In certain tumors of antibody-producing B lymphocytes, the cyclin D1 gene is translocated & its transcription is

under the control of an antibody-gene enhancer, causing elevated cyclin D1 production.

TLS Online TPP Program

#Id: 948

#Unit 5. Developmental Biology

Active guanylyl cyclase causes the sperm cell to produce more cGMP, that activates a calcium channel in the cell membrane of the sperm tail.

TLS Online TPP Program

#Id: 949

#Unit 5. Developmental Biology

Sperm-specific calcium channels are encoded by CatSper genes

TLS Online TPP Program

#Id: 950

#Unit 5. Developmental Biology

Increase in cGMP and Ca2+ activate both mitochondrial ATP-generating apparatus and the dynein ATPase that stimulates flagellar movement in the sperm.

TLS Online TPP Program

#Id: 951

#Unit 5. Developmental Biology

In sea urchin, the acrosome reaction has 2 components:

1. Exocytosis

2. Extension of the acrosomal process

TLS Online TPP Program

#Id: 952

#Unit 5. Developmental Biology

In sea urchins, the acrosome reaction is initiated by sulfate-containing polysaccharides in the egg jelly.

TLS Online TPP Program

#Id: 953

#Unit 5. Developmental Biology

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