The hyphal tips have a polarized distribution of lipids in the plasma membrane, including enrichment of PI4,5P2 (Vernay, et al., 2012). This region also stains more strongly with the ergosterol binding agent filipin, indicating a change in ergosterol levels or increased accessibility of filipin (Martin and Konopka, 2004). The hyphal tip region is also enriched in polarisome and exocyst domains that mediate highly polarized growth. Note the presence of actin patches at a subapical region where they promote endocytosis to help maintain tip growth (Caballero-Lima, et al., 2013). Underlying the plasma membrane is a complex of vesicles termed the Spitzenkörper, which is thought to promote the rapid growth at the tip (Jones and Sudbery, 2010). Actin filaments guide secretory vesicles to the hyphal tip.