Register      Login
Reproduction, Fertility and Development Reproduction, Fertility and Development Society
Vertebrate reproductive science and technology
RESEARCH ARTICLE

The effects of glucuronic acid and N-acetyl-D-glucosamine on in vitro fertilisation of porcine oocytes

K. Schmidt A , A. Clark A , A. Mello A , C. Durfey A , A. Buck A , K. Boyd A and B. D. Whitaker A B
+ Author Affiliations
- Author Affiliations

A Department of Animal and Pre-veterinary Studies, The University of Findlay, 1000 North Main Street, Findlay, OH 45840, USA.

B Corresponding author. Email: whitaker@findlay.edu

Reproduction, Fertility and Development 28(8) 1223-1231 https://doi.org/10.1071/RD14226
Submitted: 23 June 2014  Accepted: 9 December 2014   Published: 14 January 2015

Abstract

High incidences of polyspermic penetration continue to challenge researchers during porcine in vitro fertilisation (IVF). The aim of this study was to reduce the incidence of polyspermy by increasing the perivitelline space thickness with glucuronic acid and N-acetyl-D-glucosamine (GlcNAc) supplementation during oocyte maturation. After maturation, zona pellucida and perivitelline space thicknesses, intracellular glutathione concentrations and fertilisation kinetics were measured, in addition to embryonic cleavage and blastocyst formation at 48 h and 144 h after IVF, respectively. There were no significant differences between the treatments for zona pellucida thickness, penetration rates, male pronuclear formation or cortical granule exocytosis. Glucuronic acid supplementation significantly increased (P < 0.05) the perivitelline space thickness and significantly lowered the incidence (P < 0.05) of polyspermy. GlcNAc supplementation significantly increased (P < 0.05) intracellular glutathione concentrations. Supplementation with 0.005 mM glucuronic acid plus 0.005 mM GlcNAc during oocyte maturation produced significantly higher rates (P < 0.05) of cleavage and blastocyst formation by 48 and 144 h after IVF compared with all other groups. These results indicate that supplementing with 0.005 mM glucuronic acid and 0.005 mM GlcNAc during oocyte maturation decreases the incidence of polyspermic penetration by increasing perivitelline space thickness and improving embryo development in pigs.

Additional keywords: cortical granules, perivitelline space, polyspermy.


References

Abbott, A. L., and Ducibella, T. (2001). Calcium and the control of mammalian cortical granule exocytosis. Front. Biosci. 6, d792–d806.
Calcium and the control of mammalian cortical granule exocytosis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXlslKhu7k%3D&md5=c4796111dec36141796857e54ae280a0CAS | 11438440PubMed |

Abeydeera, L. R., and Day, B. N. (1997). In vitro penetration of pig oocytes in a modified Tris-buffered medium: effect of BSA, caffeine and calcium. Theriogenology 48, 537–544.
In vitro penetration of pig oocytes in a modified Tris-buffered medium: effect of BSA, caffeine and calcium.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXmt1Whs7c%3D&md5=098c1aa9fe173cabad5bec0458c09285CAS | 16728149PubMed |

Abeydeera, L. R., Wang, W. H., Cantley, T. C., Prather, R. S., and Day, B. N. (1998). Presence of mercaptoethanol can increase the glutathione content of pig oocytes matured in vitro and the rate of blastocyst development after in vitro fertilisation. Theriogenology 50, 747–756.
Presence of mercaptoethanol can increase the glutathione content of pig oocytes matured in vitro and the rate of blastocyst development after in vitro fertilisation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXnvFaktLs%3D&md5=e71f8c1783313279ebcb3ed1bd89f7faCAS | 10734449PubMed |

Almiñana, C., Gil, M. A., Cuella, C., Roca, J., Vazquez, J. M., Rodriguez-Martinez, H., and Martinez, E. A. (2005). Adjustments in IVF system for individual boars: value of additives and time of sperm–oocyte co-incubation. Theriogenology 64, 1783–1796.
Adjustments in IVF system for individual boars: value of additives and time of sperm–oocyte co-incubation.Crossref | GoogleScholarGoogle Scholar | 15907993PubMed |

Anderson, M. E. (1985). Determination of glutathione and glutathione disulfide in biological samples. Methods Enzymol. 113, 548–555.
Determination of glutathione and glutathione disulfide in biological samples.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28XmsFenuw%3D%3D&md5=19b964a752cdf4a88971daaa3d8e2a50CAS | 4088074PubMed |

Arambašić, J., Mihailović, M., Uskoković, A., Dinić, S., Grdović, N., Marković, J., Poznanović, G., Bajec, D., and Vidaković, M. (2013). Alpha-lipoic acid upregulates antioxidant enzyme gene expression and enzymatic activity in diabetic rat kidneys through an O-GlcNAc-dependent mechanism. Eur. J. Nutr. 52, 1461–1473.
Alpha-lipoic acid upregulates antioxidant enzyme gene expression and enzymatic activity in diabetic rat kidneys through an O-GlcNAc-dependent mechanism.Crossref | GoogleScholarGoogle Scholar | 23064900PubMed |

Baker, M. A., Cerniglia, G. J., and Zaman, Z. (1990). Microtitre plate assay for the measurement of glutathione and glutathione disulfide in large numbers of biological samples. Anal. Biochem. 190, 360–365.
Microtitre plate assay for the measurement of glutathione and glutathione disulfide in large numbers of biological samples.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXmt1Ons70%3D&md5=92d078397db12455b4734441ff9a6f3aCAS | 2291479PubMed |

Bianchi, E., Doe, B., Goulding, D., and Wright, G. J. (2014). Juno is the egg izumo receptor and is essential for mammalian fertilisation. Nature 508, 483–487.
Juno is the egg izumo receptor and is essential for mammalian fertilisation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXmslaltb4%3D&md5=8b35ad5689c71ec2c9525263c2c7ae24CAS | 24739963PubMed |

Broermann, D. M., Sie, S., Nephew, K. P., and Pope, W. F. (1989). Effects of the oviduct and wheat-germ agglutinin on enzymatic digestion of porcine zona pellucidae. J. Anim. Sci. 67, 1324–1329.
| 1:CAS:528:DyaL1MXktlOisro%3D&md5=cdd4d6c755359eac9c8287739c786384CAS | 2661516PubMed |

Coy, P., Martinez, E., Ruiz, S., Vázquez, J. M., Roca, J., Matas, C., and Pellicer, M. T. (1993). In vitro fertilisation of pig oocytes after different co-incubation intervals. Theriogenology 39, 1201–1208.
In vitro fertilisation of pig oocytes after different co-incubation intervals.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zgtVSnuw%3D%3D&md5=4fac899ae5538e0dd9e9f28dad43eb1eCAS | 16727288PubMed |

Cran, D. G., and Cheng, W. T. K. (1985). Changes in cortical granules during porcine oocyte maturation. Gamete Res. 11, 311–319.
Changes in cortical granules during porcine oocyte maturation.Crossref | GoogleScholarGoogle Scholar |

Cran, D. G., and Cheng, W. T. K. (1986). The cortical reaction in pig oocytes during in vivo and in vitro fertilisation. Gamete Res. 13, 241–251.
The cortical reaction in pig oocytes during in vivo and in vitro fertilisation.Crossref | GoogleScholarGoogle Scholar |

Damiani, P., Fissore, R. A., Cibelli, J. B., Long, C. R., Balise, J. J., Robl, J. M., and Duby, R. T. (1996). Evaluation of developmental competence, nuclear and ooplasmic maturation of calf oocytes. Mol. Reprod. Dev. 45, 521–534.
Evaluation of developmental competence, nuclear and ooplasmic maturation of calf oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XnsVWgt7k%3D&md5=2c14c3830e6d65ba9c556ba365bcdddbCAS | 8956291PubMed |

Dang-Nguyen, T. Q., Somfai, T., Haraguchi, S., Kikuchi, K., Tajima, A., Kanai, Y., and Nagai, T. (2011). In vitro production of porcine embryos: current status, future perspectives and alternative applications. Anim. Sci. J. 82, 374–382.
In vitro production of porcine embryos: current status, future perspectives and alternative applications.Crossref | GoogleScholarGoogle Scholar | 21615829PubMed |

Fasshauer, D., Eliason, W. K., Brunger, A. T., and Jahn, R. (1998). Identification of a minimal core of the synaptic SNARE complex sufficient for reversible assembly and disassembly. Biochemistry 37, 10354–10362.
Identification of a minimal core of the synaptic SNARE complex sufficient for reversible assembly and disassembly.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXktFOitrc%3D&md5=eb82166667afd16a634cec02bdca0d46CAS | 9671503PubMed |

Fléchon, J. E. (1974). Application of cytochemical techniques to the study of maturation of gametes and fertilisation in mammals. Multipurpose use of glycolmethacrylate embedding. Histochem. J. 6, 65–67.

Fléchon, J. E., Degrouard, J., Kopečny, V., Pivko, J., Pavlok, A., and Motlik, J. (2003). The extracellular matrix of porcine mature oocytes: origin, composition and presumptive roles. Reprod. Biol. Endocrinol. 1, 124–137.
The extracellular matrix of porcine mature oocytes: origin, composition and presumptive roles.Crossref | GoogleScholarGoogle Scholar | 14675483PubMed |

Funahashi, H., Ekwall, H., and Rodriguez-Martinez, H. (2000). Zona reaction in porcine oocytes fertilised in vivo and in vitro as seen with scanning electron microscopy. Biol. Reprod. 63, 1437–1442.
Zona reaction in porcine oocytes fertilised in vivo and in vitro as seen with scanning electron microscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXnslCktrg%3D&md5=214cbd57b76939eab780586104c46a2fCAS | 11058549PubMed |

Gil, M. A., Cuello, C., Parrilla, I., Vazquez, J. M., Roca, J., and Martinez, E. A. (2010). Advances in swine in vitro embryo production technologies. Reprod. Domest. Anim. 45, 40–48.
Advances in swine in vitro embryo production technologies.Crossref | GoogleScholarGoogle Scholar | 20591064PubMed |

Grupen, C. G. (2014). The evolution of porcine embryo in vitro production. Theriogenology 81, 24–37.
The evolution of porcine embryo in vitro production.Crossref | GoogleScholarGoogle Scholar | 24274407PubMed |

Hoodbhoy, T., and Talbot, P. (1994). Mammalian cortical granules: contents, fate and function. Mol. Reprod. Dev. 39, 439–448.
Mammalian cortical granules: contents, fate and function.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXisFWjt7w%3D&md5=df886bd754d9e54ec60d7bc21615b3a9CAS | 7893493PubMed |

Hubbard, C., McNamara, J. T., Azumaya, C., Patel, M. S., and Zimmer, J. (2012). The hyaluronan synthase catalyses the synthesis and membrane translocation of hyaluronan. J. Mol. Biol. 418, 21–31.
The hyaluronan synthase catalyses the synthesis and membrane translocation of hyaluronan.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XjsFOitb0%3D&md5=8ece2010f14e05a69b38913f23a4d9dbCAS | 22343360PubMed |

Iwamoto, K., Ikeda, K., Yonezawa, N., Noguchi, S., Kudo, K., Hamano, S., Kumayama, M., and Nakano, M. (1999). Disulfide formation in bovine zona pellucida glycoproteins during fertilisation: evidence for the involvement of cystine cross-linkages in hardening of the zona pellucida. J. Reprod. Fertil. 117, 395–402.
Disulfide formation in bovine zona pellucida glycoproteins during fertilisation: evidence for the involvement of cystine cross-linkages in hardening of the zona pellucida.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXnvFOqtro%3D&md5=a093b884c7caf5d31723dbbc0ddbd59aCAS | 10690208PubMed |

Kim, N. H., Funahashi, H., Abeydeera, L. R., Moon, S. J., Prather, R. S., and Day, B. N. (1996). Effects of oviductal fluid on sperm penetration and cortical granule exocytosis during fertilisation of pig oocytes in vitro. J. Reprod. Fertil. 107, 79–86.
Effects of oviductal fluid on sperm penetration and cortical granule exocytosis during fertilisation of pig oocytes in vitro.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XmtFOlur4%3D&md5=04b410f54eb39f356e0b6fc749180906CAS | 8699438PubMed |

Lee, J., You, J., Lee, G. S., Hyun, S. H., and Lee, E. (2013). Pig oocytes with a large perivitelline space matured in vitro show greater developmental competence after parthenogenesis and somatic cell nuclear transfer. Mol. Reprod. Dev. 80, 753–762.
| 1:CAS:528:DC%2BC3sXhtVarsr7E&md5=8f033c1dcf2cddd9c76256ffb32918e2CAS | 23818168PubMed |

Li, Y. H., Ma, W., Li, M., Hou, Y., Jiao, L. H., and Wang, W. H. (2003). Reduced polyspermic penetration in porcine oocytes inseminated in a new in vitro fertilisation (IVF) system: straw IVF. Biol. Reprod. 69, 1580–1585.
Reduced polyspermic penetration in porcine oocytes inseminated in a new in vitro fertilisation (IVF) system: straw IVF.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXosV2ku7k%3D&md5=80e68412f1081006b7263b6ef407e775CAS | 12826575PubMed |

Liu, M. (2011). The biology and dynamics of mammalian cortical granules. Reprod. Biol. Endocrinol. 9, 149.
The biology and dynamics of mammalian cortical granules.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xht1Gg&md5=0cb1c3a812736c4d23a1d0ab5de46dcbCAS | 22088197PubMed |

Momozawa, K., and Fukuda, Y. (2011). Establishment of an advanced chemically defined medium for early embryos derived from in vitro-matured and fertilised bovine oocytes. J. Reprod. Dev. 57, 681–689.
Establishment of an advanced chemically defined medium for early embryos derived from in vitro-matured and fertilised bovine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XjtVGrsLc%3D&md5=ee8a92b91e9357d8c569cde236714adbCAS | 21804301PubMed |

Mugnier, S., Dell’Aquila, M. E., Pelaez, J., Douet, C., Ambruosi, B., De Santis, T., Lacalandra, G. M., Lebos, C., Sizaret, P. Y., Delaleu, B., Monget, P., Mermillod, P., Magistrini, M., Meyers, S. A., and Goudet, G. (2009). New insights into the mechanisms of fertilisation: comparison of the fertilisation steps, composition and structure of the zona pellucida between horses and pigs. Biol. Reprod. 81, 856–870.
New insights into the mechanisms of fertilisation: comparison of the fertilisation steps, composition and structure of the zona pellucida between horses and pigs.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtlWrtr%2FK&md5=653d896db03828ada02b53b94eb9c2d0CAS | 19587333PubMed |

Nancarrow, C. D., and Hill, J. H. (1995). Oviduct proteins in fertilisation and early embryo development. J. Reprod. Fertil. Suppl. 49, 3–13.
| 1:CAS:528:DyaK2MXmslWit70%3D&md5=152d65f65f2aa3cfa01c14156afaa3dcCAS | 7623323PubMed |

Niwa, K. (1993). Effectiveness of in vitro maturation and in vitro fertilisation techniques in pigs. J. Reprod. Fertil. Suppl. 48, 49–59.
| 1:STN:280:DyaK2c7psVCktA%3D%3D&md5=99beba7f62b21feb96bbf3820308dbc7CAS | 8145214PubMed |

Petters, R. M., and Wells, C. D. (1993). Culture of pig embryos. J. Reprod. Fertil. Suppl. 48, 61–73.
| 1:STN:280:DyaK2c7psVCktQ%3D%3D&md5=7002296cdb1ef5547c559a1807f66f2bCAS | 8145215PubMed |

Rath, D., Töpfer-Petersen, E., Michelmann, H. W., Schwartz, P., and Ebeling, S. (2005). Zona pellucida characteristics and sperm-binding patterns of in vivo- and in vitro-produced porcine oocytes inseminated with differently prepared spermatozoa. Theriogenology 63, 352–362.
Zona pellucida characteristics and sperm-binding patterns of in vivo- and in vitro-produced porcine oocytes inseminated with differently prepared spermatozoa.Crossref | GoogleScholarGoogle Scholar | 15626404PubMed |

Romar, R., Coy, P., and Rath, D. (2012). Maturation conditions and boar affect timing of cortical reaction in porcine oocytes. Theriogenology 78, 1126–1139.
Maturation conditions and boar affect timing of cortical reaction in porcine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC38jnsVejsQ%3D%3D&md5=04d5cabe31d07c8d43efc58bc6af8f17CAS | 22763072PubMed |

Selman, K., and Anderson, E. (1975). The formation and cytochemical characterisation of cortical granules in ovarian oocytes of the golden hamster (Mesocricetus auratus). J. Morphol. 147, 251–274.
The formation and cytochemical characterisation of cortical granules in ovarian oocytes of the golden hamster (Mesocricetus auratus).Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE28%2FkvVOqtA%3D%3D&md5=44441674968ab5ff64d07493149a7ce5CAS | 1185788PubMed |

Son, J., Malaweera, D. B., Lee, E., Shin, S., and Cho, J. (2013). Development of in vitro-produced porcine embryos according to serum types as macromolecule. J. Vet. Sci. 14, 315–321.
Development of in vitro-produced porcine embryos according to serum types as macromolecule.Crossref | GoogleScholarGoogle Scholar | 23820204PubMed |

Stojkovic, M., Kölle, S., Peinl, S., Stojkovic, P., Zakhartchenko, V., Thomson, J. G., Wenigerkind, H., Reichenbach, H. D., Sinovatz, F., and Wolf, E. (2002). Effects of high concentrations of hyaluronan in culture medium on development and survival rates of fresh and frozen–thawed bovine embryos produced in vitro. Reproduction 124, 141–153.
Effects of high concentrations of hyaluronan in culture medium on development and survival rates of fresh and frozen–thawed bovine embryos produced in vitro.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XmtFaksLg%3D&md5=303f30e7684871dd9f736e35908a81a6CAS | 12090927PubMed |

Sun, Q. Y., Lai, L., Park, K. K., Kuhholzer, B., Prather, R. S., and Schatten, H. (2001). Dynamic events are differently mediated by microfilaments, microtubules and mitogen-activated protein kinase during porcine oocyte maturation and fertilisation in vitro. Biol. Reprod. 64, 879–889.
Dynamic events are differently mediated by microfilaments, microtubules and mitogen-activated protein kinase during porcine oocyte maturation and fertilisation in vitro.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXhsVKjtro%3D&md5=c7fa99df7798c85dcab573c9a2b1a067CAS | 11207204PubMed |

Suzuki, K., Eriksson, B., Shimizu, H., Nagai, T., and Rodrıguez-Martinez, H. (2000). Effect of hyaluronan on monospermic penetration of porcine oocytes fertilised in vitro. Int. J. Androl. 23, 13–21.
Effect of hyaluronan on monospermic penetration of porcine oocytes fertilised in vitro.Crossref | GoogleScholarGoogle Scholar | 10632757PubMed |

Suzuki, K., Asano, A., Eriksson, B., Niwa, K., Nagai, T., and Rodrıguez-Martinez, H. (2002). Capacitation status and in vitro fertility of boar spermatozoa: effects of seminal plasma, cumulus–oocyte-complex-conditioned medium and hyaluronan. Int. J. Androl. 25, 84–93.
Capacitation status and in vitro fertility of boar spermatozoa: effects of seminal plasma, cumulus–oocyte-complex-conditioned medium and hyaluronan.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XjtFSitb8%3D&md5=b5cf02826989bd1394401ad7cb3d490cCAS | 11903657PubMed |

Szollosi, D. (1967). Development of cortical granules and the cortical reaction in rat and hamster eggs. Anat. Rec. 159, 431–446.
Development of cortical granules and the cortical reaction in rat and hamster eggs.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaF1c3jsFChsA%3D%3D&md5=8a37b34f744ca6c0724041278a223ab4CAS | 5626358PubMed |

Tatemoto, H., and Terada, T. (1999). Analysis of zona pellucida modifications due to cortical granule exocytosis in single porcine oocytes, using enhanced chemiluminescence. Theriogenology 52, 629–640.
Analysis of zona pellucida modifications due to cortical granule exocytosis in single porcine oocytes, using enhanced chemiluminescence.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3c7pvVGgtQ%3D%3D&md5=a8a9f3c4b1f91091ede28b30104c4eb0CAS | 10734362PubMed |

Wang, W. H., Hosoe, M., and Shioya, Y. (1997). Induction of cortical granule exocytosis of pig oocytes by spermatozoa during meiotic maturation. J. Reprod. Fertil. 109, 247–255.
Induction of cortical granule exocytosis of pig oocytes by spermatozoa during meiotic maturation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXivV2gtLc%3D&md5=418fa806aaaa0f45d5df6b2e12837906CAS | 9155734PubMed |

Wang, W. H., Abeydeera, L. R., Prather, R. S., and Day, B. N. (1998). Morphological comparison of ovulated and in vitro-matured porcine oocytes, with particular reference to polyspermy after in vitro fertilisation. Mol. Reprod. Dev. 49, 308–316.
Morphological comparison of ovulated and in vitro-matured porcine oocytes, with particular reference to polyspermy after in vitro fertilisation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXosVyjsQ%3D%3D&md5=e79fa5f18be89abd92d7cfb83c140780CAS | 9491383PubMed |

Wang, W. H., Machaty, Z., Abeydeera, L. R., Prather, R. S., and Day, B. N. (1999). Time course of cortical and zona reaction of pig oocytes upon intracellular calcium increase induced by thimerosal. Zygote 7, 79–86.
Time course of cortical and zona reaction of pig oocytes upon intracellular calcium increase induced by thimerosal.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXit1Klt7Y%3D&md5=4d4bad91eb9aed5c08d3350ebe240fb9CAS | 10216920PubMed |

Wang, W. H., Day, B. N., and Wu, G. M. (2003). How does polyspermy happen in mammalian oocytes? Microsc. Res. Tech. 61, 335–341.
How does polyspermy happen in mammalian oocytes?Crossref | GoogleScholarGoogle Scholar | 12811738PubMed |

Weber, T., Zemelman, B. V., McNew, J. A., Westermann, B., Gmachl, M., Parlati, F., Sollner, T. H., and Rothman, J. E. (1998). SNAREpins: minimal machinery for membrane fusion. Cell 92, 759–772.
SNAREpins: minimal machinery for membrane fusion.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXit1KlsLs%3D&md5=fd3c78af6e46d95d3c4f8efa6e582e1fCAS | 9529252PubMed |

Whitaker, B. D., and Knight, J. W. (2008). Mechanisms of oxidative stress in porcine oocytes and the role of anti-oxidants. Reprod. Fertil. Dev. 20, 694–702.
Mechanisms of oxidative stress in porcine oocytes and the role of anti-oxidants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXotlCnu7s%3D&md5=c7d58952b82f5279a456950a31cdc76fCAS | 18671917PubMed |

Yanagimachi, R. (1994). Mammalian fertilisation. In ‘The Physiology of Reproduction’. (Eds E. Knobil and J. D. Neill.) pp. 261–268. (Raven Press: New York.)

Yoshida, M., Cran, D. G., and Pursel, V. G. (1993a). Confocal and fluorescence microscopic study using lectins of the distribution of cortical granules during the maturation and fertilisation of pig oocytes. Mol. Reprod. Dev. 36, 462–468.
Confocal and fluorescence microscopic study using lectins of the distribution of cortical granules during the maturation and fertilisation of pig oocytes.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK2c7jslClsg%3D%3D&md5=aea52f004a8e9ccc075f98a2c71a654aCAS | 8305208PubMed |

Yoshida, M., Ishigaki, K., Nagai, T., Chikyu, M., and Pursel, V. G. (1993b). Glutathione concentration during maturation and after fertilisation in pig oocytes: relevance to the ability of oocytes to form male pronucleus. Biol. Reprod. 49, 89–94.
Glutathione concentration during maturation and after fertilisation in pig oocytes: relevance to the ability of oocytes to form male pronucleus.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXkvFahtLY%3D&md5=69d76b153ad02cec7e49e6cf85fe8b18CAS | 8353194PubMed |

Zhang, W., Yi, K., Yan, H., and Zhou, X. (2012). Advances on in vitro production and cryopreservation of porcine embryos. Anim. Reprod. Sci. 132, 115–122.
Advances on in vitro production and cryopreservation of porcine embryos.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XovVGqs7o%3D&md5=e3af6e143639a270bfe4dcf4d42440e8CAS | 22698497PubMed |