Mildred Gordon

The surface coat of epididymal, ejaculated and capacitated sperm

Washed and unwashed epididymal, ejaculated, and capacitated rabbit sperm were incubated for the demonstration of Concanavalin A receptors in the surface coat. In washed cauda epididymal and ejaculated sperm, a uniform, dense layer of reaction product covered the head. The surface coat of the flagellum was thinner and discontinuous. There were no Concanavalin A receptors in the neck. The majority of caput sperm showed no surface reaction. A few were coated with a thin deposit, indicating formation of components containing Concanavalin A receptors. Because unwashed cauda epididymal and ejaculated sperm did not bind to Concanavalin A, it was concluded that receptors were masked by constituents in epididymal and seminal fluid. The plasmalemma of capacitated sperm showed a loss of Concanavalin A binding over the acrosome, beginning at the tip of the head. Shedding of the surface coat may be evidence for membrane alterations during capacitation which prepare sperm for fertilization.

Cyclic changes in the fine structure of the epithelial cells of human endometrium.

Endometrial biopsies from the corpus uteri of women of reproductive age with normal 28-day cycles were processed for electron microscopy in order to examine the refinements of ultrastructure which occur as part of the cyclic hormonal input. The description of the structure of epithelial cells includes: 1) the endoplasmic reticulum and ribosomes, 2) mitochondria, 3) the nucleus, 4) the golgi complex and secretory bodies, 5) lysosomes, 6) annulate lamellae, 7) luminal surface, 8) basal surface, 9) lateral surface, and 10) the nucleolar channel system. The variations in glycogen synthesis during the cycle are presented, as well as uterine secretions. The effects of estrogen and progesterone on the epithelial cells are described.

Cytochemical differentiation of the guinea pig sperm flagellum with phosphotungstic acid

Guinea pig sperm were treated with ethanolic phosphotungstic acid (E-PTA) after glutaraldehyde fixation with and without refixation in osmium tetroxide. PTA staining differentiated the cortex from the interior of the coarse fibers, and further differentiated the cortex into two segments, one densely stained, the other pale. The internal substance of the peripheral doublets stains heavily with PTA when sperm are not fixed in osmium tetroxide, but the limiting walls around the doublets are not apparent. Outlines of the central filaments, however, are preserved by PTA. PTA-stained sperm do not show the arms on sub-filament A, irrespective of fixation procedures. Structural relationships between the coarse fibers and the peripheral doublets are also brought out by E-PTA. In addition, this cytochemical method revealed a nodule connecting the implantation and basal plates.

Fine structural cytochemical localizations of phosphatase activities of rat and guinea pig

Abstract The fine structural localization of several phosphatase activities was studied in spermatozoa obtained from the caudae epididymides of mature rats and guinea pigs. Fresh sperm and sperm fixed in hydroxyadipaldehyde or glutaraldehyde were incubated in a substrate containing medium either at pH 7.0 using lead ions as the capture agent, or at pH 9.0 with cadmium ions. Activity sensitive to sulfhydryl reagents and glutaraldehyde fixation was evident on elements of the axial filament complex at pH 7.0 with ATP and activators, Mg 2+ or Ca 2+ , and to a lesser extent with ADP and Mg 2+ or ITP and Mg 2+ . At pH 9.0, reaction product was localized on the medial surface of the coarse fibers. This activity was obtained with ATP, activated by Ca 2+ , and was resistant to both sulfhydryl agents and glutaraldehyde fixation. Calcium dependent, mercurial-stimulated ATPase activity was also demonstrated at pH 9.0 on the plasma membrane of the head and the outer membrane of the acrosome vesicle in glutaraldehyde-fixed guinea pig sperm. Mitochondrial activity was demonstrated with several substrates, including ATP at both pH 7.0 and 9.0.

The distal centriole in guinea pig spermiogenesis

Developmental changes in the distal centriole were studied in guinea pig testicular tissue exposed to ethanolic phosphotungstic acid (E-PTA) with or without acetylation, after glutaraldehyde and osmium tetroxide fixation. Caudal portions of the striated columns are synthesized initially around the distal centriole. Their further development is promoted by transient centriolar derivatives that develop in the core of the flagellum—dense rods enclosed by cylindrical structures. An E-PTA stained matrix accumulates around the centriolar triplets. Portions of the matrix remain in the sperm and form an internal coat on the coarse fibers rostral to the axial filaments. The peripheral doublets contact this dense material. Both the dense matrix, derived from the centriole, and the lateral cortex of the coarse fibers stain identically with E-PTA. Their staining reaction differs from that of the opaque doublet subfilament. The implications of these findings for motility are discussed.

Observations on the postacrosomal region and the neck membranes of rabbit spermatozoa stained en bloc with uranyl acetate

SummaryThe postacrosomal region (PAC) of the head and the neck membranes of rabbit spermatozoa have been reinvestigated with the use of en bloc uranyl acetate staining. The fine structure of the PAC and neck membranes is visualized with great clarity and departs from that seen in rabbit sperm prepared by other methods. In cells so treated, the PAC contains a heavily enfolded nuclear envelope, a dense lamina attached to the plasmalemma by periodic connecting links and scattered dense material between the lamina and nuclear envelope. Evidence is presented that the dense lamina is a discrete structure, separated from the plasmalemma by the connecting links. The latter may be of a different composition from both the lamina and the plasmalemma. The lamina is a homogenous structure which resists degeneration under conditions which affect other components of the PAC. The membranes of the neck are a complex labyrinth of nuclear envelope, individual membranes, and membranes coursing through a matrical gound substance.