38 research outputs found
The cultural and creative function of moving image literacy in the subject of English in the Greek secondary school
Teaching media literacy as a separate school subject or as part of another school subject is lacking from the Greek educational reality, despite the international academic research and the development and application of media literacy teaching models. This thesis is an analysis of two case study research projects carried out in groups of students in two Greek secondary schools with the aim to study the students’ response to media projects, which are totally new for the Greek educational reality, realized in the English as a Foreign Language class.
The data is analyzed according to Burn and Durran’s 3-Cs model of media literacy, and more precisely its Cultural and Creative functions are the aspects used that include the concepts of Cultural Taste, Identity, and Creativity. These concepts are interpreted within the framework of Cultural Studies and Psychology theories. Important theoreticians considered are Bourdieu, Bennett, Giddens, Vygotsky, Jenkins and Bakhtin.
The examination of students’ participation in the media projects and their production work suggest that their cultural taste is a combination of global and local influences, a glocal result, in which the family, the peers, the media and the education play an important role. Their identity is multi-faceted, as a reflection of various aspects of their selves, and it is closely related to their cultural taste and their cultural capital. Students’ creativity is also expressed as a complex process, affected both by the guidance of the official educational context and the youth popular culture tendencies.
The tensions that emerge in the expression of the students’ cultural taste, identity and creativity during moving image projects characterize the Greek adolescents’ response to the newly-learnt moving image literacy, and raise important questions for educators and researchers
A Gap Junction Protein, Inx2, Modulates Calcium Flux to Specify Border Cell Fate during <i>Drosophila</i> oogenesis
<div><p>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 <i>Drosophila</i> 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.</p></div
Inx2 modulates Calcium flux in outer follicle cells.
<p>(A, B): Snapshots of time lapse imaging of calcium flux in the egg chambers of indicated genotypes. Arrowheads mark the calcium flux. (C, D): GFP intensity calculation for Ca<sup>2+</sup> levels. Insets show anterior end of egg chamber of control and <i>inx2RNAi</i> respectively. 4 consecutive follicle cells (FC1-4) are marked which were considered for calcium flux intensity calculation. Graph represents mean GFP intensity in FC1-4 measured over time (seconds). Note the decrease in the GFP intensity in Inx2-depleted follicle cells (D). (E, F): Snapshots of Ca<sup>2+</sup> flux in the egg chambers under various conditions. Time interval is denoted in minutes. (E): prior to 1-octanol treatment (F): post 1-octanol treatment. White arrowheads mark Ca<sup>2+</sup> flux in the follicle cells. Note that incubation in 1-octanol results in the loss of flux in the follicle cells.</p
Inx2 is required for border cell (BC) fate specification.
<p>(A, B, G, H): Stage 9–10 egg chambers of indicated genotypes. Arrowheads mark the cluster. (A, B): anti-Armadillo (Red), GFP (Green). Inset shows magnified image of BC nuclei stained with DAPI. (C): Histogram compares the number of BC nuclei of the genotype represented in (A, B). (D-F): Mosaic analysis employing ActinGal4 resulting in overexpression of <i>inx2RNAi</i>. Follicle cell overexpressing clones are outlined in white. GFP (Green) (D) and anti-Inx2 (Red) (E). (F): Merge of (D) and (E). Note the down regulation in levels of Inx2 protein in clones over expressing <i>inx2RNAi</i> construct compared to nearby wild type cells. (G, H): anti-Slbo antibody (Green) and DAPI (Blue). Inset represents magnified image of Slbo positive BC. (I): Corresponding histogram representing number of BCs in (G) and (H). Note the decrease in the number of BCs in Inx2-depleted clusters. (J, K): MARCM analysis. Clones are identified by Moesin:Cherry (Red) expression. Arrowheads mark BCs stained with anti-Slbo (Green). (J): Dotted line marks <i>inx2</i> mutant cells. Inset is single channel magnified image of the anterior end of the sample shown in (J). Note the absence of BC cluster. (K): Single plane image of stage 10 egg chamber of <i>inx2</i><sup><i>G0173a</i></sup> homozygous MARCM mutant clones co-expressing Inx2cDNA. The rescue of the Inx2-depleted phenotype is evident with conspicuous BC cluster formation and their efficient migration. Inset represents magnified image of Slbo positive border cells (Slbo). ‘n’ represents number of egg chambers analyzed. Error bar represents Standard Error of Mean. *** represents p-value <0.001.</p
Inx2 regulates Domeless internalization by modulating distribution of Shibire.
<p>(A-B): Maximum intensity projected images depict localization of the Dome:GFP vesicles in the follicle cells in control (A) and <i>inx2RNAi</i> (B). Anti-Armadillo staining (Magenta) marks the outline of respective egg chamber. White arrowheads indicate vesicles localized to apical membrane. Yellow arrowheads mark cytoplasmic vesicles. (C): Histogram comparing the apical fraction of Dome:GFP vesicles. (D-F): Stage 9–10 egg chambers of indicated genotypes stained with anti-Armadillo (Red) and DAPI (Blue). Inset depicts the number of border cell nuclei. (G): Quantification of border cell nuclei in the migrating cluster for genotype represented in (D-F). Note the enhancement of Inx2 depletion phenotype in Shibire heterozygous background. (H-K): Mosaic analysis employing ActinGal4 resulting in overexpression GFP alone (H-I) and GFP cum <i>inx2RNAi</i> (J-K). Follicle cells overexpressing clones are outlined in white. GFP (Green) (H, J) and anti-Dynamin (Red) (I, K). Note the change in the level and distribution of Shibire (Dynamin) protein in clones over expressing <i>inx2RNAi</i> construct compared to nearby wild-type cells and the control clone in (I). Error bar represents Standard Error of Mean. ‘n’ indicates number of egg chambers analyzed. *** p-value <0.001.</p
Elevation of Ca<sup>2+</sup> rescues border cell fate in Inx2-depleted clusters.
<p>(A-D): Stage 9–10 egg chamber of indicated genotype stained with anti-Slbo antibody (Red) and DAPI (Blue). Arrowheads mark BC cluster. Inset represents magnified image of BC. (E): Histogram comparing the number of Slbo positive cells in genotypes (A-D). Note the rescue of BC fate in Inx2-depleted cluster over expressing Orai. (F-I): Anterior end of stage 8 egg chamber stained with anti-STAT antibody (Red). Dotted line outlines anterior follicle cells. Arrowheads mark follicle cell nuclei. (J): Quantification of levels of nuclear STAT for genotypes in (F-I). Error bar represents Standard Error of Mean. ** represents p-value <0.01, *** represents p-value <0.001. ‘n’ indicates number of egg chambers evaluated.</p
Supplemental Material for Shukla et al., 2018
Supplementary Figures for Manuscript "Stonewall and Brickwall: Two partially
redundant determinants required for the maintenance of
female germline in <i>Drosophila"</i
Effects of excess of BMP signaling on Vasa protein.
<p><b>A.</b> Stage 15 wild type embryo. Gonad is tightly coalesced and all germ cells stain strongly for Vasa. <b>B.</b> Stage 15 <i>nos-Gal4/UAS-dpp</i> embryo. Most germ cells stain in this embryo only faintly for Vasa. <b>C.</b> Blow-up grey scale image of Vasa accumulation in the PGCs shown in the embryos in panels A and B. Upper panel: WT PGCs. Lower panel: <i>nos-Gal4/UAS-dpp</i> PGCs. <b>D.</b> Vasa expression in WT, <i>nos-Gal4/UAS-dpp</i> and <i>nos-Gal4/UAS-lwrDN</i> stage 15 embryos. Embryos have a single copy of both the <i>Gal4</i> driver and the <i>UAS</i> transgene as indicated. Dark blue: Percent of PGCs having normal levels of Vasa. Light blue: Percent of PGCs having an obvious reduction in the levels of Vasa compared to their sibs in the same embryo. For this analysis, Vasa levels were scored by comparing staining in the PGCs of the same embryo, not between different embryos. In a wild type embryo (processed in parallel) all PGCs have a similar and uniformly high level of Vasa protein. In contrast, when BMP signaling is upregulated, the level of Vasa protein in different PGCs in the same embryo can differ.</p
<i>lesswright</i> downregulates BMP signaling in PGCs.
<p>Panels <b>A, B, C:</b> Stage 15 embryos. <b>A:</b> Wild type. <b>B: </b><i>nos-Gal4/UAS-dpp</i> embryo showing reduction in PGCs. <b>C: </b><i>UAS-lwr/+;nos-Gal4/UAS-dpp</i> embryo showing intermediate number of PGCs indicating partial rescue of PGC loss phenotype observed in <i>nos-Gal4/UAS-dpp</i> embryos. <i>UAS-lwr/+; nos-Gal4/UAS-dpp</i> stage 15 embryos have an average of 8 PGCs per gonad as compared to 5 PGCs/gonad for <i>nos-Gal4/UAS-dpp</i> and 12 PGCs/gonad for wild type. All transgenic embryos had a single copy of the <i>Gal4</i> driver.</p
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BMP Signaling and the Maintenance of Primordial Germ Cell Identity in Drosophila Embryos
<div><p>The specification of primordial germ cells (PGCs) and subsequent maintenance of germ-line identity in <i>Drosophila</i> embryos has long been thought to occur solely under the control of cell-autonomous factors deposited in the posterior pole plasm during oogenesis. However, here we document a novel role for somatic BMP signaling in the maintenance of PGC fate during the period leading up to embryonic gonad coalescence. We find that PGCs fail to maintain their germline identity when BMP signaling is compromised. They initiate but are unable to properly assemble the germline stem cell-specific organelle, the spectrosome, and they lose expression of the germline-specific gene Vasa. BMP signaling must, however, be finely tuned as there are deleterious consequences to PGCs when the pathway is excessively active. We show that one mechanism used to calibrate the effects of BMP signals is dependent on the Ubc9 homolog Lesswright (Lwr).</p></div