An Unbiased Analysis Method to Quantify mRNA Localization Reveals Its Correlation with Cell Motility

SummaryLocalization of mRNA is a critical mechanism used by a large fraction of transcripts to restrict its translation to specific cellular regions. Although current high-resolution imaging techniques provide ample information, the analysis methods for localization have either been qualitative or employed quantification in nonrandomly selected regions of interest. Here, we describe an analytical method for objective quantification of mRNA localization using a combination of two characteristics of its molecular distribution, polarization and dispersion. The validity of the method is demonstrated using single-molecule FISH images of budding yeast and fibroblasts. Live-cell analysis of endogenous β-actin mRNA in mouse fibroblasts reveals that mRNA polarization has a half-life of ∼16 min and is cross-correlated with directed cell migration. This novel approach provides insights into the dynamic regulation of mRNA localization and its physiological roles.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► An analysis method is developed to quantify intracellular mRNA localization ► Polarization and dispersion indices enable unbiased assessment of localization ► Analysis of single molecule FISH compares localization patterns of various mRNAs ► Live-cell analysis shows β-actin mRNA localization correlates with cell motility