Measurement of anionic sites of rat epididymal spermatozoa using tritiated polycationized ferritin

Toowicharanont, P.; Chulavatnatol, Montri

doi:10.1530/jrf.0.0690303

Cited by 3 publications

(1 citation statement)

References 8 publications

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“…Methods used included whole cell microelectrophoresis (Bedford 1963;Lopez et al 1987;Nevo et al 1961), isoelectric focusing (Moore 1979), labelling with tritiated polycationised ferritin followed by scintillation counts (Toowicharanont and Chulavatnatol 1983), binding of charged beads (Chulavatnatol et al 1978) and visualisation of anionic sites in transmission electron microscopy (TEM) after direct labelling with cationic probes such as colloidal iron hydroxide, ruthenium red and cationised ferritin (Danon et al 1972;Delgado et al 1990;Fléchon 1975;Lopez et al 1987;Yanagimachi et al 1972). As concluded from electrophoretic mobility and qualitative judgment of sperm labelling density in TEM, spermatozoa were thought to successively acquire acidic groups as they migrate through the epididymis (Bedford 1963;Lopez et al 1987;Toowicharanont and Chulavatnatol 1983). To date, however, this contention has defied statistical verification since methods allowing quantitative assessment of labelling densities as counts per unit cell surface area have been lacking.…”

Section: Introductionmentioning

confidence: 99%

Density and distribution of anionic sites on boar ejaculated and epididymal spermatozoa

Stoffel

Busato

Frieß

2002

Histochem Cell Biol

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Current knowledge implies that spermatozoa successively acquire negative surface charges as they migrate through the epididymis. Until recently, however, techniques used were not amenable to statistical analysis. In the present study, a novel approach allowing numerical assessment of negative charge labelling was used in order to determine the density and distribution of anionic sites on ejaculated and maturing spermatozoa collected from six regions of the boar epididymis. Labelling was assessed quantitatively for the three morphologically distinct membrane domains on the sperm head. Statistical analysis revealed that labelling density was highest on efferent duct spermatozoa, declined up to the proximal corpus and then increased again. Densities of anionic sites on distal corpus, proximal cauda and ejaculated sperm cells were similar but significantly below the values obtained for efferent duct spermatozoa. All three sperm membrane domains underwent parallel changes. However, the overall density of negative charges on the postacrosomal segment was significantly higher as compared to the acrosomal plasma membrane. These alterations reflect sperm surface modifications through removal and addition of anionic groups. Since charge interactions are considered to play a pivotal role in sperm-egg interactions, these processes should be viewed as an integral part of sperm maturation.

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Section: Introductionmentioning

confidence: 99%

Density and distribution of anionic sites on boar ejaculated and epididymal spermatozoa

Stoffel

Busato

Frieß

2002

Histochem Cell Biol

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Maturation antigen of the mouse sperm flagellum. I. Analysis of its secretion, association with sperm, and function

1988

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We report here recent findings on the sperm maturation antigen SMA4, which is secreted by holocrine cells of the distal caput epididymis and binds to the flagellar surface of mouse sperm during epididymal transit. Washed sperm from the caput and corpus epididymides of mice were examined by immunofluorescence and SDS-PAGE using wheat germ agglutinin, which binds specifically to SMA4 as a primary probe. Results indicate that sperm first exhibit WGA reactivity on their flagellae in the region of the distal caput, and that the appearance of WGA receptors is due to the binding of a 54-Kd glycoprotein (SMA4) to the cell surface. Extracts of epididymis containing SMA4 were tested for their ability to bind to the surfaces of caput and corpus sperm. Caput sperm surfaces bound SMA4 in a temperature-independent manner, and binding occurred in the presence of enzyme inhibitors, suggesting a nonenzymatic process. Biochemical studies revealed that SMA4 contains disulfide bonds which stabilize it on the sperm surface and restrict its mobility. Terminal carbohydrate residues of the molecule are sialic acids. The addition of SMA4 to caput sperm flagellae prevented tail-to-tail agglutination, normally seen when caput sperm are diluted into saline; and SMA4 was able to disperse clumps of agglutinated caput sperm. The data suggest that a primary function of SMA4 is to prevent tail-to-tail agglutination of sperm during storage in the epididymis.

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Epididymal Secretion and Resorption of Proteins

Cooper

1986

The Epididymis, Sperm Maturation and Fertilisation

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Measurement of anionic sites of rat epididymal spermatozoa using tritiated polycationized ferritin

Abstract: Summary. Anionic

Cited by 3 publications

References 8 publications

Density and distribution of anionic sites on boar ejaculated and epididymal spermatozoa

Density and distribution of anionic sites on boar ejaculated and epididymal spermatozoa

Maturation antigen of the mouse sperm flagellum. I. Analysis of its secretion, association with sperm, and function

Epididymal Secretion and Resorption of Proteins

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