Sperm surface proteins persist after fertilization.

Abstract

Certain sperm components labeled with fluorescein isothiocyanate or its radioactive derivative, 1251-diiodofluorescein isothiocyanate (t251FC), are transferred at fertilization to the egg, where they persist throughout early cleavage stages at a localized site in the embryo cytoplasm (Gabel, C. A., E. M. Eddy, and B. M. Shapiro, 1979, Cell, 18:207-215; Gundersen, G. G., C. A. Gabel, and B. M. Shapiro, 1982, Dev. Biol., 93:59-72). By using image intensification we have extended these observations in the sea urchin to the pluteus larval stage, in which >60% of the embryos have localized fluorescent sperm components. Because of the unusual persistence of the sperm components in the embryo, a characterization of the nature of the labeled species in sea urchin sperm was undertaken. ~10% of the 1251FC was in sperm polypetides of Mr > 15,000. These proteins were on the sperm surface as shown by their sensitivity to externally added proteases. The remainder of the ~251FC in sperm was in several low-molecular-weight species, none of which was ~251FC-derivatized phospholipid.To determine if any labeled sperm polypeptides remained intact in the embryo after fertilization, ~251FC-labeled sperm proteins were recovered from one-cell and late gastrula stage embryos by using an anti-IFC immunoadsorbent. Most of the labeled sperm proteins were degraded shortly after fertilization; however, distinct sets of labeled polypeptides were recovered from both one-cell and gastrula stage embryos. Six of the labeled polypeptides recovered from both embryonic stages had identical SDS gel mobilities as labeled sperm polypeptides. Other polypeptides in the embryos appeared to arise from limited proteolysis of sperm proteins. Thus, in this physiological cell fusion system, individual sperm proteins are transferred to the egg at fertilization, and some persist intact or after specific, limited degradation long after gamete fusion, until at least the late gastrula stage.Fertilization is the process whereby haploid genomes are united and development is initiated. Central to this process is the fusion of gamete membranes, which results in the incorporation of the sperm nucleus as well as other, nonnuclear, sperm components into the egg. Although the insertion of cytoplasmic sperm components during fertilization has been observed in almost every animal phyla, few examples exist in which the fates of these components have been addressed (see bibliographies in references l, 33, 34). Furthermore, the great dilution of sperm components after gamete fusion (from 104-to 10z1-fold depending on the species, [1]) has limited such studies to observations of morphological markers of the sperm, such as the axoneme or the mitochondfia, which can be identified after fertilization. The consensus of these investigations is that sperm organelles are degraded during the early cleavage stages, although notable exceptions do exist (see bibliographies in references 33 and 34). In none of these studies have individual sperm components been pursued at the mole...

Sperm cell architecture, insemination, and fertilization in the model fern, Ceratopteris richardii

“…This protein may be utilized during this period of rapid cell cycling. In animals, sperm cell surface proteins often persist after fertilization making them a contender for a potential role in embryogenesis (Gundersen and Shapiro 1984). Strong evidence supports the idea that in mammals, sperm deliver a soluble protein, PLCf (zeta) that triggers Ca 2+ oscillations and egg activation during fertilization (Swann et al 2006).…”

Advances in Cryopreservation of Bull Sperm

“…More specifically, during the cryopreservation process, changes in temperature and osmotic stress impair sperm viability because of injury to the plasma membrane (140). This method uses probes such as ethidium homodimer (EH) (141), propidium iodide (PI) (142), Yo-Pro-1 (143), and bizbenzimidazole Hoechst 33258 (144) dyes, alone, or in combination with other dyes, to excite lasers (145). Propidium iodide (PI) is excited with the 488-nm laser and able to penetrate the non-viable sperm through broken plasmalemma, then emit red fluorescence upon binding to nucleic acids (146).…”

Incorporation and fate of specific sperm plasma membrane components following insemination as revealed by ultrastructural immunocytochemistry

“…However, based on the presence of colloidal gold particles close to and within forming coated vesicles, it is possible that the 33 and/or 35 kDa polypeptides are internalized via endocytosis. Internalized sperm plasma membrane components may remain structurally and functionally intact to be utilized by the embryo during the course of development or they may be inactivated and degraded (Shapiro, 1975;Gundersen et al, 1982Gundersen et al, , 1986Gundersen and Shapiro, 1984).…”