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  • 1
    Electronic Resource
    Electronic Resource
    Interaction of isolated components from mammalian sperm and egg (1985)
    New York, NY : Wiley-Blackwell
    Gamete Research 12 (1985), S. 101-116 
    Details
    ISSN: 0148-7280
    Keywords: fertillization ; spermatozoon ; gamete interaction ; zona pellucida ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In order to identify those proteins from the plasma membrane of hamster spermatozoa that exhibit an affinity for components of the zona pellucida we have used the Western blot technique. Zonae pellucidae from postovulatory hamster oocytes were solubilized by exposure to an acidic pH and then radiolabeled using the Bolton-Hunter reagent. These 125I-zona pellucida proteins retain their immunoreactivity and migrate in three heterogeneous bands when submitted to SDS-PAGE electrophoresis. Membrane proteins from epididymal spermatozoa of mature hamsters were extracted by treatment with Nonidet P-40 and then submitted to electrophoresis (SDS-PAGE). The proteins in the gel were electrophoretically transferred to a nitrocellulose membrane and then probed with the radiolabelled zone pellucida proteins. 125I-zona pellucida proteins bind preferentially to a sperm protein with a molecular weight of 26,400 ± 1,400 daltons (n = 9). Using a similar procedure it was shown that this protein also binds 125I-Concanavalin A. The interaction between the sperm protein and the 125I-zona pellucida proteins shows species specificity as demonstrated by the fact that the hamster 125I-zona pellucida proteins do not bind to proteins extracted from ram, bull, and stallion spermatozoa. Whether this sperm protein could be implicated be implicated in the process of sperm-egg interaction is under investigation.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120120112
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  • 2
    Electronic Resource
    Electronic Resource
    Comparative immunoreactivity of mouse and hamster sperm proteins recognized by an anti-P26h hamster sperm protein (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 41 (1995), S. 249-256 
    Details
    ISSN: 1040-452X
    Keywords: Spermatozoa ; Protein ; Antigen ; Fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The binding of the spermatozoon to the zona pellucida is a species-specific phenomenon. We have previously shown that the binding of hamster sperm to the homologous zona pellucida involves a sperm 26-kDa glycoprotein, the P26h, originating in the epididymis. In order to establish to what extent this sperm protein is involved in the species-specific recognition of the egg's extracellular coat, we have compared the inhibitory properties of anti-P26h antibodies in a sperm-zona pellucida assay using hamster and mouse gametes. Anti-P26h IgGs inhibit, in a dose-dependent manner, gamete interactions in both species, although in a less efficient manner in the mouse than in the hamster. While anti-26kDa Fab fragments are as efficient as the intact IgG to inhibit hamster sperm-zona pellucida binding, they have no effect on mouse gamete interaction. ELISA, Western blot, and immunohistochemical experiments have been performed in order to characterize the mouse antigen(s) recognized by the anti-P26h antiserum. ELISA and Western blots showed that this antiserum recognized two proteins on mouse spermatozoa that are less reactive than the hamster P26h. These antigens are localized in the acrosomal region of epididymal spermatozoa of both species. These results indicate that the hamster P26H involved in zona pellucida interaction has certain unique epitopes, while others are common to the sperm of both species. © 1995 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080410216
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  • 3
    Electronic Resource
    Electronic Resource
    Aortic endothelial cells synthesize basic fibroblast growth factor which remains cell associated and platelet-derived growth factor-like protein which is secreted (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 131 (1987), S. 402-408 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cultured bovine aortic endothelial cells synthesize growth factors which markedly differ in the regulation of their storage and secretion. Endothelial cell lysates, but not conditioned medium, contain a growth factor activity that appears to be basic fibroblast growth factor (FGF) by the following criteria: (1) it elutes from heparin-Sepharose at 1.4-1.6 M NaCl; (2) it is mitogenic for bovine aortic and capillary endothelial cells; (3) it is heat sensitive but stable to dithiothreitol; (4) it has a molecular weight of about 18,000 daltons; and (5) it cross-reacts with antiserum directed against basic FGF. In contrast, endothelial cell conditioned medium, but not lysates, contains a growth factor activity that (1) elutes from heparin-Sepharose at 0.4 - 0.5 M NaCl; (2) is mitogenic for fibroblasts and vascular smooth muscle cells but not for capillary endothelial cells; (3) is heat stable and dithiothreitol sensitive; and (4) competes with platelet-derived growth factor (PDGF) for binding to fibroblasts. From these criteria, it appears that endothelial cells secrete into the medium growth factors some of which are PDGF-like, but secrete little if any basic FGF. It is suggested that endothelial cell-associated basic FGF acts in an autocrine fashion to stimulate endothelial cell proliferation in response to endothelial cell perturbation or injury. On the other hand, the endothelial cell-secreted growth factors which are smooth muscle cell but not endothelial cell mitogens might exert a paracrine function on neighboring cells of the vessel wall.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041310312
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  • 4
    Electronic Resource
    Electronic Resource
    Heterogeneity of epididymal spermatozoa of the hamster (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 24 (1989), S. 229-236 
    Details
    ISSN: 0148-7280
    Keywords: epididymis ; sperm maturation ; sperm density ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Epididymal transit is involved in the acquisition of fertilizing ability by mammalian spermato-zoa. The epididymis is implicated in the addition and/or modification of sperm surface proteins functionally involved in the processes leading to fertilization. In order to characterize these sperm components, we have studied the modifications of sperm membrane proteins during epididymal maturation. Hamster spermatozoa were collected from the caput, corpus, and proximal and distal cauda of the epididymis and submitted to a continuous Percoll gradient centrifugation. Independently of their epididymal origin, the spermatozoa were distributed into two bands of buoyant densities of 1,045 and 1,088 on the gradient. However, the proportion of more dense spermatozoa increased progressively along the epididymis. This proportion is 87-fold higher in the distal cauda compared to the caput. SDS-PAGE electrophoresis demonstrated that although they originate from different regions of the epididymis, spermatozoa of the same density exhibited similar membrane protein patterns. In contrast, the electrophoretic patterns of spermatozoa with densities of 1,045 and 1,088 were very different One of these differences involves a 26 kD protein that is implicated in zona pellucida recognition (Sullivan and Bleau, Gamete Res 12.101-116,1985). This protein is present in dense sperm obtained from all regions of the epididymis but is absent in spermatozoa of low density. If we consider that this 26 kD protein is a ‘marker’ of surface changes occurring during sperm maturation, we can hypothesize that in the proximal segments of the epididymis a certain proportion of spermatozoa are indeed mature but that this proportion increases considerably along the epididymis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120240210
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