Epithelial cells form adhesive connections through cell-cell junctions, maintaining a selective barrier despite significant cell shape changes during development and tissue homeostasis. This is accomplished through the active remodeling of cell-cell junctions, a process largely driven by actomyosin contractility. Using live microscopy of the Xenopus laevis embryonic epithelium, my lab has characterized “tricellular zipping”, a vertex remodeling process that contributes to the transition from irregular epithelial cell geometries at the blastula stage to the more regular hexagonal packing that emerges at the gastrula stage of development. Tricellular zipping involves the resolution of a long, thin cellular extension that stretches toward a vertex where four or more cells meet. As two cells 'zip' together to lengthen a new bicellular interface, the other cell recedes, thus forming a new tricellular vertex at the end of zipping. Tricellular zipping is accompanied by transient flashes of cytoplasmic calcium within the long cell extension. My research has focused on investigating these calcium flashes, whether the calcium flashes are correlated with actomyosin accumulation, and how pulsatile calcium and actin accumulations drive the elongation of the new bicellular interface between two zipping cells. My data reveals that each tricellular zipping event is accompanied by multiple calcium flashes within the long cellular extension. Following each calcium flash, there is an increase in the rate of elongation of the new bicellular interface. F-actin also accumulates in a pulsatile fashion within the long cellular extension during tricellular zipping. Cross-correlation analysis demonstrates that calcium flashes are correlated with F-actin accumulation, and calcium flashes precede F-actin accumulation, suggesting that pulsatile calcium flashes may activate actin polymerization and/or Myosin II activation during tricellular zipping. Together, these findings suggest that calcium-associated actomyosin pulses drive tricellular zipping. This research provides new information about an uncharacterized mechanism of junctional remodeling and the emerging role of localized calcium signaling in regulating epithelial junction remodeling during early embryonic development.