Biomaterial Database

Topographical distribution of phospholipids in boar sperm plasma and intracellular membranes as revealed by freeze-fracture cytochemistry. 1996

F W Kan, and Y Lin

Department of Anatomy and Cell Biology, Faculty of Medicine, Queen's University, Kingston, Ontario, Canada.

We used fracture-label and label-fracture cytochemistry in conjunction with the phospholipase A2-colloidal gold (PLA2-CG) technique to study the distribution of phospholipids in ejaculated boar spermatozoa. These techniques provide visualization of the topographical distribution of phospholipids in freeze-fractured sperm membranes in a three-dimensional view. In various freeze-fractured boar sperm membranes and crossfractured cytoplasmic structures, quantitative analysis revealed that the nuclear envelope membranes and the nuclear content possessed the highest labeling density of PLA2-CG. Moderate labeling was detected over acrosomal membranes, especially the inner acrosomal membrane. Replicas of both protoplasmic and exoplasmic fracture faces of the plasma membrane of boar sperm head showed a relatively low density of PLA2-CG labeling. Moreover, a differential distribution of phospholipids was seen over the protoplasmic face of the plasma membrane domains of the sperm head, which showed the highest concentration of gold particles in the postacrosomal region, followed by the equatorial segment and the anterior acrosome region. The PLA2-CG labeling densities over the post-acrosomal region and the equatorial segment were significantly higher than that over the anterior acrosome region. In the flagellum, an intense labeling was also seen over crossfractured mitochondria, dense fibers, and fibrous sheath. The protoplasmic fracture face of the plasma membrane over the middle piece, the annulus, and the principal piece was moderately labeled by PLA2-CG. No significant difference in mean labeling density of PLA2-CG was detected among the three membrane domains. In label-fracture preparations, exoplasmic halves of the plasma membrane of the head and the middle piece of the tail were uniformly labeled with PLA2-CG. However, the annulus and principal piece were devoid of PLA2-CG binding sites. These results indicate that differential distribution of phospholipids associated with the boar sperm membranes may reflect phospholipid composition of membrane domains characteristic of special physiological functions.

UI	MeSH Term	Description	Entries
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D008297	Male		Males
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013094	Spermatozoa	Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.	Sperm,Spermatozoon,X-Bearing Sperm,X-Chromosome-Bearing Sperm,Y-Bearing Sperm,Y-Chromosome-Bearing Sperm,Sperm, X-Bearing,Sperm, X-Chromosome-Bearing,Sperm, Y-Bearing,Sperm, Y-Chromosome-Bearing,Sperms, X-Bearing,Sperms, X-Chromosome-Bearing,Sperms, Y-Bearing,Sperms, Y-Chromosome-Bearing,X Bearing Sperm,X Chromosome Bearing Sperm,X-Bearing Sperms,X-Chromosome-Bearing Sperms,Y Bearing Sperm,Y Chromosome Bearing Sperm,Y-Bearing Sperms,Y-Chromosome-Bearing Sperms
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog