Figure 7.
Schematic representation of proposed vesicular transport during eggshell mineralisation. EVs originate from the plasma membrane of the uterine epithelial cells and accumulate in the UF. ANX and CA4 provide Ca2+ and HCO3− ions, respectively, for the accumulation of ACC inside the EV. This mechanism implies ACC stabilization by additional proteins. EDIL3 and MFGE8 are present at the EV surface due to their PS-binding motif. EVs target the mineralization site (MS) through Ca2+ binding of EDIL3/MFGE8 and deliver the ACC required for mineral formation. MK, mammillary knobs; N, nucleus; G, Golgi. Elements were from Servier Medical Art, licensed under a Creative Commons Attribution 3.0 Unported License.