Ultrastructural localization of wheat germ agglutinin binding sites on the sperm surface of water buffalo (Bubalus bubalis). A fracture label study.

In the present study we have examined the plasma membrane surface organization employing fluorescein isothiocyanate linked wheat germ agglutinin (WGA) of the cauda epididymal and ejaculated spermatozoa of water buffalo. Intramembrane particle distribution pattern in the various segments of the spermatozoa has also been observed. WGA-ovomucoid gold has been used to study the distribution of sialoproteins on the sperm surface. With fracture label, WGA receptor sites have been identified on the fractured membrane halves of the sperm plasma membrane overlying the acrosome as well as the middle piece and the principle piece.

Maturation, capacitation, and metabolism of goat spermatozoa using magnetic resonance methods.

The ability of intact cells to reduce spin labels has been utilized to characterize the activity of spermatozoa of goat. The kinetics of reduction of TEMPO has been found to be sensitive to the quantity, quality and state of epididymal maturation of the spermatozoa. Presence of alcohol caused activation and Gossypol acetic acid left sperm activity unaltered. Electron spin resonance (ESR) and 31P Nuclear magnetic resonance (NMR) indicate that the period of in vitro capacitation requires optimization. 31P NMR spectra indicate a good correlation with the progressive maturation of the cells.

Capacitated and acrosome reacted spermatozoa of goat (Capra indicus): a fluorescence and electron microscopic study.

Plasma membrane alterations accompanying in vitro capacitation and acrosome reaction of goat spermatozoa were studied using lectin labelling, scanning electron microscopy, and freeze-fracture methods. Fluorescein isothiocyanate linked lectins namely; Canavalia ensiformis (ConA), Maclura pomifera (MPA), Arachis hypogaea (PNA), Glycine max (SBA) and Triticum vulgaris (WGA) agglutinin were used to examine the distribution of surface carbohydrates during these two events. The head and the sperm tail reveal altered lectin labelling features after capacitation and acrosome reaction. After capacitation the surface coat components for MPA, SBA, and WGA are shed from the spermatozoon head. ConA receptors on the head are retained after capacitation but are partially shed in the acrosome reacted spermatozoa. SBA receptor sites appear on the sperm tail of the capacitated spermatozoa. Unusual morphological changes attending capacitation involve the sperm tail-end which develops a novel entity, which we have termed 'spatula'. The 'spatula' shows strong binding with ConA and WGA only. In the acrosome reacted spermatozoa the spatulated tail-end unwinds with a concomitant loss of lectin labelling. Highly ordered membrane particles, 'ladders' of the middle piece of the epididymal sperm tail, disappear and IMP clearings appear on the middle piece and in the spatulated ends of the capacitated spermatozoa. But in the acrosome reacted sperm IMPs reappear and are randomly disposed on the middle-piece and are clustered in small patches on the principal-piece. IMP free areas appear on the plasma membrane covering the acrosome and the outer acrosomal membrane (OAM) of the capacitated spermatozoa. The plasma membrane and OAM fuse at multiple foci and appear as acrosomal 'ghosts' which remain associated with the sperm head even after acrosome reaction.

Plasma membrane alterations of maturing goat (Capra indicus) spermatozoa: lectin-binding and freeze-fracture study.

A qualitative and quantitative analysis of lectin-binding sites has been undertaken on spermatozoa recovered from different regions of the epididymis of the goat (Capra indicus) using fluorescein isothiocyanate-linked lectins (Bauhinia purpurea BPA, Concanavalin A Con A, Dolichos biflorus DBA, Maclura pomifera MPA, Arachis hypogaea or peanut agglutinin PNA, Glycine max or soyabean agglutinin SBA, Ulex europaeus UEA, and Triticum vulgaris or wheat-germ agglutinin WGA), in conjunction with scanning and transmission electron microscopy, and freeze-fracture techniques. Flow cytometric analysis has also been used to quantitize binding affinity. Spermatozoa from caput to cauda epididymidis show no significant variation in lectin-binding ability, but the samples removed from the corpus epididymidis contain a greater number of binding sites. The passage of spermatozoa through the epididymidis is accompanied by a redistribution of the plasma membrane lectin-receptors covering the sperm head and tail. Receptors for BPA, DBA, PNA and SBA are specifically restricted to the anterior region of the acrosome in caudal spermatozoa. Freeze-fracture replicas, examined to study changes in organisation of intramembranous particles of the plasma membrane during sperm maturation, reveal distinct changes in their distribution in the acrosome, post-acrosome and spermatozoon tail, especially in the corpus and cauda epididymidis.

Spectroscopic and microscopic studies of buffalo-bull (Bubalus bubalis) spermatozoa.

We have examined the epididymal (caput, corpus and cauda) and ejaculated spermatozoa of bufallo-bull (Bubalus bubalis) employing microscopic and spectroscopic techniques. Fluorescein isothiocyanate conjugated lectins namely concanavalin A (Con A), Dolichos biflorus (DBA), Maclura pomifera (MPA), peanut agglutinin (PNA), soybean agglutinin (SBA) and wheat germ agglutinin (WGA) were used to study the changes in the sperm surface carbohydrate make up as the spermatozoa mature. Quantitative analysis of the lectin binding was made flow cytometrically. 31P-NMR (nuclear magnetic resonance) spectra of the sperms obtained from different regions (head, body and tail) of the epididymis and of the ejaculate were analyzed to assess their metabolic activity. And the kinetics of spin label reduction of these samples was monitored with ESR (electron spin resonance) spectroscopy. These observations are supplemented with the electron microscopic (SEM and TEM) examination of the epididymal and ejaculated spermatozoa.

Changes in the lectin binding sites on the testicular, epididymal, vas, and ejaculated spermatozoon surface of dog.

Changes in the localization of sperm surface glycocomponents of testicular, epididymal, vas deferens, and ejaculated spermatozoa of dog (Canis domesticus) were studied employing fluorescein isothiocyanate conjugated lectins viz., Concanavalin A (ConA), Triticum vulgaris (WGA), Maclura pomifera (MPA), and Arachis hypogaea (PNA) agglutinins. The plasma membrane clothing the acrosome of the testicular, epididymal, and vas deferens spermatozoa shows reactivity with all the lectins used. However, in the ejaculated spermatozoa, the entire sperm surface shows reactive sites for ConA, WGA, and PNA. Variation in the labelling of the cytoplasmic droplet in different stages of spermatozoon transit in the epididymis has been discussed.

Human sperm surface mapping with lectins.

Ten fluorescein isothiocyanate (FITC)-linked lectins [Bauhimia purpurea, Concanavalin A, Dolichos biflorus (DBA), Griffonia simplicifolia I, Griffonia simplicifolia II, Maclura pomifera, Arachis hypogea (PNA), Glycine max, Ulex europaeus (UEA) and Triticum vulgaris agglutinin] have been used to study their binding features on the human ejaculate spermatozoa. Qualitative changes in the labeling pattern have been observed in unfixed and acetone-treated spermatozoa. Furthermore, ultrastructural localization of some of the colloidal gold-linked lectins, namely PNA, UEA and DBA, has been attempted to delineate the binding domains of the specific sugars on the sperm surface. It needs to be emphasized that flow-cytometric methods employed in our study, which provide quantitative slant to qualitative data, should be utilized to evaluate the functional status of the spermatozoa.