Effects of the Porcine Oviduct-Specific Glycoprotein on Fertilization, Polyspermy, and Embryonic Development In Vitro1

Abstract

This study evaluated the effects of porcine oviduct-specific glycoprotein (pOSP) on in vitro fertilization (IVF), polyspermy, and development to blastocyst. Experiment 1 evaluated the effects of various concentrations (0-100 microgram/ml) of purified pOSP on fertilization parameters, including penetration, polyspermy, male pronuclear formation, and mean number of sperm penetrated per oocyte. Experiment 2 examined the ability of an anti-pOSP immunoglobulin G to inhibit the observed effects of pOSP on fertilization parameters. Experiments 3 and 4 examined various concentrations of pOSP (0-100 microgram/ml) on zona pellucida solubility and sperm binding, respectively. Lastly, experiment 5 assessed the effects of various concentrations of pOSP (0-100 microgram/ml) on the in vitro embryo cleavage rate and development to blastocyst. Pig oocytes matured and fertilized in vitro were used for all experiments. An effect of treatment (P < 0.05) was detected for pOSP on penetration, polyspermy, and mean number of sperm per oocyte. Concentrations for pOSP of 0-50 microgram/ml had no effect on sperm penetration rates; however, compared with the control, 100 microgram/ml significantly decreased the penetration rate (74% vs. 41%). Addition of 10-100 microgram/ml significantly reduced the polyspermy rate compared with the control (61% vs. 24-29%). The decrease in polyspermy achieved by addition of pOSP during preincubation and IVF was blocked with a specific antibody to pOSP. No effect of treatment was observed on zona digestion time relative to the control; however, the number of sperm bound to the zona pellucida was significantly decreased by treatment (P < 0.05). Compared with the control, all concentrations of pOSP examined reduced the number of sperm bound per oocyte (45 vs. 19-34). A treatment effect (P < 0.05) was observed for pOSP on embryo development to blastocyst but not on cleavage rates. Addition of pOSP during preincubation and fertilization significantly increased postcleavage development to blastocyst, but a synergistic stimulation on development was not detected when pOSP was included during in vitro culture. These results indicate that exposure to pOSP before and during fertilization reduces the incidence of polyspermy in pig oocytes, reduces the number of bound sperm, and increases postcleavage development to blastocyst.

Oviduct-specific glycoprotein and heparin modulate sperm–zona pellucida interaction during fertilization and contribute to the control of polyspermy

“…cycle, (ii) nucleotide and amino acid sequences of OGP are highly conserved between species (29) (Table S3), which agrees with the crossed action of porcine and bovine fluids, and (iii) OGP possesses heparin-binding consensus sequences (29) and heparin-binding sites (30), which would explain why heparin in the incubation medium stabilizes the hardening effect. To demonstrate the involvement of OGP in ZP modifications and its detachment in a medium lacking heparin, different experiments were performed.…”

The Leading Blastomere of the 2-Cell Stage Parthenogenetic Porcine Embryo Contributes to the Abembryonic Part First

“…Unlike mice, the in vitro maturation (IVM) and fertilization (IVF) processes are the most common and economic choices for obtaining 2-cell embryos in a pig model. However, polyspermic fertilization is a major problem in porcine IVF [14]. To avoid the influences of the fertilization cone, which indicates the sperm entry position, and to prevent topological change of the two or more apposing pronuclei in the egg center caused by polyspermy after IVF, we chose porcine parthenogenetic embryos for use in the present study even though they may not represent normal embryonic development in the pig.…”

Antibodies against the C-terminal peptide of rabbit oviductin inhibit mouse early embryo development to pass 2-cell stage

“…In the future, gain-of-function experiments may help to confirm the importance of the Cterminal peptide of the rabbit oviductin in the development of early embryo. It was reported that oviductin has a function on fertilization [3], [4], [16], while our research suggested that oviductin also has a function on the release of early embryonic development block.…”

“…The homology comparisons also showed that there were 40-50% smilarities between rabbit oviductin and some enzymes of chitinase gene family, but the oviductins showed no chitinase activity [14]. In recent years, few researches concerning the roles of oviductins in the development of early embryo were reported [15], [16].…”