Nuclear lamina

Fibrous network on the inner surface of the nuclear envelope composed of lamin intermediate filaments that provides structural support for the nuclear envelope and also acts as an anchoring site for chromosomes.

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#Id: 953

#Unit 5. Developmental Biology

In Strongylocentrotus purpuratus, the acrosome reaction is initiated by a repeating polymer of fucose sulfate.

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#Id: 954

#Unit 5. Developmental Biology

When sulfated polysaccharide binds to its receptor on the sperm, activates 3 sperm membrane proteins: 

(1) A calcium transport channel

(2) A sodium-hydrogen exchanger

(3) A phospholipase enzyme (IP3)

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#Id: 955

#Unit 5. Developmental Biology

Extension of the acrosomal process by the polymerization of G-actin molecules into F-actin by RhoB

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#Id: 956

#Unit 5. Developmental Biology

Acrosomal process have an insoluble, 30,500-Da protein called bindin.

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#Id: 957

#Unit 5. Developmental Biology

Species-specific bindin receptors present on the egg vitelline envelope.

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#Id: 958

#Unit 5. Developmental Biology

Fast block to polyspermy 

Within 1–3 seconds after the binding of the first sperm, the membrane potential shifts from -70mV to about +20 mV