scholarly journals The development of regionalized lipid diffusibility in the germ cell plasma membrane during spermatogenesis in the mouse.

1986 ◽  
Vol 103 (5) ◽  
pp. 1745-1750 ◽  
Author(s):  
D E Wolf ◽  
B K Scott ◽  
C F Millette
Keyword(s):  
Plasma Membrane ◽  
Somatic Cells ◽  
Sperm Cells ◽  
Testicular Spermatozoa ◽  
Epididymal Maturation ◽  
Cell Plasma ◽  
Lipid Fractions ◽  
Sperm Plasma Membrane ◽  
Diffusion Rates ◽  
Pachytene Spermatocytes

The lipids and proteins of sperm cells are highly regionalized in their lateral distribution. Fluorescence recovery after photobleaching studies of sperm membrane component lateral diffusibility have shown that the sperm plasma membrane is also highly regionalized in the extents and rates of diffusion of its surface components. These studies have also shown that regionalized changes in lateral diffusibility occur during the differentiative processes of epididymal maturation and capacitation. Unlike mammalian somatic cells, sperm cells exhibit large nondiffusing lipid fractions. In this paper, we will show that both regionalized lipid diffusibility and nondiffusing lipid fractions develop with the morphogenesis of cell shape during spermatogenesis in the mouse. Pachytene spermatocytes and round spermatids show diffusion rates and the nearly complete recoveries (80-90%) typical of mammalian somatic cells. In contrast, stage 10-11 condensing spermatids, testicular spermatozoa, cauda epididymal spermatozoa, as well as the anucleate structures associated with these later stages of spermatogenesis (residual bodies and the cytoplasmic droplets of condensing spermatids and testicular spermatozoa), exhibit large nondiffusing fractions. Both the diffusion rates and diffusing fractions observed on the anterior and posterior regions of the head of stage 10-11 condensing spermatids are the same as the values obtained for these regions on testicular spermatozoa. Possible mechanisms of lipid immobilization and possible physiological implications of this nondiffusing lipid are discussed.

Bicarbonate stimulated phospholipid scrambling induces cholesterol redistribution and enables cholesterol depletion in the sperm plasma membrane

2001 ◽  
Vol 114 (19) ◽  
pp. 3543-3555 ◽  
Author(s):  
Frits M. Flesch ◽  
Jos F. H. M. Brouwers ◽  
Patricia F. E. M. Nievelstein ◽  
Arie J. Verkleij ◽  
Lambert M. G. van Golde ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cholesterol Efflux ◽  
Sperm Head ◽  
Sperm Cells ◽  
Cholesterol Depletion ◽  
Apical Surface ◽  
Epididymal Maturation ◽  
Head Surface ◽  
Sperm Plasma Membrane ◽  
Phospholipid Scrambling

Mammalian sperm cells are activated prior to fertilization by high bicarbonate levels, which facilitate lipoprotein-mediated cholesterol efflux. The role of bicarbonate and cholesterol acceptors on the cholesterol organization in the sperm plasma membrane was tested. Bicarbonate induced an albumin-independent change in lipid architecture that was detectable by an increase in merocyanine staining (due to protein kinase A-mediated phospholipid scrambling). The response was limited to a subpopulation of viable sperm cells that were sorted from the non-responding subpopulation by flow cytometry. The responding cells had reduced cholesterol levels (30% reduction) compared with non-responding cells. The subpopulation differences were caused by variable efficiencies in epididymal maturation as judged by cell morphology. Membrane cholesterol organization was observed with filipin, which labeled the entire sperm surface of non-stimulated and non-responding cells, but labeled only the apical surface area of bicarbonate-responding cells. Addition of albumin caused cholesterol efflux, but only in bicarbonate-responding cells that exhibited virtually no filipin labeling in the sperm head area. Albumin had no effect on other lipid components, and no affinity for cholesterol in the absence of bicarbonate. Therefore, bicarbonate induces first a lateral redistribution in the low cholesterol containing spermatozoa, which in turn facilitates cholesterol extraction by albumin. A model is proposed in which phospholipid scrambling induces the formation of an apical membrane raft in the sperm head surface that enables albumin mediated efflux of cholesterol.

scholarly journals Diffusion and regionalization in membranes of maturing ram spermatozoa.

1984 ◽  
Vol 98 (5) ◽  
pp. 1678-1684 ◽  
Author(s):  
D E Wolf ◽  
J K Voglmayr
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Membrane Lipids ◽  
Essential Feature ◽  
Lateral Diffusion ◽  
Mammalian Sperm ◽  
Epididymal Maturation ◽  
Cell Plasma ◽  
Sperm Plasma Membrane ◽  
Membrane Components

An essential feature of the "fluid mosaic model" (Singer, S. J., and G. L. Nicolson , 1972, Science (Wash. DC)., 175:720-731) of the cell plasma membrane is the ability of membrane lipids and proteins to diffuse laterally in the plane of the membrane. Mammalian sperm are capable of overcoming free random diffusion and restricting specific membrane components, both lipid and protein, to defined regions of the sperm's surface. The patterns of these regionalizations evolve with the processes of sperm differentiation: spermatogenesis, epididymal maturation, and capacitation. We have used the technique of fluorescence recovery after photobleaching to measure the diffusion of the lipid analogue 1,1'- dihexadecyl 3,3,3',3'- tetramethylindocarbocyanine perchlorate ( C16dil ) on the different morphological regions of testicular and ejaculated ram spermatozoa. We have found: (a) that the major morphologically distinct regions (head, midpiece, and tail) of the plasma membrane of both testicular and ejaculated spermatozoa are also physically distinct as measured by C16dil diffusibility; (b) that despite regional differences in diffusibility there is exchange of this lipid analogue by lateral diffusion between the major morphological regions of the plasma membrane; and (c) that epididymal maturation results in changes in C16dil diffusibility in the different regions of the sperm plasma membrane. In particular, the plasma membranes of the anterior and posterior heads become physically distinct.

Lipid changes of goat sperm plasma membrane during epididymal maturation

1991 ◽  
Vol 1061 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Ajay P.S. Rana ◽  
Gopal C. Majumder ◽  
Suniti Misra ◽  
Amitabha Ghosh
Keyword(s):  
Plasma Membrane ◽  
Epididymal Maturation ◽  
Sperm Plasma Membrane

scholarly journals Visualization and quantification of glycolipid polarity dynamics in the plasma membrane of the mammalian spermatozoon

1994 ◽  
Vol 107 (8) ◽  
pp. 2151-2163 ◽  
Author(s):  
B.M. Gadella ◽  
T.W. Gadella ◽  
B. Colenbrander ◽  
L.M. van Golde ◽  
M. Lopes-Cardozo
Keyword(s):  
Plasma Membrane ◽  
Sperm Head ◽  
Breakdown Product ◽  
Prolonged Storage ◽  
Sperm Cells ◽  
Fluorescence Lifetime Imaging ◽  
Outer Leaflet ◽  
Head Surface ◽  
Sperm Plasma Membrane

Seminolipid (sulphogalactosylalkylacylglycerol), the glycolipid that is specific for mammalian germ cells, is located exclusively in the outer leaflet of the sperm plasma membrane. In this study the lateral distribution of seminolipid on sperm heads has been investigated by indirect immunofluorescence labelling and detection with digital imaging fluorescence microscopy. In freshly ejaculated sperm cells this glycolipid was present primarily at the apical ridge subdomain of the plasma membrane of the sperm head. After binding the sperm cells to zona-coated coverslips seminolipid migrated, in 40 minutes, from the apical ridge to the equatorial subdomain of the plasma membrane. A similar redistribution of seminolipid was observed during capacitation of sperm cells in vitro induced by Ca2+ or bovine serum albumin. Comparable migration of seminolipid was also found after prolonged storage of ejaculated sperm cells, albeit at a much slower rate. Addition of arylsulphatase A, an enzyme present in seminal plasma that desulphates seminolipid, significantly enhanced the migration of seminolipid during storage of sperm cells. Its breakdown product desulphoseminolipid (galactosylalkylacylglycerol) appeared highly specifically at the equatorial segment. The measured fluorescence intensity over the sperm head surface correlated linearly with the spatial probe distribution as was checked by fluorescence lifetime imaging microscopy. This paper demonstrates and quantifies for the first time the polarity of seminolipid on the surface of the sperm cell and the dynamic alterations that occur in this polarity during post-ejaculatory events.

scholarly journals Update on mammalian sperm capacitation: how much does the horse differ from other species?

Reproduction ◽  
2019 ◽  
Vol 157 (5) ◽  
pp. R181-R197 ◽  
Author(s):  
Bart Leemans ◽  
Tom A E Stout ◽  
Catharina De Schauwer ◽  
Sonia Heras ◽  
Hilde Nelis ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Zona Pellucida ◽  
Mammalian Species ◽  
Cumulus Cells ◽  
Sperm Cells ◽  
Cholesterol Depletion ◽  
Sperm Capacitation ◽  
Sperm Plasma Membrane ◽  
Species Specific

In contrast to various other mammalian species, conventional in vitro fertilization (IVF) with horse gametes is not reliably successful. In particular, stallion spermatozoa fails to penetrate the zona pellucida, most likely due to incomplete activation of stallion spermatozoa (capacitation) under in vitro conditions. In other mammalian species, specific capacitation triggers have been described; unfortunately, none of these is able to induce full capacitation in stallion spermatozoa. Nevertheless, knowledge of capacitation pathways and their molecular triggers might improve our understanding of capacitation-related events observed in stallion sperm. When sperm cells are exposed to appropriate capacitation triggers, several molecular and biochemical changes should be induced in the sperm plasma membrane and cytoplasm. At the level of the sperm plasma membrane, (1) an increase in membrane fluidity, (2) cholesterol depletion and (3) lipid raft aggregation should occur consecutively; the cytoplasmic changes consist of protein tyrosine phosphorylation and elevated pH, cAMP and Ca2+ concentrations. These capacitation-related events enable the switch from progressive to hyperactivated motility of the sperm cells, and the induction of the acrosome reaction. These final capacitation triggers are indispensable for sperm cells to migrate through the viscous oviductal environment, penetrate the cumulus cells and zona pellucida and, finally, fuse with the oolemma. This review will focus on molecular aspects of sperm capacitation and known triggers in various mammalian species. Similarities and differences with the horse will be highlighted to improve our understanding of equine sperm capacitation/fertilizing events.

Ultrastructure, osmotic tolerance, glycerol toxicity and cryopreservation of caput and cauda epididymidal kangaroo spermatozoa

2006 ◽  
Vol 18 (4) ◽  
pp. 469 ◽  
Author(s):  
Rhett McClean ◽  
Catriona MacCallum ◽  
David Blyde ◽  
William V. Holt ◽  
Stephen D. Johnston
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Membrane Damage ◽  
Citrate Buffer ◽  
Plasma Membrane Damage ◽  
Osmotic Tolerance ◽  
Epididymal Maturation ◽  
Sperm Plasma Membrane ◽  
Cauda Epididymidis ◽  
Phosphate Buffered Saline

The aim of the present study was to compare cryopreservation, osmotic tolerance and glycerol toxicity between mature and immature epididymal kangaroo spermatozoa to investigate whether the lack of cryopreservation success of cauda epididymidal spermatozoa may be related to the increased complexity of the sperm ultrastructure acquired during epididymal transit. Caput and cauda epididymidal spermatozoa were recovered from red-necked wallabies (RNW; Macropus rufogriseus) and eastern grey kangaroos (EGK; M. giganteus). In Experiment 1, caput and cauda epididymidal spermatozoa were frozen and thawed using a standard cryopreservation procedure in Tris-citrate buffer with or without 20% glycerol. Although cryopreservation of caput epididymidal spermatozoa resulted in a significant increase in sperm plasma membrane damage, they were more tolerant of the procedure than spermatozoa recovered from the cauda epididymidis (P < 0.05). In Experiment 2, caput and cauda epididymidal EGK spermatozoa were diluted into phosphate-buffered saline media of varying osmolarity and their osmotic tolerance determined. Plasma membranes of caput epididymidal spermatozoa were more tolerant of hypo-osmotic media than were cauda epididymidal spermatozoa (P < 0.05). In Experiment 3, caput and cauda epididymidal RNW spermatozoa were incubated in Tris-citrate buffer with and without 20% glycerol at 35 and 4°C to examine the cytotoxic effects of glycerol. At both temperatures, caput epididymidal spermatozoa showed less plasma membrane damage compared with cauda epididymidal spermatozoa when exposed to 20% glycerol (P < 0.05). These experiments clearly indicate that epididymal maturation of kangaroo spermatozoa results in a decreased ability to withstand the physiological stresses associated with cryopreservation.

scholarly journals Rat Sperm Plasma Membrane Mannosidase: Localization and Evidence for Proteolytic Processing during Epididymal Maturation

1995 ◽  
Vol 167 (2) ◽  
pp. 584-595 ◽  
Author(s):  
Daulat Ram P. Tulsiani ◽  
Subir K. NagDas ◽  
Marjorie D. Skudlarek ◽  
Marie-Claire Orgebin-Crist
Keyword(s):  
Plasma Membrane ◽  
Proteolytic Processing ◽  
Epididymal Maturation ◽  
Sperm Plasma Membrane
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