7More about gametes Where do sperm come from? Why do mammals have testes?What is the structure of testes? (fig 59.11, 13)What are germ cells?What are stem cells?How many sperm form from each germ stem cell?
10More about spermatogenesis What is the progression from germ stem cell to sperm?What is a germinal cell (aka germ cell stem cell)What is a primary spermatocyteWhat is a secondary spermatocyteWhat are spermatids?What are spermatozoa?What do sertoli cells do?
13More about gametes… What about eggs? What is their major cargo? Nutrients, cytoplasmic determinants, maternal chromosomesHow do they protect themselves?What sort of structural adaptations do they display?What is a jelly coat?What is a vitelline membrane?What is a zona pelucida?
15More about eggs How valuable are they? How do they find the sperm? How many are made?When are they made available?How do they find the sperm?Who finds whom?Are eggs motile?
16More about eggs… What are cytoplasmic determinants? mRNA, protein, other moleculesWhere are they located?When are they depositied?What is oogenesis?How are they distributed?What happens during cell division?What do they do?What is polarity?
21More about eggs How does egg structure differ between organisms? Jelly coat (sea urchin) vs. zona pellucida (mammal)No cell layer (sea urchin) vs. granulosa (mammal)Yolk differencesMore later…
22Back to fertilization What are model organisms? What are the models for studying fertilization?The rules of engagement…(fig 60.3)What does the sperm encounter first?How can it get through the jelly coat?
24More about fertilization What is penetration (aka. the acrosome reaction)? (fig 60.3)Remember the acrosome?Remember the jelly coat/zona pellucida?What happens when the acrosome encounters jelly coat?What are the signals?What are hydrolytic enzymes?What do they do?Fig 47.2
25More about fertilization More acrosomal reaction…How does the sperm penetrate jelly coat?What is the acrosomal processWhat happens at the vitelline membrane?Why are receptors important?What happens next?Sperm and egg membranes fuseHOORAY!!!Fig 47.1
27More about fertilization What is the situation?How many eggs are available?How many sperm are available?Only ONE winner!What is polyspermy?How is polyspermy prevented?Fast block to polyspermySlow block to polyspermy
28The fast block to polyspermy What is membrane potential?What happens to the membrane potential upon sperm fusion?How does depolarization prevent polyspermy?How long does the fast block to poplyspermy last?
29The slow block to polyspermy How does the slow block work?What is signal transduction?What are second messengers?Why do we need them?
30More about the slow block Where are intracellular Calcium stores?How is calcium release triggered?How does it radiate over surface of egg?Doing the Calcium wave…
32More about the slow block What does calcium release do?Cortical granules fuse with PMRelease contents into perivitelline spaceWhat are cortical granules?Where are they located?What do they contain?enzymesmucopolysacchariddes
33More about the slow block What do mucopolysaccharides do in perivitelline space?Remember osmosis?How do mucopolysaccharides affect osmolarity?What does this do to perivitelline space?Fig 8.10, 8.11
34More about the slow block What do the enzymes from cortical granules do?What happens when polysaccharides become crosslinked?How would this affect sperm penetration?How long does all of this take?