Effect of hyaluronan on monospermic penetration of porcine oocytes fertilized in vitro

Abstract. The influence of acute exposure to zearalenone (ZEN) on porcine oocyte maturation, fertilization or sperm penetration ability during both in vitro maturation and fertilization was evaluated. First, oocytes were cultured in ZENcontaining (0−1000 μg/l) maturation medium and then fertilized. The oocytes maturing in vitro without ZEN were then fertilized in ZEN-containing fertilization medium. The maturation rates of oocytes and penetration ability of sperm decreased significantly in the presence of 1000 μg/l of ZEN. However, neither increases in the rates of degeneration and DNA fragmentation of oocytes nor reductions in normal and polyspermic fertilization were observed. ZEN did not affect the sperm penetration rates; however, 1000 μg/l ZEN had positive effects on normal and polyspermic fertilization rates. Therefore, it can be suggested that an acute exposure of porcine oocytes during maturation and of oocytes and sperm during fertilization to ZEN up to 1000 μg/l may not affect the fertility of the oocytes.Key words: Oocytes, Porcine, Sperm, Zearalenone (J. Reprod. Dev. 57: [547][548][549][550] 2011) earalenone (ZEN) is a nonsteroidal estrogen-like mycotoxin produced by Fusarium species on several grains. It is an estrogen receptor agonist; its distinct estrogenic and anabolic properties in several animal species exert detrimental effects on the reproductive system resulting in reproductive disorders in domestic animals, particularly in swine [1][2][3][4]. Although in vitro culture systems do not always provide accurate predictions of toxicity in animals, they can be used to assess risks and can help to define the mechanisms by which mycotoxins act on germ cells [5]. Several in vitro culture assays have been employed to determine the effect of ZEN and its metabolites on the reproductive organs of swine. Previous in vitro experiments revealed that exposure to these mycotoxins affects oocyte maturation, pronucleus formation and embryonic development [6,7], as well as viability, motility and acrosome reactions in sperm [8,9]. Nevertheless, the acute effects of exposure to ZEN during in vitro fertilization remain unknown. This study aimed to examine the effects of exposure to ZEN on porcine oocytes and sperm by using an in vitro maturation (IVM) and in vitro fertilization (IVF) systems to assess the state of nuclear DNA damage and fertilization.As shown in Table 1, exposure to 1000 μg/l of ZEN had a negative effect on the meiotic competence of porcine oocytes (P<0.05). However, there were no significant differences among the groups with respect to the percentages of oocytes showing degeneration and DNA damage. Exposure to 100 and 1000 μg/l of ZEN during maturation culture decreased the total rate of sperm penetration (P<0.05) compared with the control group, but did not influence the rates of normal or polyspermic fertilization of oocytes.As shown in Table 2, exposure to ZEN during IVF did not affect total rates of sperm penetration irrespective of the ZEN concentration. However, exposure to 1000 μg/l of...

contrasting

confidence: 74%

Effects of Exposure to Zearalenone on Porcine Oocytes and Sperm During Maturation and Fertilization In Vitro

Sambuu

Takagi

Namula

et al. 2011

“…Ejaculated spermatozoa were collected from a boar of the Landrace breed and frozen [23]. Groups of 15 to 20 matured o ocytes surrounded by e x p a n d e d c u m u l u s c e l l s w e r e f e r t i l i z e d (insemination = Day 0) in vitro in 90-µL drops of P i g -F M , u s i n g f r o z e n -t h a w e d e j a c u l a t e d spermatozoa that had been at a final concentration of 1 × 10 4 cells/mL.…”

Section: In Vitro Fertilization Activation and Embryo Culturementioning

confidence: 99%

Advanced In Vitro Production of Pig Blastocysts Obtained through Determining the Time for Glucose Supplementation

Medvedev

Ōnishi

Fuchimoto

et al. 2004

Abstract.The objective was to determine the effect of glucose supplementation on development (to the blastocyst stage) of in vitro matured (IVM) porcine oocytes that were either in vitro fertilized (IVF) or electrically activated (EA). Embryos were incubated for 46 or 58 h post insemination (hpi) in an NCSU37-based medium containing 0.17 mM sodium pyruvate and 2.73 mM sodium lactate (IVCPyrLac), and then transferred to an NCSU37-based medium containing 5.55 mM glucose (IVC-Glu) and cultured until Days 6 (Day 0 = day of EA or IVF). The proportions of oocytes that had formed full blastocysts by Day 6 following transfer to IVC-glu at 46 hpi was 23.5 and 41.2% in the IVF and EA groups respectively; these were lower (P<0.001) than the proportions of oocytes that formed full blastocysts after transfer at 58 hpi (60.3 and 78.7%). However, there was no significant difference in total cell number (at Day 6) between embryos transferred at 46 vs 58 hpi. We inferred that in vitroderived pig embryos can efficiently use glucose as an energy source starting at approximately 58 hpi; exposure to glucose at that time enhanced development to the blastocyst stage as well as blastocyst quality. Key words: Pig embryo, Blastocyst, Glucose usage, In vitro fertilization, Activation (J. Reprod. Dev. 50: [71][72][73][74][75][76] 2004) wine are increasingly used in transgenic technologies, including gene manipulation and nuclear transfer; both of these technologies require in vitro production of large quantities of matured oocytes and embryos. Although substantial progress has been ma de in in vitro cult ure, maturation and fertilization (IVC, IVM and IVF, respectively) of porcine oocytes, the overall efficiency of in vitro production of porcine embryos remains relatively low. Several critical aspects should be considered, i.e. variation in oocyte sources and quality of IVM [1][2][3][4][5][6], and increased polyspermy [7,8] and morphological abnormalities [4,9 ] in porcine embryos produced by IVF. Although substantial efforts have been made to optimize culture conditions for preimplantation porcine embryos, the metabolic needs of the embryo are still not well understood. In many mammals, the utilization of glucose increases as pr e im pl an t at io n d ev el op m en t p r og re s s es ; glycolysis becomes the dominant pathway during preimplantation development [10][11][12][13]. In the pig (as in many other mammals), glucose utilization in highest in morulae and blastocysts [13,14], consistent with the energy required for the f o r m a t i o n a n d e x p a n s i o n o f b l a s t o c y s t s . Furthermore, glucose supplementation enhanced in vitro development of pig embryos [4,16,17], with

“…The increases in [Ca 2+ ]i due to hyaluronic acid exposure in human and macaque sperm are not in sufficient to induce the AR [35,37], but they do dramatically increase the number of sperm that undergo the AR in response to the ZP [38,39]. Although the hyaluronic acid binding f u n c t i o n o f P H -2 0 i s s t i l l u n c l e a r i n b o a r spermatozoa, addition of hyaluronic acid to IVF medium improves the rate at which oocytes are penetrated in a conventional porcine IVF protocol using frozen-thawed ejaculated boar spermatozoa [40]. In general, spermatozoa penetrate the expanded cumulus mass containing the hyaluronic acid-rich viscoelastic matrix to fertilize the egg, but antihyaluronidase agents interfere with the transit of sperm through the expanded cumulus mass and led to a reduction in the penetration rate [10,11,22].…”

mentioning

confidence: 99%

Antihyaluronidase Action of Ellagic Acid Effectively Prevents Polyspermy As a Result of Suppression of the Acrosome Reaction Induced by Sperm-Zona Interaction During In Vitro Fertilization of Porcine Oocytes

Tokeshi

Yoshimoto

Muto

et al. 2007

Abstract. The present study was conducted to examine the effects of three tannin relatives (tannic acid, TA; gallic acid, GA; and ellagic acid, EA) on antihyaluronidase and reactive oxygen species (ROS) scavenging activity, in vitro fertilization (IVF) parameters, and the acrosome reaction (AR) induced by sperm-zona interaction. Among the three tannin relatives, TA and EA showed the strongest potency for blocking the hyaluronidase activity of boar sperm, with concentrationdependent inhibition over the range of 2-10 µg/ml. In contrast, ROSs were effectively scavenged by TA and GA, but not EA. When cumulus-free oocytes were inseminated in IVF medium containing 5 µg/ml of the tannin relatives, polyspermy was significantly reduced by TA and EA (32 and 29%, respectively) compared with oocytes treated with or without GA (51 and 69%, respectively) under conditions that maintained a high sperm penetration rate (P<0.05). Interestingly, induction of the AR by treatment of preincubated sperm with progesterone was blocked by TA and GA as a result of their higher levels of ROS scavenging activity, while EA, which possessed weak ROS scavenging activity, did not disturb induction of the AR with progesterone. However, the incidence of AR induced by sperm-zona interaction was significantly decreased by the strong antihyaluronidase actions of TA and EA compared with that in the absence of these compounds. Treatment with the compounds caused neither a protective proteolytic modification of the zona pellucida matrix before fertilization nor a reduction in acrosomal proteolytic activity or the number of zona-bound sperm. These findings suggest that the antihyaluronidase action of EA effectively prevents polyspermy by suppression of AR functionality induced by sperm-zona interaction and that hyaluronidase intervention is therefore required during porcine IVF.