BIOL130 Lecture Notes - Tx Network, Oct-4, Endometrium
28 Jan 2013
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Document Summary
Outline of lecture 03: fertilization, penetration of corona radiata subunits membrane. Corona radiata is hyaluronic rich ecm; sperm has hyaluronidase. A ca2+ channel, catsper, is required in sperm for penetration: binding to zona pellucida. Zona pellucida is a coat of glycoproteins, 13 m m thick, made of zp1,2,3. Zp3 is the target of species specific receptor on sperm, perhaps. 1,4-galactosyltransferase: acrosome reaction and penetration of zona pellucida. Acrosome reaction is fusion of acrosomal membrane with sperm plasma. Sperm binding to zp3 causes rise in [ca2+]in; signaling also requires. Sperm remains bound to zp2 during this time. Acrosin plays a non-critical role in penetration, not fully understood: fusion of sperm and egg membrane. Mediated by egg integrin binding to sperm fertilin: cortical reaction. Oscillating waves of ca2+ causes cortical granules to be released, triggered by plcz: block to polyspermy. Hardening of zona pellucida by cortical enzymes that alter zp2 and zp3. Preimplantation development (single cell to blastocyst: cleavage divisions, compaction.
