• mRNA imaging
• neuron targeting

Neurons are highly polarized cells that exhibit different functional domains equipped with distinct set of molecular components. Among them, a wide set of mRNAs is selectively localized at the dendritic or axonal level, and eventually translated. The work presented here constitutes the beginning of a project which aims at the establishment of differential patterns in neurons, and targeting optogenetic probes at the mRNA level either to the dendritic arbor or to the axonal compartment. We based the visualization of the mRNA on the MS2 system, that allows to follow its changing dynamics in living cell by fluorescence microscopy thaks to the recognition of specific sequences in the RNA. The response of two different variants that differed in the structural orientation of the elements that compose the fluorescent mRNA-recognising polipeptide was evaluated under multiple functional aspects. The best performing variant was then used to visualize mRNA distribution in neuronal models and primary cortex neurons when dendritic targeting elements were cloned in its 3'UTR. We evaluated the effect of such elements with regard to mRNA localization and expression, as we designed it to encode for a fluorescent protein, and to have MS2 tagging sequences and dendritic targeting elements in its 3'UTR. Accordingly, we present here our preliminary analysis on mRNA targeting and translation in neuronal cells.