In mammals, RNA interference (RNAi) was historically studied as a cytoplasmic event; however, in the last decade, a growing number of reports convincingly show the nuclear localization of the Argonaute (AGO) proteins. Nevertheless, the extent of nuclear RNAi and its implication in biological mechanisms remain to be elucidated. We found that reduced Lamin A levels significantly induce nuclear influx of AGO2 in SHSY5Y neuroblastoma and A375 melanoma cancer cell lines, which normally have no nuclear AGO2.
View Article and Find Full Text PDFGenes are expressed in stochastic transcriptional bursts linked to alternating active and inactive promoter states. A major challenge in transcription is understanding how promoter composition dictates bursting, particularly in multicellular organisms. We investigate two key Drosophila developmental promoter motifs, the TATA box (TATA) and the Initiator (INR).
View Article and Find Full Text PDFWith its rapid development, ease of collection, and the presence of a unique layer of nuclei located close to the surface, the Drosophila syncytial embryo is ideally suited to study the establishment of gene expression patterns during development. Recent improvements in RNA labeling technologies and confocal microscopy allow for visualizing gene activation and quantifying transcriptional dynamics in living Drosophila embryos. Here we review the available tools for mRNA fluorescent labeling and detection in live embryos and precisely describe the overall procedure, from design to mounting and confocal imaging.
View Article and Find Full Text PDFThe original version of this Article contained an error in Fig. 4a, in which the "=" sign of the equation was inadvertently replaced with a "-" sign. This has been corrected in the PDF and HTML versions of the Article.
View Article and Find Full Text PDFPioneer transcription factors can engage nucleosomal DNA, which leads to local chromatin remodeling and to the establishment of transcriptional competence. However, the impact of enhancer priming by pioneer factors on the temporal control of gene expression and on mitotic memory remains unclear. Here we employ quantitative live imaging methods and mathematical modeling to test the effect of the pioneer factor Zelda on transcriptional dynamics and memory in Drosophila embryos.
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