in sdt mRNA localization in which apical transcripts are only found during early stages of epithelial development, while unlocalized transcripts predominate in mature epithelia. This work represents the first demonstration that Dynein is required for epithelial polarity and suggests that mRNA localization may have a functional role in the regulation of apico-basal organization. Moreover, we introduce a unique mechanism in which alternative splicing of a coding exon is used to control mRNA localization during development.

  18. The dynamics of the primordial follicle reserve.

    Science.gov (United States)

    Kerr, Jeffrey B; Myers, Michelle; Anderson, Richard A

    2013-12-01

    The female germline comprises a reserve population of primordial (non-growing) follicles containing diplotene oocytes arrested in the first meiotic prophase. By convention, the reserve is established when all individual oocytes are enclosed by granulosa cells. This commonly occurs prior to or around birth, according to species. Histologically, the 'reserve' is the number of primordial follicles in the ovary at any given age and is ultimately depleted by degeneration and progression through folliculogenesis until exhausted. How and when the reserve reaches its peak number of follicles is determined by ovarian morphogenesis and germ cell dynamics involving i) oogonial proliferation and entry into meiosis producing an oversupply of oocytes and ii) large-scale germ cell death resulting in markedly reduced numbers surviving as the primordial follicle reserve. Our understanding of the processes maintaining the reserve comes primarily from genetically engineered mouse models, experimental activation or destruction of oocytes, and quantitative histological analysis. As the source of ovulated oocytes in postnatal life, the primordial follicle reserve requires regulation of i) its survival or maintenance, ii) suppression of development (dormancy), and iii) activation for growth and entry into folliculogenesis. The mechanisms influencing these alternate and complex inter-related phenomena remain to be fully elucidated. Drawing upon direct and indirect evidence, we discuss the controversial concept of postnatal oogenesis. This posits a rare population of oogonial stem cells that contribute new oocytes to partially compensate for the age-related decline in the primordial follicle reserve.

  19. Proteomic Analysis of Hair Follicles

    Science.gov (United States)

    Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

    2013-02-01

    Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

  20. Autosomal P[ovoD1] dominant female-sterile insertions in Drosophila and their use in generating germ-line chimeras.

    Science.gov (United States)

    Chou, T B; Noll, E; Perrimon, N

    1993-12-01

    The 'dominant female-sterile' technique used to generate germ-line mosaics in Drosophila is a powerful tool to determine the tissue specificity (germ line versus somatic) of recessive female-sterile mutations as well as to analyze the maternal effect of recessive zygotic lethal mutations. This technique requires the availability of germ-line-dependent, dominant female-sterile (DFS) mutations that block egg laying but do not affect viability. To date only one X-linked mutation, ovoD1 has been isolated that completely fulfills these criteria. Thus the 'DFS technique' has been largely limited to the X-chromosome. To extend this technique to the autosomes, we have cloned the ovoD1 mutation into a P-element vector and recovered fully expressed P[ovoD1] insertions on each autosomal arm. We describe the generation of these P[ovoD1] strains as well as demonstrate their use in generating germ-line chimeras. Specifically, we show that the Gap1 gene, which encodes a Drosophila homologue of mammalian GTPase-activating protein, is required in somatic follicle cells for embryonic dorsoventral polarity determination.

  1. windbeutel, a gene required for dorsoventral patterning in Drosophila, encodes a protein that has homologies to vertebrate proteins of the endoplasmic reticulum

    OpenAIRE

    Konsolaki, Mary; Schüpbach, Trudi

    1998-01-01

    The formation of the dorsoventral axis of the Drosophila embryo depends on cell–cell interactions that take place in the female ovary and involve the activation of transmembrane receptors by secreted ligands. The gene windbeutel functions in the somatic follicle cells of the ovary and is required for the generation of a signal that will determine the ventral side of the embryo. This signal originates in the follicle cells during oogenesis, but its actions are only manifested after fertilizati...

  2. The Invasion and Reproductive Toxicity of QDs-Transferrin Bioconjugates on Preantral Follicle in vitro

    Directory of Open Access Journals (Sweden)

    Gaixia Xu, Suxia Lin, Wing-Cheung Law, Indrajit Roy, Xiaotan Lin, Shujiang Mei, Hanwu Ma, Siping Chen, Hanben Niu, Xiaomei Wang

    2012-01-01

    Full Text Available The toxicity of QD has been extensively studied over the past decade. However, the potential toxicity of QDs impedes its use for clinical research. In this work, we established a preantral follicle in vitro culture system to investigate the effects of QD-Transferrin (QDs-Tf bioconjugates on follicle development and oocyte maturation. The preantral follicles were cultured and exposed to CdTe/ZnTe QDs-Tf bioconjugates with various concentrations and the reproductive toxicity was assessed at different time points post-treatment. The invasion of QDs-Tf for oocytes was verified by laser scanning confocal microscope. Steroid production was evaluated by immunoassay. C-band Giemsa staining was performed to observe the chromosome abnormality of oocytes. The results showed that the QDs-Tf bioconjugates could permeate into granulosa cells and theca cells, but not into oocyte. There are no obvious changes of oocyte diameter, the mucification of cumulus-oocyte-complexes and the occurrence of aneulpoidy as compared with the control group. However, delay in the antrum formation and decrease in the ratio of oocytes with first polar body were observed in QDs-Tf-treated groups. The matured oocytes with first polar body decreased significantly by ~16% (from 79.6±10 % to 63±2.9 % when the concentration of QDs-Tf bioconjugates exceeded 2.89 nmol·L-1 (P < 0.05. Our results implied that the CdTe/ZnTe QDs-Tf bioconjugates were reproductive toxic for follicle development, and thus also revealed that this in vitro culture system of preantral follicle is a highly sensitive tool for study on the reproductive toxicity of nanoparticles.

  3. Coupling planar cell polarity signaling to morphogenesis.

    Science.gov (United States)

    Axelrod, Jeffrey D; McNeill, Helen

    2002-02-15

    Epithelial cells and other groups of cells acquire a polarity orthogonal to their apical-basal axes, referred to as Planar Cell Polarity (PCP). The process by which these cells become polarized requires a signaling pathway using Frizzled as a receptor. Responding cells sense cues from their environment that provide directional information, and they translate this information into cellular asymmetry. Most of what is known about PCP derives from studies in the fruit fly, Drosophila. We review what is known about how cells translate an unknown signal into asymmetric cytoskeletal reorganization. We then discuss how the vertebrate processes of convergent extension and cochlear hair-cell development may relate to Drosophila PCP signaling.

  4. Drosophila PATJ supports adherens junction stability by modulating Myosin light chain activity

    National Research Council Canada - National Science Library

    Sen, Arnab; Nagy-Zsvér-Vadas, Zsanett; Krahn, Michael P

    2012-01-01

    ... (Pals1-associated tight junction protein) was not per se crucial for the maintenance of apical-basal polarity in Drosophila melanogaster epithelial cells but rather regulated Myosin localization and phosphorylation...

  5. Gene and stem cell therapy of the hair follicle.

    Science.gov (United States)

    Hoffman, Robert M

    2005-01-01

    The hair follicle is a highly complex appendage of the skin containing a multiplicity of cell types. The follicle undergoes constant cycling through the life of the organism including growth and resorption with growth dependent on specific stem cells. The targeting of the follicle by genes and stem cells to change its properties, in particular, the nature of the hair shaft is discussed. Hair follicle delivery systems are described such as liposomes and viral vectors for gene therapy. The nature of the hair follicle stem cells is discussed, in particular, its pluripotency.

  6. Fascin regulates nuclear actin during Drosophila oogenesis.

    Science.gov (United States)

    Kelpsch, Daniel J; Groen, Christopher M; Fagan, Tiffany N; Sudhir, Sweta; Tootle, Tina L

    2016-10-01

    Drosophila oogenesis provides a developmental system with which to study nuclear actin. During Stages 5-9, nuclear actin levels are high in the oocyte and exhibit variation within the nurse cells. Cofilin and Profilin, which regulate the nuclear import and export of actin, also localize to the nuclei. Expression of GFP-tagged Actin results in nuclear actin rod formation. These findings indicate that nuclear actin must be tightly regulated during oogenesis. One factor mediating this regulation is Fascin. Overexpression of Fascin enhances nuclear GFP-Actin rod formation, and Fascin colocalizes with the rods. Loss of Fascin reduces, whereas overexpression of Fascin increases, the frequency of nurse cells with high levels of nuclear actin, but neither alters the overall nuclear level of actin within the ovary. These data suggest that Fascin regulates the ability of specific cells to accumulate nuclear actin. Evidence indicates that Fascin positively regulates nuclear actin through Cofilin. Loss of Fascin results in decreased nuclear Cofilin. In addition, Fascin and Cofilin genetically interact, as double heterozygotes exhibit a reduction in the number of nurse cells with high nuclear actin levels. These findings are likely applicable beyond Drosophila follicle development, as the localization and functions of Fascin and the mechanisms regulating nuclear actin are widely conserved.

  7. Translating cell polarity into tissue elongation

    OpenAIRE

    2011-01-01

    Planar cell polarity, the orientation of single-cell asymmetries within the plane of a multicellular tissue, is essential to generating the shape and dimensions of organs and organisms. Planar polarity systems align cell behavior with the body axes and orient the cellular processes that lead to tissue elongation. Using Drosophila as a model system, significant progress has been made toward understanding how planar polarity is generated by biochemical and mechanical signals. Recent studies usi...

  8. Combined activities of Gurken and decapentaplegic specify dorsal chorion structures of the Drosophila egg.

    Science.gov (United States)

    Peri, F; Roth, S

    2000-02-01

    During Drosophila oogenesis Gurken, associated with the oocyte nucleus, activates the Drosophila EGF receptor in the follicular epithelium. Gurken first specifies posterior follicle cells, which in turn signal back to the oocyte to induce the migration of the oocyte nucleus from a posterior to an anterior-dorsal position. Here, Gurken signals again to specify dorsal follicle cells, which give rise to dorsal chorion structures including the dorsal appendages. If Gurken signaling is delayed and starts after stage 6 of oogenesis the nucleus remains at the posterior pole of the oocyte. Eggs develop with a posterior ring of dorsal appendage material that is produced by main-body follicle cells expressing the gene Broad-Complex. They encircle terminal follicle cells expressing variable amounts of the TGFbeta homologue, decapentaplegic. By ectopically expressing decapentaplegic and clonal analysis with Mothers against dpp we show that Decapentaplegic signaling is required for Broad-Complex expression. Thus, the specification and positioning of dorsal appendages along the anterior-posterior axis depends on the intersection of both Gurken and Decapentaplegic signaling. This intersection also induces rhomboid expression and thereby initiates the positive feedback loop of EGF receptor activation, which positions the dorsal appendages along the dorsal-ventral egg axis.

  9. Notch2 is required in somatic cells for breakdown of ovarian germ-cell nests and formation of primordial follicles

    Science.gov (United States)

    2013-01-01

    Background In the mouse ovary, oocytes initially develop in clusters termed germ-cell nests. Shortly after birth, these germ-cell nests break apart, and the oocytes individually become surrounded by somatic granulosa cells to form primordial follicles. Notch signaling plays essential roles during oogenesis in Drosophila, and recent studies have suggested that Notch signaling also plays an essential role during oogenesis and ovary development in mammals. However, no in vivo loss-of-function studies have been performed to establish whether Notch family receptors have an essential physiological role during normal ovarian development in mutant mice. Results Female mice with conditional deletion of the Notch2 gene in somatic granulosa cells of the ovary exhibited reduced fertility, accompanied by the formation of multi-oocyte follicles, which became hemorrhagic by 7 weeks of age. Formation of multi-oocyte follicles resulted from defects in breakdown of the primordial germ-cell nests. The ovaries of the Notch2 conditional mutant mice had increased numbers of oocytes, but decreased numbers of primordial follicles. Oocyte numbers in the Notch2 conditional mutants were increased not by excess or extended cellular proliferation, but as a result of decreased oocyte apoptosis. Conclusions Our work demonstrates that Notch2-mediated signaling in the somatic-cell lineage of the mouse ovary regulates oocyte apoptosis non-cell autonomously, and is essential for regulating breakdown of germ-cell nests and formation of primordial follicles. This model provides a new resource for studying the developmental and physiological roles of Notch signaling during mammalian reproductive biology. PMID:23406467

  10. Follicle stimulating hormone alleviates radiation-induced degeneration of mouse ovarian follicles

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.J. [Hanyang Univ., Seoul (Korea, Republic of); Kim, J.K.; Chun, K.J.

    2000-05-01

    The present study was performed to analyze the influences of (FSH) follicle stimulating hormone and {gamma}-radiation on the morphological changes of ovarian follicles and serum concentrations of testosterone, and estradiol-17{beta} in prepubertal mice. Female mice (ICR strain, three weeks old) were irradiated with 8.33 Gy of {gamma}-ray and followed by a 5 IU i.p.-injection of FSH to know the effect of FSH on the ovarian follicles. Left ovaries were collected at 0 h, 1 d, and 2 d after irradiation or saline/ FSH injection. Another group was received 5 IU of FSH 2 hours before irradiation to analyze the changes of ovarian steroidogenic abilities. By the morphometrical analysis, the number of normal or atretic follicles was counted and the ratio of normal to atretic follicle numbers was calculated. The percentage of atretic follicles was significantly reduced by the treatment of FSH. In the case of the FSH-injected group, the cellular debris caused by radiation was engulfed by the immune cells and the neighboring granulosa cells within the follicles. In concurrence with the morphometric analysis, the changes of the serum concentrations (pg/ml) of testosterone (T) and estradiol (E{sub 2}) were determined by radioimmunoassays. The concentration of T was 336.8{+-}61.3 in the control mice. One day after irradiation, the concentration went up to 484.8{+-}80.0 in the irradiated group, and down to 243.5{+-}80.7 in the FSH-treated one. The concentration of E{sub 2} was 174.9{+-}15.0 in the control group. One day after irradiation, however, the concentration was decreased to 94.8{+-}19.8, and 155.9{+-}8.7 in the irradiated and FSH-treated group, respectively. The alleviation of the follicular degeneration by the treatment of FSH is closely related to the elimination of the cellular debris and to the activities of the steroidogenic enzymes. (Author)

  11. The hedgehog system in ovarian follicles of cattle selected for twin ovulations and births: evidence of a link between the IGF and hedgehog systems.

    Science.gov (United States)

    Aad, Pauline Y; Echternkamp, Sherrill E; Sypherd, David D; Schreiber, Nicole B; Spicer, Leon J

    2012-10-01

    Hedgehog signaling is involved in regulation of ovarian function in Drosophila, but its role in regulating mammalian ovarian folliculogenesis is less clear. Therefore, gene expression of Indian hedgehog (IHH) and its type 1 receptor, patched 1 (PTCH1), were quantified in bovine granulosa (GC) or theca (TC) cells of small (1-5 mm) antral follicles by in situ hybridization and of larger (5-17 mm) antral follicles by real-time RT-PCR from ovaries of cyclic cows genetically selected (Twinner) or not selected (control) for twin ovulations. Expression of IHH mRNA was localized to GC and cumulus cells, whereas PTCH1 mRNA was greater in TC than in GC. Estrogen-active (E-A; follicular fluid concentration of estradiol > progesterone) versus estrogen-inactive follicles had a greater abundance of mRNA for IHH in GC and PTCH1 in TC. Abundance of IHH mRNA in GC was not affected by cow genotype, whereas TC PTCH1 mRNA was less in large E-A follicles of Twinners than in controls. In vitro, estradiol and wingless-type (WNT) 3A increased IHH mRNA in IGF1-treated GC. IGF1 and BMP4 treatments decreased PTCH1 mRNA in small TC. Estradiol and LH increased PTCH1 mRNA in IGF1-treated TC from large and small follicles, respectively. In summary, functional status of ovarian follicles was associated with differences in hedgehog signaling in GC and TC. We hypothesize that as follicles grow and develop, increased free IGF1 may suppress expression of IHH mRNA by GC and PTCH1 mRNA by TC, and these effects are regulated in a paracrine way by estradiol and other intra- and extragonadal factors.

  12. Cellular and molecular regulation of the activation of mammalian primordial follicles: somatic cells initiate follicle activation in adulthood.

    Science.gov (United States)

    Zhang, Hua; Liu, Kui

    2015-01-01

    The first small follicles to appear in the mammalian ovaries are primordial follicles. The initial pool of primordial follicles serves as the source of developing follicles and oocytes for the entire reproductive lifespan of the animal. Although the selective activation of primordial follicles is critical for female fertility, its underlying mechanisms have remained poorly understood. A search of PubMed was conducted to identify peer-reviewed literature pertinent to the study of mammalian primordial follicle activation, especially recent reports of the role of primordial follicle granulosa cells (pfGCs) in regulating this process. In recent years, molecular mechanisms that regulate the activation of primordial follicles have been elucidated, mostly through the use of genetically modified mouse models. Several molecules and pathways operating in both the somatic pfGCs and oocytes, such as the phosphatidylinositol 3 kinase (PI3K) and the mechanistic target of rapamycin complex 1 (mTORC1) pathways, have been shown to be important for primordial follicle activation. More importantly, recent studies have provided an updated view of how exactly signaling pathways in pfGCs and in oocytes, such as the KIT ligand (KL) and KIT, coordinate in adult ovaries so that the activation of primordial follicles is achieved. In this review, we have provided an updated picture of how mammalian primordial follicles are activated. The functional roles of pfGCs in governing the activation of primordial follicles in adulthood are highlighted. The in-depth understanding of the cellular and molecular mechanisms of primordial follicle activation will hopefully lead to more treatments of female infertility, and the current progress indicates that the use of existing primordial follicles as a source for obtaining fertilizable oocytes as a new treatment for female infertility is just around the corner. © The Author 2015. Published by Oxford University Press on behalf of the European Society of

  13. Empty follicle syndrome-Still an enigma

    Directory of Open Access Journals (Sweden)

    Deepika Krishna

    2008-01-01

    Full Text Available Empty follicle syndrome (EFS, although rare with an incidence of 0.2-7%, is a frustrating condition where no oocytes are retrieved in in vitro fertilization (IVF, even though ultrasound and estradiol measurements show the presence of many potential follicles. It is a complex phenomenon that cannot be explained by low bioavailability of human chorionic gonadotrophin alone; neither can it be reliably diagnosed by the measurement of serum beta-human chorionic gonadotrophin (bhCG on the day of oocyte retrieval (OR, except possibly when the bhCG concentration is very low. Here we report a case who underwent intracytoplasmic sperm injection (ICSI for her partner′s severe oligoasthenozoospermia. Controlled ovarian hyperstimulation (COH was done in her first cycle of ICSI, using a gonadotrophin-releasing hormone (GnRH agonist long protocol with follicle-stimulating hormone (FSH and human menopausal gonadotrophin (HMG. However, as we were unable to retrieve any oocytes, her COH protocol was changed in the subsequent cycle with a successful outcome.

  14. Prostaglandins temporally regulate cytoplasmic actin bundle formation during Drosophila oogenesis.

    Science.gov (United States)

    Spracklen, Andrew J; Kelpsch, Daniel J; Chen, Xiang; Spracklen, Cassandra N; Tootle, Tina L

    2014-02-01

    Prostaglandins (PGs)--lipid signals produced downstream of cyclooxygenase (COX) enzymes--regulate actin dynamics in cell culture and platelets, but their roles during development are largely unknown. Here we define a new role for Pxt, the Drosophila COX-like enzyme, in regulating the actin cytoskeleton--temporal restriction of actin remodeling during oogenesis. PGs are required for actin filament bundle formation during stage 10B (S10B). In addition, loss of Pxt results in extensive early actin remodeling, including actin filaments and aggregates, within the posterior nurse cells of S9 follicles; wild-type follicles exhibit similar structures at a low frequency. Hu li tai shao (Hts-RC) and Villin (Quail), an actin bundler, localize to all early actin structures, whereas Enabled (Ena), an actin elongation factor, preferentially localizes to those in pxt mutants. Reduced Ena levels strongly suppress early actin remodeling in pxt mutants. Furthermore, loss of Pxt results in reduced Ena localization to the sites of bundle formation during S10B. Together these data lead to a model in which PGs temporally regulate actin remodeling during Drosophila oogenesis by controlling Ena localization/activity, such that in S9, PG signaling inhibits, whereas at S10B, it promotes Ena-dependent actin remodeling.

  15. Developmental profiles of PERIOD and DOUBLETIME in Drosophila melanogaster ovary.

    Science.gov (United States)

    Kotwica, Joanna; Larson, Maureen K; Bebas, Piotr; Giebultowicz, Jadwiga M

    2009-05-01

    The clock protein PERIOD (PER) displays circadian cycles of accumulation, phosphorylation, nuclear translocation and degradation in Drosophila melanogaster clock cells. One exception to this pattern is in follicular cells enclosing previtellogenic ovarian egg chambers. In these cells, PER remains high and cytoplasmic at all times of day. Genetic evidence suggest that PER and its clock partner TIMELESS (TIM) interact in these cells, yet, they do not translocate to the nucleus. Here, we investigated the levels and subcellular localization of PER in older vitellogenic follicles. Cytoplasmic PER levels decreased in the follicular cells at the onset of vitellogenesis (stage 9). Interestingly, PER was observed in the nuclei of some follicular cells at this stage. PER signal disappeared in more advanced (stage 10) vitellogenic follicles. Since the phosphorylation state of PER is critical for the progression of circadian cycle, we investigated the status of PER phosphorylation in the ovary and the expression patterns of DOUBLETIME (DBT), a kinase known to affect PER in the clock cells. DBT was absent in previtellogenic follicular cells, but present in the cytoplasm of some stage 9 follicular cells. DBT was not distributed uniformly but was present in patches of adjacent cells, in a pattern resembling PER distribution at the same stage. Our data suggest that the absence of dbt expression in the follicular cells of previtellogenic egg chambers may be related to stable and cytoplasmic expression of PER in these cells. Onset of dbt expression in vitellogenic follicles coincides with nuclear localization of PER protein.

  16. Modelling hair follicle growth dynamics as an excitable medium.

    Directory of Open Access Journals (Sweden)

    Philip J Murray

    Full Text Available The hair follicle system represents a tractable model for the study of stem cell behaviour in regenerative adult epithelial tissue. However, although there are numerous spatial scales of observation (molecular, cellular, follicle and multi follicle, it is not yet clear what mechanisms underpin the follicle growth cycle. In this study we seek to address this problem by describing how the growth dynamics of a large population of follicles can be treated as a classical excitable medium. Defining caricature interactions at the molecular scale and treating a single follicle as a functional unit, a minimal model is proposed in which the follicle growth cycle is an emergent phenomenon. Expressions are derived, in terms of parameters representing molecular regulation, for the time spent in the different functional phases of the cycle, a formalism that allows the model to be directly compared with a previous cellular automaton model and experimental measurements made at the single follicle scale. A multi follicle model is constructed and numerical simulations are used to demonstrate excellent qualitative agreement with a range of experimental observations. Notably, the excitable medium equations exhibit a wider family of solutions than the previous work and we demonstrate how parameter changes representing altered molecular regulation can explain perturbed patterns in Wnt over-expression and BMP down-regulation mouse models. Further experimental scenarios that could be used to test the fundamental premise of the model are suggested. The key conclusion from our work is that positive and negative regulatory interactions between activators and inhibitors can give rise to a range of experimentally observed phenomena at the follicle and multi follicle spatial scales and, as such, could represent a core mechanism underlying hair follicle growth.

  17. Introduction to Hair-Follicle-Associated Pluripotent Stem Cells.

    Science.gov (United States)

    Hoffman, Robert M

    2016-01-01

    Nestin-expressing stem cells of the hair follicle, discovered by our laboratory, have been shown to be able to form outer-root sheaths of the follicle as well as neurons and many other non-follicle cell types. We have termed the nestin-expressing stem cells of the hair follicle as hair-follicle-associated pluripotent (HAP) stem cells. We have shown that the HAP stem cells from the hair follicle can effect the repair of peripheral nerve and spinal cord injury. The hair follicle stem cells differentiate into neuronal and glial cells after transplantation to the injured peripheral nerve and spinal cord, and enhance injury repair and locomotor recovery. When the excised hair follicle with its nerve stump was placed in Gelfoam(®) 3D histoculture, HAP stem cells grew and extended the hair follicle nerve which consisted of βIII-tubulin-positive fibers with F-actin expression at the tip. These findings indicate that βIII-tubulin-positive fibers elongating from the whisker follicle sensory nerve stump were growing axons. The growing whisker sensory nerve was highly enriched in HAP stem cells, which appeared to play a major role in its elongation and interaction with other nerves in 3D Gelfoam(®) histoculture, including the sciatic nerve, the trigeminal nerve, and the trigeminal nerve ganglion. These results suggest that a major function of the HAP stem cells in the hair follicle is for growth of the follicle sensory nerve. Recently, we have shown that HAP stem cells can differentiate into beating cardiac muscle cells. HAP stem cells have critical advantages for regenerative medicine over embryonic stem (ES) cells and induced pluripotent stem (iPS) cells in that they are highly accessible from each patient, thereby eliminating immunological issues since they are autologous, require no genetic manipulation, are non-tumorigenic, and do not present ethical issues.

  18. Ring canals in the ovarian follicles of Aedes aegypti

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, G.; Rai, K.S.

    1976-07-01

    In the ovarian follicles of Aedes aegypti, the oocyte develops from 1 of 8 interconnected cystocytes. The cytoplasmic interconnections, the ring canals, have an electron dense rim in which are embedded an array of parallel filaments. The ring canal in presumptive follicle is generally devoid of organelles, while that in the more advanced secondary follicle encloses ribosomes, vesicles and mitochondria. Ring canals may furnish a means for the transfer of materials including ribosomes and mitochondria from nurse cells to the oocyte.

  19. Adult Neurogenesis in Drosophila

    OpenAIRE

    Ismael Fernández-Hernández; Christa Rhiner; Eduardo Moreno

    2013-01-01

    Adult neurogenesis has been linked to several cognitive functions and neurological disorders. Description of adult neurogenesis in a model organism like Drosophila could facilitate the genetic study of normal and abnormal neurogenesis in the adult brain. So far, formation of new neurons has not been detected in adult fly brains and hence has been thought to be absent in Drosophila. Here, we used an improved lineage-labeling method to show that, surprisingly, adult neurogenesis occurs in the m...

  20. The hair follicle as a target for gene therapy.

    Science.gov (United States)

    Gupta, S; Domashenko, A; Cotsarelis, G

    2001-01-01

    The hair follicle possesses progenitor cells for continued hair follicle cycling and for epidermal keratinocytes, melanocytes and Langerhans cells. These different cell types can be targeted by topical gene delivery to mouse skin. Using a combination of liposomes and DNA, we demonstrated the feasibility of targeting hair follicle cells in human scalp xenografts as well. We defined liposome composition and stage of the hair cycle as important parameters influencing transfection of human hair follicles. Transfection occurred only during anagen onset. Considerations and obstacles for using gene therapy to treat alopecias and skin disease are discussed. A theoretical framework for future gene therapy treatments for cutaneous and systemic disorders is presented.

  1. Alginate: A Versatile Biomaterial to Encapsulate Isolated Ovarian Follicles.

    Science.gov (United States)

    Vanacker, Julie; Amorim, Christiani A

    2017-02-28

    In vitro culture of ovarian follicles isolated or enclosed in ovarian tissue fragments and grafting of isolated ovarian follicles represent a potential alternative to restore fertility in cancer patients who cannot undergo cryopreservation of embryos or oocytes or transplantation of frozen-thawed ovarian tissue. In this regard, respecting the three-dimensional (3D) architecture of isolated follicles is crucial to maintaining their proper follicular physiology. To this end, alginate hydrogel has been widely investigated using follicles from numerous animal species, yielding promising results. The goal of this review is therefore to provide an overview of alginate applications utilizing the biomaterial as a scaffold for 3D encapsulation of isolated ovarian follicles. Different methods of isolated follicle encapsulation in alginate are discussed in this review, as its use of 3D alginate culture systems as a tool for in vitro follicle analysis. Possible improvements of this matrix, namely modification with arginine-glycine-aspartic acid peptide or combination with fibrin, are also summarized. Encouraging results have been obtained in different animal models, and particularly with isolated follicles encapsulated in alginate matrices and grafted to mice. This summary is designed to guide the reader towards development of next-generation alginate scaffolds, with enhanced properties for follicle encapsulation.

  2. Regulation of cell polarity determinants by the Retinoblastoma tumor suppressor protein

    OpenAIRE

    2016-01-01

    In addition to their canonical roles in the cell cycle, RB family proteins regulate numerous developmental pathways, although the mechanisms remain obscure. We found that Drosophila Rbf1 associates with genes encoding components of the highly conserved apical–basal and planar cell polarity pathways, suggesting a possible regulatory role. Here, we show that depletion of Rbf1 in Drosophila tissues is indeed associated with polarity defects in the wing and eye. Key polarity genes aPKC, par6, van...

  3. Characterization of the Drosophila ortholog of the human Usher Syndrome type 1G protein sans.

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    Fabio Demontis

    Full Text Available BACKGROUND: The Usher syndrome (USH is the most frequent deaf-blindness hereditary disease in humans. Deafness is attributed to the disorganization of stereocilia in the inner ear. USH1, the most severe subtype, is associated with mutations in genes encoding myosin VIIa, harmonin, cadherin 23, protocadherin 15, and sans. Myosin VIIa, harmonin, cadherin 23, and protocadherin 15 physically interact in vitro and localize to stereocilia tips in vivo, indicating that they form functional complexes. Sans, in contrast, localizes to vesicle-like structures beneath the apical membrane of stereocilia-displaying hair cells. How mutations in sans result in deafness and blindness is not well understood. Orthologs of myosin VIIa and protocadherin 15 have been identified in Drosophila melanogaster and their genetic analysis has identified essential roles in auditory perception and microvilli morphogenesis, respectively. PRINCIPAL FINDINGS: Here, we have identified and characterized the Drosophila ortholog of human sans. Drosophila Sans is expressed in tubular organs of the embryo, in lens-secreting cone cells of the adult eye, and in microvilli-displaying follicle cells during oogenesis. Sans mutants are viable, fertile, and mutant follicle cells appear to form microvilli, indicating that Sans is dispensable for fly development and microvilli morphogenesis in the follicle epithelium. In follicle cells, Sans protein localizes, similar to its vertebrate ortholog, to intracellular punctate structures, which we have identified as early endosomes associated with the syntaxin Avalanche. CONCLUSIONS: Our work is consistent with an evolutionary conserved function of Sans in vesicle trafficking. Furthermore it provides a significant basis for further understanding of the role of this Usher syndrome ortholog in development and disease.

  4. Hair Follicle Nevus: A Case Report

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    İnci Mevlitoğlu

    2014-06-01

    Full Text Available Hair follicle nevus (HFN is a rare hamartoma showing follicular differentiation. Hamartomas are benign tumoral formations caused by overproduction of normal tissues and cells. HFN was first introduced by Gans et al in 1928. There are a few reports in literature on HFN appearing as multiple lesions, which is often observed as a single papule or nodule. We are hereby present our patient having complaints beginning in early childhood as his lesions might be confused with other dermatoses located on face area. As far as we know, our patient is the first HFN case with bilateral, multiple, perioral, perinasal, periorbital and genital involvements.

  5. Deflection of a vibrissa leads to a gradient of strain across mechanoreceptors in a mystacial follicle.

    Science.gov (United States)

    Whiteley, Samuel J; Knutsen, Per M; Matthews, David W; Kleinfeld, David

    2015-07-01

    Rodents use their vibrissae to detect and discriminate tactile features during active exploration. The site of mechanical transduction in the vibrissa sensorimotor system is the follicle sinus complex and its associated vibrissa. We study the mechanics within the ring sinus (RS) of the follicle in an ex vivo preparation of the mouse mystacial pad. The sinus region has a relatively dense representation of Merkel mechanoreceptors and longitudinal lanceolate endings. Two-photon laser-scanning microscopy was used to visualize labeled cell nuclei in an ∼ 100-nl vol before and after passive deflection of a vibrissa, which results in localized displacements of the mechanoreceptor cells, primarily in the radial and polar directions about the vibrissa. These displacements are used to compute the strain field across the follicle in response to the deflection. We observe compression in the lower region of the RS, whereas dilation, with lower magnitude, occurs in the upper region, with volumetric strain ΔV/V ∼ 0.01 for a 10° deflection. The extrapolated strain for a 0.1° deflection, the minimum angle that is reported to initiate a spike by primary neurons, corresponds to the minimum strain that activates Piezo2 mechanoreceptor channels.

  6. Lengthened superstimulatory treatment in cattle: Evidence for rescue of follicles within a wave rather than continuous recruitment of new follicles.

    Science.gov (United States)

    García Guerra, A; Tribulo, A; Yapura, J; Adams, G P; Singh, J; Mapletoft, R J

    2015-08-01

    A study was designed to compare the effects of a conventional (4 days) versus a lengthened (7 days) superstimulation protocol on follicle dynamics and to test the hypothesis that superstimulatory treatment only rescues small follicles within the wave. Nonlactating beef cows received a progesterone-releasing intravaginal device [PRID] and were superstimulated with 400-mg FSH on the day of follicle ablation-induced wave emergence (Day 0). The control group (n = 5) received FSH over 4 days, whereas the long group (n = 5) received FSH over 7 days. PGF was administered twice on Day 2 (control group) or 5 (long group), and PRIDs were removed 24 hours after the first PGF. Cows received 25-mg LH 24 hours after PRID removal. The cows chosen for the present study represented a subset from a larger group of 24 cows in which superovulation results were obtained and published. Cows in the present study were those with the lowest antral follicle counts at the time of wave emergence in order to facilitate tracking of individual follicles. Daily ultrasonographic examinations monitored follicle diameters and numbers. A reduction (P protocols rescue small antral follicles present at the time of wave emergence; there was no evidence for continuous recruitment of new follicles. Results also provide rationale for the hypothesis that a lengthened treatment protocol is associated with greater follicle maturation and capacity to ovulate.

  7. Gene bionetworks that regulate ovarian primordial follicle assembly.

    Science.gov (United States)

    Nilsson, Eric; Zhang, Bin; Skinner, Michael K

    2013-07-23

    Primordial follicle assembly is the process by which ovarian primordial follicles are formed. During follicle assembly oocyte nests break down and a layer of pre-granulosa cells surrounds individual oocytes to form primordial follicles. The pool of primordial follicles formed is the source of oocytes for ovulation during a female's reproductive life. The current study utilized a systems approach to detect all genes that are differentially expressed in response to seven different growth factor and hormone treatments known to influence (increase or decrease) primordial follicle assembly in a neonatal rat ovary culture system. One novel factor, basic fibroblast growth factor (FGF2), was experimentally determined to inhibit follicle assembly. The different growth factor and hormone treatments were all found to affect similar physiological pathways, but each treatment affected a unique set of differentially expressed genes (signature gene set). A gene bionetwork analysis identified gene modules of coordinately expressed interconnected genes and it was found that different gene modules appear to accomplish distinct tasks during primordial follicle assembly. Predictions of physiological pathways important to follicle assembly were validated using ovary culture experiments in which ERK1/2 (MAPK1) activity was increased. A number of the highly interconnected genes in these gene networks have previously been linked to primary ovarian insufficiency (POI) and polycystic ovarian disease syndrome (PCOS). Observations have identified novel factors and gene networks that regulate primordial follicle assembly. This systems biology approach has helped elucidate the molecular control of primordial follicle assembly and provided potential therapeutic targets for the treatment of ovarian disease.

  8. Role of spectraplakin in Drosophila photoreceptor morphogenesis.

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    Uyen Ngoc Mui

    Full Text Available BACKGROUND: Crumbs (Crb, a cell polarity gene, has been shown to provide a positional cue for the apical membrane domain and adherens junction during Drosophila photoreceptor morphogenesis. It has recently been found that stable microtubules in developing Drosophila photoreceptors were linked to Crb localization. Coordinated interactions between microtubule and actin cytoskeletons are involved in many polarized cellular processes. Since Spectraplakin is able to bind both microtubule and actin cytoskeletons, the role of Spectraplakin was analyzed in the regulations of apical Crb domain in developing Drosophila photoreceptors. METHODOLOGY/PRINCIPAL FINDINGS: The localization pattern of Spectraplakin in developing pupal photoreceptors showed a unique intracellular distribution. Spectraplakin localized at rhabdomere terminal web which is at the basal side of the apical Crb or rhabdomere, and in between the adherens junctions. The spectraplakin mutant photoreceptors showed dramatic mislocalizations of Crb, adherens junctions, and the stable microtubules. This role of Spectraplakin in Crb and adherens junction regulation was further supported by spectraplakin's gain-of-function phenotype. Spectraplakin overexpression in photoreceptors caused a cell polarity defect including dramatic mislocalization of Crb, adherens junctions and the stable microtubules in the developing photoreceptors. Furthermore, a strong genetic interaction between spectraplakin and crb was found using a genetic modifier test. CONCLUSIONS/SIGNIFICANCE: In summary, we found a unique localization of Spectraplakin in photoreceptors, and identified the role of spectraplakin in the regulation of the apical Crb domain and adherens junctions through genetic mutational analysis. Our data suggest that Spectraplakin, an actin-microtubule cross-linker, is essential in the apical and adherens junction controls during the photoreceptors morphogenesis.

  9. Osteogenic Differentiation of Dental Follicle Stem Cells

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    Giorgio Mori, Andrea Ballini, Claudia Carbone, Angela Oranger, Giacomina Brunetti, Adriana Di Benedetto, Biagio Rapone, Stefania Cantore, Mariasevera Di Comite, Silvia Colucci, Maria Grano, Felice R. Grassi

    2012-01-01

    Full Text Available Background: Stem cells are defined as clonogenic cells capable of self-renewal and multi-lineage differentiation. A population of these cells has been identified in human Dental Follicle (DF.Dental Follicle Stem Cells (DFSCs were found in pediatric unerupted wisdom teeth and have been shown to differentiate, under particular conditions, into various cell types of the mesenchymal tissues.Aim: The aim of this study was to investigate if cells isolated from DF show stem features, differentiate toward osteoblastic phenotype and express osteoblastic markers.Methods: We studied the immunophenotype of DFSCs by flow cytometric analysis, the osteoblastic markers of differentiated DFSCs were assayed by histochemical methods and real-time PCR.Results: We demonstrated that DFSCs expressed a heterogeneous assortment of makers associated with stemness. Moreover DFSCs differentiated into osteoblast-like cells, producing mineralized matrix nodules and expressed the typical osteoblastic markers, Alkaline Phosphatase (ALP and Collagen I (Coll I.Conclusion: This study suggests that DFSCs may provide a cell source for tissue engineering of bone.

  10. Superficially located enlarged lymphoid follicles characterise nodular gastritis.

    Science.gov (United States)

    Okamura, Takuma; Sakai, Yasuhiro; Hoshino, Hitomi; Iwaya, Yugo; Tanaka, Eiji; Kobayashi, Motohiro

    2015-01-01

    Nodular gastritis is a form of chronic Helicobacter pylori gastritis affecting the gastric antrum and characterised endoscopically by the presence of small nodular lesions resembling gooseflesh. It is generally accepted that hyperplasia of lymphoid follicles histologically characterises nodular gastritis; however, quantitative analysis in support of this hypothesis has not been reported. Our goal was to determine whether nodular gastritis is characterised by lymphoid follicle hyperplasia.The number, size, and location of lymphoid follicles in nodular gastritis were determined and those properties compared to samples of atrophic gastritis. The percentages of high endothelial venule (HEV)-like vessels were also evaluated.The number of lymphoid follicles was comparable between nodular and atrophic gastritis; however, follicle size in nodular gastritis was significantly greater than that seen in atrophic gastritis. Moreover, lymphoid follicles in nodular gastritis were positioned more superficially than were those in atrophic gastritis. The percentage of MECA-79 HEV-like vessels was greater in areas with gooseflesh-like lesions in nodular versus atrophic gastritis.Superficially located hyperplastic lymphoid follicles characterise nodular gastritis, and these follicles correspond to gooseflesh-like nodular lesions observed endoscopically. These observations suggest that MECA-79 HEV-like vessels could play at least a partial role in the pathogenesis of nodular gastritis.

  11. 21 CFR 522.1002 - Follicle stimulating hormone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Follicle stimulating hormone. 522.1002 Section 522....1002 Follicle stimulating hormone. (a)(1) Specifications. Each package contains 2 vials. One vial... hormone. The other vial contains 10 milliliters of aqueous diluent. (2) Sponsor. See 059521 in §...

  12. Role of adenohypophyseal mixed cell-follicles in age estimation.

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    Ishikawa T

    2003-04-01

    Full Text Available In this study we used paraffin-embedded human pituitary obtained from 248 autopsy cases and identified mixed cell follicles by the immunohistochemical method. We examined the number and size of the mixed cell follicles, and the ratio of each component cell of these follicles, in the anterior pituitary at various age groups. The number of follicles increased with age, and the size of the follicles also tended to enlarge with age. Statistical analysis showed that a high correlation existed between age and the number or the size of the mixed cell-follicles formed by various adenohypophyseal cells. In addition, when the proportions of the different cell types that formed the follicles were examined, sex differences were observed with aging for the GH cells, the PRL cells, and the gonadotroph (GTH cells, while no changes were observed with aging in both men and women for the ACTH cells and TSH cells. These results indicate that the number, size, and ratio of each component cell of follicles in the anterior pituitary are adequately applicable for the purpose of age estimation in routine forensic medicine.

  13. Involvement of Notch signaling in early chick ovarian follicle development.

    Science.gov (United States)

    Li, Jun; Zhao, Dan; Guo, Changquan; Li, Jian; Mi, Yuling; Zhang, Caiqiao

    2016-01-01

    The formation of primordial follicles is a crucial process in the establishment of follicle pools required for the female's reproductive life span. For laying hens, ample follicles are a prerequisite for high laying performance. Notch signaling plays critical roles in germ cell cysts breakdown and in the formation of primordial follicles. Here, we investigated the role of Notch signaling in the ovarian development of post-hatch chicks. Results showed that around post-hatch day 4 (H4), the germ cell cysts broke apart, oocytes became surrounded by squamous pregranulosa cells, and the primordial follicles were then formed. Subsequently, we detected the expression of Notch signaling-related genes including Notch receptors (Notch1, 2), ligands (Jag1, 2 and Dll1, 4), and target genes (Hes1, Hey1). These genes all showed expression at H4 and some of these genes were up-regulated during primordial follicle formation. To evaluate the Notch signaling requirement for early follicular development, we adopted an in vitro ovary culture system. Suppression of Notch signaling by γ-secretase inhibitor induced a decrease of primordial follicles and an increase of germ cells in cysts. Attenuating Notch signaling also inhibited the phosphatidylinositol 3-kinase/protein kinase B pathways and suppressed cadherin expression. These results suggest that Notch signaling is endowed with an indispensable role in primordial follicle formation in post-hatch chicks.

  14. Piscine follicle-stimulating hormone triggers progestin production in gilthead seabream primary ovarian follicles.

    Science.gov (United States)

    Zapater, Cinta; Chauvigné, François; Scott, Alexander P; Gómez, Ana; Katsiadaki, Ioanna; Cerdà, Joan

    2012-11-01

    Ovarian growth (vitellogenesis) in most lower vertebrates is mediated by estradiol-17beta (E2) secreted by the follicles in response to follicle-stimulating hormone (Fsh), whereas oocyte maturation and ovulation are mediated by progestins, such as 17alpha,20beta-dihydroxypregn-4-en-3-one (17,20beta-P), produced in response to luteinizing hormone (Lh). In teleosts, follicular synthesis of 17,20beta-P at the time of maturation is due primarily to up-regulation of the enzymes P450c17-II (Cyp17a2) and 20beta-hydroxysteroid dehydrogenase (Cbr1). Here, we show that follicular cells associated with primary growth (previtellogenic) oocytes of the gilthead seabream also express cyp17a2 and cbr1, in addition to P450c17-I (cyp17a1) and aromatase (cyp19a1), enzymes required for E2 synthesis. Ovaries containing only oogonia and early primary ovarian follicles had a 60-fold higher concentration of 17,20beta-P than ovaries in the succeeding stages and had a higher expression of cbr1 and Fsh receptor (fshra). Stimulation of explants of primary follicles in vitro with recombinant piscine Fsh (rFsh), which specifically activates the seabream Fshra, promoted a rapid accumulation of 17,20beta-P, and synthesis was sustained by an external supply of 17alpha-hydroxyprogesterone. In the presence of Cbr1 inhibitors, rFsh-mediated 17,20beta-P production was reduced, with a concomitant increase in testosterone and E2 synthesis. In primary explants, rFsh up-regulated cyp17a2 and cbr1 transcription and simultaneously down-regulated cyp17a1 and cyp19a1 steady-state mRNA levels within 24 h. In contrast, in explants containing vitellogenic follicles, rFsh had no effect on cyp17a2 and cbr1 expression, but increased that of cyp17a1 and cyp19a1. These data suggest a functional Fshra-activated Cyp17a2/Cbr1 steroidogenic pathway in gilthead seabream primary ovarian follicles triggering the production of 17,20beta-P.

  15. Ultrasonographic characterization of follicle deviation in follicular waves with single dominant and codominant follicles in dromedary camels (Camelus dromedarius).

    Science.gov (United States)

    Manjunatha, B M; Al-Bulushi, S; Pratap, N

    2014-04-01

    Follicular wave emergence was synchronized by treating camels with GnRH when a dominant follicle (DF) was present in the ovaries. Animals were scanned twice a day from day 0 (day of GnRH treatment) to day 10, to characterize emergence and deviation of follicles during the development of the follicular wave. Follicle deviation in individual animals was determined by graphical method. Single DFs were found in 16, double DFs in 9 and triple DFs in two camels. The incidence of codominant (double and triple DFs) follicles was 41%. The interval from GnRH treatment to wave emergence, wave emergence to deviation, diameter and growth rate of F1 follicle before or after deviation did not differ between the animals with single and double DFs. The size difference between future DF(s) and the largest subordinate follicle (SF) was apparent from the day of wave emergence in single and double DFs. Overall, interval from GnRH treatment to wave emergence and wave emergence to the beginning of follicle deviation was 70.6 ± 1.4 and 58.6 ± 2.7 h, respectively. Mean size of the DF and largest SF at the beginning of deviation was 7.4 ± 0.2 and 6.3 ± 0.1 mm, respectively. In conclusion, the characteristics of follicle deviation are similar between the animals that developed single or double DFs.

  16. Developmental effects of imatinib mesylate on follicle assembly and early activation of primordial follicle pool in postnatal rat ovary.

    Science.gov (United States)

    Asadi-Azarbaijani, Babak; Santos, Regiane R; Jahnukainen, Kirsi; Braber, Saskia; van Duursen, Majorie B M; Toppari, Jorma; Saugstad, Ola D; Nurmio, Mirja; Oskam, Irma C

    2017-03-01

    Imatinib mesylate is an anti-cancer agent that competitively inhibits several receptor tyrosine kinases (RTKs). RTKs play important roles in the regulation of primordial follicle formation, the recruitment of primordial follicles into the pool of growing follicles and maturation of the follicles. In the present study, we investigated the effects of the tyrosine kinase inhibitor imatinib on primordial follicle assembly and early folliculogenesis in postnatal rats. Female Sprague-Dawley rats were treated with either imatinib (150mg/kg) or placebo (water) on postnatal days 2-4. Bilateral ovariectomy was performed on postnatal day 2 and 5. Histology, immunohistochemistry, and mRNA analysis were performed. Imatinib treatment was associated with increased density of the multi-oocyte follicles (Pprimordial follicles, increased expression of c-Kit and AMH, and decreased protein expression of Kit-ligand and GDF9 when compared to age-matched controls. In conclusion, imatinib affects folliculogenesis in postnatal rat ovaries by delaying the cluster breakdown, follicular assembly and early activation of the primordial follicle pool. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. Effects of 5α-dihydrotestosterone and 17β-estradiol on the mouse ovarian follicle development and oocyte maturation.

    Directory of Open Access Journals (Sweden)

    Wataru Tarumi

    Full Text Available We have previously reported that androstenedione induces abnormalities of follicle development and oocyte maturation in the mouse ovary. In granulosa cells of the ovarian follicle, androstenedione is aromatized to 17β-estradiol (E2. To determine whether the androgen or estrogen acts directly on the follicle to induce the above-mentioned abnormalities, we compared the effects of a non-aromatizable androgen, 5α-dihydrotestosterone (DHT, with those of E2 on murine follicular development and oocyte maturation in a single follicle culture system. The high dose (10(-6 M of DHT prompted normal follicular development, and there was no effect on oocyte meiotic maturation after stimulation with human chorionic gonadotropin (hCG and epidermal growth factor (EGF. In contrast, culture with the high dose (10(-6 M of E2 delayed follicular growth and also suppressed proliferation of granulosa cells and antrum formation. Furthermore, culture with E2 delayed or inhibited oocyte meiotic maturation, such as chromosome alignment on the metaphase plate and extrusion of the first polar body, after addition of hCG and EGF. In conclusion, these findings demonstrate that E2, but not DHT, induces abnormalities of follicular development, which leads to delay or inhibition of oocyte meiotic maturation.

  18. Monohaloacetic acid drinking water disinfection by-products inhibit follicle growth and steroidogenesis in mouse ovarian antral follicles in vitro.

    Science.gov (United States)

    Jeong, Clara H; Gao, Liying; Dettro, Tyler; Wagner, Elizabeth D; Ricke, William A; Plewa, Michael J; Flaws, Jodi A

    2016-07-01

    Water disinfection greatly reduced the incidence of waterborne diseases, but the reaction between disinfectants and natural organic matter in water leads to the formation of drinking water disinfection by-products (DBPs). DBPs have been shown to be toxic, but their effects on the ovary are not well defined. This study tested the hypothesis that monohalogenated DBPs (chloroacetic acid, CAA; bromoacetic acid, BAA; iodoacetic acid, IAA) inhibit antral follicle growth and steroidogenesis in mouse ovarian follicles. Antral follicles were isolated and cultured with either vehicle or DBPs (0.25-1.00mM of CAA; 2-15μM of BAA or IAA) for 48 and 96h. Follicle growth was measured every 24h and the media were analyzed for estradiol levels at 96h. Exposure to DBPs significantly inhibited antral follicle growth and reduced estradiol levels compared to controls. These data demonstrate that DBP exposure caused ovarian toxicity in vitro.

  19. Effect of Follicle Size and Follicle Stimulating Hormone Concentration on Nuclear Maturation of Bovine Oocytes In Vitro

    Directory of Open Access Journals (Sweden)

    Uğur Şen

    2015-07-01

    Full Text Available The aim of the study was to investigate the effect of follicle size and follicle stimulating hormone (FSH concentration on nuclear maturation of bovine oocytes in vitro. Follicles on bovine ovary were classified into 3 groups according to the diameter; small (<3 mm, medium (3–8 mm and large (9–12 mm. Oocytes were aspirated from follicles with different size and matured in tissue culture medium (TCM–199 supplemented with 10% FCS and various concentrations of FSH (0.5, 1.0 or 10 and μg/ml for 22 hours filled with approximately 95% humidified and 5% CO2 in air at 38.5 °C. At the end of culture period, nuclear maturation (at metaphase II; MII of oocytes were determined by Bisbenzimide (Hoechst 33258 DNA staining under fluorescent microscope. In the present study, effect of follicle size on nuclear maturation of bovine oocytes were determined and the percentage of oocytes reached to M II stage was significantly lower in oocytes obtained small follicle than those of medium and large follicles. Supplementation of 10.0 μg/ml FSH into maturation media increased percentage of nuclear maturation compare to 0.5 and 1.0 μg/ml. Additionally, improving effect of high FSH concentration on nuclear maturation were more observed in oocytes obtained small follicles. The results of present study showed that oocytes from follicles with 3–8 mm diameters exhibited a more successful maturation, but oocytes obtained small follicles exhibited more maturation as a ratio under high FSH concentration.

  20. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  1. Understanding Autoinhibition of Drosophila Formin Cappuccino in vitro and in vivo

    OpenAIRE

    Bor, Batbileg

    2014-01-01

    Cappuccino (Capu) is an actin assembly factor that is necessary to establish Drosophila oocyte polarity. Disrupting normal polarity leads to female sterility. It is thought that Capu helps establish oocyte polarity by creating a mesh-like actin structure that spans the oocyte during early stages of development. Disappearance of this actin mesh in later stages of oogenesis coincides with rapid coordinated flows of the cytoplasm, referred to as cytoplasmic streaming. When cytoplasmic streaming ...

  2. Human hair growth ex vivo is correlated with in vivo hair growth: selective categorization of hair follicles for more reliable hair follicle organ culture.

    Science.gov (United States)

    Kwon, Oh Sang; Oh, Jun Kyu; Kim, Mi Hyang; Park, So Hyun; Pyo, Hyun Keol; Kim, Kyu Han; Cho, Kwang Hyun; Eun, Hee Chul

    2006-02-01

    Of the numerous assays used to assess hair growth, hair follicle organ culture model is one of the most popular and powerful in vitro systems. Changes in hair growth are commonly employed as a measurement of follicular activity. Hair cycle stage of mouse vibrissa follicles in vivo is known to determine subsequent hair growth and follicle behavior in vitro and it is recommended that follicles be taken at precisely the same cyclic stage. This study was performed to evaluate whether categorization of human hair follicles by the growth in vivo could be used to select follicles of the defined anagen stage for more consistent culture. Occipital scalp samples were obtained from three subjects, 2 weeks later after hair bleaching. Hair growth and follicle length of isolated anagen VI follicles were measured under a videomicroscope. Follicles were categorized into four groups according to hair growth and some were cultured ex vivo for 6 days. Follicles showed considerable variations with respect to hair growth and follicle length; however, these two variables were relatively well correlated. Hair growth in culture was closely related with hair growth rate in vivo. Moreover, minoxidil uniquely demonstrated a significant increase of hair growth in categorized hair follicles assumed at a similar early anagen VI stage of hair cycle. Selection of follicles at a defined stage based on hair-growth rate would permit a more reliable outcome in human hair follicle organ culture.

  3. Protein composition in the fluid of individual bovine follicles.

    Science.gov (United States)

    Andersen, M M; Kroll, J; Byskov, A G; Faber, M

    1976-09-01

    The proteins in follicular fluid from individual and pooled bovine follicles were studied by gel chromatography and quantitative immunoelectrophoresis. The mean protein concentration was 86-4% of serum; very large proteins were present in only low concentrations. A minimum of 40 individual proteins was distinguished in follicular fluid, and 15 of these proteins were quantitated. A correlation between molecular weight and follicular fluid: serum concentration ratio was found. Fluid from individual follicles differed only in the relative concentrations of small and large proteins. An exception to this was IgG which was occasionally, but never in healthy growing follicles, present in concetrations above 150% of serum. Healthy growing, preovulatory and atretic follicles had higher, and cystic follicles mostly lower, concentrations of small proteins than serum. The concentration of alpha2-macroglobulin in healthy growing follicles never exceeded 16% of serum. The concentration of large proteins in follicular fluid increased with increasing follicle size. Attempts to detect proteins specific to follicular fluid by immunizing rabbits with pooled follicular samples and the follicular fluid proteins not bound by anti-bovine antiserum resulted in production of antibodies against fibrinogen and its split products D+E only.

  4. Immunohistochemical localization of basement membrane components during hair follicle morphogenesis

    DEFF Research Database (Denmark)

    Westgate, G E; Shaw, D A; Harrap, G J

    1984-01-01

    Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA was not ......Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA...... of the elongating follicle. HSPG was associated with the basal cell layer prior to the appearance of hair follicle primordia and became BMZ-associated before birth but after follicle buds were first observed. HSPG was also found to be associated with the basal cell surfaces in the epidermis, but not in the hair...... follicle. Laminin and type IV collagen were continually present in epidermal and follicular BMZ both before and during development of hair follicles and were later present in the dermal papilla matrix. From these observations we conclude that (1) laminin and type IV collagen are functionally important...

  5. Novel Cl- currents elicited by follicle stimulating hormone and acetylcholine in follicle-enclosed Xenopus oocytes

    Science.gov (United States)

    1993-01-01

    Voltage-clamp techniques were used to study the membrane currents elicited by follicle stimulating hormone (FSH) and acetylcholine (ACh) in follicle-enclosed oocytes of Xenopus laevis (follicles). Both agonists caused complex responses that were more evident when the follicles were in hypotonic Ringer solution (HR; 190.4 mosM). In this medium, currents activated by FSH regularly showed three phases whereas currents activated by ACh displayed three to six phases. At a holding potential of -60 mV, FSH, and ACh responses involved combinations of inward and outward currents. Both FSH and ACh responses included a slow smooth inward component that was associated with an increase in membrane conductance, mainly to Cl- (S(in)). This current was strongly dependent on the osmolarity of the external solution: an increase in osmolarity of the HR solution of 18-20 mosM caused a 50% decrease in S(in). In contrast, a fast and transient Cl- current (F(in)) specifically elicited by ACh was not dependent on osmolarity. Both, F(in) and S(in) currents required the presence of follicular cells, since defolliculation using three different methods abolished all the response to FSH and at least four components of the ACh responses. The membrane channels carrying F(in) and oscillatory Cl- currents elicited by stimulation of ACh or serum receptors, were much more permeable to I- and Br- than Cl-, whereas S(in) channels were equally permeable to these anions. Unlike the oscillatory Cl- currents generated in the oocyte itself, S(in) and F(in) currents in follicle-enclosed oocytes were not abolished by chelation of intracellular Ca2+, either with EGTA or BAPTA, which suggests that intracellular Ca2+ does not play a critical role in the activation of these currents. Our experiments show that S(in) and F(in) currents are quite distinct from the previously characterized oscillatory Cl- responses of oocytes. Moreover, the results strongly suggest that the FSH and ACh receptors, the Cl- channels

  6. BMAA neurotoxicity in Drosophila.

    Science.gov (United States)

    Zhou, Xianchong; Escala, Wilfredo; Papapetropoulos, Spyridon; Bradley, Walter G; Zhai, R Grace

    2009-01-01

    We report the establishment of an in vivo model using the fruit fly Drosophila melanogaster to investigate the toxic effects of L-BMAA. We found that dietary intake of BMAA reduced the lifespan as well as the neurological functions of flies. Furthermore, we have developed an HPLC method to reliably detect both free and protein-bound BMAA in fly tissue extracts.

  7. Cancer in Drosophila

    DEFF Research Database (Denmark)

    Herranz, Héctor; Eichenlaub, Teresa; Cohen, Stephen M

    2016-01-01

    Cancer genomics has greatly increased our understanding of the complexity of the genetic and epigenetic changes found in human tumors. Understanding the functional relationships among these elements calls for the use of flexible genetic models. We discuss the use of Drosophila models to study...

  8. Coupling Planar Cell Polarity Signaling to Morphogenesis

    Directory of Open Access Journals (Sweden)

    Jeffrey D. Axelrod

    2002-01-01

    Full Text Available Epithelial cells and other groups of cells acquire a polarity orthogonal to their apical–basal axes, referred to as Planar Cell Polarity (PCP. The process by which these cells become polarized requires a signaling pathway using Frizzled as a receptor. Responding cells sense cues from their environment that provide directional information, and they translate this information into cellular asymmetry. Most of what is known about PCP derives from studies in the fruit fly, Drosophila. We review what is known about how cells translate an unknown signal into asymmetric cytoskeletal reorganization. We then discuss how the vertebrate processes of convergent extension and cochlear hair-cell development may relate to Drosophila PCP signaling.

  9. Top-DER- and Dpp-dependent requirements for the Drosophila fos/kayak gene in follicular epithelium morphogenesis.

    Science.gov (United States)

    Dequier, E; Souid, S; Pál, M; Maróy, P; Lepesant, J A; Yanicostas, C

    2001-08-01

    The Drosophila fos (Dfos)/kayak gene has been previously identified as a key regulator of epithelial cell morphogenesis during dorsal closure of the embryo and fusion of the adult thorax. We show here that it is also required for two morphogenetic movements of the follicular epithelium during oogenesis. Firstly, it is necessary for the proper posteriorward migration of main body follicle cells during stage 9. Secondly, it controls, from stage 11 onwards, the morphogenetic reorganization of the follicle cells that are committed to secrete the respiratory appendages. We demonstrate that DER pathway activation and a critical level of Dpp/TGFbeta signalling are required to pattern a high level of transcription of Dfos at the anterior and dorsal edges of the two groups of cells that will give rise to the respiratory appendages. In addition, we provide evidence that, within the dorsal-anterior territory, the level of paracrine Dpp/TGFbeta signalling controls the commitment of follicle cells towards either an operculum or an appendage secretion fate. Finally, we show that Dfos is required in follicle cells for the dumping of the nurse cell cytoplasm into the oocyte and the subsequent apoptosis of nurse cells. This suggests that in somatic follicle cells, Dfos controls the expression of one or several factors that are necessary for these processes in underlying germinal nurse cells.

  10. Extensive Hair Shaft Growth after Mouse Whisker Follicle Isolation, Cryopreservation and Transplantation in Nude Mice.

    Directory of Open Access Journals (Sweden)

    Wenluo Cao

    Full Text Available We previously demonstrated that whole hair follicles could be cryopreserved to maintain their stem-cells differentation potential. In the present study, we demonstrated that cryopreserved mouse whisker hair follicles maintain their hair growth potential. DMSO better cryopreserved mouse whisker follicles compared to glycerol. Cryopreserved hair follicles also maintained the hair follicle-associated-pluripotent (HAP stem cells, evidenced by P75NTR expression. Subcutaneous transplantation of DMSO-cryopreserved hair follicles in nude mice resulted in extensive hair fiber growth over 8 weeks, indicating the functional recovery of hair shaft growth of cryopreserved hair follicles.

  11. Extensive Hair Shaft Growth after Mouse Whisker Follicle Isolation, Cryopreservation and Transplantation in Nude Mice.

    Science.gov (United States)

    Cao, Wenluo; Li, Lingna; Tran, Benjamin; Kajiura, Satoshi; Amoh, Yasuyuki; Liu, Fang; Hoffman, Robert M

    2015-01-01

    We previously demonstrated that whole hair follicles could be cryopreserved to maintain their stem-cells differentation potential. In the present study, we demonstrated that cryopreserved mouse whisker hair follicles maintain their hair growth potential. DMSO better cryopreserved mouse whisker follicles compared to glycerol. Cryopreserved hair follicles also maintained the hair follicle-associated-pluripotent (HAP) stem cells, evidenced by P75NTR expression. Subcutaneous transplantation of DMSO-cryopreserved hair follicles in nude mice resulted in extensive hair fiber growth over 8 weeks, indicating the functional recovery of hair shaft growth of cryopreserved hair follicles.

  12. Extensive Hair Shaft Growth after Mouse Whisker Follicle Isolation, Cryopreservation and Transplantation in Nude Mice

    Science.gov (United States)

    Cao, Wenluo; Li, Lingna; Tran, Benjamin; Kajiura, Satoshi; Amoh, Yasuyuki; Liu, Fang; Hoffman, Robert M.

    2015-01-01

    We previously demonstrated that whole hair follicles could be cryopreserved to maintain their stem-cells differentation potential. In the present study, we demonstrated that cryopreserved mouse whisker hair follicles maintain their hair growth potential. DMSO better cryopreserved mouse whisker follicles compared to glycerol. Cryopreserved hair follicles also maintained the hair follicle-associated-pluripotent (HAP) stem cells, evidenced by P75NTR expression. Subcutaneous transplantation of DMSO-cryopreserved hair follicles in nude mice resulted in extensive hair fiber growth over 8 weeks, indicating the functional recovery of hair shaft growth of cryopreserved hair follicles. PMID:26716690

  13. Expression of COPI components during development of Drosophila melanogaster.

    Science.gov (United States)

    Grieder, Nicole C; Kloter, Urs; Gehring, Walter J

    2005-12-01

    In a P{lArB} enhancer detector collection, a line was found that showed upregulated expression within centrally to posteriorly located germarial cysts. It was inserted in the gammaCOP locus on chromosome 3R. GammaCOP is a component of the COPI coatomer involved in membrane traffic. Most of the other known components of the COPI coatomer also showed higher expression in the posterior half of the germarium. Not only meiotic germline cysts but also migrating follicle cells upregulate the COPI subunits. During embryonic and larval development, the COPI subunits are expressed ubiquitously as expected for genes required for cell viability. In addition, they are strongly expressed in the salivary glands and the proventriculus. Whether tissue-specific transcriptional upregulation of COPI subunits is required for the reorganization of membranous compartments that are needed for the developmental processes that confer cyst polarity and follicle maturation will have to be addressed in a genetic study.

  14. [The hair follicle as a target for gene therapy].

    Science.gov (United States)

    Cotsarelis, G

    2002-05-01

    The hair follicle possesses progenitor cells required for continuous hair follicle cycling and for epidermal keratinocytes, melanocytes and Langerhans cells. These different cell types can be the target of topical gene delivery in the skin of the mouse. Using a combination of liposomes and DNA, we demonstrate the feasibility of targeting hair follicle cells in human scalp xenografts. We consider liposome composition and stage of the hair cycle as important parameters influencing transfection of human hair follicles. Transfection is possible only during the early anagen phase. Factors and obstacles for the use of gene therapy in treating alopecia and skin diseases are discussed. A theoretical framework for future treatment of cutaneous and systemic disorders using gene therapy is presented.

  15. Development of Chemiluminscence Immunoaasy Kit for Follicle-Stimulating Hormone

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Follicle-stimulating hormone (FSH) is a gonadotropic hormone, and it is synthesized and secreted by basophilic cell of anterior lobe of hypophysis. Detection of FSH levels in human serum is useful in

  16. Follicle dynamics and anovulation in polycystic ovary syndrome

    National Research Council Canada - National Science Library

    Franks, Stephen; Stark, Jaroslav; Hardy, Kate

    2008-01-01

    .... METHOD Source is authors' own studies and search of the relevant literature. RESULTS Arrest of antral follicle growth is associated with an abnormal endocrine environment involving hypersecretion of luteinizing hormone and insulin...

  17. Collecting Tail Hair Follicle for Bison DNA Sample

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — SOP guiding collection and processing of tail hair follicles from Bison for genetics analysis. Provides stepwise instructions and guidance on how to collect tail...

  18. Follicle profile and plasma gonadotropin concentration in pubertal female ponies

    Directory of Open Access Journals (Sweden)

    Nogueira G.P.

    2004-01-01

    Full Text Available Twelve female ponies were examined daily for 30 days and classified as ovulating (OV; N = 6; 197 ± 6 kg or prepubertal (PP; N = 6; 196 ± 9 kg. Follicles were detected by ultrasound and gonadotropins quantified by radioimmunoassay. The mean diameter of the largest follicles was significantly larger in OV (38 ± 1 mm than in PP (26 ± 2 mm but there was no difference between groups in the size of the second largest follicle. There were more small follicles (29 mm than the OV fillies. Follicle-stimulating hormone (FSH levels did not differ between groups but PP fillies had lower luteinizing hormone (LH peak (8 ± 1 ng/ml and basal (4 ± 0.5 ng/ml levels, lower peak magnitude (2 ± 0.2 ng/ml and period average (5 ± 0.6 ng/ml than OV fillies (32 ± 4.5, 8 ± 1.2, 17.1 ± 6, and 15 ± 2.3 ng/ml, respectively. The PP group, in contrast to the OV group, showed no relationship between FSH surge and follicle wave emergence. We conclude that an LH concentration higher than 8 ng/ml is needed for follicle growth to a preovulatory size. Wave emergence and FSH secretion seem to be independent events, probably due to an inhibitory neural system in these PP animals. PP fillies may provide a physiological model for the study of follicle wave emergence which apparently does not depend on gonadotropin levels.

  19. Multiple calcifying hyperplastic dental follicles: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Ulkem [Dept. of Dentomaxillofacial Radiology, Baskent University Faculty of Dentistry, Ankara (Turkey); Baykul, Timucin [Dept. of Oral and Maxillofacial Surgery, Suleyman Demirel University Faculty of Dentistry, Isparta (Turkey); Yildirim, Benay [Dept. of Oral Pathology, Gazi University Faculty of Dentistry, Ankara (Turkey); Yildirim, Derya; Bozdemir, Esin [Dept. of Dentomaxillofacial Radiology, Suleyman Demirel University Faculty of Dentistry, Isparta (Turkey); Karaduman, Ayse [Atlas Dent Dental Health Center, Aydin (Turkey)

    2013-12-15

    This report describes a 31-year-old female patient with six impacted teeth. The crowns of the impacted teeth were surrounded with cyst-like lesions with a mixed internal structure and well-defined cortical borders. Microscopic examination of the specimen obtained from the follicle of the left mandibular third molar tooth revealed loose to moderately dense collagenous connective tissue with abundant calcified material and sparse epithelial islands. A diagnosis of multiple calcifying hyperplastic dental follicles was made.

  20. Putting the Human Hair Follicle Cycle on the Map.

    Science.gov (United States)

    Panteleyev, Andrey A

    2016-01-01

    A detailed characterization of the normal (in situ) human hair follicle cycle, supplemented with expressional data on specific hair follicle markers, has been awaited by basic hair researchers and dermatologists. Combining this hair cycle guide, together with a thorough analysis of the human-on-mouse hair xenograft model, provides solid ground for examining human hair cycle biology and pathology and for hair cycle-related pharmacological testing.

  1. Gene Bionetwork Analysis of Ovarian Primordial Follicle Development

    Science.gov (United States)

    Nilsson, Eric E.; Savenkova, Marina I.; Schindler, Ryan; Zhang, Bin; Schadt, Eric E.; Skinner, Michael K.

    2010-01-01

    Ovarian primordial follicles are critical for female reproduction and comprise a finite pool of gametes arrested in development. A systems biology approach was used to identify regulatory gene networks essential for primordial follicle development. Transcriptional responses to eight different growth factors known to influence primordial follicles were used to construct a bionetwork of regulatory genes involved in rat primordial follicle development. Over 1,500 genes were found to be regulated by the various growth factors and a network analysis identified critical gene modules involved in a number of signaling pathways and cellular processes. A set of 55 genes was identified as potential critical regulators of these gene modules, and a sub-network associated with development was determined. Within the network two previously identified regulatory genes were confirmed (i.e., Pdgfa and Fgfr2) and a new factor was identified, connective tissue growth factor (CTGF). CTGF was tested in ovarian organ cultures and found to stimulate primordial follicle development. Therefore, the relevant gene network associated with primordial follicle development was validated and the critical genes and pathways involved in this process were identified. This is one of the first applications of network analysis to a normal developmental process. These observations provide insights into potential therapeutic targets for preventing ovarian disease and promoting female reproduction. PMID:20661288

  2. Gene bionetwork analysis of ovarian primordial follicle development.

    Directory of Open Access Journals (Sweden)

    Eric E Nilsson

    Full Text Available Ovarian primordial follicles are critical for female reproduction and comprise a finite pool of gametes arrested in development. A systems biology approach was used to identify regulatory gene networks essential for primordial follicle development. Transcriptional responses to eight different growth factors known to influence primordial follicles were used to construct a bionetwork of regulatory genes involved in rat primordial follicle development. Over 1,500 genes were found to be regulated by the various growth factors and a network analysis identified critical gene modules involved in a number of signaling pathways and cellular processes. A set of 55 genes was identified as potential critical regulators of these gene modules, and a sub-network associated with development was determined. Within the network two previously identified regulatory genes were confirmed (i.e., Pdgfa and Fgfr2 and a new factor was identified, connective tissue growth factor (CTGF. CTGF was tested in ovarian organ cultures and found to stimulate primordial follicle development. Therefore, the relevant gene network associated with primordial follicle development was validated and the critical genes and pathways involved in this process were identified. This is one of the first applications of network analysis to a normal developmental process. These observations provide insights into potential therapeutic targets for preventing ovarian disease and promoting female reproduction.

  3. Empty Follicle Syndrome: The Possible Cause of Occurrence

    Directory of Open Access Journals (Sweden)

    Tahereh Madani

    2015-11-01

    Full Text Available Objectives: Empty follicle syndrome (EFS, although rare, is a disappointing condition in which no oocytes are retrieved from mature follicle after ovulation induction in in vitro fertilization (IVF cycles. The aim of this study was to estimate the incidence and factors associated with EFS. Methods: All cycles resulting in EFS from May 2012 to September 2013 were retrospectively identified at a tertiary referral infertility center. Among the 3,356 cycles performed, 58 (1.7% women who underwent their first IVF cycle and had no oocyte retrieval were enrolled in the study. Three different stimulation protocols (long, antagonist, and miniflare were mainly used for induction of follicular growth. Data relating to the age, follicle stimulating hormone (FSH level, anti-Müllerain hormone (AMH level, and the number of ampules and follicles for each patient was obtained. Results: Out of 58 individuals, 10 (17.2% showed false type and 48 (82.8% showed genuine EFS. The most frequent findings in our study were diminished ovarian reserve, low anti-Müllerian hormone (AMH; ≤0.5 ng/mL, and less than four mature follicles, indicating EFS in 1.7% of the patients. Conclusion: Low serum AMH levels and a small number of follicles after ovarian stimulation is the manifestation of diminished ovarian reserve. Thus, we suggest that EFS could be a manifestation of low ovarian reserve.

  4. Sources of cumulus expansion enabling factor (CEEF) in porcine follicles

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    It was shown that expansion of porcine cumulus did not depend on oocyte-secreted factor(s), and it is therefore presumed that porcine CEEF may not be produced exclusively by the oocyte. In this experiment, we used mouse oocytectomized complexes (OOX), which were incapable of CEEF production, to assess the secretion of CEEF by evacuated zona, oocytes of different quality and somatic cells in the porcine follicles. The results showed that: (ⅰ) Evacuated zonae from both porcine and mouse oocytes did not produce CEEF. (ⅱ) Porcine oocytes of A, B and C types from 3 - 6 mm follicles were not significantly different in both production and activity of CEEF. (ⅲ) Both porcine OOX from 3 - 6 mm follicles and granulose cells from < 1 mm follicles secreted CEEF in a large quantity, independent of gonadotropins; mural granulose cells from 3-6 mm follicles, however, produced neglectable amount of CEEF. (ⅳ) The follicular fluid from 3-6 mm porcine follicles contained CEEF activity that was concentration-dependent, and thus it enabled cumulus expansion in 60% mouse OOX when used at 10% of concentration, but the expansion rate of mouse OOX decreased to 9% when the concentration was increased to 50%. (ⅴ) Mouse OOX cultured in porcine CEEF-containing M199 expanded only in the presence of gonadotropins, suggesting that the activity of porcine CEEF is hormone-de- pendent.

  5. Alterations in hair follicle dynamics in women.

    Science.gov (United States)

    Piérard-Franchimont, Claudine; Piérard, Gérald E

    2013-01-01

    Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium), alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturbances in this chronobiological feature. Of note, any correlation between a biologic abnormality and hair cycling disturbance does not prove a relationship of causality. The proportion of postmenopausal women is rising in the overall population. Therefore, the prevalence of these hair follicle disturbances is globally on the rise. Current therapies aim at correcting the underlying hormonal imbalances, and at improving the overall cosmetic appearance. However, in absence of pathogenic diagnosis and causality criteria, chances are low that a treatment given by the whims of fate will adequately control hair effluvium. The risk and frequency of therapeutic inertia are further increased. When the hair loss is not controlled and/or compensated by growth of new hairs, several clinical aspects of alopecia inexorably develop. Currently, there is little evidence supporting any specific treatment for these endocrine hair disorders in post-partum and postmenopausal women. Current hair treatment strategies are symptomatic and nonspecific so current researchers aim at developing new, targeted methods.

  6. Alterations in Hair Follicle Dynamics in Women

    Directory of Open Access Journals (Sweden)

    Claudine Piérard-Franchimont

    2013-01-01

    Full Text Available Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium, alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturbances in this chronobiological feature. Of note, any correlation between a biologic abnormality and hair cycling disturbance does not prove a relationship of causality. The proportion of postmenopausal women is rising in the overall population. Therefore, the prevalence of these hair follicle disturbances is globally on the rise. Current therapies aim at correcting the underlying hormonal imbalances, and at improving the overall cosmetic appearance. However, in absence of pathogenic diagnosis and causality criteria, chances are low that a treatment given by the whims of fate will adequately control hair effluvium. The risk and frequency of therapeutic inertia are further increased. When the hair loss is not controlled and/or compensated by growth of new hairs, several clinical aspects of alopecia inexorably develop. Currently, there is little evidence supporting any specific treatment for these endocrine hair disorders in post-partum and postmenopausal women. Current hair treatment strategies are symptomatic and nonspecific so current researchers aim at developing new, targeted methods.

  7. Integral hair lipid in human hair follicle.

    Science.gov (United States)

    Lee, Won-Soo

    2011-12-01

    Integral hair lipid (IHL) is bound to the keratinized cell surface to make an environmentally resistant lipid envelope. It is mainly positioned on the hair cuticle and inner root sheath. IHL in the hair follicle may regard as hair barrier to be similar to the epidermal lipid layer functioning as skin barrier. Major constituents of IHL are fatty acid, phytosphingosine, ceramide in decreasing order. Minor constituents of IHL are cholesterol, cholesterol sulfate and cholesterol oleate. Cuticle or cortical cell surface in hair are abundant in fatty acids unlike the keratinized area of epidermis or sebaceous gland, and about 30-40% of such fatty acids are composed of 18-methyl-eicosanoic acid which is known to be bound to proteins by ester or thioester bond. Various factors including moisture, solvent, oxidative damage during bleaching or permanent waving affect IHL. Photochemical changes also can occur in IHL as well as in hair protein and hair pigment. Lipid metabolism is thought to play an essential role in lipid envelope of hair, but also involvement in hair development and function. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Wnt7b is an important intrinsic regulator of hair follicle stem cell homeostasis and hair follicle cycling

    OpenAIRE

    Kandyba, Eve; Kobielak, Krzysztof

    2014-01-01

    The hair follicle (HF) is an exceptional mini-organ to study the mechanisms which regulate HF morphogenesis, cycling, hair follicle stem cell (hfSCs) homeostasis and progeny differentiation. During morphogenesis, Wnt signaling is well characterized in the initiation of HF patterning but less is known about which particular Wnt ligands are required and whether individual Wnt ligands act in an indispensable or redundant manner during postnatal hfSCs anagen onset and HF cycle progression. Previo...

  9. Effect of epidermal growth factor on follicle-stimulating hormone-induced proliferation of granulosa cells from chicken prehierarchical follicles

    Institute of Scientific and Technical Information of China (English)

    Jin-xing LIN; Yu-dong JIA; Cai-qiao ZHANG

    2011-01-01

    The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors,including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF).In this study,the stagespecific effect of EGF on FSH-induced proliferation of granulosa cells was evaluated in the ovarian follicles of egg-laying chickens.Results showed that EGF and its receptor (EGFR) mRNAs displayed a high expression in granulosa cells from the prehierarchical follicles,including the large white follicle (LWF) and small yellow follicle (SYF),and thereafter the expression decreased markedly to the stage of the largest preovulatory follicle.SYF represents a turning point of EGF/EGFR mRNA expression during follicle selection.Subsequently the granulosa cells from SYF were cultured to reveal the mediation of EGF in FSH action.Cell proliferation was remarkably increased by treatment with either EGF or FSH (0.1-100 ng/ml).This result was confirmed by elevated proliferating cell nuclear antigen (PCNA) expression and decreased cell apoptosis.Furthermore,EGF-induced cell proliferation was accompanied by increased mRNA expressions of EGFR,FSH receptor,and the cell cycle-regulating genes (cyclins D1 and E1,cyclin-dependent kinases 2 and 6) as well as decreased expression of luteinizing hormone receptor mRNA.However,the EGF or FSH-elicited effect was reversed by simultaneous treatment with an EGFR inhibitor AG1478.In conclusion,EGF and EGFR expressions manifested stage-specific changes during follicular development and EGF mediated FSH-induced cell proliferation and retarded cell differentiation in the prehierarchical follicles.These expressions thus stimulated follicular growth before selection in the egg-laying chicken.

  10. Drosophila by the dozen

    Energy Technology Data Exchange (ETDEWEB)

    Celniker, Susan E.; Hoskins, Roger A.

    2007-07-13

    This year's conference on Drosophila research illustratedwell the current focus of Drosophila genomics on the comprehensiveidentification of functional elements in the genome sequence, includingmRNA transcripts arising from multiple alternative start sites and splicesites, a multiplicity of noncoding transcripts and small RNAs,identification of binding sites for transcription factors, sequenceconservation in related species and sequence variation within species.Resources and technologies for genetics and functional genomics aresteadily being improved, including the building of collections oftransposon insertion mutants and hairpin constructs for RNA interference(RNAi). The conference also highlighted progress in the use of genomicinformation by many laboratories to study diverse aspects of biology andmodels of human disease. Here we will review a few highlights of especialinterest to readers of Genome Biology.

  11. Lhx8 regulates primordial follicle activation and postnatal folliculogenesis.

    Science.gov (United States)

    Ren, Yu; Suzuki, Hitomi; Jagarlamudi, Krishna; Golnoski, Kayla; McGuire, Megan; Lopes, Rita; Pachnis, Vassilis; Rajkovic, Aleksandar

    2015-06-16

    The early stages of ovarian follicle formation-beginning with the breakdown of germ cell cysts and continuing with the formation of primordial follicles and transition to primary and secondary follicles-are critical in determining reproductive life span and fertility. Previously, we discovered that global knockouts of germ cell-specific transcriptional co-regulators Sohlh1, Sohlh2, Lhx8, and Nobox, cause rapid oocyte loss and ovarian failure. Also factors such as Nobox and Sohlh1 are associated with human premature ovarian failure. In this study, we developed a conditional knockout of Lhx8 to study oocyte-specific pathways in postnatal folliculogenesis. The conditional deficiency of Lhx8 in the oocytes of primordial follicles leads to massive primordial oocyte activation, in part, by indirectly interacting with the PI3K-AKT pathway, as shown by synergistic effects on FOXO3 nucleocytoplasmic translocation and rpS6 activation. However, LHX8 does not directly regulate members of the PI3K-AKT pathway; instead, we show that LHX8 represses Lin28a expression, a known regulator of mammalian metabolism and of the AKT/mTOR pathway. LHX8 can bind to the Lin28a promoter, and the depletion of Lin28a in Lhx8-deficient oocytes partially suppresses primordial oocyte activation. Moreover, unlike the PI3K-AKT pathway, LHX8 is critical beyond primordial follicle activation, and blocks the primary to secondary follicle transition. Our results indicate that the LHX8-LIN28A pathway is essential in the earliest stages of primordial follicle activation, and LHX8 is an important oocyte-specific transcription factor in the ovary for regulating postnatal folliculogenesis.

  12. Glycomic analyses of ovarian follicles during development and atresia

    Science.gov (United States)

    Hatzirodos, Nicholas; Nigro, Julie; Irving-Rodgers, Helen F.; Vashi, Aditya V.; Hummitzsch, Katja; Caterson, Bruce; Sullivan, Thomas R.; Rodgers, Raymond J.

    2012-01-01

    To examine the detailed composition of glycosaminoglycans during bovine ovarian follicular development and atresia, the specialized stromal theca layers were separated from the stratified epithelial granulosa cells of healthy (n = 6) and atretic (n = 6) follicles in each of three size ranges: small (3–5 mm), medium (6-9 mm) and large (10 mm or more) (n = 29 animals). Fluorophore-assisted carbohydrate electrophoresis analyses (on a per cell basis) and immunohistochemistry (n = 14) were undertaken. We identified the major disaccharides in thecal layers and the membrana granulosa as chondroitin sulfate-derived ∆uronic acid with 4-sulfated N-acetylgalactosamine and ∆uronic acid with 6-sulfated N-acetylgalactosamine and the heparan sulfate-derived Δuronic acid with N-acetlyglucosamine, with elevated levels in the thecal layers. Increasing follicle size and atresia was associated with increased levels of some disaccharides. We concluded that versican contains 4-sulfated N-acetylgalactosamine and it is the predominant 4-sulfated N-acetylgalactosamine proteoglycan in antral follicles. At least one other non- or 6-sulfated N-acetylgalactosamine proteoglycan(s), which is not decorin or an inter-α-trypsin inhibitor family member, is present in bovine antral follicles and associated with hitherto unknown groups of cells around some larger blood vessels. These areas stained positively for chondroitin/dermatan sulfate epitopes [antibodies 7D4, 3C5, and 4C3], similar to stem cell niches observed in other tissues. The sulfation pattern of heparan sulfate glycosaminoglycans appears uniform across follicles of different sizes and in healthy and atretic follicles. The heparan sulfate products detected in the follicles are likely to be associated with perlecan, collagen XVIII or betaglycan. PMID:22057033

  13. Two classes of ovarian primordial follicles exhibit distinct developmental dynamics and physiological functions.

    Science.gov (United States)

    Zheng, Wenjing; Zhang, Hua; Gorre, Nagaraju; Risal, Sanjiv; Shen, Yan; Liu, Kui

    2014-02-15

    In the mammalian ovary, progressive activation of primordial follicles serves as the source of fertilizable ova, and disorders in the development of primordial follicles lead to various ovarian diseases. However, very little is known about the developmental dynamics of primordial follicles under physiological conditions, and the fates of distinct populations of primordial follicles also remain unclear. In this study, by generating the Foxl2-CreER(T2) and Sohlh1-CreER(T2) inducible mouse models, we have specifically labeled and traced the in vivo development of two classes of primordial follicles, the first wave of simultaneously activated follicles after birth and the primordial follicles that are gradually activated in adulthood. Our results show that the first wave of follicles exists in the ovaries for ∼3 months and contributes to the onset of puberty and to early fertility. The primordial follicles at the ovarian cortex gradually replace the first wave of follicles and dominate the ovary after 3 months of age, providing fertility until the end of reproductive life. Moreover, by tracing the time periods needed for primordial follicles to reach various advanced stages in vivo, we were able to determine the exact developmental dynamics of the two classes of primordial follicles. We have now revealed the lifelong developmental dynamics of ovarian primordial follicles under physiological conditions and have clearly shown that two classes of primordial follicles follow distinct, age-dependent developmental paths and play different roles in the mammalian reproductive lifespan.

  14. Ecdysone signalling and ovarian development in insects: from stem cells to ovarian follicle formation.

    Science.gov (United States)

    Belles, Xavier; Piulachs, Maria-Dolors

    2015-02-01

    Although a great deal of information is available concerning the role of ecdysone in insect oogenesis, research has tended to focus on vitellogenesis and choriogenesis. As such, the study of oogenesis in a strict sense has received much less attention. This situation changed recently when a number of observations carried out in the meroistic polytrophic ovarioles of Drosophila melanogaster started to unravel the key roles played by ecdysone in different steps of oogenesis. Thus, in larval stages, a non-autonomous role of ecdysone, first in repression and later in activation, of stem cell niche and primordial germ cell differentiation has been reported. In the adult, ecdysone stimulates the proliferation of germline stem cells, plays a role in stem cell niche maintenance and is needed non-cell-autonomously for correct differentiation of germline stem cells. Moreover, in somatic cells ecdysone is required for 16-cell cyst formation and for ovarian follicle development. In the transition from stages 8 to 9 of oogenesis, ecdysone signalling is fundamental when deciding whether or not to go ahead with vitellogenesis depending on the nutritional status, as well as to start border cell migration. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  15. The Drosophila melanogaster host model

    Science.gov (United States)

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  16. The Drosophila melanogaster host model

    Directory of Open Access Journals (Sweden)

    Christina O. Igboin

    2012-02-01

    Full Text Available The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  17. Isolated primate primordial follicles require a rigid physical environment to survive and grow in vitro.

    Science.gov (United States)

    Hornick, J E; Duncan, F E; Shea, L D; Woodruff, T K

    2012-06-01

    In vitro follicle growth is a promising fertility preservation strategy in which ovarian follicles are cultured to produce mature and fertilization-competent oocytes. However, in primates, there has been limited success with in vitro follicle growth starting from primordial and primary follicles because adequate isolation methods and culture strategies have not been established. Understanding how to use primordial follicles for fertility preservation has significant implications because these follicles are the most abundant in the ovary, are found in all females and are fairly resistant to cryopreservation and chemotherapeutics. In the primate ovary, primordial follicles are concentrated near the collagen-rich ovarian cortex. To obtain these follicles, we separated the ovarian cortex prior to enzymatic digestion and enriched the primordial follicle concentration by using a novel double filtration system. To test the hypothesis that a rigid physical environment, as found in vivo, is optimal for survival, primordial follicles were cultured in different concentrations of alginate for up to 6 days. Follicle survival and morphology were monitored throughout the culture. We found that primate ovarian tissue can be maintained for up to 24 h at 4°C without compromising tissue or follicle health. Hundreds of intact and viable primordial follicles were isolated from each ovary independent of animal age. Follicle survival and morphology were more optimal when follicles were cultured in 2% alginate compared with 0.5% alginate. By mimicking the rigid ovarian environment through the use of biomaterials, we have established conditions that support primordial follicle culture. These results lay the foundations for studying the basic biology of primordial follicles in a controlled environment and for using primordial follicles for fertility preservation methods.

  18. Computer-generated ovaries to assist follicle counting experiments.

    Directory of Open Access Journals (Sweden)

    Angelos Skodras

    Full Text Available Precise estimation of the number of follicles in ovaries is of key importance in the field of reproductive biology, both from a developmental point of view, where follicle numbers are determined at specific time points, as well as from a therapeutic perspective, determining the adverse effects of environmental toxins and cancer chemotherapeutics on the reproductive system. The two main factors affecting follicle number estimates are the sampling method and the variation in follicle numbers within animals of the same strain, due to biological variability. This study aims at assessing the effect of these two factors, when estimating ovarian follicle numbers of neonatal mice. We developed computer algorithms, which generate models of neonatal mouse ovaries (simulated ovaries, with characteristics derived from experimental measurements already available in the published literature. The simulated ovaries are used to reproduce in-silico counting experiments based on unbiased stereological techniques; the proposed approach provides the necessary number of ovaries and sampling frequency to be used in the experiments given a specific biological variability and a desirable degree of accuracy. The simulated ovary is a novel, versatile tool which can be used in the planning phase of experiments to estimate the expected number of animals and workload, ensuring appropriate statistical power of the resulting measurements. Moreover, the idea of the simulated ovary can be applied to other organs made up of large numbers of individual functional units.

  19. Is the mouse follicle culture a good model for the goat with respect to the development of preantral follicles in vitro?

    Science.gov (United States)

    Rocha, R M P; Alves, A M C V; Lima, L F; Duarte, A B G; Chaves, R N; Brito, I R; Costa, E C; Bernuci, M P; Rosa-e-Silva, A C J S; Xu, M; Rodrigues, A P R; Campello, C C; Figueiredo, J R

    2014-10-01

    The present study evaluated the efficiency of using 2 culture media developed for mice and for goats in the in vitro preantral follicle culture of each species. Murine and caprine secondary follicles were cultured in vitro with human recombinant follicle-stimulating hormone (murine medium) or with bovine recombinant follicle-stimulating hormone in association with growth hormone (caprine medium). The results showed that murine follicles cultured in caprine medium had lower (P 0.05). After in vitro maturation, a higher (P cultured under the same in vitro culture medium conditions respond differently; caprine oocytes grown in vitro in the presence of the murine medium show the greatest developmental competence among the tested combinations. Therefore, under the present experimental conditions, the mouse follicle culture has proved be a good model for the development of new culture media for caprine preantral follicles.

  20. Exploring Autophagy in Drosophila

    Directory of Open Access Journals (Sweden)

    Péter Lőrincz

    2017-07-01

    Full Text Available Autophagy is a catabolic process in eukaryotic cells promoting bulk or selective degradation of cellular components within lysosomes. In recent decades, several model systems were utilized to dissect the molecular machinery of autophagy and to identify the impact of this cellular “self-eating” process on various physiological and pathological processes. Here we briefly discuss the advantages and limitations of using the fruit fly Drosophila melanogaster, a popular model in cell and developmental biology, to apprehend the main pathway of autophagy in a complete animal.

  1. Targeting to the hair follicles: current status and potential.

    Science.gov (United States)

    Wosicka, Hanna; Cal, Krzysztof

    2010-02-01

    The pilosebaceous unit is a complex structure that undergoes a specific growth cycle and comprises a few important drug targeting sites. For example, drugs can be targeted to the bulge region with stem cells or to the sebaceous glands. Interest in pilosebaceous units is directed towards their utilization as reservoirs for localized therapy and also as a transport pathway for systemic drug delivery. Improved investigative methods, such as differential stripping, are being developed in order to determine follicular penetration. This article reviews relevant aspects of effective follicle-targeting formulations and delivery systems as well as the activity status of hair follicles, and variations in follicle size and distribution throughout various body regions. Each of these factors strongly affects follicular permeation. We provide examples of improved penetration of particle-based formulations and of a size-dependent manner of follicular penetration. Contradictions are also discussed, indicating the need for detailed future investigations.

  2. Cytoplasmic Streaming in the Drosophila Oocyte.

    Science.gov (United States)

    Quinlan, Margot E

    2016-10-06

    Objects are commonly moved within the cell by either passive diffusion or active directed transport. A third possibility is advection, in which objects within the cytoplasm are moved with the flow of the cytoplasm. Bulk movement of the cytoplasm, or streaming, as required for advection, is more common in large cells than in small cells. For example, streaming is observed in elongated plant cells and the oocytes of several species. In the Drosophila oocyte, two stages of streaming are observed: relatively slow streaming during mid-oogenesis and streaming that is approximately ten times faster during late oogenesis. These flows are implicated in two processes: polarity establishment and mixing. In this review, I discuss the underlying mechanism of streaming, how slow and fast streaming are differentiated, and what we know about the physiological roles of the two types of streaming.

  3. Studying cytokinesis in Drosophila epithelial tissues.

    Science.gov (United States)

    Pinheiro, D; Bellaïche, Y

    2017-01-01

    Epithelial tissue cohesiveness is ensured through cell-cell junctions that maintain both adhesion and mechanical coupling between neighboring cells. During development, epithelial tissues undergo intensive cell proliferation. Cell division, and particularly cytokinesis, is coupled to the formation of new adhesive contacts, thereby preserving tissue integrity and propagating cell polarity. Remarkably, the geometry of the new interfaces is determined by the combined action of the dividing cell and its neighbors. To further understand the interplay between the dividing cell and its neighbors, as well as the role of cell division for tissue morphogenesis, it is important to analyze cytokinesis in vivo. Here we present methods to perform live imaging of cell division in Drosophila epithelial tissues and discuss some aspects of image processing and analysis.

  4. Follicular development and oocyte maturation in hypogonadotrophic women employing recombinant follicle-stimulating hormone: the role of oestradiol

    NARCIS (Netherlands)

    B.C.J.M. Fauser (Bart)

    1997-01-01

    textabstractBoth luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are required for follicle development and oestrogen production. Moreover, under normal conditions a close association between dominant follicle size and serum and intrafollicular oestradiol

  5. Induction of ovarian primordial follicle assembly by connective tissue growth factor CTGF.

    Science.gov (United States)

    Schindler, Ryan; Nilsson, Eric; Skinner, Michael K

    2010-09-24

    Primordial follicle assembly is a process that occurs when oocyte nests break down to form individual primordial follicles. The size of this initial pool of primordial follicles in part determines the reproductive lifespan of the female. Connective tissue growth factor (CTGF) was identified as a potential regulatory candidate for this process in a previous microarray analysis of follicle development. The current study examines the effects of CTGF and associated transforming growth factor beta 1 (TGFβ-1) on follicle assembly. Ovaries were removed from newborn rat pups and placed in an organ culture system. The ovaries treated with CTGF for two days were found to have an increased proportion of assembled follicles. CTGF was found to regulate the ovarian transcriptome during primordial follicle assembly and an integrative network of genes was identified. TGFβ-1 had no effect on primordial follicle assembly and in combination with CTGF decreased oocyte number in the ovary after two days of culture. Over ten days of treatment only the combined treatment of CTGF and TGFβ-1 was found to cause an increase in the proportion of assembled follicles. Interestingly, treatment with TGFβ-1 alone resulted in fewer total oocytes in the ovary and decreased the primordial follicle pool size after ten days of culture. Observations indicate that CTGF alone or in combination with TGFβ-1 stimulates primordial follicle assembly and TGFβ-1 can decrease the primordial follicle pool size. These observations suggest the possibility of manipulating primordial follicle pool size and influencing female reproductive lifespan.

  6. Atresia of large ovarian follicles of the rat

    Directory of Open Access Journals (Sweden)

    Maria Słomczyn´ ska

    2011-08-01

    Full Text Available In the rat, at the beginning of pregnancy a cohort of antral follicles develops until the preovulatory stage. However, these follicles, differentiating in the hyperprolactinemic milieu, produce only small amount of estradiol, do not ovulate and undergo rapid degeneration. They constitute an interesting physiological model of atresia. In the present study, we analysed the development and subsequent degeneration of such follicles. The study was performed on Wistar female rats killed in succession between days 1-9 of pregnancy. Excised ovaries were submitted to a routine histological procedure. Paraffin sections were subjected to hematoxylin and eosin staining or in situ DNA labelling. Histological and TUNEL staining revealed that the investigated group of follicles grew slower than that on the corresponding days of the estrous cycle and reached a preovulatory size and morphological appearance on day 5 of pregnancy. They did not ovulate and between days 6 and 9 of pregnancy an increasing number of apoptotic cells appeared within these follicles. They were localized predominantly in the antral granulosa layer, especially near the cumulus oophorus complex (COC and in the region linking the COC with the follicular wall. The COC and the theca layer were much less affected. In late stages of atresia, also cumulus cells became apoptotic but degenerating oocytes did not exhibit positive TUNEL staining. Only limited number of the theca cells have undergone apoptosis and generally they were not hypertrophied. Our findings indicate that much smaller than normal amount of intrafollicular estradiol was sufficient to support a normal, according to the morphological criteria, although slower development of antral follicles to the late preovulatory stage.

  7. Primordial follicle activation in the ovary of Ames dwarf mice

    OpenAIRE

    Schneider, Augusto; Zhi, Xu; Moreira, Fabiana; Lucia, Thomaz; Mondadori,Rafael Gianella; Masternak, Michal M.

    2014-01-01

    Background The insulin receptor substrate 1 (IRS1), phosphoinositide 3-kinase (Pi3k), protein kinase B (Akt1), Forkhead Box O3a (FOXO3a) pathway is directly involved in aging and ovarian activation of follicle growth. Therefore, the aim of this work was to measure the expression of genes related to the ovarian pathway for activation of primordial follicles and FOXO3a protein phosphorylation between young and old female Ames dwarf (df/df) and normal (N) mice. Methods For this study ovaries fro...

  8. Myoblast fusion in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Haralalka, Shruti [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Abmayr, Susan M., E-mail: sma@stowers.org [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, MO 66160 (United States)

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  9. SUMOylation in Drosophila Development

    Directory of Open Access Journals (Sweden)

    Albert J. Courey

    2012-07-01

    Full Text Available Small ubiquitin-related modifier (SUMO, an ~90 amino acid ubiquitin-like protein, is highly conserved throughout the eukaryotic domain. Like ubiquitin, SUMO is covalently attached to lysine side chains in a large number of target proteins. In contrast to ubiquitin, SUMO does not have a direct role in targeting proteins for proteasomal degradation. However, like ubiquitin, SUMO does modulate protein function in a variety of other ways. This includes effects on protein conformation, subcellular localization, and protein–protein interactions. Significant insight into the in vivo role of SUMOylation has been provided by studies in Drosophila that combine genetic manipulation, proteomic, and biochemical analysis. Such studies have revealed that the SUMO conjugation pathway regulates a wide variety of critical cellular and developmental processes, including chromatin/chromosome function, eggshell patterning, embryonic pattern formation, metamorphosis, larval and pupal development, neurogenesis, development of the innate immune system, and apoptosis. This review discusses our current understanding of the diverse roles for SUMO in Drosophila development.

  10. Beef heifers with diminished numbers of antral follicles have decreased uterine protein concentrations

    Science.gov (United States)

    Previous research demonstrated a favorable relationship between the number of follicles detectable in the bovine ovary by ultrasonography and fertility, and bovine females with diminished numbers of antral follicles had smaller reproductive tracts. Therefore, we hypothesized that uterine function w...

  11. Effect of age and sex on fiber and follicle characteristics of an Iranian ...

    African Journals Online (AJOL)

    HP USER

    histological features of all Bakhtiari sheep fibers used in this study were similar to many other breeds sited in ... in compound hair follicles was 4. ... study was to investigate the histological ... follicles, cluster of 4 were most common (Plate III).

  12. 76 FR 2807 - New Animal Drugs; Change of Sponsor; Follicle Stimulating Hormone

    Science.gov (United States)

    2011-01-18

    ... sponsor for a new animal drug application (NADA) for follicle stimulating hormone from Ausa International... transferred ownership of, and all rights and interest in, NADA 141-014 for SUPER-OV (follicle...

  13. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

    OpenAIRE

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-01-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular di...

  14. Targeted Expression of GFP in the Hair Follicle Using Ex Vivo Viral Transduction

    OpenAIRE

    Hoffman, Robert M.; Li, Lingna

    2008-01-01

    The hair follicle is a highly complex appendage of the skin containing a multiplicity of cell types. The follicle undergoes constant cycling through the life of the organism including growth and resorption with growth dependent on specific stem cells. The targeting of the follicle by genes and stem cells to change its properties, in particular, the nature of the hair shaft is, discussed. Hair follicle delivery systems are described, such as liposomes and viral vectors for gene therapy. The na...

  15. A Gap Junction Protein, Inx2, Modulates Calcium Flux to Specify Border Cell Fate during Drosophila oogenesis

    Science.gov (United States)

    Ghosh, Ritabrata; Deshpande, Girish

    2017-01-01

    Intercellular communication mediated by gap junction (GJ) proteins is indispensable during embryogenesis, tissue regeneration and wound healing. Here we report functional analysis of a gap junction protein, Innexin 2 (Inx2), in cell type specification during Drosophila oogenesis. Our data reveal a novel involvement of Inx2 in the specification of Border Cells (BCs), a migratory cell type, whose identity is determined by the cell autonomous STAT activity. We show that Inx2 influences BC fate specification by modulating STAT activity via Domeless receptor endocytosis. Furthermore, detailed experimental analysis has uncovered that Inx2 also regulates a calcium flux that transmits across the follicle cells. We propose that Inx2 mediated calcium flux in the follicle cells stimulates endocytosis by altering Dynamin (Shibire) distribution which is in turn critical for careful calibration of STAT activation and, thus for BC specification. Together our data provide unprecedented molecular insights into how gap junction proteins can regulate cell-type specification. PMID:28114410

  16. Unlike in Drosophila Meroistic Ovaries, hippo represses notch in Blattella germanica Panoistic ovaries, triggering the mitosis-endocycle switch in the follicular cells.

    Directory of Open Access Journals (Sweden)

    Paula Irles

    Full Text Available During insect oogenesis, the follicular epithelium undergoes both cell proliferation and apoptosis, thus modulating ovarian follicle growth. The Hippo pathway is key in these processes, and has been thoroughly studied in the meroistic ovaries of Drosophila melanogaster. However, nothing is known about the role of the Hippo pathway in primitive panoistic ovaries. This work examines the mRNA expression levels of the main components of the Hippo pathway in the panoistic ovary of the basal insect species Blattella germanica, and demonstrates the function of Hippo through RNAi. In Hippo-depleted specimens, the follicular cells of the basal ovarian follicles proliferate without arresting cytokinesis; the epithelium therefore becomes bilayered, impairing ovarian follicle growth. This phenotype is accompanied by long stalks between the ovarian follicles. In D. melanogaster loss of function of Notch determines that the stalk is not developed. With this in mind, we tested whether Hippo and Notch pathways are related in B. germanica. In Notch (only-depleted females, no stalks were formed between the ovarian follicles. Simultaneous depletion of Hippo and Notch rescued partially the stalk to wild-type. Unlike in the meroistic ovaries of D. melanogaster, in panoistic ovaries the Hippo pathway appears to regulate follicular cell proliferation by acting as a repressor of Notch, triggering the switch from mitosis to the endocycle in the follicular cells. The phylogenetically basal position of B. germanica suggests that this might be the ancestral function of Hippo in insect ovaries.

  17. Anti-Mullerian hormone attenuates the effects of FSH on follicle development in the mouse ovary

    NARCIS (Netherlands)

    A.L.L. Durlinger (Alexandra); A.P.N. Themmen (Axel); M.J.G. Gruijters (Maria); P. Kramer; B. Karels (Bas); T.R. Kumar (Rajendra); M.M. Matzuk; U.M. Rose; F.H. de Jong (Frank); J.Th.J. Uilenbroek (Jan); J.A. Grootegoed (Anton)

    2001-01-01

    textabstractAlthough ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The ai

  18. Ultrastructure of the basal lamina of bovine ovarian follicles and its relationship to the membrana granulosa.

    Science.gov (United States)

    Irving-Rodgers, H F; Rodgers, R J

    2000-03-01

    Different morphological phenotypes of follicular basal lamina and of membrana granulosa have been observed. Ten preantral follicles (membrana granulosa. Within each antral follicle, the shape of the basal cells of the membrana granulosa was uniform, and either rounded or columnar. There were equal proportions of follicles membrana granulosa.

  19. File list: InP.Epd.50.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: ALL.Epd.10.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. File list: InP.Epd.20.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  2. File list: InP.Epd.10.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  3. File list: ALL.Epd.20.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  4. File list: InP.Epd.05.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: ALL.Epd.50.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: ALL.Epd.05.AllAg.Hair_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: Oth.Gon.20.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Gon.20.AllAg.Ovarian_Follicle mm9 TFs and others Gonad Ovarian Follicle SRX7370...10,SRX737011 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Gon.20.AllAg.Ovarian_Follicle.bed ...

  8. File list: ALL.Gon.20.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  9. File list: Oth.Gon.05.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  10. File list: ALL.Gon.10.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: InP.Gon.05.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Gon.05.AllAg.Ovarian_Follicle mm9 Input control Gonad Ovarian Follicle SRX73700...9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Gon.05.AllAg.Ovarian_Follicle.bed ...

  12. File list: InP.Gon.20.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: ALL.Gon.50.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: Oth.Gon.50.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. File list: Oth.Gon.10.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: InP.Gon.50.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Gon.50.AllAg.Ovarian_Follicle mm9 Input control Gonad Ovarian Follicle SRX73700...9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Gon.50.AllAg.Ovarian_Follicle.bed ...

  17. File list: ALL.Gon.05.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: InP.Gon.10.AllAg.Ovarian_Follicle [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Gon.10.AllAg.Ovarian_Follicle mm9 Input control Gonad Ovarian Follicle SRX73700...9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Gon.10.AllAg.Ovarian_Follicle.bed ...

  19. Sterol requirements in Drosophila melanogaster

    OpenAIRE

    Almeida de Carvalho, Maria Joao

    2009-01-01

    Sterol is an abundant component of eukaryotic cell membranes and is thought to influence membrane properties such as permeability, fluidity and microdomain formation. Drosophila is an excellent model system in which to study functional requirements for membrane sterol because, although it does not synthesize sterol, it nevertheless requires sterols to complete development. Moreover, Drosophila normally incorporates sterols into cell membranes. Thus, dietary sterol depletion can be used to ...

  20. Metabolism throughout follicle and oocyte development in mammals.

    Science.gov (United States)

    Collado-Fernandez, Esther; Picton, Helen M; Dumollard, Rémi

    2012-01-01

    Metabolic studies of mammalian embryos started with the development of in vitro culture systems more than 40 years ago. More recently, metabolic studies have begun to shed light on the requirements of growing oocytes/follicles from the earliest stages of folliculogenesis. While growing oocytes preferentially metabolise pyruvate over glucose, the somatic compartment of ovarian follicles is more glycolytic. The metabolic preferences of the oocyte are reflected in the early zygote, which becomes increasingly dependent on glycolytic energy production as development progresses to the blastocyst stage. Furthermore, the intricate metabolic relationship between each oocyte and its somatic surroundings is critical for oocyte growth and developmental competence. Measurements of amino acid turnover in bovine oocytes indicate that glutamine, arginine and leucine are consistently depleted, while alanine is produced, showing similarities with amino acid turnover in preimplantation embryos. Amino acid profiling is a good predictor of embryo quality and might also turn out to be a predictor of oocyte developmental competence. Finally, recent studies have uncovered lipid metabolism in oocytes and early embryos, suggesting that endogenous fatty acids might be used for energy production. Together, metabolic studies have revealed the multiplicity of energetic substrates used by oocytes and early embryos, and suggest that the versatility of the metabolic pathways available for energy production is key for high developmental potential. Metabolic studies of early embryos are now being applied to follicle culture, and the goal of describing the metabolome of the growing oocyte in its follicle is now very attainable.

  1. Follicle Development during Luteal Phase and Altrenogest Treatment in Pigs

    NARCIS (Netherlands)

    Soede, N.M.; Bouwman, E.G.; Langendijk, P.; Laan, van der I.; Kanora, A.; Kemp, B.

    2007-01-01

    Synchronization of the oestrous cycle of gilts using altrenogest treatment has been found to increase ovulation rate. The current experiment investigated if the increase in ovulation rate after altrenogest treatment is related to increased follicle size at the end of altrenogest treatment compared w

  2. Polarization developments

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist.

  3. Cytokines in Drosophila immunity.

    Science.gov (United States)

    Vanha-Aho, Leena-Maija; Valanne, Susanna; Rämet, Mika

    2016-02-01

    Cytokines are a large and diverse group of small proteins that can affect many biological processes, but most commonly cytokines are known as mediators of the immune response. In the event of an infection, cytokines are produced in response to an immune stimulus, and they function as key regulators of the immune response. Cytokines come in many shapes and sizes, and although they vary greatly in structure, their functions have been well conserved in evolution. The immune signaling pathways that respond to cytokines are remarkably conserved from fly to man. Therefore, Drosophila melanogaster, provides an excellent platform for studying the biology and function of cytokines. In this review, we will describe the cytokines and cytokine-like molecules found in the fly and discuss their roles in host immunity.

  4. Optogenetics in Drosophila Neuroscience.

    Science.gov (United States)

    Riemensperger, Thomas; Kittel, Robert J; Fiala, André

    2016-01-01

    Optogenetic techniques enable one to target specific neurons with light-sensitive proteins, e.g., ion channels, ion pumps, or enzymes, and to manipulate their physiological state through illumination. Such artificial interference with selected elements of complex neuronal circuits can help to determine causal relationships between neuronal activity and the effect on the functioning of neuronal circuits controlling animal behavior. The advantages of optogenetics can best be exploited in genetically tractable animals whose nervous systems are, on the one hand, small enough in terms of cell numbers and to a certain degree stereotypically organized, such that distinct and identifiable neurons can be targeted reproducibly. On the other hand, the neuronal circuitry and the behavioral repertoire should be complex enough to enable one to address interesting questions. The fruit fly Drosophila melanogaster is a favorable model organism in this regard. However, the application of optogenetic tools to depolarize or hyperpolarize neurons through light-induced ionic currents has been difficult in adult flies. Only recently, several variants of Channelrhodopsin-2 (ChR2) have been introduced that provide sufficient light sensitivity, expression, and stability to depolarize central brain neurons efficiently in adult Drosophila. Here, we focus on the version currently providing highest photostimulation efficiency, ChR2-XXL. We exemplify the use of this optogenetic tool by applying it to a widely used aversive olfactory learning paradigm. Optogenetic activation of a population of dopamine-releasing neurons mimics the reinforcing properties of a punitive electric shock typically used as an unconditioned stimulus. In temporal coincidence with an odor stimulus this artificially induced neuronal activity causes learning of the odor signal, thereby creating a light-induced memory.

  5. Comparison of antral and preantral ovarian follicle populations between Bos indicus and Bos indicus-taurus cows with high or low antral follicles counts.

    Science.gov (United States)

    Silva-Santos, K C; Siloto, L S; Santos, G M G; Morotti, F; Marcantonio, T N; Seneda, M M

    2014-02-01

    The objective was to compare populations of antral and pre-antral ovarian follicles in Bos indicus and Bos indicus-taurus cows with high and low antral follicle counts. Nelore (Bos indicus, n = 20) and Nelore X Angus (1/2 Bos indicus-taurus, n = 20) cows were subjected to follicular aspiration without regard to the stage of their oestrous cycle (day of aspiration = D0) to remove all follicles ≥3 mm and induce growth of a new follicular wave. Ovaries were examined by ultrasonography on D4, D19, D34, D49 and D64, and antral follicles ≥3 mm were counted. Thereafter, cows were assigned to one of two groups: high or low antral follicular count (AFC, ≥30 and ≤15 antral follicles, respectively). After D64, ovaries were collected after slaughter and processed for histological evaluation. There was high repeatability in the numbers of antral follicles for all groups (range 0.77-0.96). The mean (±SD) numbers of antral follicles were 35 ± 9 (Bos indicus) and 38 ± 6 (Bos indicus-taurus) for the high AFC group and 10 ± 3 (Bos indicus) and 12 ± 2 (Bos indicus-taurus) follicles for the low AFC. The mean number of preantral follicles in the ovaries of Bos indicus-taurus cows with high AFC (116 226 ± 83 156 follicles) was greater (p < 0.05) than that of Bos indicus cows (63 032 ± 58 705 follicles) with high AFC. However, there was no significant correlation between numbers of antral and preantral follicles.

  6. Planar cell polarity: one or two pathways?

    Science.gov (United States)

    Lawrence, Peter A; Struhl, Gary; Casal, José

    2007-07-01

    In multicellular organisms, cells are polarized in the plane of the epithelial sheet, revealed in some cell types by oriented hairs or cilia. Many of the underlying genes have been identified in Drosophila melanogaster and are conserved in vertebrates. Here we dissect the logic of planar cell polarity (PCP). We review studies of genetic mosaics in adult flies - marked cells of different genotypes help us to understand how polarizing information is generated and how it passes from one cell to another. We argue that the prevailing opinion that planar polarity depends on a single genetic pathway is wrong and conclude that there are (at least) two independently acting processes. This conclusion has major consequences for the PCP field.

  7. Scavenger receptors mediate the role of SUMO and Ftz-f1 in Drosophila steroidogenesis.

    Directory of Open Access Journals (Sweden)

    Ana Talamillo

    2013-04-01

    Full Text Available SUMOylation participates in ecdysteroid biosynthesis at the onset of metamorphosis in Drosophila melanogaster. Silencing the Drosophila SUMO homologue smt3 in the prothoracic gland leads to reduced lipid content, low ecdysone titers, and a block in the larval-pupal transition. Here we show that the SR-BI family of Scavenger Receptors mediates SUMO functions. Reduced levels of Snmp1 compromise lipid uptake in the prothoracic gland. In addition, overexpression of Snmp1 is able to recover lipid droplet levels in the smt3 knockdown prothoracic gland cells. Snmp1 expression depends on Ftz-f1 (an NR5A-type orphan nuclear receptor, the expression of which, in turn, depends on SUMO. Furthermore, we show by in vitro and in vivo experiments that Ftz-f1 is SUMOylated. RNAi-mediated knockdown of ftz-f1 phenocopies that of smt3 at the larval to pupal transition, thus Ftz-f1 is an interesting candidate to mediate some of the functions of SUMO at the onset of metamorphosis. Additionally, we demonstrate that the role of SUMOylation, Ftz-f1, and the Scavenger Receptors in lipid capture and mobilization is conserved in other steroidogenic tissues such as the follicle cells of the ovary. smt3 knockdown, as well as ftz-f1 or Scavenger knockdown, depleted the lipid content of the follicle cells, which could be rescued by Snmp1 overexpression. Therefore, our data provide new insights into the regulation of metamorphosis via lipid homeostasis, showing that Drosophila Smt3, Ftz-f1, and SR-BIs are part of a general mechanism for uptake of lipids such as cholesterol, required during development in steroidogenic tissues.

  8. [Signaling molecules and pathways involved in maintaining the quiescence of primordial follicles].

    Science.gov (United States)

    Hu, Liao-Liao; Xiang, Cheng; Zheng, Li-Ping

    2015-02-25

    Reproductive lifespan in female mammals is related to the size of primordial follicles pool, which relies on the balance between activated and quiescent primordial follicles. Therefore, the molecular mechanisms of recruiting and maintaining quiescence of primordial follicles have become hot research topics recently. Multiple studies have shown that genetic mutations, local ovarian autocrine and paracrine factors, proto-oncogene and tumor-suppressor genes are involved in the maintenance of balance between quiescent and activated primordial follicles. In the present review, we summarize recent research progress of the important signaling molecules and pathways that maintain the quiescence of primordial follicles.

  9. Polarization, political

    NARCIS (Netherlands)

    M. Wojcieszak

    2015-01-01

    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass pol

  10. Polar Codes

    Science.gov (United States)

    2014-12-01

    QPSK Gaussian channels . .......................................................................... 39 vi 1. INTRODUCTION Forward error correction (FEC...Capacity of BSC. 7 Figure 5. Capacity of AWGN channel . 8 4. INTRODUCTION TO POLAR CODES Polar codes were introduced by E. Arikan in [1]. This paper...Under authority of C. A. Wilgenbusch, Head ISR Division EXECUTIVE SUMMARY This report describes the results of the project “More reliable wireless

  11. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  12. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication......Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  13. Vasoactive intestinal peptide can promote the development of neonatal rat primordial follicles during in vitro culture.

    Science.gov (United States)

    Chen, Niannian; Li, Yu; Wang, Wenjun; Ma, Yun; Yang, Dongzi; Zhang, Qingxue

    2013-01-01

    Recruitment of primordial follicles is essential for female fertility. Some of the intraovarian growth factors involved in the initiation of primordial follicle growth have been identified, but the exact mechanisms regulating follicle activation are poorly understood. Strong evidence indicates that vasoactive intestinal peptide (VIP), a neuropeptide found in ovarian nerves, plays a role in the physiology of follicle development and function. The aim of the present study was to determine whether VIP might regulate the activation and growth of neonatal rat primordial follicles in an in vitro culture system. Ovaries from 4-day-old rats were cultured for 14 days in medium containing 10(-7) M VIP. At the end of the culture, the developmental stages and viability of the follicles were evaluated using histological sections. Immunohistochemistry studies for proliferating cell nuclear antigen (PCNA) were performed to assess the mitotic activity of granulosa cells. In addition, the expression level of kit ligand (KL) mRNA was examined after culture. Histology showed that primordial follicles could survive and start to grow in vitro. The proportion of primordial follicles was decreased and the proportion of early primary follicles increased after in vitro culture with VIP. Immunolocalization of PCNA showed that follicle growth was initiated after VIP treatment. The expression level of KL mRNA was increased in the VIP treatment group. Thus, VIP can promote primordial follicle development, possibly mediated in part through upregulating the expression of KL.

  14. Hair follicle transcriptome profiles during the transition from anagen to catagen in Cashmere goat (Capra hircus).

    Science.gov (United States)

    Fan, Y X; Wu, R B; Qiao, X; Zhang, Y J; Wang, R J; Su, R; Wu, J H; Dong, Y; Li, J Q

    2015-12-22

    Previous molecular genetic studies of the goat hair life cycle have focused primarily on a limited number of genes and proteins. To identify additional genes that may play important roles in hair follicle cycle regulation, Illumina sequencing technology was used to catalog differential gene expression profiles in the hair growth cycle (anagen to catagen) of goat, comparing the primary hair follicle with the secondary hair follicle. There were 13,769 and 12,240 unigenes assembled from the reads obtained from primary hair follicle and secondary hair follicle, respectively. Genes encoding keratin proteins and keratin-associated proteins were the most highly expressed. A total of 5899 genes were differentially expressed in anagen vs catagen primary hair follicles, with 532 genes up-regulated and 5367 genes down-regulated. A total of 5208 genes were differentially expressed in anagen vs catagen secondary hair follicle, including 545 genes that were up-regulated and 4663 genes that were down-regulated. Numerous hair growth genes are expressed in the goat hair follicle, of which 73 genes showed co-up-regulation in both hair follicles during the anagen stage. Many of these up-regulated genes, such as STC2, VEGFR, and ROR2, are known to be transfactors in the process of cell differentiation and in the cell cycle. The differential gene expression profiles between primary hair follicles and secondary hair follicles obtained provide a foundation for future studies examining the network of gene expression controlling hair growth cycle in Cashmere goat.

  15. The primordial follicle reserve is not renewed after chemical or γ-irradiation mediated depletion.

    Science.gov (United States)

    Kerr, J B; Brogan, L; Myers, M; Hutt, K J; Mladenovska, T; Ricardo, S; Hamza, K; Scott, C L; Strasser, A; Findlay, J K

    2012-04-01

    Reports indicate that germ-line stem cells present in adult mice can rapidly generate new oocytes and contribute to the primordial follicle reserve following conditions of ovotoxic stress. We further investigated the hypothesis that adult mice have the capacity to generate new oocytes by monitoring primordial follicle numbers throughout postnatal life and following depletion of the primordial follicle reserve by exposure to doxorubicin (DXR), trichostatin A (TSA), or whole-body γ-irradiation. We show that primordial follicle number remains stable in adult C57BL/6 mice between the ages of 25 and 100 days. However, within 2 days of treatment with DXR or TSA, primordial follicle numbers had declined to 65 and 51% respectively (Pprimordial follicles 5 days after treatment, with no indication of follicular renewal. We conclude that neo-folliculogenesis does not occur following chemical or γ-irradiation mediated depletion of the primordial follicle reserve.

  16. Targeted expression of GFP in the hair follicle using ex vivo viral transduction.

    Science.gov (United States)

    Hoffman, Robert M; Li, Lingna

    2008-03-17

    There are many cell types in the hair follicle, including hair matrix cells which form the hair shaft and stem cells which can initiate the hair shaft during early anagen, the growth phase of the hair cycle, as well as pluripotent stem cells that play a role in hair follicle growth but have the potential to differentiate to non-follicle cells such as neurons. These properties of the hair follicle are discussed. The various cell types of the hair follicle are potential targets for gene therapy. Gene delivery system for the hair follicle using viral vectors or liposomes for gene targeting to the various cell types in the hair follicle and the results obtained are also discussed [corrected].

  17. The hair follicle and its stem cells as drug delivery targets.

    Science.gov (United States)

    Hoffman, Robert M

    2006-05-01

    The hair follicle is a skin appendage with a complex structure containing many cell types that produce highly specialised proteins. The hair follicle is in a continuous cycle: anagen is the hair growth phase, catagen the involution phase and telogen is the resting phase. The follicle offers many potential therapeutic targets. Hoffman and colleagues have pioneered hair-follicle-specific targeting using liposomes to deliver small and large molecules, including genes. They have also pioneered ex vivo hair-follicle targeting with continued expression of the introduced gene following transplantation. Recently, it has been discovered that hair follicle stem cells are highly pluripotent and can form neurons, glial cells and other cell types, and this has suggested that hair follicle stem cells may serve as gene therapy targets for regenerative medicine.

  18. Migration and keratinization of cells in wool follicles.

    Science.gov (United States)

    Chapman, R E; Downes, A M; Wilson, P A

    1980-10-01

    Migration of cells in wool follicles of an adult Merino sheep was studied autoradiographically in skin samples taken at intervals after an intravenous injection of [3H]thymidine. Fibre and inner root sheath cells incorporated [3H]thymidine in a cone-shape region of the follicle bulb. Labelled inner sheath cells migrated out of the bulb ahead of contemporaneous cells in the fibre and remained in advance, although to a progressively lesser extent, until the inner sheath cells sloughed into the follicle lumen. Outer root sheath cells incorporated [3H]thymidine along the length of the follicle. Cells in the proximal half of the outer sheath migrated inwards and distally and sloughed into the follicle lumen before contemporaneous inner sheath cells. Other cells in the distal half of the outer sheath migrated past the level where cells from the proximal population were shed and also sloughed into the lumen. In the most distal part of the outer sheath, which formed the epidermis-like lining of the follicle canal, little migration of cells was observed during 8 days of observation. The specific activity of tritium in fibres plucked from the same sheep at intervals after the intravenous injection of [3H]thymidine was determined by scintillation counting and assessed in terms of cell migration and hardening of the fibres. The time which the specific activity of solvent-degreased fibres reached a maximum was found to give an estimate of the time for cells in the fibre to migrate to the upper limit of the keratogenous zone. When the plucked fibres were extracted with 8 M urea the times of the maximum specific activities of the urea-dispersible and urea-insoluble material provided respectively estimates of the times at which hardening of the fibres began and ended. The effects of different planes of nutrition were examined in two other Merino sheep by radioassay of fibres plucked after intravenous injections of [3H]thymidine given after equilibration period of at least 2 months

  19. Alginate encapsulation supports the growth and differentiation of human primordial follicles within ovarian cortical tissue.

    Science.gov (United States)

    Laronda, Monica M; Duncan, Francesca E; Hornick, Jessica E; Xu, Min; Pahnke, Jennifer E; Whelan, Kelly A; Shea, Lonnie D; Woodruff, Teresa K

    2014-08-01

    In vitro follicle growth (IVFG) is an investigational fertility preservation technique in which immature follicles are grown in culture to produce mature eggs that can ultimately be fertilized. Although progress has been made in growing primate primary and secondary follicles in vitro, it has been a relatively greater challenge to isolate and culture primordial follicles. The purpose of this study was to develop methods to grow human primordial follicles in vitro using alginate hydrogels. We obtained human ovarian tissue for research purposes through the National Physicians Cooperative from nationwide sites and used it to test two methods for culturing primordial follicles. First, primordial follicles were isolated from the ovarian cortex and encapsulated in alginate hydrogels. Second, 1 mm × 1 mm pieces of 500 μm-thick human ovarian cortex containing primordial follicles were encapsulated in alginate hydrogels, and survival and follicle development within the tissue was assessed for up to 6 weeks. We found that human ovarian tissue could be kept at 4 °C for up to 24 h while still maintaining follicle viability. Primordial follicles isolated from ovarian tissue did not survive culture. However, encapsulation and culture of ovarian cortical pieces supported the survival, differentiation, and growth of primordial and primary follicles. Within several weeks of culture, many of the ovarian tissue pieces had formed a defined surface epithelium and contained growing preantral and antral follicles. The early stages of in vitro human follicle development require the support of the native ovarian cortex.

  20. Cytokine (IL16) and tyrphostin actions on ovarian primordial follicle development.

    Science.gov (United States)

    Feeney, Amanda; Nilsson, Eric; Skinner, Michael K

    2014-09-01

    An ovarian follicle is composed of an oocyte and surrounding theca and granulosa cells. Oocytes are stored in an arrested state within primordial follicles until they are signaled to re-initiate development by undergoing primordial-to-primary follicle transition. Previous gene bionetwork analyses of primordial follicle development identified a number of critical cytokine signaling pathways and genes potentially involved in the process. In the current study, candidate regulatory genes and pathways from the gene network analyses were tested for their effects on the formation of primordial follicles (follicle assembly) and on primordial follicle transition using whole ovary organ culture experiments. Observations indicate that the tyrphostin inhibitor (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased follicle assembly significantly, supporting a role for the MAPK signaling pathway in follicle assembly. The cytokine interleukin 16 (IL16) promotes primordial-to-primary follicle transition as compared with the controls, where as Delta-like ligand 4 (DLL4) and WNT-3A treatments have no effect. Immunohistochemical experiments demonstrated the localization of both the cytokine IL16 and its receptor CD4 in the granulosa cells surrounding each oocyte within the ovarian follicle. The tyrphostin LDN193189 (LDN) is an inhibitor of the bone morphogenic protein receptor 1 within the TGFB signaling pathway and was found to promote the primordial-to-primary follicle transition. Observations support the importance of cytokines (i.e., IL16) and cytokine signaling pathways in the regulation of early follicle development. Insights into regulatory factors affecting early primordial follicle development are provided that may associate with ovarian disease and translate to improved therapy in the future. © 2014 Society for Reproduction and Fertility.

  1. Mechanisms of asymmetric cell divisions in Drosophila melanogaster neuroblasts

    Directory of Open Access Journals (Sweden)

    X Jiang

    2014-04-01

    Full Text Available Stem cells possess the properties of self-renewal and differentiation, and mainly rely on two strategies for division, including symmetric and asymmetric cell divisions. In this review, we summarize the latest progress on asymmetric cell divisions in Drosophila melanogaster neuroblasts (NBs, which focus on the establishment of cell polarity, mitotic spindle orientation, the asymmetric segregation of cell fate determinants as well as cell-cycle control. Here we also introduce five major cell fate determinants, including Numb, Prospero, Brat, Miranda, and Pon, which are thought to be unequally segregated to the ganglion mother cells (GMCs and play an important role in the formation of stem cell-derived tumors

  2. Delivery and targeting of nanoparticles into hair follicles.

    Science.gov (United States)

    Fang, Chia-Lang; Aljuffali, Ibrahim A; Li, Yi-Ching; Fang, Jia-You

    2014-01-01

    It has been demonstrated that nanoparticles used for follicular delivery provide some advantages over conventional pathways, including improved skin bioavailability, enhanced penetration depth, prolonged residence duration, fast transport into the skin and tissue targeting. This review describes recent developments using nanotechnology approaches for drug delivery into the follicles. Different types of nanosystems may be employed for management of follicular permeation, such as polymeric nanoparticles, metallic nanocrystals, liposomes, and lipid nanoparticles. This review systematically introduces the mechanisms of follicles for nanoparticulate penetration, highlighting the therapeutic potential of drug-loaded nanoparticles for treating skin diseases. Special attention is paid to the use of nanoparticles in treating appendage-related disorders, in particular, nanomedical strategies for treating alopecia, acne, and transcutaneous immunization.

  3. Constructing skin-equivalents using hair follicle stem cells

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To establish the method of constructing skin-equivalents (SE) using hair follicle stem cells(HFSC).Methods: K19 positive cells derived from hair were cultivated using serum-free medium KGM and seeded on dermal equivalents (DE).After the culture between the air-liquid interface for 14 days, SE were harvested and used for evaluation. Results: K19 positive cells chosen as HFSC were located in bulge of out root sheet in hair follicle. Cultivated HFSC could build a fully developed, multi-layered epidermis on the basis of DE, resembling the skin structure. Conclusion: HFSC located in out root sheet can differentiate into keratinocyte in vitro and be used for SE construction.

  4. Evaluation of polylactic acid nanoparticles safety using Drosophila model.

    Science.gov (United States)

    Legaz, Sophie; Exposito, Jean-Yves; Lethias, Claire; Viginier, Barbara; Terzian, Christophe; Verrier, Bernard

    2016-10-01

    Cytotoxicity of nanoparticles and their sub-lethal effect on cell behavior and cell fate are a high topic of studies in the nanomaterial field. With an explosion of nanoparticle types (size, shape, polarity, stiffness, composition, etc.), Drosophila has become an attractive animal model for high throughput analysis of these nanocarriers in the drug delivery field with applications in cancer therapy, or simply to generate a fast and complete cytotoxic study of a peculiar nanoparticle. In respect to that, we have conducted an in cellulo study of poly(lactic acid) (PLA) nanoparticle cytotoxicity, and determined that near lethal nanoparticle doses, oxidative stress as well as P53 and ATP pathways may lead to cell cycle arrest at G1, and ultimately to cell death. Neither viability nor the development of Drosophila larvae are affected by the ingestion of PLA nanoparticles at sub-lethal concentrations. Drosophila will be a useful model to study PLA and PLA-modified nanoparticle toxicity, and nanoparticle fate after ingestion.

  5. Biological characterization of cultured dermal papilla cells and hair follicle regeneration in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    Lü Zhong-fa; CAI Sui-qing; WU Jin-jin; ZHENG Min

    2006-01-01

    Background Dermal papilla cells (DPC) are a group of mesenchyme-derived cells at the base of the hair follicle, where they regulate and control hair follicle growth through the expression and secretion of cytokines. Nevertheless, the role of DPC derived chemokines and other cytokines in the hair follicle biology remain speculative. In this study, we investigated the expression of basic fibroblast growth factor (bFGF), endothelin-1 (ET-1) and stem cell factor (SCF) in different passages of cultured DPC and their effects on the biological behaviour of DPC.Methods The expression of bFGF, ET-1 and SCF in different passages of cultured DPC and their possible effects on the biological behavior of DPC are investigated using in situ hybridization and immunochemistry. In addition, we performed transplantation of hair follicle cells into nude mice. The cultured DPC, dermal sheath cells and fibroblast of human scalp, respectively, were mixed with cells of the hair follicle epithelium in different ratios, and then were cultured in hair follicle organotypic cultures or implanted into the subcutis of nude mice.Results The expression of ET-1 and SCF in early passages of cultured DPC became stronger, but turned weaker and even negative in late passages (>6 passages). Hair follicle-like structures were formed after DPC combined with the cells of hair follicle epithelium cells in hair follicle organotypic cultures. When hair follicle organotypic cultures were implanted into the subcutis of nude mice, the relative intact hair follicles were formed. After the transplantation of hair follicle cells into the nude mice, the hair follicle-like structure was formed in the group that contained DPC mixed with hair follicle epithelium cells. However, no hair follicles were formed in the other two groups. It was found that the higher the expression of ET-1 and SCF in DPC, the stronger the ability of DPC to induce hair follicle regeneration.Conclusions The cultured DPC can induce hair follicle

  6. Polarizing cues.

    Science.gov (United States)

    Nicholson, Stephen P

    2012-01-01

    People categorize themselves and others, creating ingroup and outgroup distinctions. In American politics, parties constitute the in- and outgroups, and party leaders hold sway in articulating party positions. A party leader's endorsement of a policy can be persuasive, inducing co-partisans to take the same position. In contrast, a party leader's endorsement may polarize opinion, inducing out-party identifiers to take a contrary position. Using survey experiments from the 2008 presidential election, I examine whether in- and out-party candidate cues—John McCain and Barack Obama—affected partisan opinion. The results indicate that in-party leader cues do not persuade but that out-party leader cues polarize. This finding holds in an experiment featuring President Bush in which his endorsement did not persuade Republicans but it polarized Democrats. Lastly, I compare the effect of party leader cues to party label cues. The results suggest that politicians, not parties, function as polarizing cues.

  7. The eye of Drosophila as a model system for studying intracellular signaling in ontogenesis and pathogenesis.

    Science.gov (United States)

    Katanaev, V L; Kryuchkov, M V

    2011-12-01

    Many human diseases are caused by malfunction of basic types of cellular activity such as proliferation, differentiation, apoptosis, cell polarization, and migration. In turn, these processes are associated with different routes of intracellular signal transduction. A number of model systems have been designed to study normal and abnormal cellular and molecular processes associated with pathogenesis. The developing eye of the fruit fly Drosophila melanogaster is one of these systems. The sequential development of compound eyes of this insect makes it possible to model human neurodegenerative diseases and mechanisms of carcinogenesis. In this paper we overview the program of the eye development in Drosophila, with emphasis on intracellular signaling pathways that regulate this complex process. We discuss in detail the roles of the Notch, Hedgehog, TGFβ, Wnt, and receptor tyrosine kinase signaling pathways in Drosophila eye development and human pathology. We also briefly describe the modern methods of experimentation with this model organism to analyze the function of human pathogenic proteins.

  8. Ultrastructure of Amelanotic Melanocytes from Human Hair Follicles

    Institute of Scientific and Technical Information of China (English)

    Ruzhi Zhang; Wenyuan Zhu; Mingyu Xia; Daguang Wang; Huijun Ma

    2007-01-01

    Objective: To investigate the ultra structure of amelanotic melanocytes (AMMC). Methods: The hair follicles obtained from normal human scalp by 0.50% collagenase type V treatment were washed with 0.1mol/L phosphate buffer salt (PBS). Hair-follicle cell suspensions were prepared by trypsin treatment and cultured in melanocyte medium. Remaining keratinocytes were removed by differential trypsinization. 100μg/ml geneticin was used to eliminate the contaminating fibroblasts. At third passage, the cells were trypsinized, and then washed in phosphate-buffered saline and processed for transmission electron microscopy. Results: Under transmission electron microscope, the cultured cells showed round or oval shape, with single large nuclear and the karyotheca were double deck. There were obvious euchromosome within the nucleus, and sparse heterochromosome. There were various organelles in the cytoplasm, including plentiful melanosomes with nearly similar size, mitochondria, rough endoplasmic reticule (RER) and ribosome. The electron density granules in most of the melanosomes disposed along concentric circularities. Golgi apparatus in the cells was inconspicuous. Conclusion: The ultra structure of AMMC from human hair follicles is different from that of epidermal melanocytes, and these characteristics determine the functional immature of AMMC.

  9. Non-coding RNAs in the Ovarian Follicle

    Directory of Open Access Journals (Sweden)

    Rosalia Battaglia

    2017-05-01

    Full Text Available The mammalian ovarian follicle is the complex reproductive unit comprising germ cell, somatic cells (Cumulus and Granulosa cells, and follicular fluid (FF: paracrine communication among the different cell types through FF ensures the development of a mature oocyte ready for fertilization. This paper is focused on non-coding RNAs in ovarian follicles and their predicted role in the pathways involved in oocyte growth and maturation. We determined the expression profiles of microRNAs in human oocytes and FF by high-throughput analysis and identified 267 microRNAs in FF and 176 in oocytes. Most of these were FF microRNAs, while 9 were oocyte specific. By bioinformatic analysis, independently performed on FF and oocyte microRNAs, we identified the most significant Biological Processes and the pathways regulated by their validated targets. We found many pathways shared between the two compartments and some specific for oocyte microRNAs. Moreover, we found 41 long non-coding RNAs able to interact with oocyte microRNAs and potentially involved in the regulation of folliculogenesis. These data are important in basic reproductive research and could also be useful for clinical applications. In fact, the characterization of non-coding RNAs in ovarian follicles could improve reproductive disease diagnosis, provide biomarkers of oocyte quality in Assisted Reproductive Treatment, and allow the development of therapies for infertility disorders.

  10. Mitotic activity in cells of the wool follicle bulb.

    Science.gov (United States)

    Hynd, P I; Schlink, A C; Phillips, P M; Scobie, D R

    1986-01-01

    Mitotic activity in the cells of the germinative region of wool follicle bulbs was quantified by using small (0.1-0.5 ml) intradermal doses of colchicine and selective staining of the metaphase-blocked nuclei using either crystal violet, iodine and eosin or haematoxylin and eosin. The number of metaphase nuclei present 3 h after colchicine administration increased with colchicine dose from 0 to 1 microgram and thereafter remained relatively constant up to 200 micrograms colchicine. The accumulation of metaphase nuclei was linear for up to 6 h after intradermal colchicine. The metaphase-blocking effect of intradermal colchicine was confined to a radius of less than 5 cm from the injection site, allowing a number of estimates of mitotic rates to be made over a small area of skin. Such estimates revealed little variation in mitotic activity over the midside region of the sheep, although there were substantial differences in follicle activity at different sites over the body. The technique is simple, allows serial or concurrent estimates of mitotic activity to be made in the same animal, and eliminates problems associated with intravenous colchicine administration. It was used to derive the relationship between follicle activity and fibre production after nutritional changes, and to define the time course of mitotic events after administration of the antimitotic defleecing agent cyclophosphamide.

  11. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae).

    Science.gov (United States)

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-12-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves.

  12. Low expression of SEMA6C accelerates the primordial follicle activation in the neonatal mouse ovary.

    Science.gov (United States)

    Zhou, Su; Yan, Wei; Shen, Wei; Cheng, Jing; Xi, Yueyue; Yuan, Suzhen; Fu, Fangfang; Ding, Ting; Luo, Aiyue; Wang, Shixuan

    2017-09-07

    The primordial follicle assembly, activation and the subsequent development are critical processes for female reproduction. A limited number of primordial follicles are activated to enter the growing follicle pool each wave, and the primordial follicle pool progressively diminishes over a woman's life-time. The number of remaining primordial follicles represents the ovarian reserve. Identification and functional investigation of the factors involved in follicular initial recruitment will be of great significance to the understanding of the female reproduction process and ovarian ageing. In this study, we aimed to study whether and how semaphorin 6C (Sema6c) regulated the primordial follicle activation in the neonatal mouse ovary. The attenuation of SEMA6C expression by SiRNA accelerated the primordial follicle activation in the in vitro ovary culture system. PI3K-AKT-rpS6 pathway was activated when SEMA6C expression was down-regulated. And the LY294002 could reverse the effect of low SEMA6C expression on primordial follicle activation. Our findings revealed that Sema6c was involved in the activation of primordial follicles, and the down-regulation of SEMA6C led to massive primordial follicle activation by interacting with the PI3K-AKT-rpS6 pathway, which might also provide valuable information for understanding premature ovarian failure and ovarian ageing. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  13. A novel method for toxicology: in vitro culture system of a rat preantral follicle.

    Science.gov (United States)

    Wan Xuying; Zhu Jiangbo; Zhu Yuping; Xili, Ma; Liu Zhen; Wang Fei; Xu Guifeng; Zhang Tianbao

    2011-08-01

    Preantral follicle in vitro culture systems have been successfully or nearly successfully established for sheep, pig and mouse, and applied on follicle development and regulation research on reproductive biology and physiology. However, there have been few studies concerning rat preantral follicle in vitro development. The objective is to establish an in vitro culture system for rat preantral follicles which can be used for reproductive biology and toxicology research. Rat preantral follicles are mechanically separated, cultured in vitro in single follicle mode for continuous 12 days using 96-well plates, and then administrated ovulation induction. The observation on follicle development, hormone level, and ovum formation are recorded and assessed. Taking in vivo growth and in vitro maturation of oocytes group as control group, in vitro growth and maturation of oocytes group is assessed to see whether this in vitro culture method is successful. The conditions for rat follicle culture are determined based on the mouse pre-antral follicle culture. The in vitro culture system for rat preantral follicles established in this study is feasible and successful, and can serve as model for reproductive biology and toxicology research.

  14. Ultrastructural observations of previtellogenic ovarian follicles of the caecilians Ichthyophis tricolor and Gegeneophis ramaswamii.

    Science.gov (United States)

    Beyo, Reston S; Sreejith, Parameswaran; Divya, Lekha; Oommen, Oommen V; Akbarsha, Mohammad A

    2007-04-01

    The ultrastructural organization of the previtellogenic follicles of the caecilians Ichthyophis tricolor and Gegeneophis ramaswamii, of the Western Ghats of India, were observed. Both species follow a similar seasonal reproductive pattern. The ovaries contain primordial follicles throughout the year with previtellogenic, vitellogenic, or postvitellogenic follicles, depending upon the reproductive status. The just-recruited primordial follicle includes an oocyte surrounded by a single layer of follicle and thecal cells. The differentiation of the theca into externa and interna layers, the follicle cells into dark and light variants, and the appearance of primordial yolk platelets and mitochondrial clouds in the ooplasm mark the transition of the primordial follicle into a previtellogenic follicle. During further development of the previtellogenic follicle the following changes occur: i) the theca loses distinction as externa and interna; ii) all the follicle cells become the dark variant and increase in the complexity of ultrastructural organization; iii) the nucleus of the oocyte transforms into the germinal vesicle and there is amplification of the nucleoli; iv) the primordial yolk platelets of the cortical cytoplasm of the oocyte increase in abundance; v) the mitochondrial clouds fragment and the mitochondria move away from the clouds, leaving behind the cementing matrix, which contains membrane-bound vesicles of various sizes, either empty or filled with a lipid material; vi) the perivitelline space appears first as troughs at the junctional points between the follicle cells and oocyte, which subsequently spread all around to become continuous; vii) macrovilli and microvilli develop from the follicle cells and oocyte, respectively; and viii) the precursor material of the vitelline envelop arrives at the perivitelline space. The sequential changes in the previtellogenic follicles of two species of caecilians are described.

  15. Destruction of the germinal disc region of an immature preovulatory chicken follicle induces atresia and apoptosis.

    Science.gov (United States)

    Yao, H H; Volentine, K K; Bahr, J M

    1998-09-01

    The germinal disc region (GDR), which contains the germinal disc and overlying granulosa cells, is essential for completion of maturation of the preovulatory chicken follicle. The current study was conducted to test the hypothesis that destruction of the GDR (GDRX) of an immature preovulatory chicken follicle blocks ovulation, induces apoptosis, and causes atresia. The GDR of immature preovulatory follicles (F2) were destroyed by freezing with dry ice (3 mm in diameter) 48-50 h before ovulation. As a control for the effect of freezing, a nonGDR portion (a portion of the follicular wall opposite to the GDR relative to the follicular stalk) of other F2 follicles were destroyed (nonGDRX). Treatment of F2 follicles by GDRX caused atresia and blocked ovulation of all treated follicles (6 of 6), whereas none of the nonGDRX follicles (0 of 5) underwent atresia. Treatment of follicles by GDRX induced apoptotic DNA fragmentation (laddering) in theca and granulosa layers obtained from the frozen area and in the theca layer obtained from the follicular wall distal to the frozen area. In contrast, apoptosis was only present in theca and granulosa layers in the frozen area of the nonGDRX follicle. Furthermore, the in situ DNA end-labeling technique demonstrated that in the GDRX follicle 24 h after treatment, cells in the theca interna, endothelial cells in blood vessels of the theca externa, and a few granulosa cells underwent apoptosis. These results indicate that destruction of the GDR of an immature preovulatory follicle causes atresia and apoptosis and blocks ovulation. These novel findings suggest that the GDR maintains development of the chicken preovulatory follicle by producing one or more survival factors. Without the GDR, chicken follicles cannot develop further and they eventually die.

  16. Drosophila models for cancer research.

    Science.gov (United States)

    Vidal, Marcos; Cagan, Ross L

    2006-02-01

    Drosophila is a model system for cancer research. Investigation with fruit flies has facilitated a number of important recent discoveries in the field: the hippo signaling pathway, which coordinates cell proliferation and death to achieve normal tissue size; 'social' behaviors of cells, including cell competition and apoptosis-induced compensatory proliferation, that help ensure normal tissue size; and a growing understanding of how oncogenes and tumor suppressors cooperate to achieve tumor growth and metastasis in situ. In the future, Drosophila models can be extended beyond basic research in the search for human therapeutics.

  17. Isolation of Crb1, a mouse homologue of Drosophila crumbs, and analysis of its expression pattern in eye and brain.

    NARCIS (Netherlands)

    Hollander, A.I. den; Ghiani, M.; Kok, Y.J.M. de; Wijnholds, J.; Ballabio, A.; Cremers, F.P.M.; Broccoli, V.

    2002-01-01

    Mutations in the human Crumbs homologue 1 (CRB1) gene cause severe retinal dystrophies. CRB1 is homologous to Drosophila Crumbs, a protein essential for establishing and maintaining epithelial polarity. We have isolated the mouse orthologue, Crb1, and analyzed its expression pattern in embryonic and

  18. A simplified model of ephitelial cell hair orientation in Drosophila

    Science.gov (United States)

    Garcia-Vergara, Mauricio; Gomez-Correa, Gilberto; Ramirez-Santiago, Guillermo

    2012-02-01

    Epithelia cells are polarized along an axis perpendicular to the apical-basal axis, --``Planar cell polarization'' (PCP)--. In Drosophila adult cuticle cells are hexagonally packed and the PCP gives rise to the elaboration of an actin-rich hair that develops from one of the hexagon vertex and pointing distally. Genetic analyses have identified a group of proteins whose activities are required to polarize each cell and produce the phenomenon of PCP. To describe the PCP in the epithelia some quantitative models intended to explain this phenomenon by invoking diffusion of several proteins and all their interactions. Here we propose a simpler model consisting of two reaction-diffusion equations that describe the redistribution process of two chemical agents inside a cell. This redistribution occurs as a response to an external gradient of a quimio-attractor. We emulate the collective cell polarization by introducing ``interactions'' between neighboring cells that propagate trough the epithelia. This collective polarization gives rise to an orientational pattern in the actin-rich hairs.

  19. Histological Characteristics of Hair Follicle Structure of Hezuo Swine from Gansu Province

    Institute of Scientific and Technical Information of China (English)

    Lei WANG; Yanfei LIU

    2012-01-01

    The characteristics of skin hair follicle structure of Hezuo swine were in- vestigated using frozen section method and HE staining. Experimental results showed that the hair root, hair tip, outer sheath, inner sheath, hair follicle group, fi- brous sheath, outer epidermis, inner epidermis, sebaceous gland and other organiza- tional structures of hair follicles of Hezuo swine can be clearly observed. The hair follicle pore size varied extremely significantly (P〈0.01) among different parts, showing a downward trend of shoulder 〈 body side 〈 buttocks; the hair follicle density ranged from 5.59 to 7.26 hair follicles/mm^2. This study provides reference for the in-dustrial and medical applications.

  20. Phagocytosis of sperm by follicle cells of the carnivorous sponge Asbestopluma occidentalis (Porifera, Demospongiae).

    Science.gov (United States)

    Riesgo, Ana

    2010-06-01

    During spermatogenesis of the carnivorous sponge Asbestopluma occidentalis, follicle cells that lined the spermatocysts phagocytosed unreleased mature sperm. Such follicle cells are part of the complex envelope that limits spermatocysts of A. occidentalis, which is also comprised of a collagen layer, a thick layer of intertwined cells, and spicules. Follicle cells showed vesicles containing single phagocytosed spermatozoa within their cytoplasm. Additionally, lipids and other inclusions were observed within the cytoplasm of follicle cells. It is likely that follicle cells recapture nutrients by phagocytosing spermatozoa and use them to form lipids and other inclusions. Such sperm phagocytosis is usually performed in higher invertebrates and vertebrates by Sertoli cells that are located in the testis wall. While Sertoli cells develop a wide range of functions such as creating a blood-testis barrier, providing crucial factors to ensure correct progression of spermatogenesis, and phagocytosis of aberrant, degenerating, and unreleased sperm cells, sponge follicle cells may only display phagocytotic activity on spermatogenic cells.

  1. Iron Absorption in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Fanis Missirlis

    2013-05-01

    Full Text Available The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import, the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export and the role of ferritin in the process of iron acquisition (iron storage. We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration.

  2. Iron Absorption in Drosophila melanogaster

    Science.gov (United States)

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  3. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro.

    Science.gov (United States)

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A

    2016-03-15

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles.

  4. Drosophila phosphopantothenoylcysteine synthetase is required for tissue morphogenesis during oogenesis

    Directory of Open Access Journals (Sweden)

    Kampinga Harm H

    2008-08-01

    Full Text Available Abstract Background Coenzyme A (CoA is an essential metabolite, synthesized from vitamin B5 by the subsequent action of five enzymes: PANK, PPCS, PPCDC, PPAT and DPCK. Mutations in Drosophila dPPCS disrupt female fecundity and in this study we analyzed the female sterile phenotype of dPPCS mutants in detail. Results We demonstrate that dPPCS is required for various processes that occur during oogenesis including chorion patterning. Our analysis demonstrates that a mutation in dPPCS disrupts the organization of the somatic and germ line cells, affects F-actin organization and results in abnormal PtdIns(4,5P2 localization. Improper cell organization coincides with aberrant localization of the membrane molecules Gurken (Grk and Notch, whose activities are required for specification of the follicle cells that pattern the eggshell. Mutations in dPPCS also induce alterations in scutellar patterning and cause wing vein abnormalities. Interestingly, mutations in dPANK and dPPAT-DPCK result in similar patterning defects. Conclusion Together, our results demonstrate that de novo CoA biosynthesis is required for proper tissue morphogenesis.

  5. Dynamic expression pattern of kinesin accessory protein in Drosophila

    Indian Academy of Sciences (India)

    Ritu Sarpal; Krishanu Ray

    2002-09-01

    We have identified the Drosophila homologue of the non-motor accessory subunit of kinesin-II motor complex. It is homologous to the SpKAP115 of the sea urchin, KAP3A and KAP3B of the mouse, and SMAP protein in humans. In situ hybridization using a DmKAP specific cRNA probe has revealed a dynamic pattern of expression in the developing nervous system. The staining first appears in a subset of cells in the embryonic central nervous system at stage 13 and continues till the first instar larva stage. At the third instar larva stage the staining gets restricted to a few cells in the optic lobe and in the ventral ganglion region. It has also stained a subset of sensory neurons from late stage 13 and till the first instar larva stage. The DmKAP expression pattern in the nervous system corresponds well with that of Klp64D and Klp68D as reported earlier. In addition, we have found that the DmKAP gene is constitutively expressed in the germline cells and in follicle cells during oogenesis. These cells are also stained using an antibody to KLP68D protein, but mRNA in situ hybridization using KLP64D specific probe has not stained these cells. Together these results proved a basis for further analysis of tissue specific function of DmKAP in future.

  6. Characterization of ovulatory capacity development in the dominant follicle of dromedary camels (Camelus dromedarius).

    Science.gov (United States)

    Manjunatha, Bodhaganahalli M; Al-Bulushi, Samir; Pratap, Narayan

    2015-09-01

    The acquisition of ovulatory capacity in the growing dominant follicle (DF) of dromedary camels was examined in the current study. Ovulation occurred in response to hCG (1500 IU) in 27.3%, 58.3% or 100% of camels with follicles of 9, 10 or 11 mm diameter, respectively. A high dose of hCG (4500 IU) resulted in ovulation of 77.8% and 100% of camels with follicles of 9 and 10mm, respectively. In naturally mated animals, ovulation occurred in 36.4% and 92.8% of camels with 10 and 11 mm follicles, respectively.

  7. Inhibitory actions of Anti-Müllerian Hormone (AMH) on ovarian primordial follicle assembly.

    Science.gov (United States)

    Nilsson, Eric E; Schindler, Ryan; Savenkova, Marina I; Skinner, Michael K

    2011-01-01

    The current study was designed to investigate the actions of Anti-Müllerian Hormone (AMH) on primordial follicle assembly. Ovarian primordial follicles develop from the breakdown of oocyte nests during fetal development for the human and immediately after birth in rodents. AMH was found to inhibit primordial follicle assembly and decrease the initial primordial follicle pool size in a rat ovarian organ culture. The AMH expression was found to be primarily in the stromal tissue of the ovaries at this period of development, suggesting a stromal-epithelial cell interaction for primordial follicle assembly. AMH was found to promote alterations in the ovarian transcriptome during primordial follicle assembly with over 200 genes with altered expression. A gene network was identified suggesting a potential central role for the Fgf2/Nudt6 antisense transcript in the follicle assembly process. A number of signal transduction pathways are regulated by AMH actions on the ovarian transcriptome, in particular the transforming growth factor-beta (TGFß) signaling process. AMH is the first hormone/protein shown to have an inhibitory action on primordial follicle assembly. Due to the critical role of the primordial follicle pool size for female reproduction, elucidation of factors, such as AMH, that regulate the assembly process will provide insights into potential therapeutics to manipulate the pool size and female reproduction.

  8. Proteomic Analysis of Fetal Ovaries Reveals That Primordial Follicle Formation and Transition Are Differentially Regulated.

    Science.gov (United States)

    Xu, Mengmeng; Che, Long; Yang, Zhenguo; Zhang, Pan; Shi, Jiankai; Li, Jian; Lin, Yan; Fang, Zhengfeng; Che, Lianqiang; Feng, Bin; Wu, De; Xu, Shengyu

    2017-01-01

    Primordial follicle formation represents a critical phase of the initiation of embryonic reproductive organ development, while the primordial follicle transition into primary follicle determines whether oestrus or ovulation will occur in female animals. To identify molecular mechanism of new proteins which are involved in ovarian development, we employed 2D-DIGE to compare the protein expression profiles of primordial follicles and primary follicles of fetal ovaries in pigs. Fetal ovaries were collected at distinct time-points of the gestation cycle (g55 and g90). The identified proteins at the g55 time-point are mainly involved in the development of anatomical structures [reticulocalbin-1 (RCN1), reticulocalbin-3 (RCN3)], cell differentiation (actin), and stress response [heterogeneous nuclear ribonucleoprotein K (HNRNPK)]. Meanwhile, at the g90 stage, the isolated proteins with altered expression levels were mainly associated with cell proliferation [major vault protein (MVP)] and stress response [heat shock-related 70 kDa protein 2 (HSPA2)]. In conclusion, our work revealed that primordial follicle formation is regulated by RCN1, RCN3, actin, and HNRNPK, while the primordial follicle transformation to primary follicle is regulated by MVP and HSPA2. Therefore, our results provide further information for the prospective understanding of the molecular mechanism(s) involved in the regulation of the ovarian follicle development.

  9. Effect of gonadotropin-releasing hormone antagonist on primordial follicle survival in the primate ovary.

    Science.gov (United States)

    Attaman, Jill; Arbogast, Laura K; Friedman, Chad I; Danforth, Douglas R

    2014-01-01

    To examine the effects of gonadotropin-releasing hormone (GnRH) antagonist on primordial follicle reserve in the primate ovary. A prospective basic research study in which 10 juvenile cynomolgus monkeys (Macaca fascicularis) had 1 ovary surgically removed. Six animals were then treated with the GnRH antagonist antide (1.0 mg/kg/day) for 14 days, and 4 animals were treated with vehicle. After treatment the contralateral ovary was removed and both ovaries were prepared for assessment of primordial, primary, and secondary follicle numbers. Antide treatment resulted in a modest (13%) but significant decrease in primordial follicle number in juvenile macaques (p = 0.048, n = 6). Three animals demonstrated a marked reduction in primordial follicles (19%, 25%, 36%) and 3 animals had no (primordial follicles after antide treatment. Control animals demonstrated no change in primordial follicle number following vehicle treatment. Antide had no effect on primary, secondary, or early antral follicle numbers and did not affect circulating estradiol concentrations. In contrast to mice, in which GnRH antagonist treatment markedly reduces primordial follicle reserve, the effect of antide in nonhuman primates was less dramatic and somewhat variable. These data suggest there may be a subset of animals susceptible to the adverse effects of GnRH antagonist on primordial follicle survival.

  10. Inhibitory actions of Anti-Mullerian Hormone (AMH on ovarian primordial follicle assembly.

    Directory of Open Access Journals (Sweden)

    Eric E Nilsson

    Full Text Available The current study was designed to investigate the actions of Anti-Müllerian Hormone (AMH on primordial follicle assembly. Ovarian primordial follicles develop from the breakdown of oocyte nests during fetal development for the human and immediately after birth in rodents. AMH was found to inhibit primordial follicle assembly and decrease the initial primordial follicle pool size in a rat ovarian organ culture. The AMH expression was found to be primarily in the stromal tissue of the ovaries at this period of development, suggesting a stromal-epithelial cell interaction for primordial follicle assembly. AMH was found to promote alterations in the ovarian transcriptome during primordial follicle assembly with over 200 genes with altered expression. A gene network was identified suggesting a potential central role for the Fgf2/Nudt6 antisense transcript in the follicle assembly process. A number of signal transduction pathways are regulated by AMH actions on the ovarian transcriptome, in particular the transforming growth factor-beta (TGFß signaling process. AMH is the first hormone/protein shown to have an inhibitory action on primordial follicle assembly. Due to the critical role of the primordial follicle pool size for female reproduction, elucidation of factors, such as AMH, that regulate the assembly process will provide insights into potential therapeutics to manipulate the pool size and female reproduction.

  11. Does AMH Reflect Follicle Number Similarly in Women with and without PCOS?

    Directory of Open Access Journals (Sweden)

    Sverre C Christiansen

    Full Text Available Increased Anti-Mullerian Hormone in polycystic ovary syndrome, may be due to overactive follicles rather than reflect antral follicle count.Does Anti-Mullerian Hormone reflect antral follicle count similarly in women with or without polycystic ovary syndrome or polycystic ovarian morphology?Cross-sectional, case-control.Women who delivered preterm in 1999-2006. For each index woman, a woman with a term delivery was identified.Participation rate was 69%. Between 2006-2008, 262 women were included, and diagnosed to have polycystic ovary syndrome, polycystic ovarian morphology or to be normal controls.Blood tests, a clinical examination and vaginal ultrasound.Anti-Mullerian Hormone/antral follicle count-ratio, SHBG, androstenedione and insulin, to test potential influence on the Anti-Mullerian Hormone/antral follicle count -ratio.Mean Anti-Mullerian Hormone/antral follicle count ratio in women with polycystic ovary syndrome or polycystic ovarian morphology was similar to that of the controls (polycystic ovary syndrome: 1,2 p = 0,10 polycystic ovarian morphology: 1,2, p = 0,27 Controls 1,3. Anti-Mullerian Hormone showed a positive linear correlation to antral follicle count in all groups. Multivariate analysis did not change the results.We confirmed the positive correlation between AMH and follicle count. Anti-Mullerian Hormone seems to be a reliable predictor of antral follicle count, independent of polycystic ovary syndrome diagnosis or ovarian morphology.

  12. windbeutel, a gene required for dorsoventral patterning in Drosophila, encodes a protein that has homologies to vertebrate proteins of the endoplasmic reticulum.

    Science.gov (United States)

    Konsolaki, M; Schüpbach, T

    1998-01-01

    The formation of the dorsoventral axis of the Drosophila embryo depends on cell-cell interactions that take place in the female ovary and involve the activation of transmembrane receptors by secreted ligands. The gene windbeutel functions in the somatic follicle cells of the ovary and is required for the generation of a signal that will determine the ventral side of the embryo. This signal originates in the follicle cells during oogenesis, but its actions are only manifested after fertilization, when the egg has already been laid. We have performed a molecular analysis of windbeutel. We have found that windbeutel encodes a putative resident protein of the endoplasmic reticulum, and has homologs in rats and humans. The gene is expressed for a brief period of time in the follicle cells of the ovary, at around the time when the dorsoventral axis of the egg chamber is first established. We propose that Windbeutel is responsible for the folding and/or modification of a specific factor that is secreted from the follicle cells and participates in the activation of the ventralizing signal.

  13. Slit and Robo control cardiac cell polarity and morphogenesis.

    Science.gov (United States)

    Qian, Li; Liu, Jiandong; Bodmer, Rolf

    2005-12-20

    Basic aspects of heart morphogenesis involving migration, cell polarization, tissue alignment, and lumen formation may be conserved between Drosophila and humans, but little is known about the mechanisms that orchestrate the assembly of the heart tube in either organism. The extracellular-matrix molecule Slit and its Robo-family receptors are conserved regulators of axonal guidance. Here, we report a novel role of the Drosophila slit, robo, and robo2 genes in heart morphogenesis. Slit and Robo proteins specifically accumulate at the dorsal midline between the bilateral myocardial progenitors forming a linear tube. Manipulation of Slit localization or its overexpression causes disruption in heart tube alignment and assembly, and slit-deficient hearts show disruptions in cell-polarity marker localization within the myocardium. Similar phenotypes are observed when Robo and Robo2 are manipulated. Rescue experiments suggest that Slit is secreted from the myocardial progenitors and that Robo and Robo2 act in myocardial and pericardial cells, respectively. Genetic interactions suggest a cardiac morphogenesis network involving Slit/Robo, cell-polarity proteins, and other membrane-associated proteins. We conclude that Slit and Robo proteins contribute significantly to Drosophila heart morphogenesis by guiding heart cell alignment and adhesion and/or by inhibiting cell mixing between the bilateral compartments of heart cell progenitors and ensuring proper polarity of the myocardial epithelium.

  14. Expression of E-cadherin and N-cadherin in perinatal hamster ovary: possible involvement in primordial follicle formation and regulation by follicle-stimulating hormone.

    Science.gov (United States)

    Wang, Cheng; Roy, Shyamal K

    2010-05-01

    We examined the expression and hormonal regulation of E-cadherin (CDH1) and N-cadherin (CDH2) with respect to primordial follicle formation. Hamster Cdh1 and Cdh2 cDNA and amino acid sequences were more than 90% similar to those of the mouse, rat, and human. Although CDH1 expression remained exclusively in the oocytes during neonatal ovary development, CDH2 expression shifted from the oocytes to granulosa cells of primordial follicles on postnatal day (P)8. Subsequently, strong CDH2 expression was restricted to granulosa cells of growing follicles. Cdh2 mRNA levels in the ovary decreased from embryonic d 13 through P10 with a transient increase on P7, which was the day before the appearance of primordial follicles. Cdh1 mRNA levels decreased from embryonic d 13 through P3 and then showed a transient increase on P8, coinciding with the formation of primordial follicles. CDH1 and CDH2 expression were consistent with that of mRNA. Neutralization of FSH in utero impaired primordial follicle formation with an associated decrease in Cdh2 mRNA and CDH2, but an increase in Cdh1 mRNA and CDH1 expression. The altered expression was reversed by equine chorionic gonadotropin treatment on P1. Whereas a CDH2 antibody significantly reduced the formation of primordial and primary follicles in vitro, a CDH1 antibody had the opposite effect. This is the first evidence to suggest that primordial follicle formation requires a differential spatiotemporal expression and action of CDH1 and CDH2. Further, FSH regulation of primordial follicle formation may involve the action of CDH1 and CDH2.

  15. Lymphoid follicles in children with Helicobacter pylori-negative gastritis

    Science.gov (United States)

    Broide, Efrat; Richter, Vered; Mendlovic, Sonia; Shalem, Tzippora; Eindor-Abarbanel, Adi; Moss, Steven F; Shirin, Haim

    2017-01-01

    Purpose The prevalence of Helicobacter pylori gastritis has been declining, whereas H. pylori-negative gastritis has become more common. We evaluated chronic gastritis in children with regard to H. pylori status and celiac disease (CD). Patients and methods Demographic, clinical, endoscopic, and histologic features of children who underwent elective esophagogastroduodenoscopy were reviewed retrospectively. Gastric biopsies from the antrum and corpus of the stomach were graded using the Updated Sydney System. H. pylori presence was defined by hematoxylin and eosin, Giemsa, or immunohistochemical staining and urease testing. Results A total of 184 children (61.9% female) met the study criteria with a mean age of 10 years. A total of 122 (66.3%) patients had chronic gastritis; 74 (60.7%) were H. pylori-negative. Children with H. pylori-negative gastritis were younger (p=0.003), were less likely to present with abdominal pain (p=0.02), and were mostly of non-Arabic origin (p=0.011). Nodular gastritis was found to be less prevalent in H. pylori-negative gastritis (6.8%) compared with H. pylori-positive gastritis (35.4%, pgastritis and lymphoid follicles were associated most commonly with H. pylori. Although less typical, lymphoid follicles were demonstrated in 51.3% of H. pylori-negative patients. The presence or absence of CD was not associated with histologic findings in H. pylori-negative gastritis. Conclusion Our findings suggest that lymphoid follicles are a feature of H. pylori-negative gastritis in children independent of their CD status. PMID:28860835

  16. Polarized Campuses.

    Science.gov (United States)

    Parr, Susan Resneck

    1991-01-01

    On college campuses, the climate is polarized because of intolerance and discrimination, censorship, factionalism, and anger among students and faculty. As a result, the campus is in danger of becoming dominated by political issues and discouraging the exchange of ideas characteristic of a true liberal arts education. (MSE)

  17. Histopathologic Changes in Dental Follicles: Are They Serious?

    Directory of Open Access Journals (Sweden)

    M.H.K Motamedi

    2011-03-01

    Full Text Available Pathologic changes within pericoronal tissues of impacted third molars are not uncommon. Retained impacted teeth within the bone may be associated with pathologic changes in pericoronal tissues due to unknown mechanisms. Thus, when an impacted third molar is removed its pericoronal tissue must be assessed for pathologic changes microscopically. Although most of these pathologic changes are benign, however, as these changes are asymptomatic in nature differential diagnosis of a normal follicle from an abnormal one both radiographically and microscopically is important because this is difficult if not impossible to do clinically.

  18. Muscarinic receptor heterogeneity in follicle-enclosed Xenopus oocytes

    Science.gov (United States)

    Arellano, Rogelio O; Garay, Edith; Miledi, Ricardo

    1999-01-01

    Ionic current responses elicited by acetylcholine (ACh) in follicle-enclosed Xenopus oocytes (follicles) were studied using the two-electrode voltage-clamp technique. ACh generated a fast chloride current (Fin) and inhibited K+ currents gated by cAMP (IK,cAMP) following receptor activation by adenosine, follicle-stimulating hormone or noradrenaline. These previously described cholinergic responses were confirmed to be of the muscarinic type, and were independently generated among follicles from different frogs.Inhibition of IK,cAMP was about 100 times more sensitive to ACh than Fin activation; the half-maximal effective concentrations (EC50) were 6.6 ± 0.4 and 784 ± 4 nm, respectively.Both responses were blocked by several muscarinic receptor antagonists. Using the respective EC50 concentrations of ACh as standard, the antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide blocked the two effects with very different potencies. Fin was blocked with a half-maximal inhibitory concentration (IC50) of 2.4 ± 0.07 nm, whilst the IC50 for IK,cAMP inhibition was 5.9 ± 0.2 μm.Oxotremorine, a muscarinic agonist, preferentially stimulated IK,cAMP inhibition (EC50= 15.8 ± 1.4 μm), whilst Fin was only weakly activated. In contrast, oxotremorine inhibited Fin generated by ACh with an IC50 of 2.3 ± 0.7 μm.Fin elicited via purinergic receptor stimulation was not affected by oxotremorine, indicating that the inhibition produced was specific to the muscarinic receptor, and suggesting that muscarinic actions do not exert a strong effect on follicular cell-oocyte coupling.Using reverse transcription-PCR, transcripts of a previously cloned muscarinic receptor from Xenopus (XlmR) were amplified from the RNA of both the isolated follicular cells and the oocyte. The pharmacological and molecular characteristics suggest that XlmR is involved in IK,cAMP inhibition.In conclusion, follicular cells possess two different muscarinic receptors, one resembling the M2 (or M4) subtype

  19. Automatic stage identification of Drosophila egg chamber based on DAPI images.

    Science.gov (United States)

    Jia, Dongyu; Xu, Qiuping; Xie, Qian; Mio, Washington; Deng, Wu-Min

    2016-01-06

    The Drosophila egg chamber, whose development is divided into 14 stages, is a well-established model for developmental biology. However, visual stage determination can be a tedious, subjective and time-consuming task prone to errors. Our study presents an objective, reliable and repeatable automated method for quantifying cell features and classifying egg chamber stages based on DAPI images. The proposed approach is composed of two steps: 1) a feature extraction step and 2) a statistical modeling step. The egg chamber features used are egg chamber size, oocyte size, egg chamber ratio and distribution of follicle cells. Methods for determining the on-site of the polytene stage and centripetal migration are also discussed. The statistical model uses linear and ordinal regression to explore the stage-feature relationships and classify egg chamber stages. Combined with machine learning, our method has great potential to enable discovery of hidden developmental mechanisms.

  20. emc has a role in dorsal appendage fate formation in Drosophila oogenesis.

    Science.gov (United States)

    Papadia, Sofia; Tzolovsky, George; Zhao, Debiao; Leaper, Kevin; Clyde, Dorothy; Taylor, Paul; Asscher, Eva; Kirk, Graeme; Bownes, Mary

    2005-09-01

    extramacrochaetae (emc) functions during many developmental processes in Drosophila, such as sensory organ formation, sex determination, wing vein differentiation, regulation of eye photoreceptor differentiation, cell proliferation and development of the Malpighian tubules, trachea and muscles in the embryo. It encodes a Helix-Loop-Helix transcription factor that negatively regulates bHLH proteins. We show here that emc mRNA and protein are present throughout oogenesis in a dynamic expression pattern and that emc is involved in the regulation of chorionic appendage formation during late oogenesis. Expression of sense and antisense emc constructs as well as emc follicle cell clones leads to eggs with shorter, thicker dorsal appendages that are closer together at base than in the wild type. We demonstrate that emc lies downstream of fs(1)K10, gurken and EGFR in the Grk/EGFR signalling pathway and that it participates in controlling Broad-Complex expression at late stages of oogenesis.

  1. Drosophila comes of age as a model system for understanding the function of cytoskeletal proteins in cells, tissues, and organisms.

    Science.gov (United States)

    Rodal, Avital A; Del Signore, Steven J; Martin, Adam C

    2015-05-01

    For the last 100 years, Drosophila melanogaster has been a powerhouse genetic system for understanding mechanisms of inheritance, development, and behavior in animals. In recent years, advances in imaging and genetic tools have led to Drosophila becoming one of the most effective systems for unlocking the subcellular functions of proteins (and particularly cytoskeletal proteins) in complex developmental settings. In this review, written for non-Drosophila experts, we will discuss critical technical advances that have enabled these cell biological insights, highlighting three examples of cytoskeletal discoveries that have arisen as a result: (1) regulation of Arp2/3 complex in myoblast fusion, (2) cooperation of the actin filament nucleators Spire and Cappuccino in establishment of oocyte polarity, and (3) coordination of supracellular myosin cables. These specific examples illustrate the unique power of Drosophila both to uncover new cytoskeletal structures and functions, and to place these discoveries in a broader in vivo context, providing insights that would have been impossible in a cell culture model or in vitro. Many of the cellular structures identified in Drosophila have clear counterparts in mammalian cells and tissues, and therefore elucidating cytoskeletal functions in Drosophila will be broadly applicable to other organisms.

  2. Identification of Astrotactin2 as a Genetic Modifier That Regulates the Global Orientation of Mammalian Hair Follicles.

    Directory of Open Access Journals (Sweden)

    Hao Chang

    Full Text Available Planar cell polarity (PCP signaling controls the global orientation of surface structures, such as hairs and bristles, in both vertebrates and invertebrates. In Frizzled6(-/- (Fz6(-/- mice, hair follicle orientations on the head and back are nearly random at birth, but reorient during early postnatal development to eventually generate a nearly parallel anterior-to-posterior array. We report the identification of a naturally occurring exon 5 deletion in Astrotactin2 (Astn2 that acts as a recessive genetic modifier of the Fz6(-/- hair patterning phenotype. A genetically engineered Astn2 exon 5 deletion recapitulates the modifier phenotype. In Fz6(-/-;Astn2(ex5del/del mice, hair orientation on the back is subtly biased from posterior-to-anterior, leading to a 180-degree orientation reversal in mature mice. These experiments suggest that Astn2, an endosomal membrane protein, modulates PCP signaling.

  3. Direct interaction between two actin nucleators is required in Drosophila oogenesis

    OpenAIRE

    Quinlan, Margot E.

    2013-01-01

    Controlled actin assembly is crucial to a wide variety of cellular processes, including polarity establishment during early development. The recently discovered actin mesh, a structure that traverses the Drosophila oocyte during mid-oogenesis, is essential for proper establishment of the major body axes. Genetic experiments indicate that at least two proteins, Spire (Spir) and Cappuccino (Capu), are required to build this mesh. The spire and cappuccino genetic loci were first identified as ma...

  4. Drosophila Cappuccino alleles provide insight into formin mechanism and role in oogenesis

    OpenAIRE

    Yoo, Haneul; Roth-Johnson, Elizabeth A.; Bor, Batbileg; Quinlan, Margot E.

    2015-01-01

    During Drosophila development, the formin actin nucleator Cappuccino (Capu) helps build a cytoplasmic actin mesh throughout the oocyte. Loss of Capu leads to female sterility, presumably because polarity determinants fail to localize properly in the absence of the mesh. To gain deeper insight into how Capu builds this actin mesh, we systematically characterized seven capu alleles, which have missense mutations in Capu's formin homology 2 (FH2) domain. We report that all seven alleles have del...

  5. Control of Growth Within Drosophila Peripheral Nerves by Ras and Protein Kinase A

    Science.gov (United States)

    2009-02-01

    downstream of the EGF receptor to determine dorsoventral polarity during Drosophila oogenesis . Genes Dev 8:629 – 639. Brunet A, Bonni A, Zigmond MJ...are increased following induction of seizures in rats , and in the hippocampi of epileptic patients [56]. This activity- induced increase in phospho...nucleus tractus solitarius is depressed by Group II and III but not Group I presynaptic metabotropic glutamate receptors in rats . J Physiol 538: 773

  6. Drosophila as a model for antiviral immunity

    Institute of Scientific and Technical Information of China (English)

    Susanna; Valanne; Mika; Rmet

    2010-01-01

    The fruit fly Drosophila melanogaster has been successfully used to study numerous biological processes including immune response.Flies are naturally infected with more than twenty RNA viruses making it a valid model organism to study host-pathogen interactions during viral infections.The Drosophila antiviral immunity includes RNA interference,activation of the JAK/STAT and other signaling cascades and other mechanisms such as autophagy and interactions with other microorganisms.Here we review Drosophila as an immunological research model as well as recent advances in the field ofDrosophila antiviral immunity.

  7. The lack of autophagy triggers precocious activation of Notch signaling during Drosophila oogenesis

    Directory of Open Access Journals (Sweden)

    Barth Julia MI

    2012-12-01

    Full Text Available Abstract Background The proper balance of autophagy, a lysosome-mediated degradation process, is indispensable for oogenesis in Drosophila. We recently demonstrated that egg development depends on autophagy in the somatic follicle cells (FC, but not in the germline cells (GCs. However, the lack of autophagy only affects oogenesis when FCs are autophagy-deficient but GCs are wild type, indicating that a dysfunctional signaling between soma and germline may be responsible for the oogenesis defects. Thus, autophagy could play an essential role in modulating signal transduction pathways during egg development. Results Here, we provide further evidence for the necessity of autophagy during oogenesis and demonstrate that autophagy is especially required in subsets of FCs. Generation of autophagy-deficient FCs leads to a wide range of phenotypes that are similar to mutants with defects in the classical cell-cell signaling pathways in the ovary. Interestingly, we observe that loss of autophagy leads to a precocious activation of the Notch pathway in the FCs as monitored by the expression of Cut and Hindsight, two downstream effectors of Notch signaling. Conclusion Our findings point to an unexpected function for autophagy in the modulation of the Notch signaling pathway during Drosophila oogenesis and suggest a function for autophagy in proper receptor activation. Egg development is affected by an imbalance of autophagy between signal sending (germline and signal receiving cell (FC, thus the lack of autophagy in the germline is likely to decrease the amount of active ligand and accordingly compensates for increased signaling in autophagy-defective follicle cells.

  8. A comprehensive curated resource for follicle stimulating hormone signaling

    Directory of Open Access Journals (Sweden)

    Sharma Jyoti

    2011-10-01

    Full Text Available Abstract Background Follicle stimulating hormone (FSH is an important hormone responsible for growth, maturation and function of the human reproductive system. FSH regulates the synthesis of steroid hormones such as estrogen and progesterone, proliferation and maturation of follicles in the ovary and spermatogenesis in the testes. FSH is a glycoprotein heterodimer that binds and acts through the FSH receptor, a G-protein coupled receptor. Although online pathway repositories provide information about G-protein coupled receptor mediated signal transduction, the signaling events initiated specifically by FSH are not cataloged in any public database in a detailed fashion. Findings We performed comprehensive curation of the published literature to identify the components of FSH signaling pathway and the molecular interactions that occur upon FSH receptor activation. Our effort yielded 64 reactions comprising 35 enzyme-substrate reactions, 11 molecular association events, 11 activation events and 7 protein translocation events that occur in response to FSH receptor activation. We also cataloged 265 genes, which were differentially expressed upon FSH stimulation in normal human reproductive tissues. Conclusions We anticipate that the information provided in this resource will provide better insights into the physiological role of FSH in reproductive biology, its signaling mediators and aid in further research in this area. The curated FSH pathway data is freely available through NetPath (http://www.netpath.org, a pathway resource developed previously by our group.

  9. Evaluation of glucose metabolism in women with multiple ovarian follicles

    Institute of Scientific and Technical Information of China (English)

    Shulan Lü; Xiaoyan Guo; Zuansun Cao; Wenjun Mao

    2007-01-01

    Objective:To investigate glucose metabolism in women with multiple ovarian follicles (MOF) and explore the relationship between glucose metabolism, insulin resistance and body weight. Methods:We evaluated 46 women with MFO and 30 nor mal women as controls. All the subjects were given 75g of glucose orally in order to perform the oral glucose tolerance test(OGTT) and insulin releasing test(IRT), and they were also evaluated for insulin resistance using the insulin resistance index with homeostatic model assessment (HOMA). Results:The occurrence of impaired glucose tolerance in women with MOF was 10.87%, which was significantly higher than that in the control group (3.33% ,P < 0.05). The rate of insulin resistance was 30.43% in the study group as compared to 10.00% in the control group. The results showed that there was significant difference between the two groups(P < 0.05). The levels of FSH,LH,PRL,E2,T and P between the two groups had no significant difference (P > 0.05). BMI in women with impaired glucose tolerance was correlated positively to insulin resistance (r =0.567, P < 0.05). Conclusion :Abnormal glucose metabolism was observed in women with unitary multiple ovarian follicles,and this could be attributed to obesity and insulin resistance. Women with MOF and associated obesity should be subjected to OGTT so that their glucose levels can be monitored as a preventive measure.

  10. The nuage mediates retrotransposon silencing in mouse primordial ovarian follicles

    Science.gov (United States)

    Lim, Ai Khim; Lorthongpanich, Chanchao; Chew, Ting Gang; Tan, Chin Wee Godwin; Shue, Yan Ting; Balu, Sathish; Gounko, Natalia; Kuramochi-Miyagawa, Satomi; Matzuk, Martin M.; Chuma, Shinichiro; Messerschmidt, Daniel M.; Solter, Davor; Knowles, Barbara B.

    2013-01-01

    Mobilization of endogenous retrotransposons can destabilize the genome, an imminent danger during epigenetic reprogramming of cells in the germline. The P-element-induced wimpy testis (PIWI)-interacting RNA (piRNA) pathway is known to silence retrotransposons in the mouse testes. Several piRNA pathway components localize to the unique, germline structure known as the nuage. In this study, we surveyed mouse ovaries and found, for the first time, transient appearance of nuage-like structures in oocytes of primordial follicles. Mouse vasa homolog (MVH), Piwi-like 2 (PIWIL2/MILI) and tudor domain-containing 9 (TDRD9) are present in these structures, whereas aggregates of germ cell protein with ankyrin repeats, sterile alpha motif and leucine zipper (GASZ) localize separately in the cytoplasm. Retrotransposons are silenced in primordial ovarian follicles, and de-repressed upon reduction of piRNA expression in Mvh, Mili or Gasz mutants. However, these null-mutant females, unlike their male counterparts, are fertile, uncoupling retrotransposon activation from sterility. PMID:23924633

  11. Follicle-stimulating hormone accelerates mouse oocyte development in vivo.

    Science.gov (United States)

    Demeestere, Isabelle; Streiff, Agathe K; Suzuki, João; Al-Khabouri, Shaima; Mahrous, Enas; Tan, Seang Lin; Clarke, Hugh J

    2012-07-01

    During folliculogenesis, oocytes grow and acquire developmental competence in a mutually dependent relationship with their adjacent somatic cells. Follicle-stimulating hormone (FSH) plays an essential and well-established role in the differentiation of somatic follicular cells, but its function in the development of the oocyte has still not been elucidated. We report here that oocytes of Fshb(-/-) mice, which cannot produce FSH, grow at the same rate and reach the same size as those of wild-type mice. Consistent with this observation, the granulosa cells of Fshb(-/-) mice express the normal quantity of mRNA encoding Kit ligand, which has been implicated in oocyte growth. Oocytes of Fshb(-/-) mice also accumulate normal quantities of cyclin B1 and CDK1 proteins and mitochondrial DNA. Moreover, they acquire the ability to complete meiotic maturation in vitro and undergo transition from non-surrounded nucleolus to surrounded nucleolus. However, these events of late oocyte development are significantly delayed. Following in vitro maturation and fertilization, only a small number of embryos derived from oocytes of Fshb(-/-) mice reach the blastocyst stage. Administration of equine chorionic gonadotropin, which provides FSH activity, 48 h before in vitro maturation increases the number of blastocysts obtained subsequently. These results indicate that FSH is not absolutely required for oocyte development in vivo but that this process occurs more rapidly in its presence. We suggest that FSH may coordinate the development of the germline and somatic compartments of the follicle, ensuring that ovulation releases a developmentally competent egg.

  12. Lymphoid follicles in children with Helicobacter pylori-negative gastritis.

    Science.gov (United States)

    Broide, Efrat; Richter, Vered; Mendlovic, Sonia; Shalem, Tzippora; Eindor-Abarbanel, Adi; Moss, Steven F; Shirin, Haim

    2017-01-01

    The prevalence of Helicobacter pylori gastritis has been declining, whereas H. pylori-negative gastritis has become more common. We evaluated chronic gastritis in children with regard to H. pylori status and celiac disease (CD). Demographic, clinical, endoscopic, and histologic features of children who underwent elective esophagogastroduodenoscopy were reviewed retrospectively. Gastric biopsies from the antrum and corpus of the stomach were graded using the Updated Sydney System. H. pylori presence was defined by hematoxylin and eosin, Giemsa, or immunohistochemical staining and urease testing. A total of 184 children (61.9% female) met the study criteria with a mean age of 10 years. A total of 122 (66.3%) patients had chronic gastritis; 74 (60.7%) were H. pylori-negative. Children with H. pylori-negative gastritis were younger (p=0.003), were less likely to present with abdominal pain (p=0.02), and were mostly of non-Arabic origin (p=0.011). Nodular gastritis was found to be less prevalent in H. pylori-negative gastritis (6.8%) compared with H. pylori-positive gastritis (35.4%, ppylori-positive group (ppylori. Although less typical, lymphoid follicles were demonstrated in 51.3% of H. pylori-negative patients. The presence or absence of CD was not associated with histologic findings in H. pylori-negative gastritis. Our findings suggest that lymphoid follicles are a feature of H. pylori-negative gastritis in children independent of their CD status.

  13. Palmitoylation regulates epidermal homeostasis and hair follicle differentiation.

    Directory of Open Access Journals (Sweden)

    Pleasantine Mill

    2009-11-01

    Full Text Available Palmitoylation is a key post-translational modification mediated by a family of DHHC-containing palmitoyl acyl-transferases (PATs. Unlike other lipid modifications, palmitoylation is reversible and thus often regulates dynamic protein interactions. We find that the mouse hair loss mutant, depilated, (dep is due to a single amino acid deletion in the PAT, Zdhhc21, resulting in protein mislocalization and loss of palmitoylation activity. We examined expression of Zdhhc21 protein in skin and find it restricted to specific hair lineages. Loss of Zdhhc21 function results in delayed hair shaft differentiation, at the site of expression of the gene, but also leads to hyperplasia of the interfollicular epidermis (IFE and sebaceous glands, distant from the expression site. The specific delay in follicle differentiation is associated with attenuated anagen propagation and is reflected by decreased levels of Lef1, nuclear beta-catenin, and Foxn1 in hair shaft progenitors. In the thickened basal compartment of mutant IFE, phospho-ERK and cell proliferation are increased, suggesting increased signaling through EGFR or integrin-related receptors, with a parallel reduction in expression of the key differentiation factor Gata3. We show that the Src-family kinase, Fyn, involved in keratinocyte differentiation, is a direct palmitoylation target of Zdhhc21 and is mislocalized in mutant follicles. This study is the first to demonstrate a key role for palmitoylation in regulating developmental signals in mammalian tissue homeostasis.

  14. Polar Diving

    Science.gov (United States)

    2006-01-01

    3 July 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows layers exposed by erosion in a trough within the north polar residual cap of Mars, diving beneath a younger covering of polar materials. The layers have, since the Mariner 9 mission in 1972, been interpreted to be composed of a combination of dust and ice in unknown proportions. In this scene, a layer of solid carbon dioxide, which was deposited during the previous autumn and winter, blankets the trough as well as the adjacent terrain. Throughout northern spring, the carbon dioxide will be removed; by summer, the layers will be frost-free. Location near: 81.4oN, 352.2oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  15. Does cell polarity matter during spermatogenesis?

    Science.gov (United States)

    Gao, Ying; Cheng, C Yan

    2016-01-01

    Cell polarity is crucial to development since apico-basal polarity conferred by the 3 polarity protein modules (or complexes) is essential during embryogenesis, namely the Par (partition defective)-, the CRB (Crumbs)-, and the Scribble-based polarity protein modules. While these protein complexes and their component proteins have been extensively studied in Drosophila and C. elegans and also other mammalian tissues and/or cells, their presence and physiological significance in the testis remain unexplored until the first paper on the Par-based protein published in 2008. Since then, the Par-, the Scribble- and the CRB-based protein complexes and their component proteins in the testis have been studied. These proteins are known to confer Sertoli and spermatid polarity in the seminiferous epithelium, and they are also integrated components of the tight junction (TJ) and the basal ectoplasmic specialization (ES) at the Sertoli cell-cell interface near the basement membrane, which in turn constitute the blood-testis barrier (BTB). These proteins are also found at the apical ES at the Sertoli-spermatid interface. Thus, these polarity proteins also play a significant role in regulating Sertoli and spermatid adhesion in the testis through their actions on actin-based cytoskeletal function. Recent studies have shown that these polarity proteins are having antagonistic effects on the BTB integrity in which the Par6- and CRB3-based polarity complexes promotes the integrity of the Sertoli cell TJ-permeability barrier, whereas the Scribble-based complex promotes restructuring/remodeling of the Sertoli TJ-barrier function. Herein, we carefully evaluate these findings and provide a hypothetic model regarding their role in the testis in the context of the functions of these polarity proteins in other epithelia, so that better experiments can be designed in future studies to explore their significance in spermatogenesis.

  16. Storage of bovine isolated follicles: a new alternative way to improve the recovery rate of viable embryos from ovarian follicles of slaughtered cows.

    Science.gov (United States)

    Pavlok, A; Cech, S; Kubelka, M; Lopatárová, M; Holý, L; Jindra, M

    2006-11-01

    The vitality of bovine oocytes stored in isolated follicles was examined. The aim of this work was to prolong the time of in vitro manipulation of oocytes before their maturation and develop a new alternative of oocyte "capacitation" to improve the quality of in vitro produced embryos. Follicles were dissected from the ovaries of slaughtered cows; subsequently, follicles were divided according to their diameter into three categories (2-3, 3-4 and 4-6 mm), and stored at 17-18 degrees C for 24 or 48 h in a modified tissue culture medium-199 (TCM-199) with reduced pH. After that time, the cumulus-oocyte complexes (COCs) were isolated, matured, fertilized, and embryos cultured in vitro for a total of 9 days. The percentage of total blastocysts, and hatched blastocysts developed from oocytes, initially kept ("capacitated") for 24h at 17-18 degrees C, within follicles of 3-6mm size categories, were significantly higher than that oocytes of the control [of control oocytes] (44.9 and 30.3% versus 36.2 and 20.4%, respectively). The oocytes of follicles stored for 48 h at 17-18 degrees C already had decreased developmental capacity. Interesting data were obtained when COCs of the 3-4 and 4-6 categories were additionally divided into two subgroups according to their presumed developmental history (originating from the supposed growing "fit" in contrast to the supposed regressing "unfit" follicles). The higher improvement in the rate of hatched blastocysts from 24h stored oocytes was observed only in the subgroup originated from "fit" COCs (15.3 versus 25.0%, and 20.0 versus 34.4%, in the 3-4 and 4-6mm categories, respectively). The transfer of 26 blastocysts (developed of follicles kept for 24h at 17-18 degrees C) to 26 recipient heifers resulted in 18 pregnancies. Storage of follicles at 17-18 degrees C in vitro resulted not only in recovery of higher numbers of blastocysts of better quality but also facilitated the safe transport of follicles for a long distance. The

  17. DNA sequence templates adjacent nucleosome and ORC sites at gene amplification origins in Drosophila.

    Science.gov (United States)

    Liu, Jun; Zimmer, Kurt; Rusch, Douglas B; Paranjape, Neha; Podicheti, Ram; Tang, Haixu; Calvi, Brian R

    2015-10-15

    Eukaryotic origins of DNA replication are bound by the origin recognition complex (ORC), which scaffolds assembly of a pre-replicative complex (pre-RC) that is then activated to initiate replication. Both pre-RC assembly and activation are strongly influenced by developmental changes to the epigenome, but molecular mechanisms remain incompletely defined. We have been examining the activation of origins responsible for developmental gene amplification in Drosophila. At a specific time in oogenesis, somatic follicle cells transition from genomic replication to a locus-specific replication from six amplicon origins. Previous evidence indicated that these amplicon origins are activated by nucleosome acetylation, but how this affects origin chromatin is unknown. Here, we examine nucleosome position in follicle cells using micrococcal nuclease digestion with Ilumina sequencing. The results indicate that ORC binding sites and other essential origin sequences are nucleosome-depleted regions (NDRs). Nucleosome position at the amplicons was highly similar among developmental stages during which ORC is or is not bound, indicating that being an NDR is not sufficient to specify ORC binding. Importantly, the data suggest that nucleosomes and ORC have opposite preferences for DNA sequence and structure. We propose that nucleosome hyperacetylation promotes pre-RC assembly onto adjacent DNA sequences that are disfavored by nucleosomes but favored by ORC.

  18. Which follicles make the most anti-Mullerian hormone in humans?

    DEFF Research Database (Denmark)

    Jeppesen, J V; Anderson, R A; Kelsey, T W

    2013-01-01

    Anti-Müllerian hormone (AMH) is exclusively produced by granulosa cells (GC) of the developing pre-antral and antral follicles, and AMH is increasingly used to assess ovarian function. It is unclear which size follicles make the most AMH (total content) and are the main contributors to circulating...

  19. Comparative proteomic analysis of primordial follicles from ovaries of immature and aged rats.

    Science.gov (United States)

    Govindaraj, Vijayakumar; Rao, A Jagannadha

    2015-01-01

    Age related decline in reproductive performance in women is well documented and apoptosis has been considered as one of the reasons for the decline of primordial follicle reserve. Recently we observed a decline in the efficiency of DNA repair ability in aged rat primordial follicles as demonstrated by decreased mRNA levels of DNA repair genes BRCA1 and H2AX. In the present study, a two-dimensional electrophoresis (2DE) proteomic approach was employed to identify differentially expressed proteins in primordial follicles isolated from ovaries of immature (∼20 days) and aged (∼400-450 days) rats. Using MALDI-TOF/TOF MS, we identified 13 differentially expressed proteins (p primordial follicles. These proteins are involved in a wide range of biological functions including apoptosis, DNA repair, and the immune system. Interestingly, the differentially expressed proteins such as FIGNL1 (DNA repair) and BOK (apoptotic protein) have not been previously reported in the rat primordial follicles and these proteins can be related to some common features of ovarian aging such as loss of follicle reserve and genome integrity. The quantitative differences of two important proteins BOK and FIGNL1 observed by the proteomic analysis were correlated with the transcript levels, as determined by semi-quantitative RT-PCR. Our results improve the current knowledge about protein factors associated with molecular changes in rat primordial follicles as a function of aging and our understanding of the proteomic processes involved in degenerative changes observed in aging primordial follicles.

  20. Quantitative bioluminescence imaging of transgene expression in intact porcine antral follicles in vitro

    Science.gov (United States)

    The porcine oocyte maturation in vivo occurs within the ovarian follicle and is regulated by the interactions between oocytes and surrounding follicular components, including theca, granulosa, and cumulus cells, and follicular fluid. Therefore, the antral follicle is an essential microenvironment fo...

  1. Genes Involved in Initial Follicle Recruitment May Be Associated with Age at Menopause

    NARCIS (Netherlands)

    Voorhuis, Marlies; Broekmans, Frank J.; Fauser, Bart C. J. M.; Onland-Moret, N. Charlotte; van der Schouw, Yvonne T.

    2011-01-01

    Context: Timing of menopause is largely influenced by genetic factors. Because menopause occurs when the follicle pool in the ovaries has become exhausted, genes involved in primordial follicle recruitment can be considered as candidate genes for timing of menopause. Objective: The aim was to study

  2. Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH

    DEFF Research Database (Denmark)

    Andrade, Evelyn Rabelo; Hyttel, Poul; Landim-Alvarenga, Fernanda Da Cruz;

    2011-01-01

    The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured...

  3. Topical liposome targeting of dyes, melanins, genes, and proteins selectively to hair follicles.

    Science.gov (United States)

    Hoffman, R M

    1998-01-01

    For therapeutic and cosmetic modification of hair, we have developed a hair-follicle-selective macromolecule and small molecule targeting system with topical application of phosphatidylcholine-based liposomes. Liposome-entrapped melanins, proteins, genes, and small-molecules have been selectively targeted to the hair follicle and hair shafts of mice. Liposomal delivery of these molecules is time dependent. Negligible amounts of delivered molecules enter the dermis, epidermis, or bloodstream thereby demonstrating selective follicle delivery. Naked molecules are trapped in the stratum corneum and are unable to enter the follicle. The potential of the hair-follicle liposome delivery system for therapeutic use for hair disease as well as for cosmesis has been demonstrated in 3-dimensional histoculture of hair-growing skin and mouse in vivo models. Topical liposome selective delivery to hair follicles has demonstrated the ability to color hair with melanin, the delivery of the active lac-Z gene to hair matrix cells and delivery of proteins as well. Liposome-targeting of molecules to hair follicles has also been achieved in human scalp in histoculture. Liposomes thus have high potential in selective hair follicle targeting of large and small molecules, including genes, opening the field of gene therapy and other molecular therapy of the hair process to restore hair growth, physiologically restore or alter hair pigment, and to prevent or accelerate hair loss.

  4. [Histopathological Study of the Relationship between Lymphoid Follicles and Different Endoscopic Types of Nodular Gastritis].

    Science.gov (United States)

    Nagata, Takuo; Ishitake, Hisahito; Shimamoto, Fumio; Tamura, Tadamasa; Matsumura, Kazunori; Sumii, Masaharu; Nakai, Shirou

    2014-11-01

    Nodular gastritis is characterized histologically by hyperplasia and enlargement of lymphoid follicles in the lamina propria. With the objective of elucidating the relationship between different endoscopic types of nodular gastritis and lymphoid follicles, distributions of lymphoid follicles in the lamina propria were investigated in young gastric cancer patients with nodular gastritis. For the study, whole-mucosal step sectioning of each resected stomach was performed, the densities of lymphoid follicles of all specimens were measured microscopically, and the horizontal and depth distributions were calculated. For assessment in the horizontal direction, density distribution diagrams of lymphoid follicles were created. For assessment in the depth direction, the different endoscopic types of nodular gastritis were compared in the five different analysis sites. In the assessment of the horizontal distribution, no characteristic distribution tendencies were observed in either the granular type group or the scattered type group; however, it was found that areas with relatively high densities of lymphoid follicles generally coincided with the areas where nodular gastritis was observed endoscopically. These results suggested that hyperplasia and aggregation of lymphoid follicles in the lamina propria are involved at the sites where nodular gastritis is observed endoscopically. In the assessment of the depth distribution, lymphoid follicles tended to be more unevenly distributed in the upper lamina propria in the granular type group than in the scattered type at the three different analysis sites where nodular gastritis was observed endoscopically. These results suggested the possibility of a granular type characteristic.

  5. The relationship between variation in size of the primordial follicle pool and age at natural menopause

    NARCIS (Netherlands)

    Depmann, M.; Faddy, M. J.; Van Der Schouw, Y. T.; Peeters, P. H M; Broer, S. L.; Kelsey, T. W.; Nelson, S. M.; Broekmans, F. J M

    2015-01-01

    Context: Menopause has been hypothesized to occur when the nongrowing follicle (NGF) number falls below a critical threshold. Age at natural menopause can be predicted using NGF numbers and this threshold. These predictions support the use of ovarian reserve tests, reflective of the ovarian follicle

  6. Increased T-regulatory cells within lymphocyte follicles in moderate COPD

    DEFF Research Database (Denmark)

    Plumb, J; Smyth, L J C; Adams, H R

    2009-01-01

    Lymphoid follicles in the lung parenchyma are a characteristic feature of chronic obstructive pulmonary disease (COPD). There are reports of altered CD4 T-regulatory cell numbers in COPD lungs, but the location of these cells within COPD lung tissue specific follicles has not been investigated. T...

  7. Hydrostatic Pressure Affects In Vitro Maturation of Oocytes and Follicles and Increases Granulosa Cell Death

    Directory of Open Access Journals (Sweden)

    Isac Karimi

    2013-01-01

    Full Text Available Objective: This study examines the effects of hydrostatic pressure on in vitro maturation (IVM of oocytes derived from in vitro grown follicles.Materials and Methods: In this experimental study, preantral follicles were isolated from 12-day-old female NMRI mice. Each follicle was cultured individually in Alpha Minimal Essential Medium (α-MEM under mineral oil for 12 days. Then, follicles were induced for IVM and divided into two groups, control and experiment. In the experiment group follicles were subjected to 20 mmHg pressure for 30 minutes and cultured for 24-48 hours. We assessed for viability and IVM of the oocytes. The percentage of apoptosis in cumulus cells was determined by the TUNEL assay. A comparison between groups was made using the student’s t test.Results: The percentage of metaphase II oocytes (MII increased in hydrostatic pressure-treated follicles compared to controls (p<0.05. Cumulus cell viability reduced in hydrostatic pressure-treated follicles compared to controls (p<0.05. Exposure of follicles to pressure increased apoptosis in cumulus cells compared to controls (p<0.05.Conclusion: Hydrostatic pressure, by inducing apoptosis in cumulus cells, participates in the cumulus oocyte coupled relationship with oocyte maturation.

  8. Effect of helium-neon laser irradiation on hair follicle growth cycle of Swiss albino mice.

    Science.gov (United States)

    Shukla, S; Sahu, K; Verma, Y; Rao, K D; Dube, A; Gupta, P K

    2010-01-01

    We report the results of a study carried out to investigate the effect of helium-neon (He-Ne) laser (632.8 nm) irradiation on the hair follicle growth cycle of testosterone-treated and untreated mice. Both histology and optical coherence tomography (OCT) were used for the measurement of hair follicle length and the relative percentage of hair follicles in different growth phases. A positive correlation (R = 0.96) was observed for the lengths of hair follicles measured by both methods. Further, the ratios of the lengths of hair follicles in the anagen and catagen phases obtained by both methods were nearly the same. However, the length of the hair follicles measured by both methods differed by a factor of 1.6, with histology showing smaller lengths. He-Ne laser irradiation (at approximately 1 J/cm(2)) of the skin of both the control and the testosterone-treated mice was observed to lead to a significant increase (p < 0.05) in % anagen, indicating stimulation of hair growth. The study also demonstrates that OCT can be used to monitor the hair follicle growth cycle, and thus hair follicle disorders or treatment efficacy during alopecia.

  9. Methoxychlor and its metabolites inhibit growth and induce atresia of baboon antral follicles.

    Science.gov (United States)

    Gupta, Rupesh K; Aberdeen, Graham; Babus, Janice K; Albrecht, Eugene D; Flaws, Jodi A

    2007-08-01

    Methoxychlor (MXC), an organochlorine pesticide, inhibits growth and induces atresia of antral follicles in rodents. MXC metabolites, mono-OH MXC (mono-OH) and bis-OH MXC (HPTE), are thought to be more toxic than the parent compound. Although studies have examined effects of MXC in rodents, few studies have evaluated the effects of MXC in primates. Therefore, the present study tested the hypothesis that MXC, mono-OH, and HPTE inhibit growth and induce atresia of baboon antral follicles. To test this hypothesis, antral follicles were isolated from adult baboon ovaries and cultured with vehicle (dimethylsulfoxide; DMSO), MXC (1-100 micro g/ml), mono-OH (0.1-10 micro g/ml), or HPTE (0.1-10 micro g/ml) for 96 hr. Growth was monitored at 24 hr intervals. After culture, follicles were processed for histological evaluation of atresia. MXC, mono-OH, and HPTE significantly inhibited follicular growth and increased atresia compared to DMSO. Moreover, the adverse effects of MXC and its metabolites on growth and atresia in baboon antral follicles were observed at lower (100-fold) doses than those causing similar effects in rodents. These data suggest that MXC and its metabolites inhibit growth and induce atresia of baboon antral follicles, and that primate follicles are more sensitive to MXC than rodent follicles.

  10. Genes Involved in Initial Follicle Recruitment May Be Associated with Age at Menopause

    NARCIS (Netherlands)

    Voorhuis, Marlies; Broekmans, Frank J.; Fauser, Bart C. J. M.; Onland-Moret, N. Charlotte; van der Schouw, Yvonne T.

    Context: Timing of menopause is largely influenced by genetic factors. Because menopause occurs when the follicle pool in the ovaries has become exhausted, genes involved in primordial follicle recruitment can be considered as candidate genes for timing of menopause. Objective: The aim was to study

  11. The relationship between variation in size of the primordial follicle pool and age at natural menopause

    NARCIS (Netherlands)

    Depmann, M.; Faddy, M. J.; Van Der Schouw, Y. T.; Peeters, P. H M; Broer, S. L.; Kelsey, T. W.; Nelson, S. M.; Broekmans, F. J M

    2015-01-01

    Context: Menopause has been hypothesized to occur when the nongrowing follicle (NGF) number falls below a critical threshold. Age at natural menopause can be predicted using NGF numbers and this threshold. These predictions support the use of ovarian reserve tests, reflective of the ovarian follicle

  12. Protein and messenger RNA expression of interleukin 1 system members in bovine ovarian follicles and effects of interleukin 1β on primordial follicle activation and survival in vitro.

    Science.gov (United States)

    Passos, J R S; Costa, J J N; da Cunha, E V; Silva, A W B; Ribeiro, R P; de Souza, G B; Barroso, P A A; Dau, A M P; Saraiva, M V A; Gonçalves, P B D; van den Hurk, R; Silva, J R V

    2016-01-01

    This study aimed to investigate the expression of interleukin 1 (IL-1) system members (proteins and messenger RNA of ligands and receptors) and its distribution in ovarian follicles of cyclic cows and to evaluate the effects of IL-1β on the survival and activation of primordial follicles in vitro. The ovaries were processed for localization of IL-1 system in preantral and antral follicles by immunohistochemical, real-time polymerase chain reaction, and Western blot analysis. For in vitro studies, ovarian fragments were cultured in α-MEM(+) supplemented with IL-1β (0, 1, 10, 50, or 100 ng/mL), and after 6 d, the cultured tissues were processed for histologic analysis. Immunohistochemical results showed that the IL-1 system proteins IL-1β, IL-1RA, IL-1RI, and IL-1RII were detected in the cytoplasm of oocytes and granulosa cells from all follicular categories and theca cells of antral follicles. Variable levels of messenger RNA for the IL-1 system members were observed at different stages of development. After 6 d of culture, the presence of IL-1β (10 or 50 ng/mL) was effective in maintaining the percentage of normal follicles and in promoting primordial follicle activation. In conclusion, IL-1 system members are differentially expressed in ovarian follicles according to their stage of development. Moreover, IL-1β promotes the development of primordial follicles. These results indicate an important role of the IL-1 system in the regulation of bovine folliculogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Complex interactions between GSK3 and aPKC in Drosophila embryonic epithelial morphogenesis.

    Directory of Open Access Journals (Sweden)

    Nicole A Kaplan

    Full Text Available Generally, epithelial cells must organize in three dimensions to form functional tissue sheets. Here we investigate one such sheet, the Drosophila embryonic epidermis, and the morphogenetic processes organizing cells within it. We report that epidermal morphogenesis requires the proper distribution of the apical polarity determinant aPKC. Specifically, we find roles for the kinases GSK3 and aPKC in cellular alignment, asymmetric protein distribution, and adhesion during the development of this polarized tissue. Finally, we propose a model explaining how regulation of aPKC protein levels can reorganize both adhesion and the cytoskeleton.

  14. Emergence and Dynamics of Polar Order in Developing Epithelia

    Science.gov (United States)

    Farhadifar, Reza

    2011-03-01

    Planar Cell Polarity (PCP) is a conserved process in many vertebrate and invertebrate tissues, and is fundamental for the coordination of cell behavior and patterning. A well-studied example is the orientational pattern of hairs in the wing of the adult fruit fly Drosophila, which is an important model organism in biology. The Drosophila wing is an epithelium, i.e., a two-dimensional sheet of cells, which grows from a few cells to thousands of cells during the course of development. In the wing epithelium, planar polarity is established by an anisotropic distribution of PCP proteins within cells. The distribution of these proteins in a given cell affects the polarity of neighboring cells, such that at the end of wing development a large-scale PCP orientational order emerges. Here we present a theoretical study of planar polarity in developing epithelia based on a vertex model, which takes into account cell mechanics, cell adhesion, and cell division, combined with experimental results obtained from time-lapse imaging of the wing development. We show that in experiment, polarity order does not develop de novo at the end of wing development, but rather cells are initially polarized at an angle with respect to their final polarity axis. During wing development, the polarity axes of cells reorient towards their final direction. We identify a basic mechanism to generate such a large-scale initial polarization, based on the growth of a small number of cells with an initially random PCP distribution. Finally, we study the effect of shear and oriented cell division on dynamics of PCP order, showing that these two processes can robustly reorient the polarity axes of cells.

  15. Chromatin assembly using Drosophila systems.

    Science.gov (United States)

    Fyodorov, Dmitry V; Levenstein, Mark E

    2002-05-01

    To successfully study chromatin structure and activity in vitro, it is essential to have a chromatin assembly system that will prepare extended nucleosome arrays with highly defined protein content that resemble bulk chromatin isolated from living cell nuclei in terms of periodicity and nucleosome positioning. The Drosophila ATP-dependent chromatin assembly system described in this unit meets these requirements. The end product of the reaction described here has highly periodic extended arrays with physiologic spacing and positioning of the nucleosomes.

  16. Sphingosine-1-phosphate and ceramide are associated with health and atresia of bovine ovarian antral follicles.

    Science.gov (United States)

    Hernández-Coronado, C G; Guzmán, A; Espinosa-Cervantes, R; Romano, M C; Verde-Calvo, J R; Rosales-Torres, A M

    2015-02-01

    The follicle destiny towards ovulation or atresia is multi-factorial in nature and involves outcries, paracrine and endocrine factors that promote cell proliferation and survival (development) or unchain apoptosis as part of the atresia process. In several types of cells, sphingosine-1-phospate (S1P) promotes cellular proliferation and survival, whereas ceramide (CER) triggers cell death, and the S1P/CER ratio may determine the fate of the cell. The aim of present study was to quantify S1P and CER concentrations and their ratio in bovine antral follicles of 8 to 17 mm classified as healthy and atretic antral follicles. Follicles were dissected from cow ovaries collected from a local abattoir. The theca cell layer, the granulosa cells and follicular fluid were separated, and 17β-estradiol (E2) and progesterone (P4) concentrations were measured in the follicular fluid by radioimmunoassay. Based on the E2/P4 ratio, the follicles were classified as healthy (2.2±0.3) or atretic (0.2±0.3). In both follicular compartments (granulosa and theca cell layer), sphingolipids were extracted and S1P and CER concentrations were quantified by HPLC (XTerra RP18; 5 µm, 3.0×150 mm column). Results showed that in both follicular compartments, S1P concentrations were higher in healthy antral follicles than in atretic antral follicles (P<0.05). The concentration of CER in the granulosa cells was higher in atretic antral follicles than in healthy antral follicles, but no differences were observed in the theca cell layer. The S1P/CER ratio in both follicular compartments was also higher in healthy antral follicles. Interestingly, in these follicles, there was a 45-fold greater concentration of S1P than CER in the granulosa cells (P<0.05), whereas in the theca cell layer, S1P had only a 14-fold greater concentration than CER when compared with atretic antral follicles. These results suggest that S1P plays a role in follicle health, increasing cellular proliferation and survival. In

  17. Regulation of polarized extension and planar cell polarity in the cochlea by the vertebrate PCP pathway.

    Science.gov (United States)

    Wang, Jianbo; Mark, Sharayne; Zhang, Xiaohui; Qian, Dong; Yoo, Seung-Jong; Radde-Gallwitz, Kristen; Zhang, Yanping; Lin, Xi; Collazo, Andres; Wynshaw-Boris, Anthony; Chen, Ping

    2005-09-01

    The mammalian auditory sensory organ, the organ of Corti, consists of sensory hair cells with uniformly oriented stereocilia on the apical surfaces and has a distinct planar cell polarity (PCP) parallel to the sensory epithelium. It is not certain how this polarity is achieved during differentiation. Here we show that the organ of Corti is formed from a thicker and shorter postmitotic primordium through unidirectional extension, characteristic of cellular intercalation known as convergent extension. Mutations in the PCP pathway interfere with this extension, resulting a shorter and wider cochlea as well as misorientation of stereocilia. Furthermore, parallel to the homologous pathway in Drosophila melanogaster, a mammalian PCP component Dishevelled2 shows PCP-dependent polarized subcellular localization across the organ of Corti. Taken together, these data suggest that there is a conserved molecular mechanism for PCP pathways in invertebrates and vertebrates and indicate that the mammalian PCP pathway might directly couple cellular intercalations to PCP establishment in the cochlea.

  18. 'Peer pressure' in larval Drosophila?

    Science.gov (United States)

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-06-06

    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila.

  19. Drosophila's view on insect vision.

    Science.gov (United States)

    Borst, Alexander

    2009-01-13

    Within the last 400 million years, insects have radiated into at least a million species, accounting for more than half of all known living organisms: they are the most successful group in the animal kingdom, found in almost all environments of the planet, ranging in body size from a mere 0.1 mm up to half a meter. Their eyes, together with the respective parts of the nervous system dedicated to the processing of visual information, have long been the subject of intense investigation but, with the exception of some very basic reflexes, it is still not possible to link an insect's visual input to its behavioral output. Fortunately for the field, the fruit fly Drosophila is an insect, too. This genetic workhorse holds great promise for the insect vision field, offering the possibility of recording, suppressing or stimulating any single neuron in its nervous system. Here, I shall give a brief synopsis of what we currently know about insect vision, describe the genetic toolset available in Drosophila and give some recent examples of how the application of these tools have furthered our understanding of color and motion vision in Drosophila.

  20. Primordial follicle assembly was regulated by Notch signaling pathway in the mice.

    Science.gov (United States)

    Chen, Chun-Lei; Fu, Xia-Fei; Wang, Lin-Qing; Wang, Jun-Jie; Ma, Hua-Gang; Cheng, Shun-Feng; Hou, Zhu-Mei; Ma, Jin-Mei; Quan, Guo-Bo; Shen, Wei; Li, Lan

    2014-03-01

    Notch signaling pathway, a highly conserved cell signaling system, exists in most multicellular organisms. The objective of this study was to examine Notch signaling pathway in germ cell cyst breakdown and primordial follicle formation. The receptor and ligand genes of Notch pathway (Notch1, Notch2, Jagged1, Jagged2 and Hes1) were extremely down-regulated after newborn mouse ovaries were cultured then exposed to DAPT or L-685,458 in vitro (P primordial follicles. Down-regulated mRNA expression of specific genes including Lhx8, Figla, Sohlh2 and Nobox, were also observed. The percentages of female germ cells in germ cell cysts and primordial follicles were counted after culture of newborn ovaries for 3 days in vitro. The result showed female germ cells in cysts was remarkably up-regulated while as the oocytes in primordial follicles was significantly down-regulated (P primordial follicle in mice.

  1. Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary.

    Science.gov (United States)

    Wang, Zhengpin; Niu, Wanbao; Wang, Yijing; Teng, Zhen; Wen, Jia; Xia, Guoliang; Wang, Chao

    2015-01-01

    In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-β (TGF-β) family member activin (ACT) contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST), during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation.

  2. Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary.

    Directory of Open Access Journals (Sweden)

    Zhengpin Wang

    Full Text Available In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-β (TGF-β family member activin (ACT contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST, during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation.

  3. Effect of EGF on initiation of primordial follicle growth in ovary of newborn rat

    Institute of Scientific and Technical Information of China (English)

    柳海珍; 许复华; 刘以训

    2000-01-01

    The present study was designed to look at the effect of epidermal growth factor (EGF) and tomcie-stimulating hormone (FSH) on initiation of primordial follicle growth and differentiation in the ovary of newborn rat with a sensitive marker of proliferating cell nuclear antigen (PCNA). The results showed that more cuboidal granulosa cells (GC) were found in the ovary two days after injection of EGF. More proliferative GC were observed on D4. No such action of FSH on primordial follicles was demonstrated. Using in situ hybridization, inhibin a mRNA expression in GC was detected from D5, while FSH receptor (FSHR) mRNA expression started from D6 after birth. Both mRNAs increased following further development of the follicles. These results suggest that it is EGF, but not FSH, that may play a certain role in initiation of primordial follicle growth. FSH may be involved in further differentiation and growth of the early developmental follicles.

  4. Hair Follicle Melanocyte Cells as a Renewable Source of Melanocytes for Culture and Transplantation

    Directory of Open Access Journals (Sweden)

    Kwon, Ho

    2008-01-01

    Full Text Available Objective: Advances in melanocyte culture techniques have not yet led to reliable clinical methods for treating hypopigmentation disorders. We hypothesized that melanocytes harvested from plucked hair follicles may provide a renewable source of melanocytes for the treatment of hypopigmentation. Methods: Hairs with attached cells from the follicles were plucked from Yucatan pigs and implanted in a collagen-glycosaminoglycan matrix for either immediate or delayed implantation into full-thickness excisional porcine wounds. Wounds were allowed to heal and were biopsied at 2 and 4 weeks, respectively. Results: Fully healed wounds with transplanted hair follicles showed central areas of dark pigmentation corresponding to the location of implanted hair follicles. Corresponding collagen-glycosaminoglycan matrix wounds showed no central areas of pigmentation. Conclusions: Hair follicle--derived melanocytes may potentially serve as a renewable source of pigment-producing cells for treating hypopigmentation disorders.

  5. Drosophila CK1-γ, gilgamesh, controls PCP-mediated morphogenesis through regulation of vesicle trafficking.

    Science.gov (United States)

    Gault, William J; Olguin, Patricio; Weber, Ursula; Mlodzik, Marek

    2012-03-05

    Cellular morphogenesis, including polarized outgrowth, promotes tissue shape and function. Polarized vesicle trafficking has emerged as a fundamental mechanism by which protein and membrane can be targeted to discrete subcellular domains to promote localized protrusions. Frizzled (Fz)/planar cell polarity (PCP) signaling orchestrates cytoskeletal polarization and drives morphogenetic changes in such contexts as the vertebrate body axis and external Drosophila melanogaster tissues. Although regulation of Fz/PCP signaling via vesicle trafficking has been identified, the interplay between the vesicle trafficking machinery and downstream terminal PCP-directed processes is less established. In this paper, we show that Drosophila CK1-γ/gilgamesh (gish) regulates the PCP-associated process of trichome formation through effects on Rab11-mediated vesicle recycling. Although the core Fz/PCP proteins dictate prehair formation broadly, CK1-γ/gish restricts nucleation to a single site. Moreover, CK1-γ/gish works in parallel with the Fz/PCP effector multiple wing hairs, which restricts prehair formation along the perpendicular axis to Gish. Our findings suggest that polarized Rab11-mediated vesicle trafficking regulated by CK1-γ is required for PCP-directed processes.

  6. Planar Cell Polarity Signaling: Coordination of cellular orientation across tissues

    OpenAIRE

    Singh, Jaskirat; Mlodzik, Marek

    2012-01-01

    Establishment of Planar Cell Polarity (PCP) in epithelia, in the plane of an epithelium, is an important feature of the development and homeostasis of most organs. Studies in different model organisms have contributed a wealth of information regarding the mechanisms that govern PCP regulation. Genetic studies in Drosophila have identified two signaling systems, the Fz/PCP and Fat/Dachsous system, which are both required for PCP establishment in many different tissues in a largely non-redundan...

  7. In vitro growth and development of isolated secondary follicles from vitrified caprine ovarian cortex.

    Science.gov (United States)

    Leal, Érica S S; Vieira, Luis A; Sá, Naíza A R; Silva, Gerlane M; Lunardi, Franciele O; Ferreira, Anna C A; Campello, Cláudio C; Alves, Benner G; Cibin, Francielli W S; Smitz, Johan; Figueiredo, José R; Rodrigues, Ana P R

    2017-08-03

    The aim of this study was to evaluate the viability, antrum formation and in vitro development of isolated secondary follicles from vitrified caprine ovarian cortex in a medium previously established for fresh isolated secondary follicles, in the absence (α-minimum essential medium (α-MEM+) alone) or presence of FSH and vascular endothelial growth factor (VEGF; α-MEM++FSH+VEGF). Ovarian fragments were distributed among five treatments (T1 to T5): fresh follicles were fixed immediately (T1), follicles from fresh tissue were cultured in vitro in α-MEM+ (T2) or α-MEM++FSH+VEGF (T3) and follicles from vitrified tissue were cultured in vitro in α-MEM+ (T4) or α-MEM++FSH+VEGF (T5). After 6 days of culture, treated follicles (T2, T3, T4 and T5) were evaluated for morphology, viability and follicular development (growth, antrum formation and proliferation of granulosa cells by Ki67 and argyrophilic nucleolar organiser region (AgNOR) staining). The levels of reactive oxygen species (ROS) in the culture media were also assessed. Overall, morphology of vitrified follicles was altered (P0.05). The average overall and daily follicular growth was highest (Ppositive for Ki67. However, fresh follicles from T3 had significantly higher AgNOR staining (P<0.05) compared with follicles of T1, T2, T4 and T5. In conclusion, secondary follicles can be isolated from vitrified and warmed ovarian cortex and survive and form an antrum when growing in an in vitro culture for 6 days.

  8. Increased sensitivity of estrogen receptor alpha overexpressing antral follicles to methoxychlor and its metabolites.

    Science.gov (United States)

    Paulose, Tessie; Hernández-Ochoa, Isabel; Basavarajappa, Mallikarjuna S; Peretz, Jackye; Flaws, Jodi A

    2011-04-01

    Methoxychlor (MXC), an organochlorine pesticide, and its metabolites, mono-hydroxy MXC (MOH) and bis-hydroxy MXC (HPTE) are known ovarian toxicants and can cause inhibition of antral follicle growth. Since these chemicals bind to estrogen receptor alpha (ESR1), we hypothesized that ovaries overexpressing ESR1 (ESR1 OE) would be more susceptible to toxicity induced by MXC and its metabolites because the chemicals can bind to more ESR1 in the antral follicles. We cultured antral follicles from controls and ESR1 OE mouse ovaries with either the vehicle dimethylsulfoxide (DMSO), MXC, MOH, or HPTE. The data show that at 96 h, the cultured antral follicles from ESR1 OE antral follicles are more susceptible to toxicity induced by MXC, MOH, and HPTE because low doses of these chemicals cause follicle growth inhibition in ESR1 OE mice but not in control mice. On comparing gene expression levels of nuclear receptors in the cultured antral follicles of ESR1 OE and control follicles, we found differential messenger RNA (mRNA) expression of Esr1, estrogen receptor beta (Esr2), androgen receptor (Ar), progesterone receptor (Pr), and aryl hydrocarbon receptor (Ahr) between the genotypes. We also analyzed mRNA levels of Cyp3a41a, the enzyme metabolizing MOH and HPTE, in the cultured follicles and found that Cyp3a41a was significantly lower in DMSO-treated ESR1 OE follicles compared with controls. In ESR1 OE livers, we found that Cyp3a41a levels were significantly lower compared with control livers. Collectively, these data suggest that MXC and its metabolites cause differential gene expression in ESR1 OE mice compared with controls. The results also suggest that the increased sensitivity of ESR1 OE mouse ovaries to toxicity induced by MXC and its metabolites is due to low clearance of the metabolites by the liver and ovary.

  9. Using Drosophila for Studies of Intermediate Filaments.

    Science.gov (United States)

    Bohnekamp, Jens; Cryderman, Diane E; Thiemann, Dylan A; Magin, Thomas M; Wallrath, Lori L

    2016-01-01

    Drosophila melanogaster is a useful organism for determining protein function and modeling human disease. Drosophila offers a rapid generation time and an abundance of genomic resources and genetic tools. Conservation in protein structure, signaling pathways, and developmental processes make studies performed in Drosophila relevant to other species, including humans. Drosophila models have been generated for neurodegenerative diseases, muscular dystrophy, cancer, and many other disorders. Recently, intermediate filament protein diseases have been modeled in Drosophila. These models have revealed novel mechanisms of pathology, illuminated potential new routes of therapy, and make whole organism compound screens feasible. The goal of this chapter is to outline steps to study intermediate filament function and model intermediate filament-associated diseases in Drosophila. The steps are general and can be applied to study the function of almost any protein. The protocols outlined here are for both the novice and experienced Drosophila researcher, allowing the rich developmental and cell biology that Drosophila offers to be applied to studies of intermediate filaments.

  10. Asymmetric distribution of Echinoid defines the epidermal leading edge during Drosophila dorsal closure

    Science.gov (United States)

    Laplante, Caroline

    2011-01-01

    During Drosophila melanogaster dorsal closure, lateral sheets of embryonic epidermis assemble an actomyosin cable at their leading edge and migrate dorsally over the amnioserosa, converging at the dorsal midline. We show that disappearance of the homophilic cell adhesion molecule Echinoid (Ed) from the amnioserosa just before dorsal closure eliminates homophilic interactions with the adjacent dorsal-most epidermal (DME) cells, which comprise the leading edge. The resulting planar polarized distribution of Ed in the DME cells is essential for the localized accumulation of actin regulators and for actomyosin cable formation at the leading edge and for the polarized localization of the scaffolding protein Bazooka/PAR-3. DME cells with uniform Ed fail to assemble a cable and protrude dorsally, suggesting that the cable restricts dorsal migration. The planar polarized distribution of Ed in the DME cells thus provides a spatial cue that polarizes the DME cell actin cytoskeleton, defining the epidermal leading edge and establishing its contractile properties. PMID:21263031

  11. Capping protein beta is required for actin cytoskeleton organisation and cell migration during Drosophila oogenesis.

    Science.gov (United States)

    Ogienko, Anna A; Karagodin, Dmitry A; Lashina, Valentina V; Baiborodin, Sergey I; Omelina, Eugeniya S; Baricheva, Elina M

    2013-02-01

    Capping protein (CP) is a well-characterised actin-binding protein important for regulation of actin filament (AF) assembly. CP caps the barbed end of AFs, inhibiting the addition and loss of actin monomers. In Drosophila melanogaster, the gene encoding CP β-subunit is named capping protein beta (cpb; see Hopmann et al. [1996] J Cell Biol 133: 1293-305). The cpb level is reduced in the Drosophila bristle actin cytoskeleton and becomes disorganised with abnormal morphology. A reduced level of the CP protein in ovary results in disruption of oocyte determination, and disturbance of nurse cell (NC) cortical integrity and dumping. We describe novel defects appearing in cpb mutants during oogenesis, in which cpb plays an important role in border and centripetal follicle cell migration, ring canal development and cytoplasmic AF formation. The number of long cytoplasmic AFs was dramatically reduced in cpb hypomorphs and abnormal actin aggregates was seen on the inner side of NC membranes. A hypothesis to explain the formation of abnormal short-cut cytoplasmic AFs and actin aggregates in the cpb mutant NCs was proffered, along with a discussion of the reasons for 'dumpless' phenotype formation in the mutants.

  12. Differential genome-wide gene expression profiling of bovine largest and second-largest follicles: identification of genes associated with growth of dominant follicles

    Directory of Open Access Journals (Sweden)

    Takahashi Toru

    2010-02-01

    Full Text Available Abstract Background Bovine follicular development is regulated by numerous molecular mechanisms and biological pathways. In this study, we tried to identify differentially expressed genes between largest (F1 and second-largest follicles (F2, and classify them by global gene expression profiling using a combination of microarray and quantitative real-time PCR (QPCR analysis. The follicular status of F1 and F2 were further evaluated in terms of healthy and atretic conditions by investigating mRNA localization of identified genes. Methods Global gene expression profiles of F1 (10.7 +/- 0.7 mm and F2 (7.8 +/- 0.2 mm were analyzed by hierarchical cluster analysis and expression profiles of 16 representative genes were confirmed by QPCR analysis. In addition, localization of six identified transcripts was investigated in healthy and atretic follicles using in situ hybridization. The healthy or atretic condition of examined follicles was classified by progesterone and estradiol concentrations in follicular fluid. Results Hierarchical cluster analysis of microarray data classified the follicles into two clusters. Cluster A was composed of only F2 and was characterized by high expression of 31 genes including IGFBP5, whereas cluster B contained only F1 and predominantly expressed 45 genes including CYP19 and FSHR. QPCR analysis confirmed AMH, CYP19, FSHR, GPX3, PlGF, PLA2G1B, SCD and TRB2 were greater in F1 than F2, while CCL2, GADD45A, IGFBP5, PLAUR, SELP, SPP1, TIMP1 and TSP2 were greater in F2 than in F1. In situ hybridization showed that AMH and CYP19 were detected in granulosa cells (GC of healthy as well as atretic follicles. PlGF was localized in GC and in the theca layer (TL of healthy follicles. IGFBP5 was detected in both GC and TL of atretic follicles. GADD45A and TSP2 were localized in both GC and TL of atretic follicles, whereas healthy follicles expressed them only in GC. Conclusion We demonstrated that global gene expression profiling of F

  13. Conserved mechanisms of tumorigenesis in the Drosophila adult midgut.

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    Òscar Martorell

    Full Text Available Whereas the series of genetic events leading to colorectal cancer (CRC have been well established, the precise functions that these alterations play in tumor progression and how they disrupt intestinal homeostasis remain poorly characterized. Activation of the Wnt/Wg signaling pathway by a mutation in the gene APC is the most common trigger for CRC, inducing benign lesions that progress to carcinomas due to the accumulation of other genetic alterations. Among those, Ras mutations drive tumour progression in CRC, as well as in most epithelial cancers. As mammalian and Drosophila's intestines share many similarities, we decided to explore the alterations induced in the Drosophila midgut by the combined activation of the Wnt signaling pathway with gain of function of Ras signaling in the intestinal stem cells. Here we show that compound Apc-Ras clones, but not clones bearing the individual mutations, expand as aggressive intestinal tumor-like outgrowths. These lesions reproduce many of the human CRC hallmarks such as increased proliferation, blockade of cell differentiation and cell polarity and disrupted organ architecture. This process is followed by expression of tumoral markers present in human lesions. Finally, a metabolic behavioral assay shows that these flies suffer a progressive deterioration in intestinal homeostasis, providing a simple readout that could be used in screens for tumor modifiers or therapeutic compounds. Taken together, our results illustrate the conservation of the mechanisms of CRC tumorigenesis in Drosophila, providing an excellent model system to unravel the events that, upon mutation in Apc and Ras, lead to CRC initiation and progression.

  14. Control of planar cell polarity by interaction of DWnt4 and four-jointed.

    Science.gov (United States)

    Lim, Janghoo; Norga, Koenraad K; Chen, Zhihong; Choi, Kwang-Wook

    2005-07-01

    The Drosophila eye and the wing display specific planar cell polarity. Although Frizzled (Fz) signaling has been implicated in the establishment of ommatidial and wing hair polarity, evidence for the Wnt gene function has been limited. Here we examined the function of a Drosophila homolog of Wnt4 (DWnt4) in the control of planar polarity. We show that DWnt4 mRNA and protein are preferentially expressed in the ventral region of eye disc. DWnt4 mutant eyes show polarity reversals mostly in the ventral domain, consistent with the ventral expression of DWnt4. Ectopic expression of DWnt4 in the dorsoventral (DV) polar margins is insufficient to induce ommatidial polarity but becomes inductive when coexpressed with Four-jointed (Fj). Similarly, DWnt4 and Fj result in synergistic induction of hair polarity toward the source of expression in the wing. Consistent with genetic interaction, we provide evidence for direct interaction of DWnt4 and Fj transmembrane protein. The extracellular domain of Fj is required for direct binding to DWnt4 and for the induction of hair polarity. In contrast to the synergy between DWnt4 and Fj, DWnt4 antagonizes the polarizing effect of Fz. Our results suggest that DWnt4 is involved in ommatidial polarity signaling in the ventral region of the eye and its function is mediated by interacting with Fj.

  15. Morphological Study of Isolated Ovarian Preantral Follicles Using Fibrin Gel Plus Platelet Lysate after Subcutaneous Transplantation

    Directory of Open Access Journals (Sweden)

    Ali Reza Rajabzadeh

    2015-04-01

    Full Text Available Objective: Ovarian and follicle transplantation may preserve fertility in young cancer survivors. In this study, we have transplanted preantral follicles using fibrin gel as a carrier and fibrin gel supplemented with platelet lysate (PL as a rich source of angiogenic and growth factors. The purpose of this study was to evaluate the role of fibrin gel and PL in follicle transplantation. Materials and Methods: In this experimental study, ovaries were taken from 14-dayold Naval Medical Research Institute (NMRI mice. Preantral follicles were dissected from the ovaries and encapsulated into fibrin gel supplemented with 5, 10, 15 or 20% PL, then transplanted back into the same donor mice. Fibrin gels supplemented with PL that contained preantral follicles were placed in a subcutaneous pocket in the back of the neck of the recipient, donor mouse (the same mouse that follicles were collected. After 14 days the grafts were processed and embedded in paraffin blocks, then serially sectioned for histological evaluation. We counted the follicles and classified them according to stage (preantral or antral. Data were presented as mean ± standard error of mean (SEM and analysed by analysis of variance (ANOVA and the Kruskal-Wallistest. Results: The mean percentage of recovered follicles encapsulated and transplanted in each group were 33.30 ± 2.47 (fibrin gel, 31.96 ± 1.90 (fibrin gel+5% PL, 34.02 ± 2.44 (fibrin gel+10% PL, 48.31 ± 2.06 (fibrin gel+15% PL and 17.60 ± 2.79 (fibrin gel+20% PL. There was a significant increase in the recovery rate of grafted follicles with fibrin gel+15% PL (48.31%; p<0.001. The percentage of preantral follicles showed no significant difference in all groups (p<0.05. The percentage of antral follicles showed a significant decrease in follicles grafted with fibrin gel+20% PL when compared to the other groups (11.77%; p<0.005 but no significant difference was observed in the other groups. Conclusion: The use of PL in follicle

  16. Fidelity in planar cell polarity signalling.

    Science.gov (United States)

    Ma, Dali; Yang, Chung-hui; McNeill, Helen; Simon, Michael A; Axelrod, Jeffrey D

    2003-01-30

    The polarity of Drosophila wing hairs displays remarkable fidelity. Each of the approximately 30,000 wing epithelial cells constructs an actin-rich prehair that protrudes from its distal vertex and points distally. The distal location and orientation of the hairs is virtually error free, thus forming a nearly perfect parallel array. This process is controlled by the planar cell polarity signalling pathway. Here we show that interaction between two tiers of the planar cell polarity signalling mechanism results in the observed high fidelity. The first tier, mediated by the cadherin Fat, dictates global orientation by transducing a directional signal to individual cells. The second tier, orchestrated by the 7-pass transmembrane receptor Frizzled, aligns each cell's polarity with that of its neighbours through the action of an intercellular feedback loop, enabling polarity to propagate from cell to cell. We show that all cells need not respond correctly to the presumably subtle signal transmitted by Fat. Subsequent action of the Frizzled feedback loop is sufficient to align all the cells cooperatively. This economical system is therefore highly robust, and produces virtually error-free arrays.

  17. Global divergence of the human follicle mite Demodex folliculorum

    DEFF Research Database (Denmark)

    Palopoli, Michael F.; Fergus, Daniel J.; Minot, Samuel

    2015-01-01

    Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans, but little molecular work has been done to understand their genetic diversity or transmission. Here we sampled mite DNA from 70 human hosts of diverse geographic ancestries...... American ancestry. To a great extent, the ancestral geography of hosts predicted the lineages of mites found on them; 27% of the total molecular variance segregated according to the regional ancestries of hosts. We found that D. folliculorum populations are stable on an individual over the course of years......, indicating that transmission requires close contact. Dating analyses indicated that D. folliculorum origins may predate modern humans. Overall, D. folliculorum evolution reflects ancient human population divergences, is consistent with an out-of-Africa dispersal hypothesis, and presents an excellent model...

  18. Empty follicle syndrome: Successful pregnancy following dual trigger

    Directory of Open Access Journals (Sweden)

    K Deepika

    2015-01-01

    Full Text Available Empty follicle syndrome (EFS is an uncommon, but the frustrating complication of assisted reproductive technology with failure to obtain oocytes after an adequate ovarian response to stimulation. Most of the reported cases of EFS are drug-related problems which are actually avoidable and do not represent any potential pathology and that the risk of genuine EFS (GEFS is much smaller than was once thought. Our case is thefirst report of a pregnancy obtained after management of GEFS with dual trigger in a gonadotropin-releasing hormone (GnRH antagonist cycle. In this report, we present a patient who underwent two oocyte retrievals, in which no oocytes were obtained. In the third in-vitrofertilization cycle, a dual trigger with the combination of GnRH agonist and human chorionic gonadotropin yielded 11 oocytes, which led to the transfer of 2 blastocysts resulting in a live birth. Changing the treatment protocol with dual trigger brought about a successful outcome.

  19. Empty follicle syndrome: Successful pregnancy following dual trigger.

    Science.gov (United States)

    Deepika, K; Rathore, Suvarna; Garg, Nupur; Rao, Kamini

    2015-01-01

    Empty follicle syndrome (EFS) is an uncommon, but the frustrating complication of assisted reproductive technology with failure to obtain oocytes after an adequate ovarian response to stimulation. Most of the reported cases of EFS are drug-related problems which are actually avoidable and do not represent any potential pathology and that the risk of genuine EFS (GEFS) is much smaller than was once thought. Our case is the first report of a pregnancy obtained after management of GEFS with dual trigger in a gonadotropin-releasing hormone (GnRH) antagonist cycle. In this report, we present a patient who underwent two oocyte retrievals, in which no oocytes were obtained. In the third in-vitro fertilization cycle, a dual trigger with the combination of GnRH agonist and human chorionic gonadotropin yielded 11 oocytes, which led to the transfer of 2 blastocysts resulting in a live birth. Changing the treatment protocol with dual trigger brought about a successful outcome.

  20. Distributions of sulphur and other elements in human hair follicles

    Energy Technology Data Exchange (ETDEWEB)

    Ollerhead, R.W.; Legge, G.J.F.; Jones, L.N.

    1989-04-01

    Distributions of sulphur and other elements have been measured in several different specimens of human hair follicles. Whole specimens, longitudinal bisections, and 10 /mu/m thick longitudinal sections have been analyzed by PIXE using the Melbourne scanning proton microprobe. Elemental maps consistently showed that sulphur contents of the presumptive hair shaft (PHS) were uniformly low from 0 to 400 /mu/m (bulb end), increased continuously from about 400 to 800 /mu/m, and reached a plateau. Sulphur levels were uniformly low in the inner rooth sheath. These observations are consistent with previous protein analysis of PHS sections, indicating sequential synthesis of the major classes of keratin proteins. Maps of other elements indicated that Si, Ca, and Fe tended to be concentrated randomly, whereas, P, Cl, K, and Zn were more uniformly distributed. Average relative concentrations of Si, P, Cl, K, Ca, Fe, Cu, and Zn were estimated from total X-ray spectra. (orig.).

  1. Planar Cell Polarity Signaling Pathway in Congenital Heart Diseases

    Directory of Open Access Journals (Sweden)

    Gang Wu

    2011-01-01

    Full Text Available Congenital heart disease (CHD is a common cardiac disorder in humans. Despite many advances in the understanding of CHD and the identification of many associated genes, the fundamental etiology for the majority of cases remains unclear. The planar cell polarity (PCP signaling pathway, responsible for tissue polarity in Drosophila and gastrulation movements and cardiogenesis in vertebrates, has been shown to play multiple roles during cardiac differentiation and development. The disrupted function of PCP signaling is connected to some CHDs. Here, we summarize our current understanding of how PCP factors affect the pathogenesis of CHD.

  2. Gradients and the Specification of Planar Polarity in the Insect Cuticle

    OpenAIRE

    2009-01-01

    In addition to specifying cell fate, there is a wealth of evidence that molecular gradients are also primarily responsible for specifying cell polarity, particularly in the plane of epithelial sheets (“planar polarity”). The first compelling evidence of a role for gradients in specifying planar polarity came from transplantation experiments in the insect cuticle. More recent molecular genetic analyses in the fruit fly Drosophila have begun to give insights into the molecular nature of the gra...

  3. Integrins are required for cardioblast polarisation in Drosophila

    Directory of Open Access Journals (Sweden)

    Vanderploeg Jessica

    2012-02-01

    Full Text Available Abstract Background The formation of a tubular organ, such as the heart, requires the communication of positional and polarity signals between migratory cells. Key to this process is the establishment of a new luminal domain on the cell surface, generally from the apical domain of a migratory cell. This domain will also acquire basal properties, as it will produce a luminal extracellular matrix. Integrin receptors are the primary means of cell adhesion and adhesion signaling with the extracellular matrix. Here we characterise the requirement of Integrins in a genetic model of vasculogenesis, the formation of the heart in Drosophila. Results As with vertebrates, the Drosophila heart arises from lateral mesoderm that migrates medially to meet their contralateral partners, to then assemble a midline vessel. During migration, Integrins are among the first proteins restricted to the presumptive luminal domain of cardioblasts. Integrins are required for normal levels of leading edge membrane motility. Apical accumulation of Integrins is enhanced by Robo, and reciprocally, apicalisation of luminal factors like Slit and Robo requires Integrin function. Integrins may provide a template for the formation of a lumen by stabilising lumen factors like Robo. Subsequent to migration, Integrin is required for normal cardioblast alignment and lumen formation. This phenotype is most readily modified by other mutations that affect adhesion, such as Talin and extracellular matrix ligands. Conclusion Our findings reveal an instructive role for Integrins in communicating polarising information to cells during migration, and during transition to an epithelial tube structure.

  4. Context based algorithmic framework for identifying and classifying embedded images of follicle units

    Science.gov (United States)

    Rahman, Md. Mahbubur; Iyengar, S. S.; Zeng, Wei; Hernandez, Frank; Nusbaum, Bernard P.; Rose, Paul

    2014-03-01

    Medical image processing has been very emerging research areas in recent days. These types of images are naturally so noisy. To count the target objects is never easy. But the proper treatment depends on the accuracy of the successful locating and counting of the desired objects in an image. Some research work can do this type of segmentation of images, but they include so many constraints on the input images that these solutions cannot be applied in a generalized way to most of the images. Even a slight variation in nature of an input image can lead to a major incorrectness of the result. So we developed a generalized way to count a very noisy part of human body, the hair follicle on the scalp. The objective of this research is to count the number of hair follicle groups and the number of follicles into each group in a microscopic image of human scalp. The follicles are nonstandard in shape i.e. they do not maintain any standard shape like rectangle, oval, circle etc. Moreover the follicles are overlapping with one another in many cases. So it is hard to separate them. Here we will present a technique to count the number of follicle group as well as number of follicles in each group. We also applied well-known techniques to cluster the objects detected and a method to generate a neighboring connected graph in order to calculate the inter follicular distances.

  5.  Hair follicle as a novel source of stem cells

    Directory of Open Access Journals (Sweden)

    Romana Joachimiak

    2012-04-01

    Full Text Available  Tissue engineering as a rapidly developing branch of science offers hope for the use of its products in medical practice. Among the components of tissue substitutes are different types of cells, especially stem cells. A promising source of adult stem cells is hair follicles. Development of follicles in the skin takes place even during fetal life. They arise due to the impact of epidermal and mesenchymal cells. The next steps in the formation of hair follicles are under the control of many factors. Hair follicles are the niche of various stem cell populations and are a major source of cells responsible for regeneration of the hair, sebaceous glands and epidermis. The term „hair follicle stem cells” is most often used in relation to the epithelial cell population. Hair follicle stem cell studies are complicated by the fact that these stem cells divide relatively rarely.The aim of this study is to present the characteristics of cells isolated from the hair follicle in the light of recent research.

  6. Epidermal Wnt controls hair follicle induction by orchestrating dynamic signaling crosstalk between the epidermis and dermis.

    Science.gov (United States)

    Fu, Jiang; Hsu, Wei

    2013-04-01

    A signal first arising in the dermis to initiate the development of hair follicles has been described for many decades. Wnt is the earliest signal known to be intimately involved in hair follicle induction. However, it is not clear whether the inductive signal of Wnt arises intradermally or intraepidermally. Whether Wnt acts as the first dermal signal to initiate hair follicle development also remains unclear. Here we report that Wnt production mediated by Gpr177, the mouse Wls ortholog, is essential for hair follicle induction. Gpr177, encoding a multipass transmembrane protein, regulates Wnt sorting and secretion. Cell type-specific abrogation of the signal reveals that only epidermal, but not dermal, production of Wnt is required. An intraepidermal Wnt signal is necessary and sufficient for hair follicle initiation. However, the subsequent development depends on reciprocal signaling crosstalk of epidermal and dermal cells. Wnt signals within the epidermis and dermis and crossing between the epidermis and dermis have distinct roles and specific functions in skin development. This study not only defines the cell type responsible for Wnt production, but also reveals a highly dynamic regulation of Wnt signaling at different steps of hair follicle morphogenesis. Our findings uncover a mechanism underlying hair follicle development orchestrated by the Wnt pathway.

  7. Follicles were reconstituted from dissociated mouse fetal ovarian cells in vitro

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Early folliculogenesis involved in the interaction of germ cellsand somatic cells is a complicated physiological event. Female germ cells are committed to differentiate into oocytes and finish complete development in the functional units of follicles. Thus there will be great significance in basal research and practices to evaluate the possibility of ovarian cells to reconstitute into follicles in vitro. In the present research, 12—16 dpc (days post coitum) mouse fetal ovarian cells were respectively isolated using collagenase digestion and cultured in droplets in vitro. The results revealed that the fetal ovarian cells of 12—16 dpc appeared to form multiple cell aggregates and tissue-like pieces in vitro. However, 12—13 dpc ovarian cells failed to form the follicles. 14—15 dpc ovarian cells were competent to form a few follicle-like complexes. Furthermore many small typical follicles were reconstituted from 16 dpc ovarian cells in vitro. The results showed for the first time that mouse embryonic ovarian cells were able to form the follicles in vitro. It was a gradual progression for the female germ cells to achieve the ability to induce somatic cells differentiation and reconstitution into follicles, which may directly lead to the success in reorganization and transplantation of genetically modified ovary in vitro.

  8. Mesenchymal Stem Cells Facilitate In Vitro Development of Human Preantral Follicle.

    Science.gov (United States)

    Xia, Xi; Wang, Tianren; Yin, Tailang; Yan, Liying; Yan, Jie; Lu, Cuilin; Zhao, Liang; Li, Min; Zhang, Yan; Jin, Hongyan; Zhu, Xiaohui; Liu, Ping; Li, Rong; Qiao, Jie

    2015-11-01

    Biological folliculogenesis is a lengthy and complicated process, and follicle growth microenvironment is poorly understood. Mesenchymal stem cells (MSCs) have been shown to establish a supportive microenvironment for wound repair, autoimmune diseases amelioration, and tumor development. Therefore, this study is aimed to investigate whether MSCs could help to reconstruct a microenvironment to facilitate the in vitro follicle development. Here we show human MSCs significantly promote the survival rates, increase the growth velocity, and improve the viability of preantral follicles in a dose-dependent manner. Further analyses reveal that growth differentiation factor 9 and bone morphogenetic protein 15 in oocytes and inhibin βA and transforming growth factor β1 in granulose cells within the follicles cocultured with MSCs express notably higher than those in the follicles cultured without MSCs. In summary, our findings demonstrate a previously unrecognized function of MSCs in promoting preantral follicle development and provide a useful strategy to optimize fertility preservation and restoration by facilitating in vitro follicle growth.

  9. Follicle Detection on the USG Images to Support Determination of Polycystic Ovary Syndrome

    Science.gov (United States)

    Adiwijaya; Purnama, B.; Hasyim, A.; Septiani, M. D.; Wisesty, U. N.; Astuti, W.

    2015-06-01

    Polycystic Ovary Syndrome(PCOS) is the most common endocrine disorders affected to female in their reproductive cycle. This has gained the attention from married couple which affected by infertility. One of the diagnostic criteria considereded by the doctor is analysing manually the ovary USG image to detect the number and size of ovary's follicle. This analysis may affect low varibilites, reproducibility, and efficiency. To overcome this problems. automatic scheme is suggested to detect the follicle on USG image in supporting PCOS diagnosis. The first scheme is determining the initial homogeneous region which will be segmented into real follicle form The next scheme is selecting the appropriate regions to follicle criteria. then measuring the segmented region attribute as the follicle. The measurement remains the number and size that aimed at categorizing the image into the PCOS or non-PCOS. The method used is region growing which includes region-based and seed-based. To measure the follicle diameter. there will be the different method including stereology and euclidean distance. The most optimum system plan to detect PCO is by using region growing and by using euclidean distance on quantification of follicle.

  10. Expression of amelogenin and effects of cyclosporin A in developing hair follicles in rats.

    Science.gov (United States)

    Yoo, Hong-Il; Lee, Gye-Hyeok; Lee, Su-Young; Kang, Jee-Hae; Moon, Jung-Sun; Kim, Min-Seok; Kim, Sun-Hun

    2016-01-01

    Amelogenin, an enamel matrix protein has been considered to be exclusively expressed by ameloblasts during odontogenesis. However, burgeoning evidence indicates that amelogenin is also expressed in non-mineralizing tissues. Under the hypothesis that amelogenin may be a functional molecule in developing hair follicles which share developmental features with odontogenesis, this study for the first time elucidated the presence and functional changes of amelogenin and its receptors during rat hair follicle development. Amelogenin was specifically localized in the outer epithelial root sheath of hair follicles. Its expression appeared in the deeper portion of hair follicles, i.e. the bulbar and suprabulbar regions rather than the superficial region. Lamp-1, an amelogenin receptor, was localized in either follicular cells or outer epithelial sheath cells, reflecting functional changes during development. The expression of amelogenin splicing variants increased in a time-dependent manner during postnatal development of hair follicles. Amelogenin expression was increased by treatment with cyclosporin A, which is an inducer of anagen in the hair follicle, whereas the level of Lamp-1 and -2 was decreased by cyclosporin A treatment. These results suggest that amelogenin may be a functional molecule involved in the development of the hair follicle rather than an inert hair shaft matrix protein. © 2015 Anatomical Society.

  11. Strategies to enhance epithelial-mesenchymal interactions for human hair follicle bioengineering.

    Science.gov (United States)

    Ohyama, Manabu; Veraitch, Ophelia

    2013-05-01

    Hair follicle morphogenesis and regeneration depend on intensive but well-orchestrated interactions between epithelial and mesenchymal components. Accordingly, the enhancement of this crosstalk represents a promising approach to achieve successful bioengineering of human hair follicles. The present article summarizes the techniques, both currently available and potentially feasible, to promote epithelial-mesenchymal interactions (EMIs) necessary for human hair follicle regeneration. The strategies include the preparation of epithelial components with high receptivity to trichogenic dermal signals and/or mesenchymal cell populations with potent hair inductive capacity. In this regard, bulge epithelial stem cells, keratinocytes predisposed to hair follicle fate or keratinocyte precursor cells with plasticity may provide favorable epithelial cell populations. Dermal papilla cells sustaining intrinsic hair inductive capacity, putative dermal papilla precursor cells in the dermal sheath/neonatal dermis or trichogenic dermal cells derived from undifferentiated stem/progenitor cells are promising candidates as hair inductive dermal cells. The most established protocol for in vivo hair follicle reconstitution is co-grafting of epithelial and mesenchymal components into immunodeficient mice. In theory, combination of individually optimized cellular components of respective lineages should elicit most intensive EMIs to form hair follicles. Still, EMIs can be further ameliorated by the modulation of non-cell autonomous conditions, including cell compartmentalization to replicate the positional relationship in vivo and humanization of host environment by preparing human stromal bed. These approaches may not always synergistically intensify EMIs, however, step-by-step investigation probing optimal combinations should maximally enhance EMIs to achieve successful human hair follicle bioengineering.

  12. Inhibitors of c-Jun phosphorylation impede ovine primordial follicle activation.

    Science.gov (United States)

    Bertoldo, Michael J; Bernard, Jérémy; Duffard, Nicolas; Tsikis, Guillaume; Alves, Sabine; Calais, Laure; Uzbekova, Svetlana; Monniaux, Danielle; Mermillod, Pascal; Locatelli, Yann

    2016-05-01

    Is the c-Jun-N-terminal kinase (JNK) pathway implicated in primordial follicle activation? Culture of ovine ovarian cortex in the presence of two different c-Jun phosphorylation inhibitors impeded pre-antral follicle activation. Despite its importance for fertility preservation therapies, the mechanisms of primordial follicle activation are poorly understood. Amongst different signalling pathways potentially involved, the JNK pathway has been previously shown to be essential for cell cycle progression and pre-antral follicle development in mice. Ovine ovarian cortex pieces were cultured with varying concentrations of SP600125, JNK inhibitor VIII or anti-Mullerian hormone (AMH) in the presence of FSH for 9 days. Follicular morphometry and immunohistochemistry for proliferating cell nuclear antigen (PCNA), apoptosis and follicle activation (Foxo3a) were assessed. Inhibition of primordial follicle activation occurred in the presence of SP600125, JNK inhibitor VIII and AMH when compared with controls (all P primordial follicle development, we did not determine the cellular targets and mechanism of action of the inhibitors. These results are the first to implicate the JNK pathway in primordial follicle activation and could have significant consequences for the successful development of fertility preservation strategies and our understanding of primordial follicle activation. n/a. Dr Michael J. Bertoldo and the laboratories involved in the present study were supported by a grant from 'Région Centre' (CRYOVAIRE, Grant number #320000268). There are no conflicts of interest to declare. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Magnetic resonance imaging for the study of ovarian follicles in the mouse.

    Science.gov (United States)

    Stephenson, A P; Tyler, D J; Carr, C A; Williams, S A

    2012-10-01

    Additional tools to analyze follicle development would be highly advantageous because current methods require sacrifice of animals at specific times and time-consuming sectioning of tissues for histologic analysis. Magnetic resonance imaging (MRI) may provide a less involved, faster and more cost-effective method to analyze follicles in whole ovaries. Fixed ovaries were collected at different stages of the estrus cycle and after stimulation with gonadotrophins (24 and 48 h post pregnant mares serum (PMSG), and 10 and 24 h post human chorionic gonadotrophin (hCG)) with or without administration of the contrast agent gadodiamide. The MR images were generated using a vertical-bore, 11.7 Tesla MR system. Analysis of the MR images revealed large antral follicles in fixed ovaries with the oocyte and cumulus mass identifiable within preovulatory follicles. The use of gadodiamide had no impact on the quality of MR images obtained. The fixed ovaries were paraffin embedded, sectioned, and hematoxylin stained. Follicles were counted using the MR images and the histology sections. Preovulatory follicle numbers determined using MR images were comparable to those using histology; however counts of smaller follicles were inconsistent. MRI of gonadotrophin-stimulated ovaries in situ did not reveal discernable ovarian structures. Therefore, MRI is a useful tool for studying whole fixed ovaries leaving the ovary intact for additional analyses or for selection of samples based on morphology. The MRI is also useful for identifying preovulatory follicles, although analysis of smaller follicles is not possible, and thus the potential exists for cyst analysis in mouse models of polycystic ovarian syndrome (PCOS).

  14. Histopathological and Radiographic Analysis of Dental Follicle of Impacted Teeth Using Modified Gallego’s Stain

    Science.gov (United States)

    Satheesan, Evie; Tamgadge, Avinash; Bhalerao, Sudhir; Periera, Treville

    2016-01-01

    Introduction In the WHO classification of odontogenic tumours, hard tissue formation has been considered as a sub-classification however, this parameter has not been much explored in dental follicle in literature. Epithelial-mesenchymal interactions play an important role in odontogenesis and its associated pathologies; therefore research on dental follicle should also include mesenchymal components along with epithelial components. Additionally, special stains to identify the nature of such depositions in dental follicle have been less explored. Modified Gallego’s stain is such an example which has not been tried in odontogenic lesions which makes this study unique. Aim Aim of this study was to study histopathological variations in dental follicle, the nature of calcification and depositions using Modified Gallego’s stain and to correlate histological features of dental follicle with pericoronal width radiographically. Materials and Methods A prospective histological study of the dental follicles of 50 impacted teeth was carried out to microscopically evaluate the dental follicular tissues for pathological changes, and to correlate it with pericoronal radiolucency. Impacted teeth with pericoronal radiographic width less than 3mm were included in the study and symptomatic teeth were excluded. Further Modified Gallego stain was used to differentiate the nature of hard tissue formation in dental follicle tissues. Results Dental follicle histologically showed pathological changes resembling dentigerous cyst, ameloblastoma, odontogenic fibroma (Simple and WHO Type), clear cell odontogenic tumour, neurofibroma, neurilemmoma and mucoepidermoid carcinoma. Conclusion The dental follicle surrounding an impacted tooth has the potential to differentiate into a wide variety of tissue types, and thus shows the potential for cyst and tumour development which was observed in this study in most of the specimens with normal follicular width radiographically. PMID:27437341

  15. High follicle density does not decrease sweat gland density in Huacaya alpacas.

    Science.gov (United States)

    Moore, K E; Maloney, S K; Blache, D

    2015-01-01

    When exposed to high ambient temperatures, mammals lose heat evaporatively by either sweating from glands in the skin or by respiratory panting. Like other camelids, alpacas are thought to evaporate more water by sweating than panting, despite a thick fleece, unlike sheep which mostly pant in response to heat stress. Alpacas were brought to Australia to develop an alternative fibre industry to sheep wool. In Australia, alpacas can be exposed to ambient temperatures higher than in their native South America. As a young industry there is a great deal of variation in the quality and quantity of the fleece produced in the national flock. There is selection pressure towards animals with finer and denser fleeces. Because the fibre from secondary follicles is finer than that from primary follicles, selecting for finer fibres might alter the ratio of primary and secondary follicles. In turn the selection might alter sweat gland density because the sweat glands are associated with the primary follicle. Skin biopsy and fibre samples were obtained from the mid-section of 33 Huacaya alpacas and the skin sections were processed into horizontal sections at the sebaceous gland level. Total, primary, and secondary follicles and the number of sweat gland ducts were quantified. Fibre samples from each alpaca were further analysed for mean fibre diameter. The finer-fibred animals had a higher total follicle density (P<0.001) and more sweat glands (P<0.001) than the thicker-fibred animals. The fibre diameter and total follicle density were negatively correlated (R(2)=0.56, P<0.001). Given that the finer-fibred animals had higher follicle density and more sweat glands than animals with thicker fibres, we conclude that alpacas with high follicle density should not be limited for potential sweating ability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Suppression of Notch signaling in the neonatal mouse ovary decreases primordial follicle formation.

    Science.gov (United States)

    Trombly, Daniel J; Woodruff, Teresa K; Mayo, Kelly E

    2009-02-01

    Notch signaling directs cell fate during embryogenesis by influencing cell proliferation, differentiation, and apoptosis. Notch genes are expressed in the adult mouse ovary, and roles for Notch in regulating folliculogenesis are beginning to emerge from mouse genetic models. We investigated how Notch signaling might influence the formation of primordial follicles. Follicle assembly takes place when germ cell syncytia within the ovary break down and germ cells are encapsulated by pregranulosa cells. In the mouse, this occurs during the first 4-5 d of postnatal life. The expression of Notch family genes in the neonatal mouse ovary was determined through RT-PCR measurements. Jagged1, Notch2, and Hes1 transcripts were the most abundantly expressed ligand, receptor, and target gene, respectively. Jagged1 and Hey2 mRNAs were up-regulated over the period of follicle formation. Localization studies demonstrated that JAGGED1 is expressed in germ cells prior to follicle assembly and in the oocytes of primordial follicles. Pregranulosa cells that surround germ cell nests express HES1. In addition, pregranulosa cells of primordial follicles expressed NOTCH2 and Hey2 mRNA. We used an ex vivo ovary culture system to assess the requirement for Notch signaling during early follicle development. Newborn ovaries cultured in the presence of gamma-secretase inhibitors, compounds that attenuate Notch signaling, had a marked reduction in primordial follicles compared with vehicle-treated ovaries, and there was a corresponding increase in germ cells that remained within nests. These data support a functional role for Notch signaling in regulating primordial follicle formation.

  17. Methoxychlor inhibits growth of antral follicles by altering cell cycle regulators.

    Science.gov (United States)

    Gupta, Rupesh K; Meachum, Sharon; Hernández-Ochoa, Isabel; Peretz, Jackye; Yao, Humphrey H; Flaws, Jodi A

    2009-10-01

    Methoxychlor (MXC) reduces fertility in female rodents, decreases antral follicle numbers, and increases atresia through oxidative stress pathways. MXC also inhibits antral follicle growth in vitro. The mechanism by which MXC inhibits growth of follicles is unknown. The growth of follicles is controlled, in part, by cell cycle regulators. Thus, we tested the hypothesis that MXC inhibits follicle growth by reducing the levels of selected cell cycle regulators. Further, we tested whether co-treatment with an antioxidant, N-acetyl cysteine (NAC), prevents the MXC-induced reduction in cell cycle regulators. For in vivo studies, adult cycling CD-1 mice were dosed with MXC or vehicle for 20 days. Treated ovaries were subjected to immunohistochemistry for proliferating cell nuclear antigen (PCNA) staining. For in vitro studies, antral follicles isolated from adult cycling CD-1 mouse ovaries were cultured with vehicle, MXC, and/or NAC for 48, 72 and 96 h. Levels of cyclin D2 (Ccnd2) and cyclin dependent kinase 4 (Cdk4) were measured using in vivo and in vitro samples. The results indicate that MXC decreased PCNA staining, and Ccnd2 and Cdk4 levels compared to controls. NAC co-treatment restored follicle growth and expression of Ccnd2 and Cdk4. Collectively, these data indicate that MXC exposure reduces the levels of Ccnd2 and Cdk4 in follicles, and that protection from oxidative stress restores Ccnd2 and Cdk4 levels. Therefore, MXC-induced oxidative stress may decrease the levels of cell cycle regulators, which in turn, results in inhibition of the growth of antral follicles.

  18. Screening candidate microRNAs (miRNAs) in different lambskin hair follicles in Hu sheep.

    Science.gov (United States)

    Gao, Wen; Sun, Wei; Yin, Jinfeng; Lv, Xiaoyang; Bao, Jianjun; Yu, Jiarui; Wang, Lihong; Jin, Chengyan; Hu, Liang

    2017-01-01

    Hu sheep lambskin is a unique white lambskin from China that exhibits three types of flower patterns, including small waves, medium waves, and large waves, with small waves considered the best quality. However, our understanding of the molecular mechanism underlying flower pattern formation in Hu sheep lambskin is limited. The aim of the present study was to further explore the relevance between candidate microRNAs (miRNAs) and developmental characteristics of hair follicles and screen miRNAs for later functional validation. Herein, we employed Illumina Hiseq 2500 to identify differentially expressed miRNAs in hair follicles of different flower patterns with small, medium, and large waves to construct a comprehensive sequence database on the mechanism of hair follicle development. Paraffin sections of lambskin tissue were prepared to assess the structure of different hair follicles. Expression levels of candidate miRNAs in different flower patterns were analyzed by relative quantitation using real-time PCR, combined with histological observation and micro-observation technologies, and the correlation between expression levels of candidate miRNAs and histological properties of hair follicles was analyzed by using SPSS 17.0. A total of 522 differentially expressed miRNAs were identified, and RNA-seq analysis detected 7,266 target genes in different groups of flower patterns. Gene ontological analysis indicated these target genes were mainly involved in cell proliferation, differentiation, growth, apoptosis, and ion transport, and 14 miRNAs, including miR-143, miR-10a, and let-7 were screened as candidate miRNAs in Hu sheep hair follicle growth and development. In the same field of vision, variance analysis showed that the number of secondary follicles in small waves was significantly larger than that in large and medium waves (Phair follicles, highly significant differences in miRNA-143 expression levels between large and small waves were observed (Phair follicle

  19. Wnt7b is an important intrinsic regulator of hair follicle stem cell homeostasis and hair follicle cycling.

    Science.gov (United States)

    Kandyba, Eve; Kobielak, Krzysztof

    2014-04-01

    The hair follicle (HF) is an exceptional mini-organ to study the mechanisms which regulate HF morphogenesis, cycling, hair follicle stem cell (hfSCs) homeostasis, and progeny differentiation. During morphogenesis, Wnt signaling is well-characterized in the initiation of HF patterning but less is known about which particular Wnt ligands are required and whether individual Wnt ligands act in an indispensable or redundant manner during postnatal hfSCs anagen onset and HF cycle progression. Previously, we described the function of the bone morphogenetic protein (BMP) signaling target gene WNT7a in intrinsic regulation of hfSCs homeostasis in vivo. Here, we investigated the role of Wnt7b, which was also intrinsically upregulated in hfSCs during physiological and precocious anagen after BMP inhibition in vivo. We demonstrated Wnt7b to be a direct target of canonical BMP signaling in hfSCs and using Wnt7b conditional gene targeting during HF morphogenesis revealed disrupted HF cycling including a shorter anagen, premature catagen onset with overall shorter hair production, and diminished HF differentiation marker expression. Additionally, we observed that postnatal ablation of Wnt7b resulted in delayed HF activation, affecting both the hair germ and bulge hfSCs but still maintaining a two-step sequence of HF stimulation. Interestingly, Wnt7b cKO hfSCs participated in reformation of the new HF bulge, but with slower self-renewal. These findings demonstrate the importance of intrinsic Wnt7b expression in hfSCs regulation and normal HF cycling and surprisingly reveal a nonredundant role for Wnt7b in the control of HF anagen length and catagen entry which was not compensated by other Wnt ligands.

  20. Follicle-stimulating hormone regulates expression and activity of epidermal growth factor receptor in the murine ovarian follicle.

    Science.gov (United States)

    El-Hayek, Stephany; Demeestere, Isabelle; Clarke, Hugh J

    2014-11-25

    Fertility depends on the precise coordination of multiple events within the ovarian follicle to ensure ovulation of a fertilizable egg. FSH promotes late follicular development, including expression of luteinizing hormone (LH) receptor by the granulosa cells. Expression of its receptor permits the subsequent LH surge to trigger the release of ligands that activate EGF receptors (EGFR) on the granulosa, thereby initiating the ovulatory events. Here we identify a previously unknown role for FSH in this signaling cascade. We show that follicles of Fshb(-/-) mice, which cannot produce FSH, have a severely impaired ability to support two essential EGFR-regulated events: expansion of the cumulus granulosa cell layer that encloses the oocyte and meiotic maturation of the oocyte. These defects are not caused by an inability of Fshb(-/-) oocytes to produce essential oocyte-secreted factors or of Fshb(-/-) cumulus cells to respond. In contrast, although expression of both Egfr and EGFR increases during late folliculogenesis in Fshb(+/-) females, these increases fail to occur in Fshb(-/-) females. Remarkably, supplying a single dose of exogenous FSH activity to Fshb(-/-) females is sufficient to increase Egfr and EGFR expression and to restore EGFR-dependent cumulus expansion and oocyte maturation. These studies show that FSH induces an increase in EGFR expression during late folliculogenesis and provide evidence that the FSH-dependent increase is necessary for EGFR physiological function. Our results demonstrate an unanticipated role for FSH in establishing the signaling axis that coordinates ovulatory events and may contribute to the diagnosis and treatment of some types of human infertility.

  1. Follicle-stimulating hormone regulates expression and activity of epidermal growth factor receptor in the murine ovarian follicle

    Science.gov (United States)

    El-Hayek, Stephany; Demeestere, Isabelle; Clarke, Hugh J.

    2014-01-01

    Fertility depends on the precise coordination of multiple events within the ovarian follicle to ensure ovulation of a fertilizable egg. FSH promotes late follicular development, including expression of luteinizing hormone (LH) receptor by the granulosa cells. Expression of its receptor permits the subsequent LH surge to trigger the release of ligands that activate EGF receptors (EGFR) on the granulosa, thereby initiating the ovulatory events. Here we identify a previously unknown role for FSH in this signaling cascade. We show that follicles of Fshb−/− mice, which cannot produce FSH, have a severely impaired ability to support two essential EGFR-regulated events: expansion of the cumulus granulosa cell layer that encloses the oocyte and meiotic maturation of the oocyte. These defects are not caused by an inability of Fshb−/− oocytes to produce essential oocyte-secreted factors or of Fshb−/− cumulus cells to respond. In contrast, although expression of both Egfr and EGFR increases during late folliculogenesis in Fshb+/− females, these increases fail to occur in Fshb−/− females. Remarkably, supplying a single dose of exogenous FSH activity to Fshb−/− females is sufficient to increase Egfr and EGFR expression and to restore EGFR-dependent cumulus expansion and oocyte maturation. These studies show that FSH induces an increase in EGFR expression during late folliculogenesis and provide evidence that the FSH-dependent increase is necessary for EGFR physiological function. Our results demonstrate an unanticipated role for FSH in establishing the signaling axis that coordinates ovulatory events and may contribute to the diagnosis and treatment of some types of human infertility. PMID:25385589

  2. Lis1/dynactin regulates metaphase spindle orientation in Drosophila neuroblasts

    Science.gov (United States)

    Siller, Karsten H.; Doe, Chris Q.

    2008-01-01

    Mitotic spindle orientation in polarized cells determines whether they divide symmetrically or asymmetrically. Moreover, regulated spindle orientation may be important for embryonic development, stem cell biology, and tumor growth. Drosophila neuroblasts align their spindle along an apical/basal cortical polarity axis to self-renew an apical neuroblast and generate a basal differentiating cell. It is unknown whether the spindle alignment requires both apical and basal cues, nor have molecular motors been identified that regulate spindle movement. Using live imaging of neuroblasts within intact larval brains, we detect independent movement of both apical and basal spindle poles, suggesting that forces act on both poles. We show that reducing astral microtubules decreases the frequency of spindle movement, but not its maximum velocity, suggesting that one or few microtubules can move the spindle. Mutants in the Lis1/dynactin complex strongly decrease maximum and average spindle velocity, consistent with this motor complex mediating spindle/cortex forces. Loss of either astral microtubules or Lis1/dynactin leads to spindle/cortical polarity alignment defects at metaphase, but these are rescued by telophase. We propose that an early Lis1/dynactin-dependent pathway and a late Lis1/dynactin-independent pathway regulate neuroblast spindle orientation. PMID:18485341

  3. Polar Shapelets

    CERN Document Server

    Massey, R; Massey, Richard; Refregier, Alexandre

    2004-01-01

    The shapelets method for astronomical image analysis is based around the decomposition of localised objects into a series of orthogonal components with particularly convenient mathematical properties. We extend the "Cartesian shapelet" formalism from earlier work, and construct "polar shapelet" basis functions that separate an image into components with explicit rotational symmetries. This provides a more compact representation of typical galaxy shapes, and its physical interpretation is frequently more intuitive. Linear coordinate transformations can be simply expressed using this basis set, and shape measures (including object photometry, astrometry and galaxy morphology estimators) take a naturally elegant form. Particular attention is paid to the analysis of astronomical survey images, and we test shapelet techniques with real data from the Hubble Space Telescope. We present a practical method to automatically optimise the quality of an arbitrary shapelet decomposition in the presence of noise, pixellisat...

  4. Taste processing in Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi A. Apostolopoulou

    2015-10-01

    Full Text Available The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances.

  5. LH-receptor gene expression in human granulosa and cumulus cells from antral and preovulatory follicles

    DEFF Research Database (Denmark)

    Jeppesen, Janni Vikkelsø; Kristensen, Stine Gry; Nielsen, Maria Eilsø

    2012-01-01

    frozen and patients undergoing infertility treatment. Interventions: Cells and fluids were isolated from surgically excised ovaries or from aspirated preovulatory follicles. Main Outcome Measures: We evaluated gene expression of LHR, FSHR, androgen receptor (AR), aromatase (CYP19a1), and AMHR2 normalized...... to the GAPDH expression and associated with FF levels of anti-Mullerian hormone, inhibin-B, and steroids. Results: LHR expression was maximal in GC from preovulatory follicles before ovulation induction. A majority of 150 antral follicles (3-10 mm in diameter) showed LHR expression at approximately 10...

  6. MicroRNA-148b promotes proliferation of hair follicle cells by targeting NFAT5

    OpenAIRE

    Wanbao YANG,Qinqun LI,Bo SU,Mei YU

    2016-01-01

    MicroRNAs (miRNAs), small non-coding RNAs, are involved in many aspects of biological processes. Previous studies have indicated that miRNAs are important for hair follicle development and growth. In our study, we found by qRT-PCR that miR-148b was significantly upregulated in sheep wool follicle bulbs in anagen phase compared with the telogen phase of the hair follicle cycle. Overexpression of miR-148b promoted proliferation of both HHDPC and HHGMC. By using the TOPFlash system we demonstrat...

  7. Coexistence of esophageal blue nevus, hair follicles and basaloid sqamous carcinoma: A case report

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We present the case of a 57-year-old man who underwent esophagectomy for esophageal carcinoma found at barium meal and gastroscopic examination. He was diagnosed as esophageal basaloid squamous carcinoma (BSC) and gastric stromal tumor, which were associated with focal proliferation of melanocytes/ pigmentophages and hair follicles in esophageal mucosa. Melanocytic hyperplasia (melanocytosis) has previously been recognized as an occasional reactive lesion, which can accompany esophageal inflammation and invasive squamous carcinoma. The present case is unusual because of its hyperplasia of not only melanocytes but also hair follicles. To our knowledge, this is the first report of esophageal blue nevus and hair follicle coexisting with BSC.

  8. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: weiwang2@illinois.edu; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbasava2@illinois.edu; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  9. Vitrified sheep isolated secondary follicles are able to grow and form antrum after a short period of in vitro culture.

    Science.gov (United States)

    Lunardi, Franciele Osmarini; Chaves, Roberta Nogueira; de Lima, Laritza Ferreira; Araújo, Valdevane Rocha; Brito, Ivina Rocha; Souza, Carlos Eduardo Azevedo; Donato, Mariana Aragão Matos; Peixoto, Christina Alves; Dinnyes, Andras; Campello, Cláudio Cabral; de Figueiredo, José Ricardo; Rodrigues, Ana Paula Ribeiro

    2015-10-01

    The risk of reintroducing malignant cells after ovarian graft into patients following post-cancer treatment is an obstacle for clinical applications (autotransplantation). In this context, in vitro follicle culture would be an alternative to transplantation in order to minimize such risks. Therefore, the aim of this study was to compare the development of secondary follicles after vitrification in isolated form (without stroma) with vitrification in in situ form (within fragments of ovarian tissue). Follicles were first isolated from ovarian fragments from mixed-breed ewes and then vitrified; these comprised the Follicle-Vitrification group (Follicle-Vit), or fragments of ovarian tissue were first vitrified, followed by isolation of the follicles, resulting in the Tissue-Vitrification group (Tissue-Vit). Control and vitrified groups were submitted to in vitro culture (6 days) and follicular morphology, viability, antrum formation, follicle and oocyte diameter, growth rate, ultrastructural characteristics and cell proliferation were evaluated. The percentages of morphologically normal follicles and antrum formation were similar among groups. Follicular viability and oocyte diameter were similar between Follicle-Vit and Tissue-Vit. The follicular diameter and growth rate of Follicle-Vit were similar to the Control, while those of Tissue-Vit were significantly lower compared to the Control. Both vitrified groups had an augmented rate of granulosa cellular proliferation compared to Control. Secondary follicles can be successfully vitrified before or after isolation from the ovarian tissue without impairing their ability to survive and grow during in vitro culture.

  10. The Common Follicle-Stimulating Hormone Receptor (FSHR Promoter Polymorphism FSHR −29G > A Affects Androgen Production in Normal Human Small Antral Follicles

    Directory of Open Access Journals (Sweden)

    Tanni Borgbo

    2017-06-01

    Full Text Available Follicle-stimulating hormone receptors (FSHRs are almost exclusively expressed on granulosa cells, and FSH action is probably most clearly reflected in intrafollicular hormone milieu of antral follicles. Little is known about the possible effects of the common single nucleotide polymorphism (SNP FSHR −29G > A (rs1394205 on hormonal conditions in humsan small antral follicles (hSAFs obtained from women in the natural menstrual cycle. This study investigated the follicle fluid (FF concentrations of anti-Müllerian hormone, estradiol, progesterone, androstenedione, and testosterone in hSAF in relation to the different genotypes of FSHR −29G > A. FF from 362 follicles was collected in 95 women undergoing fertility preservation, who did not suffer from a disease that directly affected ovarian function. The testosterone levels of the minor A/A genotype were significantly increased compared to the A/G and the G/G genotype. Furthermore, significantly reduced androstenedione levels were observed for the G/G genotype, as compared to the A/G genotype, while the other hormones did not show statistical significant differences. In conclusion, the androgen levels of hSAF were significantly elevated in the minor SNP genotype in the FSHR promoter polymorphism FSHR −29G > A.

  11. HUMAN FOLLICLE STIMULATING HORMONE (hFSH AND THYROXINE (T4 IN SURVIVAL MAINTENANCE AND IN VITRO GROWTH PROMOTION OF CAPRINE PREANTRAL FOLLICLES

    Directory of Open Access Journals (Sweden)

    Sanely Lourenço da Costa

    2015-04-01

    Full Text Available The aim of this study was to investigate the interaction of human FSH (10ng/ml with T4 (20ng/mL on survival, activation and growth of preantral follicles cultured in vitro for 28 days. Fragments of non-cultured and cultured ovarian tissue were processed for classic histology and transmission electron microscopy. The results showed a reduction in the survival rate in all the media tested (one to 28 days when compared to the fresh control. However the treatment with T4/hFSH for seven days of culture maintained the rate similar to the control. The media tested by one and 28 days reduced the percentage of primordial follicles in all periods of culture. However, T4/hFSH on day one of culture remained similar to the fresh control. None of the media were able to keep the percentage of the developing follicles. It was observed that the follicular diameter in the medium with T4/hFSH remained similar to the fresh control. The ultrastructural analysis confirmed the integrity of follicles cultured for seven days in a medium supplemented with T4/hFSH. In conclusion, the medium with T4/hFSH is able to maintain the survival, promote the activation, and the ultrastructural integrity of caprine preantral follicles for until seven days.

  12. Features of follicle-stimulating hormone-stimulated follicles in a sheep model: keys to elucidate embryo failure in assisted reproductive technique cycles.

    Science.gov (United States)

    Veiga-Lopez, Almudena; Dominguez, Veronica; Souza, Carlos J H; Garcia-Garcia, Rosa M; Ariznavarreta, Carmen; Tresguerres, Jesus A F; McNeilly, Alan S; Gonzalez-Bulnes, Antonio

    2008-05-01

    To evaluate the individual functionality of gonadotropin-stimulated preovulatory follicles, for understanding embryo failure in assisted reproductive technique cycles, in a sheep model. Observational, model study. Public research unit. Fifteen adult Manchega ewes. Synchronization of the estrous cycle with intravaginal progestagens and ovarian stimulation with FSH; evaluation of reproductive activity, plasma sampling, ovarian ultrasonography, and ovariectomies. Determination of estrus behavior, plasma and intrafollicular concentrations of E(2) and inhibin A, number and size of ovarian follicles, and developmental competence of oocytes. These results support the usefulness of serial measurements of plasma inhibin A for assessment of follicular growth during the FSH treatment, rather than of E(2) assays commonly used. Functionality of FSH-stimulated preovulatory follicles is clearly disturbed, as confirmed by a negative correlation between follicular size and intrafollicular concentrations of inhibin A and E(2) in preovulatory follicles after individual dissection; moreover, the ability of their oocytes to resume meiosis was diminished. Functionality of follicles in controlled ovarian stimulation (COS), and developmental competence of their oocytes, is disturbed by the high doses of gonadotropin supplied and finally determined by follicular sizes at starting FSH treatment.

  13. The two classes of primordial follicles in the mouse ovary: their development, physiological functions and implications for future research.

    Science.gov (United States)

    Zheng, Wenjing; Zhang, Hua; Liu, Kui

    2014-04-01

    Ovarian follicles are the basic functional units in the mammalian ovary. This review summarizes early pioneering studies and focuses on recent progress that has shown that there are two distinct classes of primordial follicles in the ovary: the first wave of primordial follicles that are activated immediately after they are formed and the adult primordial follicles that are activated gradually in later life. These two separate classes have been proposed for two decades, but sufficient experimental evidence to support this hypothesis has only been obtained recently using newly developed follicular tracing techniques in genetically modified mouse models. These two follicle populations differ from each other primarily in terms of their developmental dynamics and their contributions to ovarian physiology. It is apparent now that these two follicle populations should be treated separately, and such knowledge will hopefully lead to a more in-depth understanding of how distinct types of primordial follicles contribute to physiologic and pathologic alterations of the mammalian ovary.

  14. Keratin-6 driven ODC expression to hair follicle keratinocytes enhances stemness and tumorigenesis by negatively regulating Notch

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, Aadithya; Weng, Zhiping; Chaudhary, Sandeep C.; Afaq, Farrukh [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2014-08-29

    Highlights: • Targeting ODC to hair follicle augments skin carcinogenesis and invasive SCCs. • Hair follicle ODC expands stem cell compartment carrying CD34{sup +}/K15{sup +}/p63{sup +} keratinocytes. • Negatively regulated Notch1 is associated with expansion of stem cell compartment. - Abstract: Over-expression of ornithine decarboxylase (ODC) is known to be involved in the epidermal carcinogenesis. However, the mechanism by which it enhances skin carcinogenesis remains undefined. Recently, role of stem cells localized in various epidermal compartments has been shown in the pathogenesis of skin cancer. To direct ODC expression in distinct epidermal compartments, we have developed keratin 6 (K6)-ODC/SKH-1 and keratin 14 (K14)-ODC/SKH-1 mice and employed them to investigate the role of ODC directed to these epidermal compartments on UVB-induced carcinogenesis. K6-driven ODC over-expression directed to outer root sheath (ORS) of hair follicle was more effective in augmenting tumorigenesis as compared to mice where K14-driven ODC expression was directed to inter-follicular epidermal keratinocytes. Chronically UVB-irradiated K6-ODC/SKH-1 developed 15 ± 2.5 tumors/mouse whereas K14-ODC/SKH-1 developed only 6.8 ± 1.5 tumors/mouse. K6-ODC/SKH-1 showed augmented UVB-induced proliferation and much higher pro-inflammatory responses than K14-ODC/SKH-1 mice. Tumors induced in K6-ODC/SKH-1 were rapidly growing, invasive and ulcerative squamous cell carcinoma (SCC) showing decreased expression of epidermal polarity marker E-cadherin and enhanced mesenchymal marker, fibronectin. Interestingly, the number of CD34/CK15/p63 positive stem-like cells was significantly higher in chronically UVB-irradiated K6-ODC/SKH-1 as compared to K14-ODC/SKH-1 mice. Reduced Notch1 expression was correlated with the expansion of stem cell compartment in these animals. However, other signaling pathways such as DNA damage response or mTOR signaling pathways were not significantly different in

  15. Talin is required to position and expand the luminal domain of the Drosophila heart tube.

    Science.gov (United States)

    Vanderploeg, Jessica; Jacobs, J Roger

    2015-09-15

    Fluid- and gas-transporting tubular organs are critical to metazoan development and homeostasis. Tubulogenesis involves cell polarization and morphogenesis to specify the luminal, adhesive, and basal cell domains and to establish an open lumen. We explore a requirement for Talin, a cytoplasmic integrin adapter, during Drosophila melanogaster embryonic heart tube development. Talin marks the presumptive luminal domain and is required to orient and develop an open luminal space within the heart. Genetic analysis demonstrates that loss of zygotic or maternal-and-zygotic Talin disrupts heart cell migratory dynamics, morphogenesis, and polarity. Talin is essential for subsequent polarization of luminal determinants Slit, Robo, and Dystroglycan as well as stabilization of extracellular and intracellular integrin adhesion factors. In the absence of Talin function, mini-lumens enriched in luminal factors form in ectopic locations. Rescue experiments performed with mutant Talin transgenes suggest that actin-binding is required for normal lumen formation, but not for initial heart cell polarization. We propose that Talin provides instructive cues to position the luminal domain and coordinate the actin cytoskeleton during Drosophila heart lumen development.

  16. Lipopolysaccharide reduces the primordial follicle pool in the bovine ovarian cortex ex vivo and in the murine ovary in vivo.

    Science.gov (United States)

    Bromfield, John J; Sheldon, I Martin

    2013-04-01

    Infections of the uterus or mammary gland with Gram-negative bacteria cause infertility in cattle, not only during disease but also for some time afterward. Even though these infections are in organs distant from the ovary, metritis and mastitis perturb antral follicle development and function in vivo. Although granulosa cells from antral follicles express toll-like receptor 4 (TLR4), and detect and mount an inflammatory response to lipopolysaccharide (LPS) from Gram-negative bacteria, it is not known whether LPS impacts preantral follicle development. The present study tested the hypothesis that LPS perturbs the development of primordial ovarian follicles. Exposure of bovine ovarian cortex ex vivo to LPS reduced the primordial follicle pool associated with increased primordial follicle activation. Ovarian cortex culture supernatants accumulated the inflammatory mediators IL-1beta, IL-6, and IL-8 in an LPS concentration-dependent manner. In addition, LPS exposure modulated key intracellular regulators of follicle activation with loss of the primordial follicle PTEN and cytoplasmic translocation of FOXO3. Acute exposure of mice in vivo to LPS also reduced the primordial follicle pool associated with increased follicle atresia. The increased follicle atresia was TLR4-dependent as Tlr4-deficient mice were insensitive to LPS-mediated follicle atresia. However, LPS did not affect the diameter of individually cultured bovine secondary follicles or their enclosed oocytes. In conclusion, LPS reduced the primordial ovarian follicle pool in the bovine ovarian cortex ex vivo and in the murine ovary in vivo. These observations provide an insight into how bacterial infections distant from the ovary have long term effects on fertility.

  17. Live birth following vitrification of in vitro matured oocytes derived from sibling smaller follicles at follicle selection phase in the context of in vitro fertilization.

    Science.gov (United States)

    Chen, Hua; Lv, Jie-Qiang; Ge, Hong-Shan; Wu, Xin-Mei; Xi, Hai-Tao; Chi, Hai-Hong; Zhu, Chun-Fang; Huang, Jian-Ying

    2014-09-01

    In ovarian stimulation, a 31-year-old woman with polycystic ovary syndrome was at the risk of developing ovarian hyperstimulation syndrome, follicle aspiration was performed, and eight immature oocytes were collected from follicle fluids. After 28 h in vitro culture, six of them reached MII and were vitrified. The patient failed to conceive in her fresh in vitro fertilization cycle and next two replacement cycles. In the third replacement cycle, a successful pregnancy was obtained by vitrified-thawed oocytes. This case demonstrates that follicular aspiration during follicle selection phase has protective effects against developing ovarian hyperstimulation syndrome, and rescued immature oocytes are viable and could produce promising embryos for live birth.

  18. Human Embryonic Stem Cells Form Functional Thyroid Follicles

    Science.gov (United States)

    Latif, Rauf; Davies, Terry F.

    2015-01-01

    Objective: The molecular events that lead to human thyroid cell speciation remain incompletely characterized. It has been shown that overexpression of the regulatory transcription factors Pax8 and Nkx2-1 (ttf-1) directs murine embryonic stem (mES) cells to differentiate into thyroid follicular cells by initiating a transcriptional regulatory network. Such cells subsequently organized into three-dimensional follicular structures in the presence of extracellular matrix. In the current study, human embryonic stem (hES) cells were studied with the aim of recapitulating this scenario and producing functional human thyroid cell lines. Methods: Reporter gene tagged pEZ-lentiviral vectors were used to express human PAX8-eGFP and NKX2-1-mCherry in the H9 hES cell line followed by differentiation into thyroid cells directed by Activin A and thyrotropin (TSH). Results: Both transcription factors were expressed efficiently in hES cells expressing either PAX8, NKX2-1, or in combination in the hES cells, which had low endogenous expression of these transcription factors. Further differentiation of the double transfected cells showed the expression of thyroid-specific genes, including thyroglobulin (TG), thyroid peroxidase (TPO), the sodium/iodide symporter (NIS), and the TSH receptor (TSHR) as assessed by reverse transcription polymerase chain reaction and immunostaining. Most notably, the Activin/TSH-induced differentiation approach resulted in thyroid follicle formation and abundant TG protein expression within the follicular lumens. On stimulation with TSH, these hES-derived follicles were also capable of dose-dependent cAMP generation and radioiodine uptake, indicating functional thyroid epithelial cells. Conclusion: The induced expression of PAX8 and NKX2-1 in hES cells was followed by differentiation into thyroid epithelial cells and their commitment to form functional three-dimensional neo-follicular structures. The data provide proof of principal that hES cells can be

  19. Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH

    Directory of Open Access Journals (Sweden)

    Evelyn Rabelo Andrade

    2011-01-01

    Full Text Available The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA, Epidermal Growth Factor (EGF, and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6 d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro.

  20. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    Boxmeer, Jolanda C.; Steegers-Theunissen, Regine P. M.; Lindemans, Jan; Wildhagen, Mark F.; Martini, Elena; Steegers, Eric A. P.; Macklon, Nick S.

    2008-01-01

    BACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were collected on

  1. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    Boxmeer, Jolanda C.; Steegers-Theunissen, Regine P. M.; Lindemans, Jan; Wildhagen, Mark F.; Martini, Elena; Steegers, Eric A. P.; Macklon, Nick S.

    2008-01-01

    BACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were collected on cycl

  2. Noninvasive method for assessing the human circadian clock using hair follicle cells

    National Research Council Canada - National Science Library

    Makoto Akashi; Haruhiko Soma; Takuro Yamamoto; Asuka Tsugitomi; Shiko Yamashita; Takuya Yamamoto; Eisuke Nishida; Akio Yasuda; James K. Liao; Koichi Node; Joseph S. Takahashi

    2010-01-01

    .... This limitation has greatly hampered our understanding of human circadian rhythm. Here we report a convenient, reliable, and less invasive method for detecting human clock gene expression using biopsy samples of hair follicle cells from the head or chin...

  3. Laminin-511 and integrin beta-1 in hair follicle development and basal cell carcinoma formation

    Directory of Open Access Journals (Sweden)

    Williams Samantha

    2010-11-01

    Full Text Available Abstract Background Initiation of the hair follicle placode and its subsequent growth, maturation and cycling in post-natal skin requires signaling interactions between epithelial cells and adjacent dermal cells and involves Shh signaling via the primary cilium. Previous reports have implicated laminins in hair follicle epithelial invagination. Results Here we use a human BCC model system and mouse mutants to re-evaluate the role of laminin-511 in epithelial invagination in the skin. Blocking laminin 511 and 332 in BCCs maintains primary cilia and Shh signalling, but prevents invagination. Similarly, in laminin-511 and dermal beta-1 integrin mutants, dermal papilla development and primary cilia formation are normal. Dermal beta-1 integrin mutants have normal hair follicle development. Conclusions Our data provides support for a primary role of laminin-511 promoting hair follicle epithelial downgrowth without affecting dermal primary cilia and Shh target gene induction.

  4. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    J.C. Boxmeer (Jolanda); R.P.M. Steegers-Theunissen (Régine); J. Lindemans (Jan); M.F. Wildhagen (Mark); E. Martini (Elena); E.A.P. Steegers (Eric); N.S. Macklon (Nick)

    2008-01-01

    textabstractBACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were colle

  5. JAK/STAT signaling regulates tissue outgrowth and male germline stem cell fate in Drosophila

    Institute of Scientific and Technical Information of China (English)

    Shree Ram SINGH; Xiu CHEN; Steven X.HOU

    2005-01-01

    In multicellular organisms, biological activities are regulated by cell signaling. The various signal transduction pathways regulate cell fate, proliferation, migration, and polarity. Miscoordination of the communicative signals will lead to disasters like cancer and other fatal diseases. The JAK/STAT signal transduction pathway is one of the pathways, which was first identified in vertebrates and is highly conserved throughout evolution. Studying the JAK/STAT signal transduction pathway in Drosophila provides an excellent opportunity to understand the molecular mechanism of the cell regulation during development and tumor formation. In this review, we discuss the general overview of JAK/STAT signaling in Drosophila with respect to its functions in the eye development and stem cell fate determination.

  6. Dosimetric analysis of 123I, 125I and 131I in thyroid follicle models

    Science.gov (United States)

    2014-01-01

    Background Radioiodine is routinely used or proposed for diagnostic and therapeutic purposes: 123I, 125I and 131I for diagnostics and 125I and 131I for therapy. When radioiodine-labelled pharmaceuticals are administered to the body, radioiodide might be released into the circulation and taken up by the thyroid gland, which may then be an organ at risk. The aim of this study was to compare dosimetric properties for 123I, 125I and 131I in previously developed thyroid models for man, rat and mouse. Methods Dosimetric calculations were performed using the Monte Carlo code MCNPX 2.6.0 and nuclear decay data from ICRP 107. Only the non-radiative transitions in the decays were considered. The S value was determined for the cell nuclei in species-specific thyroid follicle models for mouse, rat and man for different spatial distributions of radioiodine. Results For the species-specific single follicle models with radioiodine homogeneously within the follicle lumen, the highest S value came from 131I, with the largest contribution from the β particles. When radioiodine was homogeneously distributed within the follicle cells or the follicle cell nucleus, the highest contribution originated from 125I, about two times higher than 123I, with the largest contribution from the Auger electrons. The mean absorbed dose calculated for our human thyroid multiple follicle model, assuming homogenous distribution of for 123I, 125I, or 131I within the follicle lumens and follicle cells, was 9%, 18% and 4% higher, respectively, compared with the mean absorbed dose according to Medical Internal Radiation Dose (MIRD) formalism and nuclear decay data. When radioiodine was homogeneously distributed in the follicle lumens, our calculations gave up to 90% lower mean absorbed dose for 125I compared to MIRD (20% lower for 123I, and 2% lower for 131I). Conclusions This study clearly demonstrates the importance of using more detailed dosimetric methods and models than MIRD formalism for radioiodine

  7. Quantification, morphology, and viability of equine preantral follicles obtained via the Biopsy Pick-Up method.

    Science.gov (United States)

    Haag, K T; Magalhães-Padilha, D M; Fonseca, G R; Wischral, A; Gastal, M O; King, S S; Jones, K L; Figueiredo, J R; Gastal, E L

    2013-03-01

    A Biopsy Pick-Up (BPU) method was tested to determine the feasibility of retrieving preantral follicles from mare ovaries in vivo. A total of 33 ovarian biopsy procedures were performed on 18 mares during the breeding season. Mares were 5 to 21 years old and biopsies were performed during the estrous and/or diestrous phase, as confirmed by transrectal ultrasonography. Follicles were mechanically isolated using a tissue chopper, counted, and classified as normal or abnormal and primordial or primary. Viability of isolated follicles was determined by Trypan Blue dye. A total of 256 biopsy attempts were made resulting in 185 successful tissue sample collections (72% success rate). The mean weight of ovarian tissue collected per procedure was 25.0 ± 1.6 mg. Overall, 620 preantral follicles were collected and isolated (95% primordial and 5% primary). The mean (±SEM) number of follicles isolated per biopsy procedure was 18.8 ± 1.9. Primordial and primary follicles had an average diameter of 31.3 ± 6.2 and 41.1 ± 6.6 μm, respectively. Viability rate was higher (P 0.05) according to phase of the estrous cycle. Younger mares (5 to 7 years old) had more (P 0.05) by any biopsy procedure, and there were no adverse effects on cyclicity or general reproductive health. In conclusion, the BPU method provided large numbers of normal and viable preantral follicles for the study of early follicular development in mares. The BPU method might be used in the future to obtain preantral follicles for in vitro culture to enable the use of numerous oocytes present within the equine ovary. This could allow for the preservation of genetic material or large-scale embryo production.

  8. Roles of Gremlin 1 and Gremlin 2 in regulating ovarian primordial to primary follicle transition.

    Science.gov (United States)

    Nilsson, Eric E; Larsen, Ginger; Skinner, Michael K

    2014-06-01

    A network of extracellular signaling factors has previously been shown to act in concert to control the ovarian primordial to primary follicle transition. The current study was designed to investigate the roles of the endogenous bone morphogenetic protein (BMP) inhibitors Gremlin 1 (GREM1) and GREM2 in primordial follicle transition in the rat ovary. GREM1 and GREM2 treatments were found to reverse the effects of anti-Müllerian hormone (AMH) to inhibit follicle transition in a whole-ovary culture system. GREM1 reversed the effect of BMP4 to stimulate primordial follicle transition. Immunohistochemical studies showed that GREM2, but not GREM1, was present in primordial follicles suggesting that GREM2 may regulate primordial follicle transition in vivo. Co-immunoprecipitation studies indicated that GREM2 directly binds to AMH, as well as to BMP4. Transcriptome analyses of ovaries treated with GREM2 or GREM1 yielded negligible numbers of differentially expressed genes, suggesting that the immediate effects of GREM2 or GREM1 appear to be at the level of protein-protein interactions, rather than direct actions on the cells. A number of other ovarian growth factors were found to influence the expression of Grem2. Observations suggest that Grem2 is a part of the signaling network of growth factors that regulate the primordial to primary follicle transition. Insights into the regulatory networks affecting the pool of primordial follicles are important to understand the molecular basis for reproductive diseases such as primary ovarian insufficiency. © 2014 Society for Reproduction and Fertility.

  9. Changes in ovarian protein expression during primordial follicle formation in the hamster.

    Science.gov (United States)

    Mukherjee, Anindit; Reisdorph, Nichole; Guda, Chttibabu; Pandey, Sanjit; Roy, Shyamal K

    2012-01-02

    Although many proteins have been shown to affect the transition of primordial follicles to the primary stage, factors regulating the formation of primordial follicles remains sketchy at best. Differentiation of somatic cells into early granulosa cells during ovarian morphogenesis is the hallmark of primordial follicle formation; hence, critical changes are expected in protein expression. We wanted to identify proteins, the expression of which would correlate with the formation of primordial follicles as a first step to determine their biological function in folliculogenesis. Proteins were extracted from embryonic (E15) and 8-day-old (P8) hamster ovaries and fractionated by two-dimensional gel electrophoresis. Gels were stained with Proteosilver, and images of protein profiles corresponding to E15 and P8 ovaries were overlayed to identify protein spots showing altered expression. Some of the protein spots were extracted from SyproRuby-stained preparative gels, digested with trypsin, and analyzed by mass spectrometry. Both E15 and P8 ovaries had high molecular weight proteins at acidic, basic, and neutral ranges; however, we focused on small molecular weight proteins at 4-7 pH range. Many of those spots might represent post-translational modification. Mass spectrometric analysis revealed the identity of these proteins. The formation of primordial follicles on P8 correlated with many differentially and newly expressed proteins. Whereas Ebp1 expression was downregulated in ovarian somatic cells, Sfrs3 expression was specifically upregulated in newly formed granulosa cells of primordial follicles on P8. The results show for the first time that the morphogenesis of primordial follicles in the hamster coincides with altered and novel expression of proteins involved in cell proliferation, transcriptional regulation, and metabolism. Therefore, formation of primordial follicles is an active process requiring differentiation of somatic cells into early granulosa cells and

  10. Phosphodiesterases in the rat ovary: effect of cAMP in primordial follicles.

    Science.gov (United States)

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding

    2015-07-01

    Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15-26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes and PDE2A in the corpora lutea. Incubating neonatal rat ovaries with PDE4 inhibitors did not increase primordial follicle activation or change the expression of the developing follicle markers Gdf9, Amh, Inha, the proliferation marker Mki67 or the primordial follicle marker Tmeff2. In addition, the cAMP analogue 8-bromo-cAMP did not increase AKT1 or FOXO3A phosphorylation associated with follicle activation or increase the expression of Kitlg known to be associated with follicle differentiation but did increase the Tmeff2, Mki67 and Inha expression in a dose-dependent manner. In conclusion, this study shows that both Pde7b and Pde8a are highly expressed in the rodent ovary and that PDE4 inhibition does not cause an increase in primordial follicle activation. © 2015 Society for Reproduction and Fertility.

  11. Gonadotropin treatment augments postnatal oogenesis and primordial follicle assembly in adult mouse ovaries?

    OpenAIRE

    Bhartiya, Deepa; Sriraman, Kalpana; Gunjal, Pranesh; Modak, Harshada

    2012-01-01

    Background Follicle stimulating hormone (FSH) exerts action on both germline and somatic compartment in both ovary and testis although FSH receptors (FSHR) are localized only on the somatic cells namely granulosa cells of growing follicles and Sertoli cells in the seminiferous tubules. High levels of FSH in females are associated with poor ovarian reserve, ovarian hyper stimulation syndrome etc. and at the same time FSH acts as a survival factor during in vitro organotypic culture of ovarian ...

  12. Follicle growth, corpus luteum function and their effects on embryo development in postpartum dairy cows

    OpenAIRE

    2003-01-01

    Absent or irregular ovarian cycles in lactating dairy cows are caused by failure to ovulate the dominant follicle at the appropriate time. The follicle then either regresses or develops into a cyst. This process can be triggered by a variety of metabolic and disease factors that act at the hypothalamus and pituitary gland to inhibit pulsatile LH secretion and the LH surge, and at the ovary to reduce follicular growth and oestradiol production. Cows of poor energy status have low circulating c...

  13. Ethnic differences in skin physiology, hair follicle morphology and follicular penetration

    OpenAIRE

    Luther, Natalie

    2012-01-01

    There is increasing evidence that different ethnic groups exhibit varieties in skin physiological parameters and penetration behaviour, although data available are inconsistent. Likewise variations in hair follicle morphology have been described although its influence on the follicular penetration process has not been investigated until now. Therefore, the aim of the present study was to investigate skin physiological parameters, the hair follicle morphology and the follicular and interce...

  14. Immunohistochemical Analysis of Proliferating Cell Nuclear Antigen (PCNA) in Dental Follicles of Impacted Third Molars

    OpenAIRE

    de OLIVEIRA, David Moraes; SILVEIRA, Marcia Maria Ferreira da; Andrade,Emanuel Savio de Souza; SOBRAL,Ana Paula Veras; Paulo Ricardo Saquete MARTINS-FILHO; SANTOS, Thiago de Santana; OLIVEIRA, Patricia Leimig Amorim de

    2011-01-01

    This study investigated the immunodetection of PCNA in epithelial components of dental follicles associated with impacted third molars without radiographical and morphological signs of pathosis. A total of 105 specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla`s stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferating was determined by using immunohistochemical labeling. Statistical analysis was perform...

  15. Ultrastructure of the ovarian follicles in the placentotrophic Andean lizard of the genus Mabuya (Squamata: Scincidae).

    Science.gov (United States)

    Vieira, Simón; de Pérez, Gloria Romero; Ramírez-Pinilla, Martha Patricia

    2010-06-01

    We studied the ultrastructural organization of the ovarian follicles in a placentotrophic Andean lizard of the genus Mabuya. The oocyte of the primary follicle is surrounded by a single layer of follicle cells. During the previtellogenic stages, these cells become stratified and differentiated in three cell types: small, intermediate, and large globoid, non pyriform cells. Fluid-filled spaces arise among follicular cells in late previtellogenic follicles and provide evidence of cell lysis. In vitellogenic follicles, the follicular cells constitute a monolayered granulosa with large lacunar spaces; the content of their cytoplasm is released to the perivitelline space where the zona pellucida is formed. The oolemma of younger oocytes presents incipient short projections; as the oocyte grows, these projections become organized in a microvillar surface. During vitellogenesis, cannaliculi develop from the base of the microvilli and internalize materials by endocytosis. In the juxtanuclear ooplasm of early previtellogenic follicles, the Balbiani's vitelline body is found as an aggregate of organelles and lipid droplets; this complex of organelles disperses in the ooplasm during oocyte growth. In late previtellogenesis, membranous organelles are especially abundant in the peripheral ooplasm, whereas abundant vesicles and granular material occur in the medullar ooplasm. The ooplasm of vitellogenic follicles shows a peripheral band constituted by abundant membranous organelles and numerous vesicular bodies, some of them with a small lipoprotein core. No organized yolk platelets, like in lecithotrophic reptiles, were observed. Toward the medullary ooplasm, electron-lucent vesicles become larger in size containing remains of cytoplasmic material in dissolution. The results of this study demonstrate structural similarities between the follicles of this species and other Squamata; however, the ooplasm of the mature oocyte of Mabuya is morphologically similar to the ooplasm of

  16. In-vitro Maturation of Immature Oocytes from Preantral Follicles in Prepuberal Mice

    Institute of Scientific and Technical Information of China (English)

    Min-zhi GAO; Yu-bao WANG; Xiao-yun WU

    2007-01-01

    Objective To observe the morphological changes in in vitro growth of preantral follicle isolated from prepuberal mice and to assess impacts of gonadotropin (Gn),insulin transferrin selenium (ITS) and epidermal growth factor (EGF) on their development.Methods Early preantral mice follicles (90-130 μm diameter) were mechanical isolated and selected from 2 weeks old mice and then cultured in alpha-minimal essential medium (α-MEM) with or without Gn, ITS and EGF. The preantral follicles were cultured singly in 20 microliters droplets for up to 14 d. The medium was replaced and the follicles were observed everyday. Granulosa cells (GC) prolification, antrum formation and oocyte maturation were recorded.Results The medium with Gn supported preantral follicle culture in vitro, during which they retained a three-dimensional structure, maintained oocytes viability and increased in diameter and number of somatic cells. Preantral follicles cultured in Gn medium grew obviously, while those without Gn grew slowly and after 6 d's culture began to shrink and blacken. Significant increase in survival rate and maturation rate of oocytes was observed in Gn group (P<0. 01), with 92.9% survived and 28. 7% formed an antrum. Further supplementation of the Gn medium with ITS and rLH, resulted in the significant increase in survival and maturation of preantral follicle (P<0. 05)Conclusions α-MEM can be the medium for in vitro culture (IVC) of preantral follicles,but need to be added with rLH/rFSH, rHCG/rEGF to facilitate thecal cell attachment,GC proliferation and oocyte maturation.

  17. In vitro developmental competence of bovine oocytes: Effect of corpus luteum and follicle size

    Science.gov (United States)

    Karami Shabankareh, Hamed; Shahsavari, Mohammad Hamed; Hajarian, Hadi; Moghaddam, Gholamali

    2015-01-01

    Background: Previous studies reported many discrepancies about the effects of corpus luteum (CL) and ovarian follicle size on the developmental competence of oocytes. Objective: The aim of this study was to investigate the effects of CL and different size of follicle on the developmental potential of bovine oocytes. Materials and Methods: After ovarian classification based on presence or absence of CL, sample follicles were placed in three groups according to their diameter; small (S; 3–6 mm), medium (M; 6–9 mm), and large (L; 10–20 mm). Collected oocytes in each group were subjected to the in vitro embryo production processes. Results: Results showed that, the percentages of blastocyst obtained from oocytes originating from small and medium follicles of ovaries bearing a CL (CL+S-oocytes and CL+M-oocytes, respectively) were lower (p<0.001) than those of small and medium follicles of ovaries not bearing a CL (CL-S-oocytes and CL-M-oocytes, respectively) (30.8% and 33.6% vs. 36.9% and 38.7% respectively). Although, the percentages of blastocyst obtained from CL-M-oocytes and CL-L-oocytes were greater (p< 0.001) than those of CL+S-oocytes and CL+M-oocytes. There were no significant differences in the percentages of blastocyst formation between controls (C-oocytes), CL-S-oocytes and CL+L-oocytes. Conclusion: According to the results of this study, the negative effect of CL on the developmental competence of bovine oocyte depends on the follicle size. Therefore, oocytes originating from large grown follicles were not influenced by negative effects of CL as much as those originating from small and medium follicles did. PMID:26644789

  18. Red Ginseng Extract Promotes the Hair Growth in Cultured Human Hair Follicles

    OpenAIRE

    Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Won, Chong Hyun; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; KANG, YONG JUNG; Lee, Dong Hun

    2015-01-01

    Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells ...

  19. Interpenetrating Fibrin-Alginate Matrices for in vitro Ovarian Follicle Development

    OpenAIRE

    Shikanov, Ariella; Xu, Min; Woodruff, Teresa K.; Shea, Lonnie D.

    2009-01-01

    In this report, we investigate the fibrin-alginate inter penetrating network (FA-IPN) to provide dynamic cell-responsive mechanical properties, which we apply to the in vitro growth of ovarian follicles. The mechanical properties and polymerization rate of the gels were investigated by rheology, and the fiber structure was imaged by electron microscopy. Using a mouse model, two-layered secondary follicles were encapsulated in FA-IPNs, and growth, morphology, hormone production, fibrin degrada...

  20. Modulating hair follicle size with Wnt10b-DKK1 pair during hair regeneration

    Science.gov (United States)

    Lei, Mingxing; Guo, Haiying; Qiu, Weiming; Lai, Xiangdong; Yang, Tian; Widelitz, Randall B.; Chuong, Cheng-Ming; Lian, Xiaohua; Yang, Li

    2015-01-01

    Hair follicles have characteristic sizes corresponding to their cycle specific stage. However, how the anagen hair follicle specifies its size remains elusive. Here, we show that in response to prolonged ectopic Wnt10b-mediated β-catenin activation, regenerating anagen hair follicles grow larger in size. In particular, the hair bulb, dermal papilla and hair shaft become enlarged. While the formation of different hair types (Guard, Awl, Auchene, and Zigzag) is unaffected. Interestingly, we found the effect of exogenous WNT10b was mainly on Zigzag and less on the other kinds of hairs. We observed dramatically enhanced proliferation within the matrix, DP and hair shaft of the enlarged AdWnt10b-treated hair follicles compared with those of normal hair follicles at P98. Furthermore, expression of CD34, a specific hair stem cell marker, was increased in its number to the bulge region after AdWnt10b treatment. Ectopic expression of CD34 throughout the ORS region was also observed. Many CD34 positive hair stem cells were actively proliferating in AdWnt10b-induced hair follicles. Importantly, subsequent co-treatment with the Wnt inhibitor, DKK1, reduced hair follicle enlargement, decreased proliferation and maintained proper hair stem cell localization. Moreover, injection of DKK1 during early anagen significantly reduced the width of prospective hairs. Together, these findings strongly suggest that a balance of Wnt10b/DKK1 governs reciprocal signaling between cutaneous epithelium and mesenchyme to regulate proper hair follicle size. PMID:24750467

  1. Differential effect of melatonin on {gamma}-irradiated ovarian follicles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Lee, C.J. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    2000-05-01

    The present study was performed to obtain evidence of the radioprotective function of melatonin on the ovarian follicles in {gamma}-irradiated immature mice. Three weeks old immature mice were i.p. injected with 10 {mu}g and 100 {mu}g of melatonin dissolved in 100 {mu}l of alcoholic saline. Two hours after the treatments, they were whole-body irradiated with a dose of LD{sub 80(30)} (8.3 Gy). The ovaries were dissected out of the animals at -2, 2, 8, and 14 h after the onset of irradiation and prepared for the histological observation using glutaraldehyde fixation. In terms of morphometry, it was observed that the number of primordial follicles of the irradiation group or the melatonin-treated group was less than that of the control. However, the number of primary, preantral, and early antral follicles was not different from that of the control group. In the group pretreated with 100 {mu}g of melatonin before irradiation, the percentage of normal primordial follicles was significantly higher than that of the irradiation group at any time after irradiation. The high concentration of melatonin also reduced radiation-induced degeneration of the primary follicles at 14 h after irradiation. The pretreatment of 10 {mu}g of melatonin had little of no effect on radiation-induced degeneration of the primordial follicles and of the primary follicles. However it gave a protective effect on the radiation-induced degeneration in the preantral and early antral follicles. From the above results, it is concluded that the exogenous melatonin has different functions depending on the follicular stages, and that the radioprotective effect of exogenous melatonin on follicular degeneration is related to its concentration. (author)

  2. Solitary luteinized follicle cyst of pregnancy complicated with persistent postpartum vaginal bleeding: case report

    Institute of Scientific and Technical Information of China (English)

    ZHANG Song-ying; HUANG He-feng; TONG Xiao-mei

    2007-01-01

    @@ Solitary luteinized follicle cyst, a rare cause of ovarian enlargement during pregnancy and puerperium, is a self-limited disease that can regress spontaneously after labor. The complications of the disease include ovarian torsion, intracystic hemorrhage, and rupture; endocrine disturbances have not been reported.1-4 Here we report a case of solitary luteinized follicle cyst of pregnancy,which required surgical intervention owing to persistent postpartum vaginal bleeding.

  3. Ecdysteroid receptors in Drosophila melanogaster adult females

    Science.gov (United States)

    Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

  4. Modeling tumor invasion and metastasis in Drosophila

    Directory of Open Access Journals (Sweden)

    Wayne O. Miles

    2011-11-01

    Full Text Available Conservation of major signaling pathways between humans and flies has made Drosophila a useful model organism for cancer research. Our understanding of the mechanisms regulating cell growth, differentiation and development has been considerably advanced by studies in Drosophila. Several recent high profile studies have examined the processes constraining the metastatic growth of tumor cells in fruit fly models. Cell invasion can be studied in the context of an in vivo setting in flies, enabling the genetic requirements of the microenvironment of tumor cells undergoing metastasis to be analyzed. This Perspective discusses the strengths and limitations of Drosophila models of cancer invasion and the unique tools that have enabled these studies. It also highlights several recent reports that together make a strong case for Drosophila as a system with the potential for both testing novel concepts in tumor progression and cell invasion, and for uncovering players in metastasis.

  5. Drosophila Cajal bodies: accessories not included

    OpenAIRE

    Matera, A. Gregory

    2006-01-01

    Cajal bodies are nuclear sites of small ribonucleoprotein (RNP) remodeling and maturation. A recent study describes the discovery of the Drosophila Cajal body, revealing some interesting insights into the subnuclear organization of RNA processing machineries among different species.

  6. Behavioral modification in choice process of Drosophila

    Institute of Scientific and Technical Information of China (English)

    WANG; Shunpeng; (王顺鹏); TANG; Shiming; (唐世明); LI; Yan; (李; 岩); GUO; Aike; (郭爱克)

    2003-01-01

    In visual operant conditioning of Drosophila at the flight simulator, only motor output of flies--yaw torque--is recorded, which is involved in the conditioning process. The current study used a newly-designed data analysis method to study the torque distribution of Drosophila. Modification of torque distribution represents the effects of operant conditioning on flies' behavioral mode. Earlier works[10] showed that, when facing contradictory visual cues, flies could make choices based upon the relative weightiness of different cues, and it was demonstrated that mushroom bodies might play an important role in such choice behavior. The new "torque-position map" method was used to explore the CS-US associative learning and choice behavior in Drosophila from the aspect of its behavioral mode. Finally, this work also discussed various possible neural bases involved in visual associative learning, choice processing and modification processing of the behavioral mode in the visual operant conditioning of Drosophila.

  7. Lipid metabolism in Drosophila: development and disease

    Institute of Scientific and Technical Information of China (English)

    Zhonghua Liu; Xun Huang

    2013-01-01

    Proteins,nucleic acids,and lipids are three major components of the cell.Despite a few basic metabolic pathways,we know very little about lipids,compared with the explosion of knowledge about proteins and nucleic acids.How many different forms of lipids are there? What are the in vivo functions of individual lipid? How does lipid metabolism contribute to normal development and human health? Many of these questions remain unanswered.For over a century,the fruit fly Drosophila melanogaster has been used as a model organism to study basic biological questions.In recent years,increasing evidences proved that Drosophila models are highly valuable for lipid metabolism and energy homeostasis researches.Some recent progresses of lipid metabolic regulation during Drosophila development and in Drosophila models of human diseases will be discussed in this review.

  8. Modeling tumor invasion and metastasis in Drosophila.

    Science.gov (United States)

    Miles, Wayne O; Dyson, Nicholas J; Walker, James A

    2011-11-01

    Conservation of major signaling pathways between humans and flies has made Drosophila a useful model organism for cancer research. Our understanding of the mechanisms regulating cell growth, differentiation and development has been considerably advanced by studies in Drosophila. Several recent high profile studies have examined the processes constraining the metastatic growth of tumor cells in fruit fly models. Cell invasion can be studied in the context of an in vivo setting in flies, enabling the genetic requirements of the microenvironment of tumor cells undergoing metastasis to be analyzed. This Perspective discusses the strengths and limitations of Drosophila models of cancer invasion and the unique tools that have enabled these studies. It also highlights several recent reports that together make a strong case for Drosophila as a system with the potential for both testing novel concepts in tumor progression and cell invasion, and for uncovering players in metastasis.

  9. On the Morphology of the Drosophila Heart

    Directory of Open Access Journals (Sweden)

    Barbara Rotstein

    2016-04-01

    Full Text Available The circulatory system of Drosophila melanogaster represents an easily amenable genetic model whose analysis at different levels, i.e., from single molecules up to functional anatomy, has provided new insights into general aspects of cardiogenesis, heart physiology and cardiac aging, to name a few examples. In recent years, the Drosophila heart has also attracted the attention of researchers in the field of biomedicine. This development is mainly due to the fact that several genes causing human heart disease are also present in Drosophila, where they play the same or similar roles in heart development, maintenance or physiology as their respective counterparts in humans. This review will attempt to briefly introduce the anatomy of the Drosophila circulatory system and then focus on the different cell types and non-cellular tissue that constitute the heart.

  10. Methods for studying planar cell polarity.

    Science.gov (United States)

    Olofsson, Jessica; Axelrod, Jeffrey D

    2014-06-15

    Planar cell polarity (PCP) is the polarity of epithelial cells in the plane orthogonal to the apical-basal axis, and is controlled by a partially defined signaling system. PCP related signaling also plays roles in cell migration, tissue re-organization and stem cell differentiation during embryonic development, and later, in regeneration and repair. Aberrant signaling has been linked to a broad range of pathophysiologies including cancer, developmental defects, and neurological disorders. The deepest mechanistic insights have come from studies of PCP in Drosophila. In this chapter we review tools and methods to study PCP signaling in Drosophila epithelia, where it was found to involve asymmetric protein localization that is coordinated between adjacent cells. Such signaling has been most extensively studied in wing, eye, and abdomen, but also in other tissues such as leg and notum. In the adult fly, PCP is manifested in the coordinated direction of hairs and bristles, as well as the organization of ommatidia in the eye. The polarity of these structures is preceded by asymmetric localization of PCP signaling proteins at the apical junctions of epithelial cells. Based on genetic and molecular criteria, the proteins that govern PCP can be divided into distinct modules, including the core module, the Fat/Dachsous/Four-jointed (Fat/Ds/Fj) module (often referred to as the 'global' module) as well as tissue specific effector modules. Different tissues and tissue regions differ in their sensitivity to disturbances in the various modules of the PCP signaling system, leading to controversies about the interactions among the modules, and emphasizing the value of studying PCP in multiple contexts. Here, we review methods including those generally applicable, as well as some that are selectively useful for analyses of PCP in eye (including eye discs), wing (including wing discs), pupal and adult abdomen, and the cuticle of larvae and embryos.

  11. Age-related changes in gene expression patterns of immature and aged rat primordial follicles.

    Science.gov (United States)

    Govindaraj, Vijayakumar; Krishnagiri, Harshini; Chakraborty, Payal; Vasudevan, Madavan; Rao, A Jagannadha

    2017-02-01

    Women are born with millions of primordial follicles which gradually decrease with increasing age and this irreversible supply of follicles completely exhausts at menopause. The fertility capacity of women diminishes in parallel with aging. The mechanisms for reproductive aging are not fully understood. We have observed a decline in Brca1 mediated DNA repair in aging rat primordial follicles. To further understand the age-related molecular changes, we performed microarray gene expression analysis using total RNA extracted from immature (18 to 20 day old) and aged (400 to 450 day old) rat primordial follicles. The results of current microarray study revealed that there were 1,011 (>1.5 fold, pprimordial follicles compared to immature primordial follicles. The gene ontology and pathway analysis of differentially expressed genes revealed a critical biological function such as cell cycle, oocyte meiosis, chromosomal stability, transcriptional activity, DNA replication, and DNA repair were affected by age. This considerable difference in gene expression profiles may have an adverse influence on oocyte quality. Our data provide information on the processes that may contribute to aging and age-related decline in fertility.

  12. Sphingosine 1-phosphate promotes activation of aprine preantral follicle in vitro

    Directory of Open Access Journals (Sweden)

    J.E. Nóbrega Jr.

    2014-08-01

    Full Text Available This study describes the effect of sphingosine 1-phosphate (S1P for development of preantral follicle, therefore the activation and follicular viability of caprine follicles cultured in vitro. Ovarian fragments were cultured for 1 or 7 days in Minimum Essential Medium with different S1P concentrations (0, 1, 10, 50, 100 or 200ng/mL. All ovarian fragments were processed for histological analysis in optical microscopy, transmission electron microscopy and fluorescence analysis. The treatment using 1ng/mL of S1P was able to maintain the percentage of normal follicles with the progression of the culture from day 1 to 7. At end of the 7-day culture period there was a significant reduction (P<0.05 in the percentage of primordial follicles in all groups treated with S1P, compared with fresh control (FC and Control Culture (CC, which was followed by an increase of activated follicles (intermediary, primary and secondary. In addition, the culture for 7 days with media supplemented with S1P with 1ng/mL preserved the ultrastructure of organelles and kept the preantral follicular viability when evaluated by fluorescence microscopy. In conclusion, after 7 days of culture, the 1ng/mL of S1P activates the development of preantral caprine follicles, cultured in situ and maintains the oocitary and follicular viability.

  13. The feasibility of targeted selective gene therapy of the hair follicle.

    Science.gov (United States)

    Li, L; Hoffman, R M

    1995-07-01

    Loss of hair and hair colour is associated with ageing, and when it involves the scalp hair, it can be distressing to both sexes. Hair loss resulting from cancer chemotherapy is particularly distressing. However, safe, effective therapies directed to hair have only just started to be developed. The hair follicle is a complex skin appendage composed of epidermal and dermal tissue, with specialized keratinocytes, the hair matrix cells, forming the hair shaft. Specific therapy of the hair follicle depends on selective targeting of specific cells of the hair follicle. We have developed the histoculture of intact hair-growing skin on sponge-gel matrices. We have recently found in histocultured skin that liposomes can selectively target hair follicles to deliver both small and large molecules. That liposomes can target the hair follicle for delivery has been confirmed independently. Two decades ago we introduced the technique of entrapping DNA in liposomes for use in gene therapy. In this report we describe the selective targeting of the lacZ reporter gene to the hair follicles in mice after topical application of the gene entrapped in liposomes. These results demonstrate that highly selective, safe gene therapy for the hair process is feasible.

  14. Mathematical modelling of decline in follicle pool during female reproductive ageing.

    Science.gov (United States)

    Thilagam, Alagu

    2016-03-01

    The factors which govern the subtle links between follicle loss and mammalian female reproductive ageing remain unclear despite extensive studies undertaken to understand the critical physiological and biochemical mechanisms that underly the accelerated decline in follicle numbers in women older than 37 years. It is not certain whether there is a sole control by the ovary or whether other factors which affect ageing also intersect with the ovarian effect. There is convincing experimental evidence for an interplay of several processes that seem to influence the follicle loss-female reproductive ageing links, with specific hormones (follicle-stimulating hormone, anti-Müllerian hormone, dehydroepiandrosterone) noted to play important roles in follicular dynamics and ovarian ageing. In this work, we examine the subtle links between the rate of follicular decline with ageing and the role of hormones via a series of non-autonomous equations. Simulation results based on the time evolution of the number of ovarian follicles and biochemical changes in the ovarian environment influenced by hormone levels is compared with empirical data based on follicle loss-reproductive ageing correlation studies. © Crown copyright 2015.

  15. Effect of age and sex on fiber and follicle characteristics of an Iranian native sheep

    Directory of Open Access Journals (Sweden)

    B Mobini

    2012-06-01

    Full Text Available The mammalian hair fibers represent an interesting biological material which also is used in the textile industry. Histological structures of the fibers and follicles differ not only among different species but also among different areas and ages in an animal species. Skin samples were collected from neonatal (1-2 months, young (3-9 months, young adult (1-2 years and old adult age groups (3 years and more. In each age group, six animals (3 each sex were utilized. Immediately after slaughtering the animals, tissues were collected from eight regions namely belly, neck, leg, rump, flank, forearm, shoulder and hip and were fixed in 10 percent neutral buffered formalin. Histologic sections were stained with hematoxylin-eosin and special stains. It was found that the general histological features of all Bakhtiari sheep fibers used in this study were similar to many other breeds sited in literature, however there were also some differences. All hairs of the various skin regions had a medulla. All the hair follicles were surrounded by associated structures such as the sweat and sebaceous glands and arrector pili muscles and located only in papillary layer of the dermis. The most common number of the secondary hair follicles in compound hair follicles was 4. The histology of all fibers and follicles in various skin regions showed no significant differences by sex in all the age groups studied. By age increase, all the fibers and their follicles were larger and well organized in all different skin regions.

  16. Ex vivo organ culture of human hair follicles: a model epithelial-neuroectodermal-mesenchymal interaction system.

    Science.gov (United States)

    Tobin, Desmond J

    2011-01-01

    The development of hair follicle organ culture techniques is a significant milestone in cutaneous biology research. The hair follicle, or more accurately the "pilo-sebaceous unit", encapsulates all the important physiologic processes found in the human body; controlled cell growth/death, interactions between cells of different histologic type, cell differentiation and migration, and hormone responsitivity to name a few. Thus, the value of the hair follicle as a model for biological scientific research goes way beyond its scope for cutaneous biology or dermatology alone. Indeed, the recent and dramatic upturn in interest in hair follicle biology has focused principally on the pursuit of two of biology's holy grails; post-embryonic morphogenesis and control of cyclical tissue activity. The hair follicle organ culture model, pioneered by Philpott and colleagues, ushered in an exceptionally accessible way to assess how cells of epithelial (e.g., keratinocytes), mesenchymal (e.g., fibroblasts), and neuroectodermal (e.g., melanocytes) origin interact in a three-dimensional manner. Moreover, this assay system allows us to assess how various natural and pharmacologic agents affect complex tissues for growth modulation. In this article, I focus on the culture of the human hair follicle mini-organ, discussing both the practical issues involved and some possible research applications of this assay.

  17. Grb10 characterization in bovine cumulus oocyte complexes from different follicle sizes

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Antunes da Rosa

    2015-05-01

    Full Text Available The objective of this study was to investigate the mRNA expression and protein localization of Grb10 gene in bovine cumulus-oocyte complexes (COCs from different follicle sizes. Firstly, it was investigated the mRNA expression to correlate with maturation rates. COCs from follicles at 1-3, 4-6, 6-8 and >8mm were used to evaluate Grb10 gene expression by qRT-PCR assay and nuclear maturation rates. It was observed that more competent oocytes (from follicles at 6-8 and >8mm; P>0.05, had lower Grb10 mRNA expression levels when compared to the oocytes from follicles at 1-3 and 4-6mm (P>0.05. After it was performed an immunofluorescence analysis in COCs from different follicle sizes (1-3, 4-6, 6-8 and >8mm to investigate Grb10 protein localization. Samples were incubated with primary antibody: Polyclonal rabbit anti-Grb10 (1:100. Primary antibody was detected using goat anti-rabbit IgG antibody conjugated with Alexa Fluor 488 (1:500. Positive fluorescence signal was detected in all analyzed samples but less evident in COCs from largest follicles. These results characterized Grb10 gene in bovine COC and provide evidences for its involvement during oocyte molecular maturation.

  18. Mapping the follicle-stimulating hormone-induced signalling networks

    Directory of Open Access Journals (Sweden)

    Pauline eGloaguen

    2011-10-01

    Full Text Available Follicle-stimulating hormone (FSH is a central regulator of male and female reproductive function. Over the last decade, there has been a growing perception of the complexity associated with FSH-induced cellular signalling. It is now clear that the canonical Gs/cAMP/PKA pathway is not the sole mechanism that must be considered in FSH biological actions. In parallel, consistent with the emerging concept of biased agonism, several examples of ligand-mediated selective signalling pathway activation by gonadotropin receptors have been reported. In this context, it is important to gain an integrative view of the signalling pathways induced by FSH and how they interconnect to form a network. In this review, we propose a first attempt at building topological maps of various pathways known to be involved in the FSH-induced signalling network. We discuss the multiple facets of FSH-induced signalling and how they converge to the hormone integrated biological response. Despite of their incompleteness, these maps of the FSH-induced signalling network represent a first step towards gaining a system-level comprehension of this hormone’s actions, which may ultimately facilitate the discovery of novel regulatory processes and therapeutic strategies for infertilities and non-steroidal contraception.

  19. Mast cells as modulators of hair follicle cycling.

    Science.gov (United States)

    Maurer, M; Paus, R; Czarnetzki, B M

    1995-08-01

    While the central role of mast cells (MC) in allergy and inflammation is well-appreciated, much less is known about their physiological functions. The impressive battery of potent growth modulatory MC products, and increasing evidence of MC involvement in hyperproliferative and fibrotic disorders suggest that tissue remodelling may be one of those, namely in the skin. Here, we delineate why this may best be studied by analysing the potential role of MC in hair growth regulation. On the background of numerous, yet widely under-appreciated hints from the older literature, we summarize and discuss our recent observations from the C57BL/6 mouse model for hair research which support the concept that MC are functionally important modulators of hair follicle cycling, specifically during anagen development. This invites to exploit the murine hair cycle as a model for dissecting the physiological growth modulatory functions of MC and encourages the exploration of MC-targeting pharmaceutical strategies for the treatment of hair growth disorders.

  20. Follicle-stimulating hormone increases bone mass in female mice.

    Science.gov (United States)

    Allan, Charles M; Kalak, Robert; Dunstan, Colin R; McTavish, Kirsten J; Zhou, Hong; Handelsman, David J; Seibel, Markus J

    2010-12-28

    Elevated follicle-stimulating hormone (FSH) activity is proposed to directly cause bone loss independent of estradiol deficiency in aging women. Using transgenic female mice expressing human FSH (TgFSH), we now reveal that TgFSH dose-dependently increased bone mass, markedly elevating tibial and vertebral trabecular bone volume. Furthermore, TgFSH stimulated a striking accrual of bone mass in hypogonadal mice lacking endogenous FSH and luteinizing hormone (LH) function, showing that FSH-induced bone mass occurred independently of background LH or estradiol levels. Higher TgFSH levels increased osteoblast surfaces in trabecular bone and stimulated de novo bone formation, filling marrow spaces with woven rather than lamellar bone, reflective of a strong anabolic stimulus. Trabecular bone volume correlated positively with ovarian-derived serum inhibin A or testosterone levels in TgFSH mice, and ovariectomy abolished TgFSH-induced bone formation, proving that FSH effects on bone require an ovary-dependent pathway. No detectable FSH receptor mRNA in mouse bone or cultured osteoblasts or osteoclasts indicated that FSH did not directly stimulate bone. Therefore, contrary to proposed FSH-induced bone loss, our findings demonstrate that FSH has dose-dependent anabolic effects on bone via an ovary-dependent mechanism, which is independent of LH activity, and does not involve direct FSH actions on bone cells.

  1. Hair follicle stem cells: In vitro and in vivo neuraldifferentiation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hair follicle stem cells (HFSCs) normally give rise tokeratinocytes, sebocytes, and transient amplifyingprogenitor cells. Along with the capacity to proliferaterapidly, HFSCs provide the basis for establishing aputative source of stem cells for cell therapy. HFSCs aremultipotent stem cells originating from the bulge area.The importance of these cells arises from two importantcharacteristics, distinguishing them from all other adultstem cells. First, they are accessible and proliferate forlong periods. Second, they are multipotent, possessingthe ability to differentiate into mesodermal andectodermal cell types. In addition to a developmentalcapacity in vitro , HFSCs display an ability to formdifferentiated cells in vivo . During the last two decades,numerous studies have led to the development of anappropriate culture condition for producing various celllineages from HFSCs. Therefore, these stem cells areconsidered as a novel source for cell therapy of a broadspectrum of neurodegenerative disorders. This reviewpresents the current status of human, rat, and mouseHFSCs from both the cellular and molecular biologyand cell therapy perspectives. The first section of thisreview highlights the importance of HFSCs and in vitrodifferentiation, while the final section emphasizes thesignificance of cell differentiation in vivo .

  2. Characterization of hair follicle development in engineered skin substitutes.

    Directory of Open Access Journals (Sweden)

    Penkanok Sriwiriyanont

    Full Text Available Generation of skin appendages in engineered skin substitutes has been limited by lack of trichogenic potency in cultured postnatal cells. To investigate the feasibility and the limitation of hair regeneration, engineered skin substitutes were prepared with chimeric populations of cultured human keratinocytes from neonatal foreskins and cultured murine dermal papilla cells from adult GFP transgenic mice and grafted orthotopically to full-thickness wounds on athymic mice. Non-cultured dissociated neonatal murine-only skin cells, or cultured human-only skin keratinocytes and fibroblasts without dermal papilla cells served as positive and negative controls respectively. In this study, neonatal murine-only skin substitutes formed external hairs and sebaceous glands, chimeric skin substitutes formed pigmented hairs without sebaceous glands, and human-only skin substitutes formed no follicles or glands. Although chimeric hair cannot erupt readily, removal of upper skin layer exposed keratinized hair shafts at the skin surface. Development of incomplete pilosebaceous units in chimeric hair corresponded with upregulation of hair-related genes, LEF1 and WNT10B, and downregulation of a marker of sebaceous glands, Steroyl-CoA desaturase. Transepidermal water loss was normal in all conditions. This study demonstrated that while sebaceous glands may be involved in hair eruption, they are not required for hair development in engineered skin substitutes.

  3. A Guide to Studying Human Hair Follicle Cycling In Vivo.

    Science.gov (United States)

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan; Kim, Moonkyu; Paus, Ralf; Plikus, Maksim V

    2016-01-01

    Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. Although available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. In this article, we present such a guide, which uses objective, well-defined, and reproducible criteria, and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in suboptimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field.

  4. Reconfigurable thz polarizer

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention provides a polarizer. The polarizer comprises a first membrane having a first polarization region comprising a first plurality of membrane perforations; a second membrane having a second polarization region comprising a second plurality of membrane perforations; and a support...... with one or more membrane perforations in the second plurality of perforations in a direction normal to the first polarization region or normal to the second polarization region, resulting in corresponding one or more openings in said direction....

  5. Promoting extracellular matrix remodeling via ascorbic acid enhances the survival of primary ovarian follicles encapsulated in alginate hydrogels.

    Science.gov (United States)

    Tagler, David; Makanji, Yogeshwar; Tu, Tao; Bernabé, Beatriz Peñalver; Lee, Raymond; Zhu, Jie; Kniazeva, Ekaterina; Hornick, Jessica E; Woodruff, Teresa K; Shea, Lonnie D

    2014-07-01

    The in vitro growth of ovarian follicles is an emerging technology for fertility preservation. Various strategies support the culture of secondary and multilayer follicles from various species including mice, non-human primate, and human; however, the culture of early stage (primary and primordial) follicles, which are more abundant in the ovary and survive cryopreservation, has been limited. Hydrogel-encapsulating follicle culture systems that employed feeder cells, such as mouse embryonic fibroblasts (MEFs), stimulated the growth of primary follicles (70-80 µm); yet, survival was low and smaller follicles (structure and degenerated. These morphologic changes were associated with a breakdown of the follicular basement membrane; hence, this study investigated ascorbic acid based on its role in extracellular matrix (ECM) deposition/remodeling for other applications. The selection of ascorbic acid was further supported by a microarray analysis that suggested a decrease in mRNA levels of enzymes within the ascorbate pathway between primordial, primary, and secondary follicles. The supplementation of ascorbic acid (50 µg/mL) significantly enhanced the survival of primary follicles (alginate hydrogels, which coincided with improved structural integrity. Follicles developed antral cavities and increased to diameters exceeding 250 µm. Consistent with improved structural integrity, the gene/protein expression of ECM and cell adhesion molecules was significantly changed. This research supports the notion that modifying the culture environment (medium components) can substantially enhance the survival and growth of early stage follicles. © 2013 Wiley Periodicals, Inc.

  6. Progress in understanding the Drosophila dnc locus.

    Science.gov (United States)

    Nighorn, A; Qiu, Y; Davis, R L

    1994-05-01

    The genetic dissection of learning and memory in Drosophila is two decades old. Recently, a great deal of progress has been made towards isolating new mutants as well as towards a better understanding of the originally isolated ones. This paper reviews the recent developments in the understanding of the structure and function of the gene identified by the first and best-characterized of these mutants, the Drosophila dunce mutant.

  7. Modeling tumor invasion and metastasis in Drosophila

    OpenAIRE

    2011-01-01

    Conservation of major signaling pathways between humans and flies has made Drosophila a useful model organism for cancer research. Our understanding of the mechanisms regulating cell growth, differentiation and development has been considerably advanced by studies in Drosophila. Several recent high profile studies have examined the processes constraining the metastatic growth of tumor cells in fruit fly models. Cell invasion can be studied in the context of an in vivo setting in flies, enabli...

  8. Prostaglandin E2 (EP) receptors mediate PGE2-specific events in ovulation and luteinization within primate ovarian follicles.

    Science.gov (United States)

    Kim, Soon Ok; Harris, Siabhon M; Duffy, Diane M

    2014-04-01

    Prostaglandin E2 (PGE2) is a key mediator of ovulation. All 4 PGE2 receptors (EP receptors) are expressed in the primate follicle, but the specific role of each EP receptor in ovulatory events is poorly understood. To examine the ovulatory events mediated via these EP receptors, preovulatory monkey follicles were injected with vehicle, the PG synthesis inhibitor indomethacin, or indomethacin plus PGE2. An ovulatory dose of human chorionic gonadotropin was administered; the injected ovary was collected 48 hours later and serially sectioned. Vehicle-injected follicles showed normal ovulatory events, including follicle rupture, absence of an oocyte, and thickening of the granulosa cell layer. Indomethacin-injected follicles did not rupture and contained oocytes surrounded by unexpanded cumulus; granulosa cell hypertrophy did not occur. Follicles injected with indomethacin plus PGE2 were similar to vehicle-injected ovaries, indicating that PGE2 restored the ovulatory changes inhibited by indomethacin. Additional follicles were injected with indomethacin plus an agonist for each EP receptor. EP1, EP2, and EP4 agonists each promoted aspects of follicle rupture, but no single EP agonist recapitulated normal follicle rupture as seen in follicles injected with either vehicle or indomethacin plus PGE2. Although EP4 agonist-injected follicles contained oocytes in unexpanded cumulus, the absence of oocytes in EP1 agonist- and EP2 agonist-injected follicles suggests that these EP receptors promote cumulus expansion. Surprisingly, the EP3 agonist did not stimulate any of these ovulatory changes, despite the high level of EP3 receptor expression in the monkey follicle. Therefore, agonists and antagonists selective for EP1 and EP2 receptors hold the most promise for control of ovulatory events in women.

  9. The Role of AMPK in Drosophila melanogaster.

    Science.gov (United States)

    Sinnett, Sarah E; Brenman, Jay E

    2016-01-01

    In the fruit fly, Drosophila melanogaster, mono-allelic expression of AMPK-α, -β, and -γ yields a single heterotrimeric energy sensor that regulates cellular and whole-body energetic homeostasis. The genetic simplicity of Drosophila, with only a single gene for each subunit, makes the fruit fly an appealing organism for elucidating the effects of AMPK mutations on signaling pathways and phenotypes. In addition, Drosophila presents researchers with an opportunity to use straightforward genetic approaches to elucidate metabolic signaling pathways that contain a level of complexity similar to that observed in mammalian pathways. Just as in mammals, however, the regulatory realm of AMPK function extends beyond metabolic rates and lipid metabolism. Indeed, experiments using Drosophila have shown that AMPK may exert protective effects with regard to life span and neurodegeneration. This chapter addresses a few of the research areas in which Drosophila has been used to elucidate the physiological functions of AMPK. In doing so, this chapter provides a primer for basic Drosophila nomenclature, thereby eliminating a communication barrier that persists for AMPK researchers trained in mammalian genetics.

  10. Characterization of Autophagic Responses in Drosophila melanogaster.

    Science.gov (United States)

    Xu, T; Kumar, S; Denton, D

    2017-01-01

    Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed. © 2017 Elsevier Inc. All rights reserved.

  11. A Drosophila Model for Screening Antiobesity Agents

    Directory of Open Access Journals (Sweden)

    Tran Thanh Men

    2016-01-01

    Full Text Available Although triacylglycerol, the major component for lipid storage, is essential for normal physiology, its excessive accumulation causes obesity in adipose tissue and is associated with organ dysfunction in nonadipose tissue. Here, we focused on the Drosophila model to develop therapeutics for preventing obesity. The brummer (bmm gene in Drosophila melanogaster is known to be homologous with human adipocyte triglyceride lipase, which is related to the regulation of lipid storage. We established a Drosophila model for monitoring bmm expression by introducing the green fluorescent protein (GFP gene as a downstream reporter of the bmm promoter. The third-instar larvae of Drosophila showed the GFP signal in all tissues observed and specifically in the salivary gland nucleus. To confirm the relationship between bmm expression and obesity, the effect of oral administration of glucose diets on bmm promoter activity was analyzed. The Drosophila flies given high-glucose diets showed higher lipid contents, indicating the obesity phenotype; this was suggested by a weaker intensity of the GFP signal as well as reduced bmm mRNA expression. These results demonstrated that the transgenic Drosophila model established in this study is useful for screening antiobesity agents. We also report the effects of oral administration of histone deacetylase inhibitors and some vegetables on the bmm promoter activity.

  12. Capu and Spire Assemble a Cytoplasmic Actin Mesh that Maintains Microtubule Organization in the Drosophila Oocyte

    OpenAIRE

    Dahlgaard, Katja; Alexandre A.S.F. Raposo; Niccoli, Teresa; St Johnston, Daniel

    2007-01-01

    Summary Mutants in the actin nucleators Cappuccino and Spire disrupt the polarized microtubule network in the Drosophila oocyte that defines the anterior-posterior axis, suggesting that microtubule organization depends on actin. Here, we show that Cappuccino and Spire organize an isotropic mesh of actin filaments in the oocyte cytoplasm. capu and spire mutants lack this mesh, whereas overexpressed truncated Cappuccino stabilizes the mesh in the presence of Latrunculin A and partially rescues ...

  13. Planar cell polarity genes, Celsr1-3, in neural development.

    Science.gov (United States)

    Feng, Jia; Han, Qi; Zhou, Libing

    2012-06-01

    flamingo is among the 'core' planar cell-polarity genes, protein of which belongs to a unique cadherin subfamily. In contrast to the classic cadherins, composed of several extracellular cadherin repeats, one transmembrane domain and one cytoplasmic segment linked to catenin binding, Drosophila Flamingo has seven transmembrane segments and a cytoplasmic tail with no catenin-binding sequence. In Drosophila, Flamingo has pleotropic roles in controlling epithelial polarity and neuronal morphogenesis. Three mammalian orthologs of flamingo, Celsr1-3, are widely expressed in the nervous system. Recent work has shown that Celsr1-3 play important roles in neural development, such as in axon guidance, neuronal migration, and cilium polarity. Celsr1-3 single-gene knockout mice exhibit different phenotypes, but there are cooperative interactions among these genes.

  14. Planar cell polarity genes, Celsr1-3, in neural development

    Institute of Scientific and Technical Information of China (English)

    Jia Feng; Qi Han; Libing Zhou

    2012-01-01

    flamingo is among the ‘core' planar cell-polarity genes,protein of which belongs to a unique cadherin subfamily.In contrast to the classic cadherins,composed of several cxtracellular cadhcrin repcats,one transmembrane domain and one cytoplasmic segment linked to catenin binding,Drosophila Flamingo has seven transmembrane segments and a cytoplasmic tail with no catenin-binding sequence.In Drosophila,Flamingo has pleotropic roles in controlling epithelial polarity and neuronal morphogenesis.Three mammalian orthologs of flamingo,Celsr1-3,are widely expressed in the nervous system.Recent work has shown that Celsr1-3 play important roles in neural development,such as in axon guidance,neuronal migration,and cilium polarity.Celsr1-3 single-gene knockout mice exhibit different phenotypes,but there are cooperative interactions among these genes.

  15. Spotted wing drosophila, Drosophila suzukii (Matsumura)(Diptera: drosophilidae), trapped with combinations of wines and vinegars

    Science.gov (United States)

    Field trapping experiments evaluated wine and vinegar baits for spotted wing drosophila flies, Drosophila suzukii (Matsumura), and assessed variance in biat attractiveness with wit type, vinegar type, and bait age. A mixture of apple cider vinegar and a Merlot wine attracted more flies than a mixtur...

  16. Molecular neurobiology of Drosophila taste.

    Science.gov (United States)

    Freeman, Erica Gene; Dahanukar, Anupama

    2015-10-01

    Drosophila is a powerful model in which to study the molecular and cellular basis of taste coding. Flies sense tastants via populations of taste neurons that are activated by compounds of distinct categories. The past few years have borne witness to studies that define the properties of taste neurons, identifying functionally distinct classes of sweet and bitter taste neurons that express unique subsets of gustatory receptor (Gr) genes, as well as water, salt, and pheromone sensing neurons that express members of the pickpocket (ppk) or ionotropic receptor (Ir) families. There has also been significant progress in terms of understanding how tastant information is processed and conveyed to higher brain centers, and modulated by prior dietary experience or starvation.

  17. Hydrogel Based 3-Dimensional (3D System for Toxicity and High-Throughput (HTP Analysis for Cultured Murine Ovarian Follicles.

    Directory of Open Access Journals (Sweden)

    Hong Zhou

    Full Text Available Various toxicants, drugs and their metabolites carry potential ovarian toxicity. Ovarian follicles, the functional unit of the ovary, are susceptible to this type of damage at all stages of their development. However, despite of the large scale of potential negative impacts, assays that study ovarian toxicity are limited. Exposure of cultured ovarian follicles to toxicants of interest served as an important tool for evaluation of toxic effects for decades. Mouse follicles cultured on the bottom of a culture dish continue to serve an important approach for mechanistic studies. In this paper, we demonstrated the usefulness of a hydrogel based 3-dimensional (3D mouse ovarian follicle culture as a tool to study ovarian toxicity in a different setup. The 3D in vitro culture, based on fibrin alginate interpenetrating network (FA-IPN, preserves the architecture of the ovarian follicle and physiological structure-function relationship. We applied the novel 3D high-throughput (HTP in vitro ovarian follicle culture system to study the ovotoxic effects of an anti-cancer drug, Doxorobucin (DXR. The fibrin component in the system is degraded by plasmin and appears as a clear circle around the encapsulated follicle. The degradation area of the follicle is strongly correlated with follicle survival and growth. To analyze fibrin degradation in a high throughput manner, we created a custom MATLAB® code that converts brightfield micrographs of follicles encapsulated in FA-IPN to binary images, followed by image analysis. We did not observe any significant difference between manually processed images to the automated MATLAB® method, thereby confirming that the automated program is suitable to measure fibrin degradation to evaluate follicle health. The cultured follicles were treated with DXR at concentrations ranging from 0.005 nM to 200 nM, corresponding to the therapeutic plasma levels of DXR in patients. Follicles treated with DXR demonstrated decreased

  18. Hydrogel Based 3-Dimensional (3D) System for Toxicity and High-Throughput (HTP) Analysis for Cultured Murine Ovarian Follicles.

    Science.gov (United States)

    Zhou, Hong; Malik, Malika Amattullah; Arab, Aarthi; Hill, Matthew Thomas; Shikanov, Ariella

    2015-01-01

    Various toxicants, drugs and their metabolites carry potential ovarian toxicity. Ovarian follicles, the functional unit of the ovary, are susceptible to this type of damage at all stages of their development. However, despite of the large scale of potential negative impacts, assays that study ovarian toxicity are limited. Exposure of cultured ovarian follicles to toxicants of interest served as an important tool for evaluation of toxic effects for decades. Mouse follicles cultured on the bottom of a culture dish continue to serve an important approach for mechanistic studies. In this paper, we demonstrated the usefulness of a hydrogel based 3-dimensional (3D) mouse ovarian follicle culture as a tool to study ovarian toxicity in a different setup. The 3D in vitro culture, based on fibrin alginate interpenetrating network (FA-IPN), preserves the architecture of the ovarian follicle and physiological structure-function relationship. We applied the novel 3D high-throughput (HTP) in vitro ovarian follicle culture system to study the ovotoxic effects of an anti-cancer drug, Doxorobucin (DXR). The fibrin component in the system is degraded by plasmin and appears as a clear circle around the encapsulated follicle. The degradation area of the follicle is strongly correlated with follicle survival and growth. To analyze fibrin degradation in a high throughput manner, we created a custom MATLAB® code that converts brightfield micrographs of follicles encapsulated in FA-IPN to binary images, followed by image analysis. We did not observe any significant difference between manually processed images to the automated MATLAB® method, thereby confirming that the automated program is suitable to measure fibrin degradation to evaluate follicle health. The cultured follicles were treated with DXR at concentrations ranging from 0.005 nM to 200 nM, corresponding to the therapeutic plasma levels of DXR in patients. Follicles treated with DXR demonstrated decreased survival rate in

  19. Effect of sequential medium with fibroblast growth factor-10 and follicle stimulating hormone on in vitro development of goat preantral follicles.

    Science.gov (United States)

    Almeida, A P; Magalhães-Padilha, D M; Araújo, V R; Costa, S L; Chaves, R N; Lopes, C A P; Donato, M A M; Peixoto, C A; Campello, C C; Junior, J Buratini; Figueiredo, J R

    2015-01-01

    A sequential medium with fibroblast growth factor-10 (FGF-10) and follicle stimulating hormone (FSH) was evaluated on the survival, ultrastructure, activation and growth rate of caprine preantral follicles submitted to long-term culture, aiming to establish an ideal in vitro culture system. Ovarian fragments were cultured for 16 days in α-MEM(+) alone or supplemented with FGF-10 and/or FSH added sequentially on different days of culture. Ovarian fragments were cultured during the first (days 0-8) and second (days 8-16) halves of the culture period, generating 10 treatments: α-MEM(+)/α-MEM(+) (cultured control), FSH/FSH, FSH/FGF-10, FSH/FSH+FGF-10, FGF-10/FGF-10, FGF-10/FSH, FGF-10/FSH+FGF-10, FSH+FGF-10/FSH+FGF-10, FSH+FGF-10/FSH and FSH+FGF-10/FGF-10. Follicle morphology, viability and ultrastructure were analyzed. The FSH/FGF-10 treatment showed a higher (Pgrowth in goat preantral follicles cultured in vitro.

  20. A three-tiered mechanism for regulation of planar cell polarity.

    Science.gov (United States)

    Tree, David R P; Ma, Dali; Axelrod, Jeffrey D

    2002-06-01

    Some epithelial cells are polarized along an axis orthogonal to their apical-basal axes. Recent studies in Drosophila lead to the view that three classes of signaling molecules govern the planar cell polarity (PCP) pathway. The first class, or module, functions across whole tissues, providing directional information to individual cells. The second module, apparently shared by all planar polarized tissues, and related to the canonical Wnt signaling pathway, interprets the directional signal to produce subcellular asymmetries. The third modules are tissue specific, acting to translate subcellular asymmetry into the appropriate morphological manifestations in the different cell types.

  1. BRCA-1 Gene Expression and Comparative Proteomic Profile of Primordial Follicles from Young and Adult Buffalo (Bubalus bubalis) Ovaries.

    Science.gov (United States)

    Govindaraj, Vijayakumar; Krishnagiri, Harshini; Chauhan, Manmohan Singh; Rao, A J

    2017-04-03

    In our previous study, we demonstrated that the repair efficiency of DNA double-strand breaks declines with increasing age in rat primordial follicles. In the present study, we extended our studies to buffalo (Bubalus bubalis) wherein we studied the expression of BRCA-1 related DNA repair genes in primordial follicles of young (12 months-22 months) and adult (72-96 months) buffaloes. The relative expression of selected genes, as determined by RT-PCR, revealed a significant (p primordial follicles as compared to the young. Western blot analysis revealed a significant (p primordial follicles. The protein expression profile of young and adult buffalo primordial follicles revealed differential expression of proteins involved in mitochondrial function, cell survival and cell metabolism. Similar to reports from aging rodent and human primordial follicles, our findings support the fact that impairment of DNA repair may be an universal mechanism involved in oocyte aging.

  2. Analysis of the penetration of a caffeine containing shampoo into the hair follicles by in vivo laser scanning microscopy

    Science.gov (United States)

    Lademann, J.; Richter, H.; Schanzer, S.; Klenk, A.; Sterry, W.; Patzelt, A.

    2010-02-01

    In previous in vitro investigations, it was demonstrated that caffeine is able to stimulate the hair growth. Therefore, a penetration of caffeine into the hair follicle is necessary. In the present study, in vivo laser scanning microscopy (LSM) was used to investigate the penetration and storage of a caffeine containing shampoo into the hair follicles. It was shown that a 2-min contact time of the shampoo with the skin was enough to accumulate significant parts of the shampoo in the hair follicles. A penetration of the shampoo up to a depth of approx. 200 μm could be detected, which represents the detection limit of the LSM. At this depth, the close network of the blood capillaries surrounding the hair follicles commences. Even after 24 h, the substance was still detectable in the hair follicles. This demonstrates the long-term reservoir function of the hair follicles for topically applied substances such as caffeine.

  3. Gonadotropin-releasing hormone, estradiol, and inhibin regulation of follicle-stimulating hormone and luteinizing hormone surges: implications for follicle emergence and selection in heifers.

    Science.gov (United States)

    Haughian, James M; Ginther, O J; Diaz, Francisco J; Wiltbank, Milo C

    2013-06-01

    Mechanisms regulating gonadotropin surges and gonadotropin requirements for follicle emergence and selection were studied in heifers. Experiment 1 evaluated whether follicular inhibins regulate the preovulatory luteinizing hormone (LH)/follicle-stimulating hormone (FSH) surges elicited by gonadotropin-releasing hormone (GnRH) injection (Hour = 0) and the subsequent periovulatory FSH surge. Treatments included control (n = 6), steroid-depleted bovine follicular fluid (bFF) at Hour -4 (n = 6), and bFF at Hour 6 (n = 6). Gonadotropins in blood were assessed hourly from Hours -6 to 36, and follicle growth tracked by ultrasound. Consistent with inhibin independence, bFF at Hour -4 did not impact the GnRH-induced preovulatory FSH surge, whereas treatment at Hour 6 delayed onset of the periovulatory FSH surge and impeded growth of a new follicular wave. Experiment 2 examined GnRH and estradiol (E2) regulation of the periovulatory FSH surge. Treatment groups were control (n = 8), GnRH-receptor antagonist (GnRHr-ant, n = 8), and E2 + GnRHr-ant (n = 4). GnRHr-ant (acyline) did not reduce the concentrations of FSH during the periovulatory surge and early follicle development (8.0 mm) was prevented by GnRHr-ant. Addition of E2 delayed both the onset of the periovulatory FSH surge and emergence of a follicular wave. Failure to select a dominant follicle in the GnRHr-ant group was associated with reduced concentrations of LH but not FSH. Maximum diameter of F1 in controls (13.3 ± 0.5 mm) was greater than in both GnRHr-ant (7.7 ± 0.3 mm) and E2 + GnRHr-ant (6.7 ± 0.8 mm) groups. Results indicated that the periovulatory FSH surge stems from removal of negative stimuli (follicular E2 and inhibin), but is independent of GnRH stimulation. Emergence and early growth of follicles (until about 8 mm) requires the periovulatory FSH surge but not LH pulses. However, follicular deviation and late-stage growth of a single dominant follicle requires GnRH-dependent LH pulses.

  4. Drosophila sosie functions with βH-Spectrin and actin organizers in cell migration, epithelial morphogenesis and cortical stability

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    Olivier Urwyler

    2012-08-01

    Morphogenesis in multicellular organisms requires the careful coordination of cytoskeletal elements, dynamic regulation of cell adhesion and extensive cell migration. sosie (sie is a novel gene required in various morphogenesis processes in Drosophila oogenesis. Lack of sie interferes with normal egg chamber packaging, maintenance of epithelial integrity and control of follicle cell migration, indicating that sie is involved in controlling epithelial integrity and cell migration. For these functions sie is required both in the germ line and in the soma. Consistent with this, Sosie localizes to plasma membranes in the germ line and in the somatic follicle cells and is predicted to present an EGF-like domain on the extracellular side. Two positively charged residues, C-terminal to the predicted transmembrane domain (on the cytoplasmic side, are required for normal plasma membrane localization of Sosie. Because sie also contributes to normal cortical localization of βH-Spectrin, it appears that cortical βH-Spectrin mediates some of the functions of sosie. sie also interacts with the genes coding for the actin organizers Filamin and Profilin and, in the absence of sie function, F-actin is less well organized and nurse cells frequently fuse.

  5. Inkjet printing of viable human dental follicle stem cells

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    Mau Robert

    2015-09-01

    Full Text Available Inkjet printing technology has the potential to be used for seeding of viable cells for tissue engineering approaches. For this reason, a piezoelectrically actuated, drop-on-demand inkjet printing system was applied to deliver viable human dental follicle stem cells (hDFSC of sizes of about 15 μm up to 20 μm in diameter. The purpose of these investigations was to verify the stability of the printing process and to evaluate cell viability post printing. Using a Nanoplotter 2.1 (Gesim, Germany equipped with the piezoelectric printhead NanoTip HV (Gesim, Germany, a concentration of 6.6 ×106 cells ml−1 in DMEM with 10% fetal calf serum (FCS could be dispensed. The piezoelectric printhead has a nominal droplet volume of ~ 400 pl and was set to a voltage of 75 V and a pulse of 50 μs while dosing 50 000 droplets over a time of 100 seconds. The volume and trajectory of the droplet were checked by a stroboscope test right before and after the printing process. It was found that the droplet volume decreases significantly by 35% during printing process, while the trajectory of the droplets remains stable with only an insignificant number of degrees deviation from the vertical line. It is highly probable that some cell sedimentations or agglomerations affect the printing performance. The cell viability post printing was assessed by using the Trypan Blue dye exclusion test. The printing process was found to have no significant influence on cell survival. In conclusion, drop-on-demand inkjet printing can be a potent tool for the seeding of viable cells.

  6. Protease activity, localization and inhibition in the human hair follicle.

    Science.gov (United States)

    Bhogal, R K; Mouser, P E; Higgins, C A; Turner, G A

    2014-02-01

    In humans, the process of hair shedding, referred to as exogen, is believed to occur independently of the other hair cycle phases. Although the actual mechanisms involved in hair shedding are not fully known, it has been hypothesized that the processes leading to the final step of hair shedding may be driven by proteases and/or protease inhibitor activity. In this study, we investigated the presence of proteases and protease activity in naturally shed human hairs and assessed enzyme inhibition activity of test materials. We measured enzyme activity using a fluorescence-based assay and protein localization by indirect immunohistochemistry (IHC). We also developed an ex vivo skin model for measuring the force required to pull hair fibres from skin. Our data demonstrate the presence of protease activity in the tissue material surrounding club roots. We also demonstrated the localization of specific serine protease protein expression in human hair follicle by IHC. These data provide evidence demonstrating the presence of proteases around the hair club roots, which may play a role during exogen. We further tested the hypothesis that a novel protease inhibitor system (combination of Trichogen) and climbazole) could inhibit protease activity in hair fibre club root extracts collected from a range of ethnic groups (U.K., Brazil, China, first-generation Mexicans in the U.S.A., Thailand and Turkey) in both males and females. Furthermore, we demonstrated that this combination is capable of increasing the force required to remove hair in an ex vivo skin model system. These studies indicate the presence of proteolytic activity in the tissue surrounding the human hair club root and show that it is possible to inhibit this activity with a combination of Trichogen and climbazole. This technology may have potential to reduce excessive hair shedding. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  7. Gene Networks Underlying Chronic Sleep Deprivation in Drosophila

    Science.gov (United States)

    2014-06-15

    SECURITY CLASSIFICATION OF: Studies of the gene network affected by sleep deprivation and stress in the fruit fly Drosophila have revealed the...15-Apr-2009 14-Apr-2013 Approved for Public Release; Distribution Unlimited Gene Networks Underlying Chronic Sleep Deprivation in Drosophila The...Chronic Sleep Deprivation in Drosophila Report Title Studies of the gene network affected by sleep deprivation and stress in the fruit fly Drosophila have

  8. The Drosophila homologue of the amyloid precursor protein is a conserved modulator of Wnt PCP signaling.

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    Alessia Soldano

    Full Text Available Wnt Planar Cell Polarity (PCP signaling is a universal regulator of polarity in epithelial cells, but it regulates axon outgrowth in neurons, suggesting the existence of axonal modulators of Wnt-PCP activity. The Amyloid precursor proteins (APPs are intensely investigated because of their link to Alzheimer's disease (AD. APP's in vivo function in the brain and the mechanisms underlying it remain unclear and controversial. Drosophila possesses a single APP homologue called APP Like, or APPL. APPL is expressed in all neurons throughout development, but has no established function in neuronal development. We therefore investigated the role of Drosophila APPL during brain development. We find that APPL is involved in the development of the Mushroom Body αβ neurons and, in particular, is required cell-autonomously for the β-axons and non-cell autonomously for the α-axons growth. Moreover, we find that APPL is a modulator of the Wnt-PCP pathway required for axonal outgrowth, but not cell polarity. Molecularly, both human APP and fly APPL form complexes with PCP receptors, thus suggesting that APPs are part of the membrane protein complex upstream of PCP signaling. Moreover, we show that APPL regulates PCP pathway activation by modulating the phosphorylation of the Wnt adaptor protein Dishevelled (Dsh by Abelson kinase (Abl. Taken together our data suggest that APPL is the first example of a modulator of the Wnt-PCP pathway specifically required for axon outgrowth.

  9. The Drosophila homologue of the amyloid precursor protein is a conserved modulator of Wnt PCP signaling.

    Science.gov (United States)

    Soldano, Alessia; Okray, Zeynep; Janovska, Pavlina; Tmejová, Kateřina; Reynaud, Elodie; Claeys, Annelies; Yan, Jiekun; Atak, Zeynep Kalender; De Strooper, Bart; Dura, Jean-Maurice; Bryja, Vítězslav; Hassan, Bassem A

    2013-01-01

    Wnt Planar Cell Polarity (PCP) signaling is a universal regulator of polarity in epithelial cells, but it regulates axon outgrowth in neurons, suggesting the existence of axonal modulators of Wnt-PCP activity. The Amyloid precursor proteins (APPs) are intensely investigated because of their link to Alzheimer's disease (AD). APP's in vivo function in the brain and the mechanisms underlying it remain unclear and controversial. Drosophila possesses a single APP homologue called APP Like, or APPL. APPL is expressed in all neurons throughout development, but has no established function in neuronal development. We therefore investigated the role of Drosophila APPL during brain development. We find that APPL is involved in the development of the Mushroom Body αβ neurons and, in particular, is required cell-autonomously for the β-axons and non-cell autonomously for the α-axons growth. Moreover, we find that APPL is a modulator of the Wnt-PCP pathway required for axonal outgrowth, but not cell polarity. Molecularly, both human APP and fly APPL form complexes with PCP receptors, thus suggesting that APPs are part of the membrane protein complex upstream of PCP signaling. Moreover, we show that APPL regulates PCP pathway activation by modulating the phosphorylation of the Wnt adaptor protein Dishevelled (Dsh) by Abelson kinase (Abl). Taken together our data suggest that APPL is the first example of a modulator of the Wnt-PCP pathway specifically required for axon outgrowth.

  10. Somatic cells initiate primordial follicle activation and govern the development of dormant oocytes in mice.

    Science.gov (United States)

    Zhang, Hua; Risal, Sanjiv; Gorre, Nagaraju; Busayavalasa, Kiran; Li, Xin; Shen, Yan; Bosbach, Benedikt; Brännström, Mats; Liu, Kui

    2014-11-03

    The majority of oocytes in the mammalian ovary are dormant oocytes that are enclosed in primordial follicles by several somatic cells, which we refer to as primordial follicle granulosa cells (pfGCs). Very little is known, however, about how the pfGCs control the activation of primordial follicles and the developmental fates of dormant oocytes. By targeting molecules in pfGCs with several mutant mouse models, we demonstrate that the somatic pfGCs initiate the activation of primordial follicles and govern the quiescence or awakening of dormant oocytes. Inhibition of mTORC1 signaling in pfGCs prevents the differentiation of pfGCs into granulosa cells, and this arrests the dormant oocytes in their quiescent states, leading to oocyte death. Overactivation of mTORC1 signaling in pfGCs accelerates the differentiation of pfGCs into granulosa cells and causes premature activation of all dormant oocytes and primordial follicles. We further show that pfGCs trigger the awakening of dormant oocytes through KIT ligand (KITL), and we present an essential communication network between the somatic cells and germ cells that is based on signaling between the mTORC1-KITL cascade in pfGCs and KIT-PI3K signaling in oocytes. Our findings provide a relatively complete picture of how mammalian primordial follicles are activated. The microenvironment surrounding primordial follicles can activate mTORC1-KITL signaling in pfGCs, and these cells trigger the awakening of dormant oocytes and complete the process of follicular activation. Such communication between the microenvironment, somatic cells, and germ cells is essential to maintaining the proper reproductive lifespan in mammals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Wnt5a attenuates Wnt3a-induced alkaline phosphatase expression in dental follicle cells

    Energy Technology Data Exchange (ETDEWEB)

    Sakisaka, Yukihiko [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tsuchiya, Masahiro [Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tohoku Fukushi University, Sendai 989-3201 (Japan); Nakamura, Takashi [Department of Pediatric Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Liason Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tamura, Masato [Department of Biochemistry and Molecular Biology, Hokkaido University Graduate School of Dentistry, Sapporo 060-8586 (Japan); Shimauchi, Hidetoshi [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Nemoto, Eiji, E-mail: e-nemoto@dent.tohoku.ac.jp [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan)

    2015-08-01

    Wnt signaling regulates multiple cellular events such as cell proliferation, differentiation, and apoptosis through β-catenin-dependent canonical and β-catenin-independent noncanonical pathways. Canonical Wnt/β-catenin signaling can promote the differentiation of dental follicle cells, putative progenitor cells for cementoblasts, osteoblasts, and periodontal ligament cells, toward a cementoblast/osteoblast phenotype during root formation, but little is known about the biological significance of noncanonical Wnt signaling in this process. We identified the expression of Wnt5a, a representative noncanonical Wnt ligand, in tooth root lining cells (i.e. precementoblasts/cementoblasts) and dental follicle cells during mouse tooth root development, as assessed by immunohistochemistry. Silencing expression of the Wnt5a gene in a dental follicle cell line resulted in enhancement of the Wnt3a (a representative canonical Wnt ligand)-mediated increase in alkaline phosphatase (ALP) expression. Conversely, treatment with recombinant Wnt5a inhibited the increase in ALP expression, suggesting that Wnt5a signaling functions as a negative regulator of canonical Wnt-mediated ALP expression of dental follicle cells. Wnt5a did not affect the nuclear translocation of β-catenin as well as β-catenin-mediated transcriptional activation of T-cell factor (Tcf) triggered by Wnt3a, suggesting that Wnt5a inhibits the downstream part of the β-catenin-Tcf pathway. These findings suggest the existence of a feedback mechanism between canonical and noncanonical Wnt signaling during the differentiation of dental follicle cells. - Highlights: • Dental follicle cells express Wnt5a during tooth root development. • Silencing of Wnt5a enhances Wnt3a-mediated ALP expression of dental follicle cells. • Conversely, treatment with rWnt5a inhibited the increase in ALP expression. • Wnt5a functions as a negative regulator of Wnt3a-mediated ALP expression.

  12. Methoxychlor inhibits growth and induces atresia of antral follicles through an oxidative stress pathway.

    Science.gov (United States)

    Gupta, Rupesh K; Miller, Kimberly P; Babus, Janice K; Flaws, Jodi A

    2006-10-01

    The mammalian ovary contains antral follicles, which are responsible for the synthesis and secretion of hormones that regulate estrous cyclicity and fertility. The organochlorine pesticide methoxychlor (MXC) causes atresia (follicle death via apoptosis) of antral follicles, but little is known about the mechanisms by which MXC does so. Oxidative stress is known to cause apoptosis in nonreproductive and reproductive tissues. Thus, we tested the hypothesis that MXC inhibits growth and induces atresia of antral follicles through an oxidative stress pathway. To test this hypothesis, antral follicles isolated from 39-day-old CD-1 mice were cultured with vehicle control (dimethylsulfoxide [DMSO]), MXC (1-100 microg/ml), or MXC + the antioxidant N-acetyl cysteine (NAC) (0.1-10 mM). During culture, growth was monitored daily. At the end of culture, follicles were processed for quantitative real-time polymerase chain reaction of Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX), and catalase (CAT) mRNA expression or for histological evaluation of atresia. The results indicate that exposure to MXC (1-100 microg/ml) inhibited growth of follicles compared to DMSO controls and that NAC (1-10 mM) blocked the ability of MXC to inhibit growth. MXC induced follicular atresia, whereas NAC (1-10 mM) blocked the ability of MXC to induce atresia. In addition, MXC reduced the expression of SOD1, GPX, and CAT, whereas NAC reduced the effects of MXC on their expression. Collectively, these data indicate MXC causes slow growth and increased atresia by inducing oxidative stress.

  13. Foxi3 deficiency compromises hair follicle stem cell specification and activation

    Science.gov (United States)

    Shirokova, Vera; Biggs, Leah C.; Jussila, Maria; Ohyama, Takahiro; Groves, Andrew K.; Mikkola, Marja L.

    2017-01-01

    The hair follicle is an ideal system to study stem cell specification and homeostasis due to its well characterized morphogenesis and stereotypic cycles of stem cell activation upon each hair cycle to produce a new hair shaft. The adult hair follicle stem cell niche consists of two distinct populations, the bulge and the more activation-prone secondary hair germ. Hair follicle stem cells are set aside during early stages of morphogenesis. This process is known to depend on the Sox9 transcription factor, but otherwise the establishment of the hair follicle stem cell niche is poorly understood. Here we show that that mutation of Foxi3, a Forkhead family transcription factor mutated in several hairless dog breeds, compromises stem cell specification. Further, loss of Foxi3 impedes hair follicle downgrowth and progression of the hair cycle. Genome-wide profiling revealed a number of downstream effectors of Foxi3 including transcription factors with a recognized function in hair follicle stem cells such as Lhx2, Runx1, and Nfatc1, suggesting that the Foxi3 mutant phenotype results from simultaneous downregulation of several stem cell signature genes. We show that Foxi3 displays a highly dynamic expression pattern during hair morphogenesis and cycling, and identify Foxi3 as a novel secondary hair germ marker. Absence of Foxi3 results in poor hair regeneration upon hair plucking, and a sparse fur phenotype in unperturbed mice that exacerbates with age, caused by impaired secondary hair germ activation leading to progressive depletion of stem cells. Thus, Foxi3 regulates multiple aspects of hair follicle development and homeostasis. PMID:26992132

  14. Identification of novel candidate genes for follicle selection in the broiler breeder ovary

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    McDerment Neil A

    2012-09-01

    Full Text Available Abstract Background Broiler breeders fed ad libitum are characterised by multiple ovulation, which leads to poor shell quality and egg production. Multiple ovulation is controlled by food restriction in commercial flocks. However, the level of food restriction raises welfare concerns, including that of severe hunger. Reducing the rate of multiple ovulation by genetic selection would facilitate progress towards developing a growth profile for optimum animal welfare. Results The study utilised 3 models of ovarian follicle development; laying hens fed ad libitum (experiment 2 and broiler breeders fed ad libitum or a restricted diet (experiments 1 & 3. This allowed us to investigate gene candidates for follicular development by comparing normal, abnormal and “controlled” follicle hierarchies at different stages of development. Several candidate genes for multiple ovulation were identified by combining microarray analysis of restricted vs. ad libitum feeding, literature searches and QPCR expression profiling throughout follicle development. Three candidate genes were confirmed by QPCR as showing significant differential expression between restricted and ad libitum feeding: FSHR, GDF9 and PDGFRL. PDGFRL, a candidate for steroidogenesis, showed significantly up-regulated expression in 6–8 mm follicles of ad libitum fed broiler breeders (P = 0.016, the period at which follicle recruitment occurs. Conclusions Gene candidates have been identified and evidence provided to support a possible role in regulation of ovarian function and follicle number. Further characterisation of these genes will be required to assess their potential for inclusion into breeding programmes to improve the regulation of follicle selection and reduce the need for feed restriction.

  15. Effects of Ascorbic Acid and FSH on the Maturation of Mice's Oocytes and Follicles

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    Barzegari Firouzabadi

    2011-11-01

    Full Text Available Introduction: Progress in laboratory culture conditions for in vitro oocyte maturation has led to development of the treatment of human and animal infertility. In this study we investigated the effects of FSH and ascorbic acid on the in vitro maturation of mouse's follicles and enclosed oocytes. Methods: For experiment, intact pre-antral follicles were isolated from the ovaries of 6 week-old female mice and cultured in TCM-199 medium. Special quantities of FSH and ascorbic acid were added to the culture medium (containing 25-30 follicles during separate experiments: 5, 20, 40, 60, 100, 140, 180 and 220 IU/L of FSH and 20, 40, 80, 240, 300 and 400 nmol/mL of ascorbic acid. Follicles were cultured for 6 days in an incubator at 37 °C, 92% humidity and 5% air CO2. Our study was semi-experimental. The entire statistical analysis was carried out by SPSS (version 14.0 for Windows using one way ANOVA. Post Hoc tests were used for the multiple comparisons at 95% confidence interval. P values < 0.05 were considered statistically significant. Results: At FSH concentration of 100 IU/L increase in follicle diameter (190µm, survival rate (91%, germinal vesicle breakdown (GVBD (81% and oocyte maturation rates (61% was observed (p ≥0.05. Ascorbic acid increased survival rate (42%, p<0.001 but didn’t affect diameter, GVBD and oocyte maturation rates. Conclusion: Ascorbic acid and FSH-containing medium showed a marked increase in all parameters except for follicle diameter. FSH and ascorbic acid increase the maturation rate of follicles and enclosed oocytes but if they are supplied in a combination, this growth rate can be significantly increased

  16. Polarized Light in Astronomy.

    Science.gov (United States)

    King, D. J.

    1983-01-01

    The application of very sensitive electronic detecting devices during the last decade has revolutionized and revitalized the study of polarization in celestial objects. The nature of polarization, how polaroids work, interstellar polarization, dichroic filters, polarization by scattering, and modern polarimetry are among the topics discussed. (JN)

  17. The domestic dog and cat as models for understanding the regulation of ovarian follicle development in vitro

    OpenAIRE

    Songsasen, N.; Comizzoli, P; Nagashima, J.; Fujihara, M; Wildt, D E

    2012-01-01

    The culture of ovarian follicles is an important tool for understanding of the mechanisms controlling follicle development and differentiation of its oocyte. The benefit of recovering meiotically and developmentally competent oocytes from early stage follicles (primordial, primary, preantral and early antral) also would be significant, ranging from rescue of genomes from endangered species to preserving fertility in women facing cancer treatments. This field of research is at an early stage o...

  18. Structures of ovary and ovarian follicle in flathead lobster,Thenus orientalis (Lund, 1793) (Crustacea: Decapoda: Scyllarida)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The ovary contains four morphological components : (1) the ovarian wall, (2) therepro ductive epithelium, (3) the cellular layer containing oocytes, oogonia (especially for early-developing ovary) and follicle cells, and (4) the extensions of the ovarian wall. The ovarian wall and its extensions consist of blood vessels, sinuses, muscle cells and others. The extensions of the ovarian wall project into among the follicles and insert on the thick basal membrane of each follicle.From inside to outside, the follicles are composed of four parts: (1) the oocyte, (2) the perivitelline space, (3) the follicle cells, and (4) the basal membrane. The surface of the oocyte during vitellogenesis is folded into numerous long microvilli that project into the perivitelline space between the oocyte surface and the bace of the follicle cell layer. In addition, the plasma membrane of the vitellogenic oocyte contains many pinocytotic pits. The perivitelline space is engorged with more electrondenser material as the development of the follicle. The inclusion of perivitelline space in the mature follicle is named specially as the chorion. The chorion is composed of two region, a thinner exochorion and a thicker endochorion containing electron-dense granular material. The follicle cell layer is composed of a single layer of polygonal follicle cells which exhibit higher synthetic activity. The synthetic product of the follicle cell layer is one source for the inclusion of the perivitelline space.The structures of the ovary and ovarian follicle in T. orientalis show that the exogenously biosynthetic yolk plays important roles in the vitellogenesis.

  19. Molecular evolution of Drosophila cuticular protein genes.

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    R Scott Cornman

    Full Text Available Several multigene families have been described that together encode scores of structural cuticular proteins in Drosophila, although the functional significance of this diversity remains to be explored. Here I investigate the evolutionary histories of several multigene families (CPR, Tweedle, CPLCG, and CPF/CPFL that vary in age, size, and sequence complexity, using sequenced Drosophila genomes and mosquito outgroups. My objective is to describe the rates and mechanisms of 'cuticle-ome' divergence, in order to identify conserved and rapidly evolving elements. I also investigate potential examples of interlocus gene conversion and concerted evolution within these families during Drosophila evolution. The absolute rate of change in gene number (per million years is an order of magnitude lower for cuticular protein families within Drosophila than it is among Drosophila and the two mosquito taxa, implying that major transitions in the cuticle proteome have occurred at higher taxonomic levels. Several hotspots of intergenic conversion and/or gene turnover were identified, e.g. some gene pairs have independently undergone intergenic conversion within different lineages. Some gene conversion hotspots were characterized by conversion tracts initiating near nucleotide repeats within coding regions, and similar repeats were found within concertedly evolving cuticular protein genes in Anopheles gambiae. Rates of amino-acid substitution were generally severalfold higher along the branch connecting the Sophophora and Drosophila species groups, and 13 genes have Ka/Ks significantly greater than one along this branch, indicating adaptive divergence. Insect cuticular proteins appear to be a source of adaptive evolution within genera and, at higher taxonomic levels, subject to periods of gene-family expansion and contraction followed by quiescence. However, this relative stasis is belied by hotspots of molecular evolution, particularly concerted evolution, during

  20. Instabilities and topology changes in planar polarized epithelial sheets

    Science.gov (United States)

    Lubensky, David

    2013-03-01

    Epithelia-sheets of cells joined together by specialized junctional structures-are one of the basic building blocks of tissues and organs in animals. In many epithelia, rotational symmetry is broken and cells become polarized in a particular direction in the plane of the sheet. Here, we study the interplay between such planar cell polarity and the shape and packing of individual cells. Using general symmetry arguments and simple phenomenological models, we give a classification of the instabilities that can occur in such a coupled system. In particular, we show that two routes to chiral symmetry breaking are possible, both of which require that cells first become elongated along one axis. We also consider the evolution of the cell packing after an initial instability, including how planar polarity affects T1 topological transitions. We close with possible applications of these results to development in Drosophila and in zebrafish. Supported by NSF grant DMR-1056456