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Showing papers on "Sperm plasma membrane published in 1977"


Journal ArticleDOI
TL;DR: The loss of fertility after vaginal insemination of glycerol-treated spermatozoa did not appear to be associated with alterations of the surface glycoproteins which bind Con A and CF, however, it may be related to the loss of plasma membrane integrity.

18 citations


Journal Article
TL;DR: The observations indicated that initial sperm degradation is due to the spermatozoas own autolytic enzymes that later dissolution takes place in macrophages in sperm granuloma that no sperm fragments occurred in or between epithelial cells and that no immunologic process was involved.

14 citations


Journal ArticleDOI
TL;DR: In this article, the effects of cytochalasin B on motility and metabolism of washed human spermatozoa at low concentrations (20 to 200μM) were discussed in terms of an interaction with the sperm plasma membrane.

12 citations


Book ChapterDOI
01 Jan 1977
TL;DR: This chapter provides an overview of spermatozoa and ova, and discusses the role of membranes in the fertilization process, supporting the generalization that the paternal chromosomes represent the sole significant contribution of the spermatozoon to the zygote.
Abstract: Publisher Summary This chapter provides an overview of spermatozoa and ova, and discusses the role of membranes in the fertilization process. In all mammals and a large proportion of non-mammals also, the spermatozoon is a motile cell consisting of a head and a flagellum or tail, and in overall size and proportionality it varies greatly. The sperm head takes many different shapes and, indeed, its precise form appears to be peculiar to each individual species and may even be used to identify strains of animals within a species. The major parts of the sperm head are the nucleus and acrosome, and these are enclosed within the expanse of plasma membrane. In most mammals, sperm entry, which initiates fertilization, occurs after the egg has undergone the first meiotic division so that the nucleus of an egg that is ready for fertilization consists of a group of condensed chromosomes in the metaphase of the second meiotic division. Observations on fertilization in mammals and other animals tend to support the generalization that the paternal chromosomes represent the sole significant contribution of the spermatozoon to the zygote. The sperm plasma membrane makes a very minor contribution to the egg plasma membrane at sperm entry, and the disposal of the inner acrosome membrane by apparent phagocytosis in the mammalian egg has been noted.

11 citations


Book ChapterDOI
Ralph B. L. Gwatkin1
01 Jan 1977
TL;DR: No morphological change has been observed in mouse or rabbit spermatozoa lying free in the ampulla of the oviduct and discharge of hyaluronidase by the sperm presumably facilitates their passage through the cumulus.
Abstract: No morphological change has been observed in mouse (Bryan, 1974) or rabbit (Bedford, 1969) spermatozoa lying free in the ampulla of the oviduct. However, as the spermatozoa pass through the cumulus oophorus the outer acrosomal membrane may invaginate to form membrane-bound vesicles within the acrosome followed by loss of the plasma membrane (Jones, 1973; Roomans and Afzelius, 1975), or multiple fusions may develop between the plasma and outer acrosomal membranes (Barros et al., 1967; Franklin et al., 1970; Yanagimachi and Noda, 1970b). These vesiculation processes mark the start of the acrosome reaction and probably permit the release of hyaluronidase (Figure 18b). Discharge of hyaluronidase by the sperm presumably facilitates their passage through the cumulus. Hyaluronidase release has been used as a criterion for the completion of the in vitro capacitation of rabbit (Lewis and Ketchell, 1972) and hamster (Rogers and Morton, 1973b) sperm and for the onset of the acrosome reaction in guinea pig sperm (Rogers and Yanagimachi, 1975a).

3 citations


Book ChapterDOI
01 Jan 1977
TL;DR: Sperm isoantigens, distinguished by the immobilization reaction, first appear on the cell surface at approximately the time spermatogenic cells migrate across the blood–testis barrier and are continually present until fertilization when at least one is transferred to the egg.
Abstract: Publisher Summary This chapter focuses on sperm surface immobilization isoantigens. Immobilization antigens, which occur on epididymal, ejaculate, and capacitated spermatozoa but are not necessarily isoantigens, are localized on sperm head and tail regions. In the case of a single, isolated immobilization antigen, the antigen is masked by seminal plasma coating antigens on ejaculate spermatozoa. Within the class of intrinsic sperm plasma membrane isoantigens, at least one is transferred from the sperm to the egg's plasma membrane during fertilization. Unfertilized, ovulated eggs do not lyse in the presence of sperm-specific isoantiserum and complement. However, following fertilization, the zygote is lysed by sperm immobilizing isoantiserum and complement. Sperm isoantigens, distinguished by the immobilization reaction, first appear on the cell surface at approximately the time spermatogenic cells migrate across the blood–testis barrier. From this stage onward, they are continually present until fertilization when at least one is transferred to the egg. As new synthesis of antigen cannot be expected until after sexual maturation of the male, the transferred isoantigens are lost during subsequent embryogenesis.

1 citations


Book ChapterDOI
Ralph B. L. Gwatkin1
01 Jan 1977
TL;DR: The role of the postacrosomal plasma membrane in initiating fusion between mammalian gametes is in striking contrast to gamete fusion in marine invertebrates in which initial contact with the egg membranes is made by an apical process extending from the inner acrosomal membrane.
Abstract: Studies with hamster gametes in vitro have shown that the microvilli of the vitellus wrap around the head of the sperm and fuse with its plasma membrane in the postacrosomal region (Yanagimachi and Noda, 1972). The role of the postacrosomal plasma membrane in initiating fusion between mammalian gametes is in striking contrast to gamete fusion in marine invertebrates in which initial contact with the egg membranes is made by an apical process extending from the inner acrosomal membrane (Colwin and Colwin, 1967; Epel, 1975; Summers et al., 1975).

1 citations