Anterior-enriched filopodia create the appearance of asymmetric membrane microdomains in polarizing zygotes.

The association of molecules within membrane microdomains is critical for the intracellular organization of cells. During polarization of the zygote, both polarity proteins and actomyosin regulators associate within dynamic membrane-associated foci. Recently, a novel class of asymmetric membrane-associated structures was described that appeared to be enriched in phosphatidylinositol 4,5-bisphosphate (PIP), suggesting that PIP domains could constitute signaling hubs to promote cell polarization and actin nucleation.