Biology 3338A Lecture Notes - Lecture 10: Capacitation, Lipid Bilayer Fusion, Acrosome
9 Jul 2016
School
Department
Course
Professor
Document Summary
Acrosomal reaction; growth of actin pushes things out. This is first triggered in the jelly layer. Actin polymerizes and eventually the bindin hits the receptor on the envelop and then. Pms fuse and nucleus is delivered in. so there is recognition in the gel and vitalline evenlope. You don"t want polyspermy (if you have inappropriate number of chromosomes you won"t have proper development), this mechanism occurs through fast block; change in membrane potential of egg. Membrane fusion needs a negative electrical charge across the membrane. As soon as a sperm pm fuses with an egg pm, the egg pm potential changes to positive. While positive, no additional sperm pm can fuse (fusion requires ve membrane potential). That positive soon starts decreases, so this fast block polyspermy transient but you want something permanent. You can see quite a change in the egg post ferilization (you see formation of new surface).
