The mechanism underpinning mRNA translational control during early development Specific Project Objective: How is the Drosophila Melanogaster anterior determinant bicoid, one of the best understood morphogens, translationally activated in the early embryo. General Importance: Localized mRNA translation is a conserved mechanism for the spatial control of gene expression, enabling cells to target protein function in space and time. Functions requiring mRNA regulation include Drosophila and Xenopus axis formation, cell division in budding yeast, motility in chicken fibroblasts and synaptic plasticity in neurons. In humans, RNA localization plays a major role in Fragile X syndrome, Alzheimer disease as well as learning and memory development. Experimental Approach: We will use advanced imaging of endogenous tagged mRNA and fluorescent protein lines to assess spatiotemporal changes in bicoid mRNA protein associations and localization at egg activation. We will specifically assess the role of the cytoskeleton through fast live, super-resolution microscopy with existing reagents. To show that bicoid mRNA translation is coordinated by changes in intracellular calcium, we will assay for translation in the presence of standard reagents for dissecting calcium signaling pathways as well as monitor changes in intracellular calcium with ratio imaging. In addition, we will use mutants of genes required for egg activation and in calcium signaling pathways. Significance: Calcium is the focus of substantial research to understand cellular processes including synaptic transmission, skeletal muscle function and the regulation of metabolic pathways. However, there are still many aspects of calcium function that are not well understood. This work will have broader implications to understanding basic cellular processes and human diseases.
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