Gamete Interactions

Question 1

Describe a method of checking sperm quality

Answer 1

Cervical mucus penetration test - sperm penetrates the cervical mucus then check distance sperm can travel = which sperm can travel faster

Question 2

What is capacitation

Answer 2

the final maturational stage of spermatozoa that takes place in the FRT before the spermatozoa is able to gain the ability to fertilise the oocyte

Question 3

Describe the process of capacitation

Answer 3

1. sperm binds to receptor on microvilli of the fallopian tube
2. signal transduction takes place in the spermatozoa
3. change in pH and intracellular Ca2+ concentration in the spermatozoa

Question 4

Describe gamete interactions in the oviduct

Answer 4

1. sperm becomes capacitated in the FRT
2. sperm penetrates cumulus oophorus cells and reaches zona pellucida
3. sperm binds zona pellucida - mediated by ZP3
4. acrosome reaction triggered by ZP3
5. penetration of acrosome-reacted sperm into the zona pellucida is mediated by ZP2
6. sperm enters perivitelline space, resulting in:
   * cortical granule reaction results in hardening of ZP, blocking polyspermy
   * fusion of pronuclei - process is called syngamy
   * extrusion of 2nd polar body
   * initiation of Ca2+ oscillation in oocyte cytoplasm