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Sperm Binding (sperm + binding)
Selected AbstractsSperm binding properties and secretory activity of the bovine oviduct immediately before and after ovulationMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2008Edita Sostaric Abstract The possibility that differences in hormonal regimes between the two oviducts in the cow around ovulation affects secretory activity of the oviduct epithelial cells and/or sperm,oviduct binding was studied. Oviducts were collected immediately after slaughter at 6 hr before to 5 hr after timed ovulation of 14 normally cyclic cows that had been inseminated (n,=,6) or not (n,=,8) and material obtained from the same cows was processed in three ways. First, in vivo, after artificial insemination of the cows, low numbers of sperm cells (approx. 15 per oviduct) were found within the entire oviducts as observed by scanning electron microscopy (SEM). Almost all sperm were located in the isthmus and then only on ciliated cells and showed without exception fully matured, intact morphology. Secretory activity of noninseminated oviduct epithelia was induced after ovulation which was most predominant in the pockets of the ipsi-lateral ampulla compared to the contra-lateral ampulla (P,<,0.01). Second, ex vivo, explants dissected from oviducts of the noniseminated cows were incubated with sperm. In all cases, the sperm bound to the explants in a similar pattern as observed in vivo and this binding was strictly fucose-dependent. The main difference with in vivo experiments was the high numbers of sperm bound at any site of the oviduct (,3,000 cells per mm2) indicating the high sperm binding capacity of the oviduct epithelia. Ovulation induced a striking drop in sperm binding capacity in the oviducts and was most pronounced in the isthmus (,1,300 cells per mm2; P,<,0.001) and to a lesser extent in the ampulla (,2,000 cells per mm2, P,<,0.01). Third, in vitro, pieces of tissue dissected from oviducts of the noninseminated cows were cultured to mono-layers. Culturing epithelial cells resulted in loss of their normal morphological appearance. In all cases, the sperm binding capacity in monolayers was very low (<50 cells per mm2) when compared to corresponding explants (P,<,0.0001). Sperm binding to monolayers originating from the isthmus (<25 cells per mm2) was lower than in those from the ampulla (40,50 cells per mm2; P,<,0.01) and remained similar after ovulation. In all three approaches, no significant differences were found in sperm,oviduct binding characteristics and sperm-distribution in the ipsi- versus contra-lateral oviducts. This indicates, that systemic endocrine changes around ovulation rather than specific oviduct changes at the ipsi,lateral oviduct induce secretion in oviduct epithelial cells, and thus induce sperm release. Mol. Reprod. Dev. 75: 60,74, 2008. © 2007 Wiley-Liss, Inc. [source] Sperm binding to the human zona pellucida and calcium influx in response to GnRH and progesteroneANDROLOGIA, Issue 5 2002P. Morales Summary. In this study the effect of the sequential exposure of spermatozoa to progesterone and gonadotrophin-releasing hormone (GnRH) upon zona binding and the intracellular free Ca2+ concentration was evaluated. Sperm aliquots were treated as follows: (a) 0.7 ,mol 1,1 progesterone or 0.1% DMSO (progesterone solvent) followed by 50 nmol 1,1 of GnRH; (b) 50 nmol 1,1 of GnRH or distilled water (GnRH solvent) followed by 0.7 ,mol 1,1 of progesterone. Additional aliquots were incubated with DMSO or distilled water (controls) and with 0.7 ,mol 1,1 of progesterone or 50 nmol 1,1 of GnRH. All treatments were for 5 min. Motile spermatozoa were incubated in modified Tyrode's medium, at 37 °, 5% CO2, 10times106 spermatozoa ml,1, for 4.5 h. Intracellular Ca2+ concentration and sperm-zona binding was evaluated using fura 2 and the hemizona assay, respectively. GnRH and progesterone increased sperm-zona binding and the Ca2+ concentration. Regarding zona binding, the effect of GnRH was significantly greater when the spermatozoa had been previously treated with progesterone (progesterone , GnRH = 185 ± 116 zona-bound spermatozoa versus DMSO , GnRH = 99 ± 15, P <0.001). On the other hand, previous treatment with GnRH did not modify their subsequent response to progesterone (GnRH , progesterone = 114 ±19 zona-bound spermatozoa versus distilled water , progesterone = 108 ± 22, NS). The results regarding intracellular Ca2+ showed a similar pattern. These findings suggest a priming effect of progesterone upon a GnRH-induced increase in sperm-zona binding and intracellular Ca2+. [source] Cellular and molecular mechanisms leading to cortical reaction and polyspermy block in mammalian eggsMICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2003Qing-Yuan Sun Abstract Following fusion of sperm and egg, the contents of cortical granules (CG), a kind of special organelle in the egg, release into the perivitelline space (cortical reaction), causing the zona pellucida to become refractory to sperm binding and penetration (zona reaction). Accumulating evidence demonstrates that mammalian cortical reaction is probably mediated by activation of the inositol phosphate (PIP2) cascade. The sperm-egg fusion, mediated by GTP-binding protein (G-protein), may elicit the generation of two second messengers, inositol 1,4,5 triphosphate (IP3) and diacylglycerol (DAG). The former induces Ca2+ release from intracellular stores and the latter activates protein kinase C (PKC), leading to CG exocytosis. Calmodulin-dependent kinase II (CaMKII) may act as a switch in the transduction of the calcium signal. The CG exudates cause zona sperm receptor modification and zona hardening, and thus block polyspermic penetration. Oolemma modification after sperm-egg fusion and formation of CG envelope following cortical reaction also contribute to polyspermy block. Microsc. Res. Tech. 61:342,348, 2003. © 2003 Wiley-Liss, Inc. [source] Effect of Carbohydrates on the Ability of Bull Sperm to Bind to Bovine Oviduct Epithelial CellsREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009Y Kon Contents In the present study, we investigated the effect of various carbohydrates on the ability of bovine spermatozoa to bind to the bovine oviduct epithelial cells (OECs). We also examined the fertilization competence and motility of spermatozoa that bind to OECs in the presence of carbohydrates. Frozen-thawed spermatozoa were incubated with OECs, with and without various carbohydrates. The sperms were then divided into two fractions: OEC-binding sperms (B-sperm) and non-OEC binding sperms (NB-sperm). The fertilization rate, ability to bind the zona pellucida, and membrane integrity of the spermatozoa as determined using a hypo-osmotic-swelling test (HOST) were lower in NB-sperm than in the unseparated spermatozoa (control). The motility of the B-sperm was maintained for a longer time than that of the control spermatozoa. The addition of N -acetyl- d -glucosamine (GlcNAc, 5 mm) to the sperm-OEC mixture increased the number of B-sperm. D -mannose (5 mm) and D -fucose (5 mm) had no effect on the number of B-sperm. The motility of B-sperm, which bound to OECs in the presence of GlcNAc, however, was not maintained. When either OECs or the spermatozoa were treated with GlcNAc prior to sperm-OEC co-incubation, only sperm-side treatment enhanced sperm-OEC binding, but B-sperm motility was not maintained. The motility of spermatozoa incubated with GlcNAc was lower than that of controls. These results indicate that GlcNAc enhances sperm binding to OECs, probably via sperm surface modification, but does not promote increased sperm survival. [source] Oviductal Fluid Proteins Associated with the Bovine Zona Pellucida and the Effect on In Vitro Sperm,Egg Binding, Fertilization and Embryo DevelopmentREPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2008RF Gonçalves Contents Studies have demonstrated that oviductal fluid (ODF) proteins associate with eggs of numerous species including the bovine. In this study, the association of three ODF proteins, the bovine oestrus-associated protein, osteopontin (OPN), lipocalin-type prostaglandin D synthase (L-PGDS), with the bovine zona pellucida (ZP) was demonstrated by immunohistochemistry and western blot. The biological function of ODF derived egg-associated OPN and L-PGDS in sperm binding, fertilization and embryonic development was also explored. In vitro matured bovine oocytes were pre-incubated with ODF collected by cannula from cows in oestrus, or ODF with antibodies to OPN, L-PGDS and bovine serum albumin (BSA). Following incubation, oocytes were inseminated with 1 × 105 frozen-thawed spermatozoa, and they were evaluated for sperm binding, fertilization and embryonic development in vitro. Pre-treatment of ODF with antibodies to all of proteins reduced sperm binding to the ZP and fertilization in vitro. Cleavage rates were not significantly different among incubations, but rates of embryo development were significantly decreased. We conclude that antibodies to OPN, L-PGDS and BSA react with oocytes incubated with ODF and inhibit sperm binding, fertilization and embryonic development in vitro, suggesting a potential role of these proteins in these events. [source] Postovulatory Effect of Intravenous Administration of Lipopolysaccharide (E. coli, O55:B5) on the Contractile Activity of the Oviduct, Ova Transport, Binding of Accessory Spermatozoa to the Zona Pellucida and Embryo Development in SowsREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2002AM Mwanza Contents The effect of lipopolysaccharide (LPS) (E. coli, O55:B5), administered 18 h after ovulation in the second oestrus after weaning, on the contractile activity of the oviduct, ova transport, sperm binding to zona pellucida (ZP) and embryo development, was studied in 14 Swedish crossbred (Landrace Yorkshire) multiparous sows. The endotoxin group (E-group) sows were administered with 300 ng/kg of LPS while the control group (C-group) sows were administered with 5 ml of saline i.v. via an indwelling jugular cannula. Immediately after evidence of standing oestrus, a Millar® pressure transducer was placed intraluminally about 3 cm into the mid-isthmus, via laparotomy. Pressure recordings of the oviduct were collected from all conscious sows until slaughter. After slaughter, the genital tract opposite to the side with the transducer was retrieved, and three equal isthmic segments and the first third of the uterine horn part adjacent to the utero-tubal-junction (UTJ) were flushed separately to recover the ova. The intervals (mean±SD) from ovulation to slaughter (OS) and insemination to ovulation (IO) were not different between the E-group (44.5±5.7 h; 13.3±6.5 h) and the C-group (42.7±5.9 h; 14.8±4.1 h), respectively. Ova recovery rate (RR) in the E-group (80.2±22.9%) did not differ from that in the C-group (85.2±4.5%). The frequency distribution of ova recovered in the different segments did not significantly (p>0.05) differ between the groups. The E-group showed higher cleavage rate than controls. A higher proportion of spermatozoa bound to the ZP was also found in the E-group compared with controls. The isthmic intraluminal pressure slightly increased (p=0.07) 18 h after ovulation and immediately following LPS in the E-group, compared with the C-group. The frequencies of phasic pressure fluctuations were significantly (p<0.05) lower at 30 and 38 h after ovulation in the E- than in the C-group. It can be concluded from the present study that a single i.v. administration of LPS (300 ng/kg body weight) to sows, 18 h after ovulation might be associated with changes in isthmic pressure and the frequency of phasic pressure fluctuations, increased numbers of spermatozoa attached to the ZP and an enhanced embryo development but not with ova transport rates. [source] | ||||||||||