Presence of Intact Cumulus Cells during In Vitro Fertilization Inhibits Sperm Penetration but Improves Blastocyst Formation In Vitro

돼지 난자의 체외 수정에 있어서 난구 세포의 존재가 정자 침투율 및 배 발육에 미치는 영향

  • Yong, H.Y. (Craniomaxillofacial Life Science BK21, Dental Research Institute, School of Dentistry, Seoul National University) ;
  • Lee, E. (School of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University)
  • 용환율 (서울대학교 치과대학 치학연구소 BK21 치의학생명과학사업단) ;
  • 이은송 (강원대학교 수의학부대학 및 동물의학종합연구소)
  • Published : 2007.03.31

Abstract

This study was conducted to examine the role of intact cumulus cells during in vitro fertilization (IVF) on sperm penetration, male pronuclear (MPN) formation and subsequent embryo development of oocytes matured and fertilized in vitro. Cumulus-oocyte complexes obtained from the slaughtered gilt ovaries were matured for 44 h in TCM199 containing 10% porcine follicular fluid, epidermal growth factor and hormones. After maturation culture, denuded oocytes or oocytes with intact cumulus cells were coincubated with frozen-thawed boar semen for 8h in a modified tris-buffered medium containing 5mM caffeine and 10mM calcium chloride. Putative zygotes were fixed and examined for sperm penetration and MPN formation (Experiments $1{\sim}3$), or cultured in North Carolina State University-23 medium fo. 156 h (Experiment 3). In Experiment 1, sperm penetration was examined after insemination of denuded oocytes and oocytes with intact cumulus cells at the concentration of $7.5{\times}10^5$ sperm/ml. Optimal sperm concentration for IVF of cumulus-intact oocytes was determined in Experiment 2 by inseminating intact oocytes with $2{\sim}5{\times}10^6$ sperm/ml. In Experiment 3, denuded or intact oocytes were inseminated at the concentrations of $7.5{\times}10^5$ and $4.0{\times}10^6$ sperm/ml, respectively, and in vitro embryo development was compared. Sperm penetration was significantly (p<0.01) decreased in cumulus-intact oocytes compared to denuded oocytes (35.2% vs. 77.4%). Based on the rates of sperm penetration and normal fertilization, the concentration of $4.0{\times}10^6$ sperm/ml was optimal for the IVF of intact oocytes compared to other sperm concentrations. The presence of intact cumulus cells during IVF significantly (p<0.05) improved embryo cleavage (48.8% vs. 58.9%), blastocyst (BL) formation (11.0% vs. 22.8%) and embryo cell number $(22{\pm}2\;vs.\;29{\pm}2\;cells)$ compared to denuded oocytes. In conclusion, these results suggest that intact cumulus cells during IVF inhibit sperm penetration but improve embryo cleavage, BL formation and embryo cell number of porcine embryos produced in vitro.

본 연구는 체외 성숙된 난자와 동결 융해 정자를 이용한 돼지의 체외 수정 과정에서 난구 세포의 존재가 정자 침투율, 웅성전핵 형성률 그리고 후기배로의 체외 발육에 미치는 영향을 알아보기 위하여 수행되었다. 돼지 난소로부터 난자-난구세포 복합체를 채취하여 eCG/hCG, 10% 돼지 난포액, epidermal growth factor 등이 첨가된 TCM 199 배양액에서 44시간 배양하여 체외 성숙을 유도하였다. 성숙 배양 후 난구 세포를 제거한 난자와 난구 세포가 부착되어 있는 난자를 돼지 동결 융해정액을 이용하여 5mM caffeine과 10mM calcium chloride를 함유한 mTBM배양액에서 8시간 체외 수정하였다. 체외 수정 후 난자를 고정, 염색하여 정자 침투율과 웅성전핵 형성률을 조사하였고(실험 $1{\sim}3$) 일부 수정란을 North Carolina State University-23 배양액에서 체외 수정 후 156시간 배양하여 후기배로의 발육능을 검토하였다(실험 3). 실험 1에서는 정자 농도를 $7.5{\times}10^5/ml$로 조정하여 나화 난자와 난구 세포 부착난자에서 정자 침투율 및 웅성전핵 형성률을 조사하였다. 실험 2에서는 난구 세포 부착 난자의 체외 수정에 적합한 정자 농도를 구하기 위해 2, 3, 4, 및 $5{\times}10^6/ml$의 농도로 난자를 수정한 후 정자 침투율 및 웅성전핵 형성률을 조사하였다. 실험 3에서는 나화 난자 및 난구 세포 부착 난자를 각각 $7.5{\times}10^5/ml$의 정자 농도로 체외 수정한 후 후기배로의 발육률을 조사하였다. 실험 1의 결과 정자 침투율은 나화 난자에 비해 난구 세포 부착 난자에서 유의적으로 감소되었다(35.2% vs. 77.4%; p<0.01). 실험 2에서 다양한 정자 농도에 의한 정자 침투율과 정상 수정률을 바탕으로 판단했을 때 $4.6{\times}10^6/ml$의 정자 농도가 다른 정자 농도에 비해 난구 세포부착 난자의 체외 수정에 적합한 것으로 나타났다. 체외 수정과정에서 난구 세포 부착된 상태로 수정된 난자는 나화 난자에 비해 유의적으로(p<0.05) 높은 분할률(48.8% vs. 58.9%), 배반포 형성률(11.0% vs. 22.8%)과 배반포 세포수$(22{\pm}2\;vs.\;29{\pm}2)$를 나타내었다. 본 연구의 결과로부터 돼지의 체외 수정과정에서 난구 세포의 존재는 정자 침투를 저해하지만 분할률, 배반포 형성률 및 배반포의 세포수를 증가시키는 것으로 사료된다.

Keywords

References

  1. Abeydeera LR and Day BN. 1997. In vitro penetration of pig oocytes in a modified Tris-buffered medium: effect of BSA, caffeine and calcium. Theriogenology, 48:537-544 https://doi.org/10.1016/S0093-691X(97)00270-7
  2. Aitken RJ. 1999. The Amoroso Lecture. The human spermatozoon - a cell in crisis? J. Reprod. Fertil., 115: 1-7 https://doi.org/10.1530/jrf.0.1150001
  3. Bavister BD. 1982. Evidence for a role of post-ovulatory cumulus components in supporting fertilizing ability of hamster spermatozoa. J. Androl., 3:365-372 https://doi.org/10.1002/j.1939-4640.1982.tb00703.x
  4. Bedford JM and Kim HH. 1993. Cumulus oophorus as a sperm sequestering device, in vivo. J. Exp. Zool., 265:321-328 https://doi.org/10.1002/jez.1402650314
  5. Chian RC, Niwa K and Sirard MA. 1994. Effects of cumulus cells on male pronuclear formation and subsequent early development of bovine oocytes in vitro. Theriogenology, 41: 1499-1508 https://doi.org/10.1016/0093-691X(94)90201-S
  6. Fatehi AN, Roelen BA, Colenbrander B, Schoevers EJ, Gadella BM, Bevers MM and van den Hurk R. 2005. Presence of cumulus cells during in vitro fertilization protects the bovine oocyte against oxidative stress and improves first cleavage but does not affect further development. Zygote, 13:177-185 https://doi.org/10.1017/S0967199405003126
  7. Fraser LR. 1985. Albumin is required to support the acrosome reaction but not capacitation in mouse spermatozoa in vitro. J. Reprod. Fertil., 74:185-196 https://doi.org/10.1530/jrf.0.0740185
  8. Gil MA, Abeydeera LR, Day BN, Vazquez JM, Roca J and Martinez EA. 2003. Effect of the volume of medium and number of oocytes during in vitro fertilization on embryo development in pigs. Theriogenology, 60:767-776 https://doi.org/10.1016/S0093-691X(03)00051-7
  9. Gil MA, Ruiz M, Cuello C, Vazquez JM, Roca J and Martinez EA. 2004. Influence of sperm:oocyte ratio during in vitro fertilization of in vitro matured cumulus-intact pig oocytes on fertilization parameters and embryo development. Theriogenology, 61:551-560 https://doi.org/10.1016/S0093-691X(03)00209-7
  10. Han YJ, Miah AG, Yoshida M, Sasada H, Hamano K, Kohsaka T and Tsujii H. 2006. Effect of relaxin on in vitro fertilization of porcine oocytes. J. Reprod. Dev., 52:657-662 https://doi.org/10.1262/jrd.18038
  11. Hao Y, Mathialagan N, Walters E, Mao J, Lai L, Becker D, Li W, Critser J and Prather RS. 2006. Osteopontin reduces polyspermy during in vitro fertilization of porcine oocytes. Biol. Reprod., 75:726-733 https://doi.org/10.1095/biolreprod.106.052589
  12. Hong JY, Yong HY, Lee BC, Hwang WS, Lim JM and Lee ES. 2004. Effects of amino acids on maturation, fertilization and embryo development of pig follicular oocytes in two IVM media. Theriogenology, 62:1473-1482 https://doi.org/10.1016/j.theriogenology.2004.02.013
  13. Kikuchi K, Nagai T, Motilik J, Shiuoya Y and Izaike Y. 1993. Effect of follicle cells on in vitro fertilization of pig follicular oocytes. Theriogenology, 39:593-599 https://doi.org/10.1016/0093-691X(93)90246-2
  14. Lavy G, Boyers SP and De Cherney AH. 1988. Hyaluronidase removal of the cumulus oophorus increases in vitro fertilization. J. In. Vitr. Fertil. Embryol. Trans., 5:257-260 https://doi.org/10.1007/BF01132173
  15. Li YH, Ma W, Li M, Hou Y, Jiao LH and Wang WH. 2003. Reduced polyspermic penetration in porcine oocytes inseminated in a new in vitro fertilization (IVF) system: straw IVF. Biol. Reprod., 69:1580-1585 https://doi.org/10.1095/biolreprod.103.018937
  16. Mahi-Brown CA and Yanagimachi R. 1983. Parameters influencing ovum pickup by the oviductal fimbria in the golden hamster. Gamete Res., 8:1-10 https://doi.org/10.1002/mrd.1120080102
  17. Motta PM, Nottola SA, Pereda J, Croxatto HB and Familiari G. 1995. Ultrastructure of human cumulus oophorus: a transmission electron microscope study on oviductal oocytes and fertilized egg. Hum. Reprod., 10:2361-2367 https://doi.org/10.1093/oxfordjournals.humrep.a136299
  18. Nakai M, Kashiwazaki N, Takizawa A, Maedomari N, Ozawa M, Noguchi J, Kaneko H, Shino M and Kikuchi K. 2006. Morphologic changes in boar sperm nuclei with reduced disulfide bonds in electrostimulated porcine oocytes. Reproduction, 131:603-611 https://doi.org/10.1530/rep.1.01001
  19. Neill JD. 2006. Knobil and Neill's Physiology of Reproduction. 3rd ed., Elsevier, Amsterdam, pp. 65-67
  20. Park YE, Hong JY, Yong HY, Lim JM and Lee ES. 2005. Effect of exogenous energy substrates in a serum-free culture medium on the development of in vitro matured and fertilized porcine embryos. Zygote, 13: 269-275 https://doi.org/10.1017/S0967199405003369
  21. Petters RM and Wells KD. 1993. Culture of pig embryos. J. Reprod. Fertil. Suppl., 48:61-73
  22. Pursel VG and Johnson LA. 1975. Freezing of boar spermatozoa: fertilizing capacity with concentrated semen and new thawing procedure. J. Anim. Sci., 40:99-102 https://doi.org/10.2527/jas1975.40199x
  23. Richter L, Romeny E, Weitze KF and Zimmermann F. 1975. Deep freezing of boar semen. VII. Communication: Laboratory and Field expenments using extender Hlilsenberg VIII. Dt. Tierarztl. Wschr., 82:155-162
  24. Salustri A, Yanagishita M and Hascall V. 1989. Synthesis and accumulation of hyaluronic acid and proteoglycans in the mouse cumulus cell oocyte complex during follicle-stimulating hormone-induced mucification. J. Biol. Chem., 264: 13840-13847
  25. Staigmiller RB and Moor RM. 1984. Effect of follicle cells on the maturation and developmental competence of ovine oocytes matured outside the follicle. Gamete Res., 9:221-229 https://doi.org/10.1002/mrd.1120090211
  26. Suzuki M, Misumi K, Ozawa M, Noguchi J, Kaneko H, Ohnuma K, Fuchimoto D, Onishi A, Iwamoto M, Saito N, Nagai T and Kikuchi K. 2006. Successful piglet production by IVF of oocytes matured in vitro using NCSU-37 supplemented with fetal bovine serum. Theriogenology, 65:374-386 https://doi.org/10.1016/j.theriogenology.2005.05.039
  27. Suzuki C, Yoshioka K, Itoh S, Kawarasaki T and Kikuchi K. 2005. In vitro fertilization and subsequent development of porcine oocytes using cryopreserved and liquid-stored spermatozoa from various boars. Theriogenology, 64:1287-1296 https://doi.org/10.1016/j.theriogenology.2005.03.009
  28. Tanghe S, Van Soom A, Nauwynck H, Coryn M and De Kruif A. 2002. Minireview: Functions of the cumulus oophorus during oocyte maturation, ovulation and fertilization. Mol. Reprod. Dev., 61:414-424 https://doi.org/10.1002/mrd.10102
  29. Tesarik J, Mendoza Oltras C and Testart J. 1990. Effect of the human cumulus oophorus on movement characteristics of human capacitated spermatozoa. J. Reprod. Fertil., 88:665-675 https://doi.org/10.1530/jrf.0.0880665
  30. Tatemoto H, Sakurai N and Muto N. 2000. Protection of porcine oocytes against apoptotic cell death caused by oxidative stress during in vitro maturation: Role of cumulus cells. Biol. Reprod., 63:805-810 https://doi.org/10.1095/biolreprod63.3.805
  31. Vanderhyden BC and Armstrong DT. 1989. Role of cumulus cells and serum on the in vitro maturation, fertilization, and subsequent development of rat oocytes. Biol. Reprod., 40: 720-728 https://doi.org/10.1095/biolreprod40.4.720
  32. Wang WH, Abeydeera LR, Okuda K and Niwa K. 1994. Penetration of porcine oocytes during maturation in vitro by cryopreserved ejaculated spermatozoa. Biol. Reprod., 50:510-515 https://doi.org/10.1095/biolreprod50.3.510
  33. Wongsrikeao P, Kaneshige Y, Ooki R, Taniguchi M, Agung B, Nii M and Otoi T. 2005. Effect of the removal of cumulus cells on the nuclear maturation, fertilization and development of porcine oocytes. Reprod. Dom. Anim., 40:166-170 https://doi.org/10.1111/j.1439-0531.2005.00576.x
  34. Yamauchi N and Nagai T. 1999. Male pronuclear formation in denuded porcine oocytes after in vitro maturation in the presence of cysteamine. Biol. Reprod., 61:828-833 https://doi.org/10.1095/biolreprod61.3.828
  35. Yoon KW, Shin TY, Park JI, Roh S, Lim JM, Lee BC, Hwang WS and Lee ES. 2000. Development of porcine oocytes from preovulatory follicles of different sizes after maturation in media supplemented with follicular fluids. Reprod. Fertil. Dev., 12:133-139 https://doi.org/10.1071/RD00027
  36. Zhang L, Jiang S, Wozniak PJ, Yang X and Godke RA. 1995. Cumulus cell function during bovine oocyte maturation, fertilization, and embryo development in vitro. Mol. Reprod. Dev., 40:338-344 https://doi.org/10.1002/mrd.1080400310