Decoding Asymmetric Cell Division Via Single-Molecule Imaging

Cell polarity is the fundamental process by which eukaryotic cells establish asymmetric organization, creating distinct membrane domains and internal compositions. This spatial orientation is essential for functional tissue assembly, homeostasis, and processes like nutrient absorption in the epithelium. When coordination fails, the results include developmental defects and cancer.

Historically, a gap existed between developmental biologists, who observed cell behavior in vivo, and biochemists, who studied protein interactions in vitro. While genetic screens in the 1980s identified key Partitioning Defective (PAR) proteins responsible for this symmetry breaking, understanding how these molecules organize into complex signaling networks within living cells remained difficult. Interpretation was often clouded by protein redundancy and the limitations of studying isolated fragments.

To bridge this gap, the Dickinson Lab at UT-Austin utilizes innovative ex vivo imaging. By combining rapid cell lysis with total internal reflection fluorescence (TIRF) microscopy, they can observe protein complex remodeling in real-time within organisms like C. elegans. This approach allows researchers to move beyond pairwise protein interactions, finally revealing how the biochemical "machinery" of polarity functions inside a developing embryo to drive cellular decision-making.