153,024 research outputs found

    Mali’s songbird, Oumou Sangaré, & Radio as research

    Get PDF
    This radio documentary and accompanying transcript seek to create, for both nonspecialist and specialist audiences, an authoritative picture of the sonic, cultural, geographical and emotional world of Mali’s iconic female artist, Oumou Sangar

    Study on differential expression of 1-aminocyclopropane-1-carboxylic acid oxidase genes in table grape cv. Thompson Seedless

    Get PDF
    As a consequence of the non-climacteric status of grapes (Vitis vinifera), ethylene biosynthesis and signal transduction have scarcely been studied in this fruit. In spite this drawback, the available information suggests a role for ethylene in ripening grape berries. In this work, we report the identification of three homologous genes that encode 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), a key component of ethylene biosynthesis. A comparison of protein sequences revealed that all three VvACOs harbor a 2OG-Fe(II) oxygenase domain, which is typical of the ACO gene family; however, VvACO1 showed a higher amino acid sequence homology with VvACO2 than with VvACO3. The expression pattern of VvACOs and the effect of exogenous ethylene on their transcript accumulation were evaluated during table grape berry development in the “Thompson Seedless” cultivar. A peak in VvACO1 transcript accumulation levels was registered around veraison that was 4-fold higher than at harvest, and this peak was confirmed during a second season in grapes that were harvested from three different vineyards. An enhancement in ethylene production and VvACO genes transcript levels was observed in grapes sprayed with ethephon during berry development. However, VvACO1 transcripts reached the highest accumulation earlier than VvACO2 and VvACO3. Altogether, these data confirmed that ethylene may have a role in some aspects of the grape ripening process, and they also highlighted the potential use of some VvACO genes as molecular markers for identifying grape veraison stages in grapes

    An Arabidopsis flavonoid transporter is required for anther dehiscence and pollen development

    Get PDF
    FLOWER FLAVONOID TRANSPORTER (FFT) encodes a multidrug and toxin efflux family transporter in Arabidopsis thaliana. FFT (AtDTX35) is highly transcribed in floral tissues, the transcript being localized to epidermal guard cells, including those of the anthers, stigma, siliques and nectaries. Mutant analysis demonstrates that the absence of FFT transcript affects flavonoid levels in the plant and that the altered flavonoid metabolism has wide-ranging consequences. Root growth, seed development and germination, and pollen development, release and viability are all affected. Spectrometry of mutant versus wild-type flowers shows altered levels of a glycosylated flavonol whereas anthocyanin seems unlikely to be the substrate as previously speculated. Thus, as well as adding FFT to the incompletely described flavonoid transport network, it is found that correct reproductive development in Arabidopsis is perturbed when this particular transporter is missing

    Neuronal Expression of Neural Nitric Oxide Synthase (nNOS) Protein is Suppressed by an Antisense RNA Transcribed from an NOS Pseudogene

    Get PDF
    Here, we show that a nitric oxide synthase (NOS) pseudogene is expressed in the CNS of the snail Lymnaea stagnalis. The pseudo-NOS transcript includes a region of significant antisense homology to a previously reported neuronal NOS (nNOS)-encoding mRNA. This suggested that the pseudo-NOS transcript acts as a natural antisense regulator of nNOS protein synthesis. In support of this, we show that both the nNOS-encoding and the pseudo-NOS transcripts are coexpressed in giant identified neurons (the cerebral giant cells) in the cerebral ganglion. Moreover, reverse transcription-PCR experiments on RNA isolated from the CNS establish that stable RNA-RNA duplex molecules do form between the two transcripts in vivo. Using an in vitro translation assay, we further demonstrate that the antisense region of the pseudogene transcript prevents the translation of nNOS protein from the nNOS-encoding mRNA. By analyzing NOS RNA and nNOS protein expression in two different identified neurons, we find that when both the nNOS-encoding and the pseudo-NOS transcripts are present in the same neuron, nNOS enzyme activity is substantially suppressed. Importantly, these results show that a natural antisense mechanism can mediate the translational control of nNOS expression in the Lymnaea CNS. Our findings also suggest that transcribed pseudogenes are not entirely without purpose and are a potential source of a new class of regulatory gene in the nervous system

    Theorising teaching

    Get PDF
    Theorising of teaching is not limited to the major theorists, as researchers and teachers also theorise teaching. This article explores theorising by researchers and a teacher in two ways: firstly, an overview or framework from the research literature on teaching as a sociocultural practice is developed, and secondly, the framework is tested by analysing the transcripts of a beginning teacher talking about her teaching

    Cloning and characterisation of the S.pombe rad15 gene, a homologue to the S.cerevisiae RAD3 and human ERCC2 genes

    Get PDF
    The RAD3 gene of Saccharomyces cerevisiae encodes an ATP-dependent 5' - 3' DNA helicase, which is involved in excision repair of ultraviolet radiation damage. By hybridisation of a Schizosaccharomyces pombe genomic library with a RAD3 gene probe we have isolated the S.pombe homologue of RAD3. We have also cloned the rad15 gene of S.pombe by complementation of radiation-sensitive phenotype of the rad15 mutant. Comparison of the restriction map and DNA sequence, shows that the S.pombe rad15 gene is identical to the gene homologous to S.cerevisiae RAD3, identified by hybridisation. The S.pombe rad15.P mutant is highly sensitive to UV radiation, but only slightly sensitive to ionising radiation, as expected for a mutant defective in excision repair. DNA sequence analysis of the rad15 gene indicates an open reading frame of 772 amino acids, and this is consistent with a transcript size of 2.6kb as detected by Northern analysis. The predicted rad15 protein has 65% identity to RAD3 and 55% identity to the human homologue ERCC2. This homology is particularly striking in the regions identified as being conserved in a group of DNA helicases. Gene deletion experiments indicate that, like the S.cerevisiae RAD3 gene, the S.pombe rad15 gene is essential for viability, suggesting that the protein product has a role in cell proliferation and not solely in DNA repair
    corecore