Figure 5.

Effects of urethane, procaine and NH₄Cl on the ultrastucture of the egg surface. (A) TEM and SEM images of P. lividus control eggs show dense microvilli with nearly uniform shape and size. In the TEM image (left panel), CG are apparently attached to the plasma membrane. (B) After urethane treatment (400 mM, 5 min), egg surface shows a sign of corrugation and significant loss of microvilli (SEM). The treatment induces invaginations on the egg surface and dislocation of some CG from the plasma membrane (TEM, black arrow). (C) Incubation with procaine (10 mM, 20 min) gives rise to microvilli elongation as well as reduction in their number. Some parts of the cell surface are deprived of microvilli (SEM, right panel). Procaine-pretreated eggs show bulges on the surface (black arrow) and some CG lost their attachment to the plasma membrane (red arrow) to form a secondary layer. (D) NH₄Cl-treatment (40 mM pH 9.0, 30 min) shows loss of microvilli and changes in their shape (SEM) as well as translocation of some CG (TEM, red arrows).