Structure of membrane domains and matrix components of the bovine acrosome.
The acrosomal membrane system of bovine spermatozoa was examined by thin-section, freeze-fracture, surface-replica, and negative staining techniques in order to identify structural differentiations of specific acrosomal membrane domains. The outer acrosomal membrane of the apical and principal segments is characterized by a prominent electron-dense complex associated with its luminal face and a random intramembranous particle distribution. In the equatorial segment, the two-dimensional organization of bridging elements extending between the outer and inner acrosomal membrane was determined and correlated to freeze-fracture images. The inner acrosomal membrane lacked the electron-dense assembly noted on the outer acrosomal membrane and in freeze-fracture it appears crystalline. Further studies identified the distribution of the electron-dense subacrosomal material in the space between the inner acrosomal membrane and outer nuclear membrane. Finally, new observations on the structural organization of the acrosomal matrix are presented.
G E
GE
Olson
V P
VP
Winfrey
D000177:Acrosome / Q000648:ultrastructure*; D000818:Animals; D002417:Cattle; D005614:Freeze Fracturing; D007425:Intracellular Membranes / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D017830:Octoxynol; D011092:Polyethylene Glycols; D013094:Spermatozoa / Q000648:ultrastructure*; D013194:Staining and Labeling
D011092:Polyethylene Glycols; D017830:Octoxynol