Search results for " Genes"

The regulation of expression of insect cuticle protein genes

2010

International audience; The exoskeleton of insects (cuticle) is an assembly of chitin and cuticle proteins. Its physical properties are determined largely by the proteins it contains, and vary widely with developmental stages and body regions. The genes encoding cuticle proteins are therefore good models to study the molecular mechanisms of signalling by ecdysteroids and juvenile hormones, which regulate molting and metamorphosis in insects. This review summarizes the studies of hormonal regulation of insect cuticle protein genes, and the recent progress in the analysis of the regulatory sequences and transcription factors important for their expression.

Discovery of an Extended Austinoid Biosynthetic Pathway in Aspergillus calidoustus

2017

Filamentous fungi produce a wide range of natural products that are commonly used in various industrial contexts (e.g., pharmaceuticals and insecticides). Meroterpenoids are natural products of interest because of their various biological activities. Among the meroterpenoids, there is a group of insecticidal compounds known as the austinoids. These compounds have also been studied because of their intriguing spiro-lactone ring formation along with various modifications. Here, we present an extension of the original austinol/dehydroaustinol biosynthesis pathway from Aspergillus nidulans in the recently identified filamentous fungus Aspergillus calidoustus. Besides the discovery and elucidati…

Unicità e relazione. Intersoggettività, genesi e io puro in Husserl

2009

Eukaryotic snoRNAs: a paradigm for gene expression flexibility.

2009

AbstractSmall nucleolar RNAs (snoRNAs) are one of the most ancient and numerous families of non-protein-coding RNAs (ncRNAs). The main function of snoRNAs – to guide site-specific rRNA modification – is the same in Archaea and all eukaryotic lineages. In contrast, as revealed by recent genomic and RNomic studies, their genomic organization and expression strategies are the most varied. Seemingly snoRNA coding units have adopted, in the course of evolution, all the possible ways of being transcribed, thus providing a unique paradigm of gene expression flexibility. By focusing on representative fungal, plant and animal genomes, we review here all the documented types of snoRNA gene organizati…

Human papillomavirus:Its identikit and controversial role in oral oncogenesis,premalignant an malignant lesions(Review)

2007

Human papillomaviruses (HPVs) are a group of host-specific DNA viruses, with a remarkable epithelial cell specificity: they have been reported principally in the ano-genital tract, urethra, skin, larynx, tracheo-bronchial and oral mucosa. More than 100 different HPV types have been identified and classified as high (e.g. 16, 18, 31) or low (e.g. 11, 42, 36) -risk (HR and LR), based on their association with cervical carcinoma. The carcinogenic role of HR-HPV revolves mainly around two of its oncoproteins: HPV-E6 which promotes degradation of the p53 tumour suppressor gene product and HPV-E7 which modifies the pRb tumour suppressor gene product, inhibiting the activity of TGF-beta2. Since th…

Cloning of branched chain amino acid biosynthesis genes and assays of alpha-acetolactate synthase activities in Leuconostoc mesenteroides subsp. crem…

1999

A genomic library from Leuconostoc mesenteroides subsp. cremoris (Lmc) in Escherichia coli was screened for alpha-acetolactate synthase (ALS) activity using a phenotypic test detecting the production of acetolactate or related C4 derivatives (diacetyl, acetoin or 2,3-butanediol) in the culture. Four recombinant E. coli clones, with plasmids containing overlapping DNA fragments and displaying anabolic ALS activity, were selected. This activity is encoded by an ilvB gene belonging to a putative operon which contains genes highly similar to the genes of the branched chain amino acid (BCAA) operon of Lactococcus lactis subsp. lactis. This putative BCAA operon is not functional as the ilvA gene …

Photosensitive Alternative Splicing of the Circadian Clock Gene timeless Is Population Specific in a Cold-Adapted Fly, Drosophila montana.

2018

To function properly, organisms must adjust their physiology, behavior and metabolism in response to a suite of varying environmental conditions. One of the central regulators of these changes is organisms' internal circadian clock, and recent evidence has suggested that the clock genes are also important in the regulation of seasonal adjustments. In particular, thermosensitive splicing of the core clock gene <i>timeless</i> in a cosmopolitan fly, <i>Drosophila melanogaster</i> , has implicated this gene to be involved in thermal adaptation. To further investigate this link we examined the splicing of <i>timeless</i> in a northern malt fly species, <i&…

Data from: Not only for egg yolk - functional and evolutionary insights from expression, selection and structural analyses of Formica ant vitellogeni…

2015

Vitellogenin, a storage protein, has been extensively studied for its egg-yolk precursor role, and it has been suggested to be fundamentally involved in caste differences in social insects. More than one vitellogenin copy has been reported in several oviparous species, including ants. However, the number and function of different vitellogenins, their phylogenetic relatedness and their role in reproductive queens and non-reproductive workers has been studied in few species only. We studied caste biased expression of vitellogenins in seven Formica ant species. Only one copy of conventional vitellogenin was identified in Formica species, and three vitellogenin homologues, derived from ancient …

Neuronal activity triggers uptake of hematopoietic extracellular vesicles in vivo

2019

Communication with the hematopoietic system is a vital component of regulating brain function in health and disease. Traditionally, the major routes considered for this neuroimmune communication are by individual molecules such as cytokines carried by blood, by neural transmission, or, in more severe pathologies, by the entry of peripheral immune cells into the brain. In addition, functional mRNA from peripheral blood can be directly transferred to neurons via extracellular vesicles (EVs), but the parameters that determine their uptake are unknown. Using varied animal models that stimulate neuronal activity by peripheral inflammation, optogenetics, and selective proteasome inhibition of dop…

Reevaluating the function of a transcription factor: MBF-1 as a sea urchin chromatin organizer ?

2014

The Zinc-finger MBF-1 factor is involved in the expression of the early histone genes during devel-opment of the sea urchin embryo (1, 2). In spite of being a transcription activator, the DNA-binding domain of MBF-1 shares high sequence similarity with that of the chromatin organizer CTCF of vertebrates and drosophila (3). On the other hand, extensive in silico analysis failed to identify the sea urchin CTCF ortholog (4). This led us to speculate that MBF-1 somehow could have co-opted the function of CTCF during evolution of the echinoderms. Since in vertebrates CTCF binds Hox chromatin, to support our hypothesis, we first identified high-score putative binding sequences for CTCF/MBF-1 with…