Fertilization Flashcards
What does fertilization accomplish? [3]
Genetic variation from meiotic recombination, restoration of diploidy, and species specific mono sperm egg activation.
What is the mechanism, and peptide that helps guide sperm travel direction?
RESACT is a chemical peptide. The sperm undergo chemotaxis to direct their motions toward this substance.
What is developed in sea urchin sperm when the sperm reaches the egg jelly?
The acrosomal process in created in the acrosomal reaction.
Describe the sea urchin acrosomal reaction:
The acrosomal membrane breaks and acrosomal enzymes are released, eating through the jelly layer. A protrusion called the acrosomal process made of actin microfilaments extrude with bindin on the outside, ready to recognize the vitellin envelope.
What triggers the acrosomal reaction?
Calcium
How do we usually test the sufficiency of calcium?
We use calcium ionophores that trigger the release of calcium in the absence of normal signals.
What is the egg’s fast block to polyspermy?
Membrane depolarization.
What is the process of an egg’s slow permanent block to polyspermy?
Cortical granules release proteases that release the vitelline envelope further away from the cell surface by releasing enzymes that harden the envelope, and swell the space with proteoglycans.
What is the major proponent for species specific fertilization?
Bindin
Human sperm: capacitation
The final maturation of sperm occurring in the oviduct.
What triggers the acrosome reaction in sperm?
The zona pellucida
Do human sperm make the acrosomal process?
No
What contributes to the slow block of polyspermy in mammals?
Once a sperm reaches the zona pellucida, it releases zona protein that blocks sperm binding, and starts to remodel the zona pellucida.
Two proteins that may have a role in mammal sperm/oocyte binding?
Izumi and Juno
