• Asian-Australasian Journal of Animal Sciences
• /
• 제15권2호
• /
• pp.172-178
• /
• 2002

The present study examined whether treatment of in vitro matured pig oocytes with calcium ionophore (A23187) could prevent polyspermic penetration in vitro. When oocytes cultured for maturation for 33, 36 or 44 h were subsequently treated with $50{\mu}M$ A23187 in medium with fetal calf serum (FCS) for 1, 2 and 3 h and then cultured for 12 h without spermatozoa, virtually no activation occurred. In the absence of FCS, however, 31-42, 45-49 and 56-64% of oocytes were activated, respectively. When oocytes treated with $50 {\mu}M$ A23187 in medium with FCS for 3 h were inseminated in vitro, the penetration rates (14-57%) were lower (p<0.01) with a higher (p<0.01) incidence (35-67%) of monospermy compared with untreated oocytes (69-80% penetration and 15-17% monospermy). However, sperm penetration was completely blocked in all oocytes treated with A23187 in the absence of FCS. When oocytes matured for 33 h were treated with different concentrations of A23187 for 3 h and inseminated in vitro, the penetration rate did not change but there was an increased incidence (p<0.05) of monospermy at $10-20{\mu}M$ and $2.5-5{\mu}M$ A23187 in the presence and absence of FCS, respectively, compared with at $0{\mu}M$ A23187. With these lower concentrations of A23187, treatment of oocytes for at least 60 and 30 min in the presence and absence of FCS, respectively, was required to increase the incidence of monospermy without reducing penetration rate. These results indicate that a high concentration ($50{\mu}M$) of A23187 in medium without FCS, but not in medium with FCS, stimulated in vitro matured pig oocytes to induce parthenogenetic activation and a complete block to sperm penetration in vitro. However, treatment of oocytes with lower concentrations of A23187 ( $10-20{\mu}M$ and $2.5-5{\mu}M$) both in the presence and absence of FCS maintained sperm penetration in vitro and increased the incidence of monospermy.

• Reproductive and Developmental Biology
• /
• 제33권3호
• /
• pp.125-131
• /
• 2009

The aim of this study is to investigate the effect of porcine epididymal fluid (pEF) on in vitro-maturation and subsequent fertilization of porcine follicular oocytes. Porcine cumulus-oocytes complexes retrieved from antral follicles were cultured in tissue culture medium (TCM)-l99 supplemented with pEF of different concentrations. At 48 h after culture, development of oocytes to germinal vesicle (GV) breakdown, metaphase I, anaphase-telophase I, and metaphase II were examined Significant (p<0.05) increase in the proportion of oocytes developed to MII stage was observed in oocytes cultured in pEF-containing TCM-l99 than in oocytes cultured in pEF-free TCM-199 (46.2% vs 16.7%), which was a dose-dependent manner. Subsequently, the proportion of monospermic fertilization were significantly (p<0.05) increased in oocytes cultured in the TCM supplemented with pEF than those cultured in pEF-free TCM-199 (51.0% vs 24.1%). In the second series of experiment, the percentage of MII oocytes was significantly (p<0.05) increased after exposure of oocytes to pEF during the first 22 h period of culture than after exposure of oocytes to pEF during the next 24 h of culture, while no significant difference in the percentage of monospermy was observed. The results of this study demonstrate that pEF contains at least enhancing component(s) for nuclear maturation.

• 한국발생생물학회지:발생과생식
• /
• 제3권1호
• /
• pp.21-28
• /
• 1999

흰쥐 난자의 체외수정에 있어서 calcium chelator처리에 따른 피질반응 및 피질과립막의 형성 여부와 피질과립막의 전자현미경적 미세구조를 관찰하고, 수정율 및 단정자수정과 다정자수정 빈도에 미치는 영향을 조사하여 수정기간중 calcium의 역할을 조사하였다. Calcium chelator로는 BAPTA/AM을 사용하였으며, 난자의 미세구조와 피질과립막은 주사전자현미경으로 관찰하였다. 투명대가 제거된 난자의 체외수정 과정에서는 피질반응에 의해 형성된 피질과립막 (cortical granule envelope)이 관찰되었고, calcium chelator (1, 5, 10, $\mu$M BAPTA/AM) 처리후 투명대가 제거 된 난자의 체외수정 에서도 마찬가지로 피질과립막이 관찰되었다. 또한 체외 수정 후 시간의 경과에 따라 피질과립막은 좀 더 발달되는 양상을 나타내었다. 수정율은 calcium chelator 처리군 (59.8, 38.1, 37.0%)이 대조군 (60.6%)에 비해 감소했으나, 단정자수정은 calcium chelator 처리군 (45.0, 47.3, 50.9%)이 대조군 (37.5%)에 비해 증가하였다. 위의 결과들로부터 흰쥐에서 수정시 피질과립막이 형성된다는 것을 밝혔고, 피질반응에 extracellular calcium이 이용됨을 알 수 있다. 또한 난자내의 적정한 free calcium 함량이 수정에 중요한 요인으로 작용하는 것으로 사료된다.

• Reproductive and Developmental Biology
• /
• 제32권4호
• /
• pp.217-222
• /
• 2008

The techniques of IVM, IVF and IVC of canine oocytes may provide useful information for gamete salvage programs and the conservation of endangered canidae. This investigation has been made to determine the efficiency of in vitro maturation (IVM) as a basic experiment to study the development of canine oocytes after in vitro fertilization (IVF). The rate of oocytes developing to the Mil stage was higher in the hormone treated group (10 IU/ml hCG+eCG, 14.7%, p<0.05) than in the control group (0 IU/ml hCG+eCG, 10.0%). The monospermy and pronuclear rates of canine oocytes were investigated after caffeine treatment on IVF. Canine oocytes were fertilized in the Fert-TALP medium supplemented with 0, 10, 20 or 30 mM caffeine (Fert I, Fert II, Fert III or Fert IV, respectively). The highest pronuclear formation rate was obtained in the Fert I for 24 h IVF (6.7%, 6/89). Therefore, it is believed that unlike in other mammals, caffeine in canine IVF does not increase the efficiency of fertilization rate, and is not an important factor.

• 한국임상수의학회지
• /
• 제35권2호
• /
• pp.39-45
• /
• 2018

We evaluated the effects of green tea extract (GTE) supplementation at different dilution steps on boar sperm freezing and in vitro fertilization. Sperm intracellular hydrogen peroxide ($H_2O_2$), motility, viability, acrosome integrity and morphology were determined. In addition, sperm IVF parameters (penetration and monospermy) and glutathione (GSH) levels of presumptive zygotes (PZs) were evaluated. Semen was diluted in lactose egg yolk (LEY) and cooled at $5^{\circ}C$ for 3 h (first dilution step) and then diluted in LEY with 9% glycerol and maintained at $5^{\circ}C$ for 30 min (second dilution step). Four experimental groups were compared: first and second dilution steps without GTE (control), first dilution step with GTE (Step 1), second dilution step with GTE (Step 2) and first and second dilution step with GTE (Step 1+2). The spermatozoa were frozen in nitrogen vapor. Higher sperm motility, viability and acrosome integrity after thawing were observed in Step 1, Step 2 and Step 1+2 groups compared with the control (P < 0.05). Lower $H_2O_2$ level was observed in Step 1+2 compared with control and Step 1 (P < 0.05). For IVF, matured oocytes were co-cultured with spermatozoa frozen according to the experimental groups. GSH levels of PZs were significantly higher in Step 2 and Step 1+2 than in control and Step 1 (P < 0.05) without a significant difference in IVF parameters. In conclusion, supplementation with GTE in both first and second dilution steps during the freezing process resulted in better boar sperm cryopreservation and might be beneficial for further embryo development.

• 한국수정란이식학회지
• /
• 제32권4호
• /
• pp.337-342
• /
• 2017

The present study was aimed to determine the effects of green tea extract (GTE) and beta-mercaptoethanol (${\beta}-ME$) supplementation in boar sperm freezing extender on in vitro fertilization (IVF) and reactive oxygen species (ROS) and glutathione (GSH) levels of presumptive zygotes (PZs). Experimental groups were allocated into lactose egg yolk (LEY) without antioxidant (control), GTE (1,000 mg/l in LEY) and ${\beta}-ME$ ($50{\mu}M$ in LEY). In freezing, spermatozoa extended with LEY were cooled to $5^{\circ}C$ for 3 h and then kept at $5^{\circ}C$ for 30 min following dilution with LEY containing 9% glycerol and 1.5% Equex STM. The final sperm concentration was $1{\times}10^8/ml$. Spermatozoa were loaded into straws and frozen in nitrogen vapor for 20 min. For IVF, oocytes were matured in NCSU-23 medium and co-cultured with spermatozoa following thawing at $37^{\circ}C$ for 25 sec. At 12 h following IVF, IVF parameters (sperm penetration and monospermy) were evaluated. In addition, GSH and ROS levels of PZs were determined by Cell Tracker Blue CMF2HC and DCHFDA, respectively. IVF parameters did not show any significant difference among the experimental groups. GSH and ROS levels of PZs were not significantly different between groups. In conclusion, antioxidant supplementation in boar sperm freezing could not influence IVF parameters, ROS and GSH levels of PZs.

• 한국가축번식학회지
• /
• 제18권3호
• /
• pp.199-206
• /
• 1994

본 연구는 생쥐 배 발생과정의 상이한 발현을 RT-PCR법에 의해 무작위 증폭함으로서 새로운 유전자를 손쉽게 크로닝하기 위해 수행되었다. mRNA의 상이한 display법은 Ling 과 Pardee (Science 257, 1992)에 의해 개발되었으며, 최근 Zimermann과 Schultz (PNAS USA 91, 1994)에 의해 재증명되었다. 이 방법은 특정 유전자의 일시적 발현의 변화가 maternal 제어로부터 접합체 제어로의 이행에 따른 발현전이, 다정자 침입과 단일 정자 침입에 의한 배발생의 기능적 차이, 성공적으로 부화한 배반포기 배와 부화에 실패한 배반포기 배에서의 발현의 차이는 물론 세포주기에 따른 유전자 발현 양식의 변화에 따른 새로운 유전자의 크로닝을 가능케 한다. 이 방법에 의해, 2세포기 특이 발현 유전자를 크로닝 하였으며, 이 유전자는 EcoRI제한 효소 처리후 Southern blot을 행한 결과 약 15kb genomic size를 가진 것으로 나타났다. 이 새로운 유전자는 간장 특이적 발현을 나타내었다. 또한, 적어도 2개의 mRNA가 존재하였으며, 이는 RNA splicing에 의한 것으로 추정되었다. (PCR, RT-PCR, cloning, preimplantation, mouse)

• 한국수정란이식학회지
• /
• 제24권2호
• /
• pp.115-119
• /
• 2009

In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed porcine oocytes were examined. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at $38^{\circ}$C in 5% $C0_2$ and air. The percentage of monospermy in the toxicity group and vitrification group (22.0 ${\pm}$ 3.0% and 31.5 ${\pm}$ 3.5%) was decreased compared with that of the control group (44.0 ${\pm}$ 4.0%). The percentage of in vitro development to blastocyst in the toxicity group and vitrification group (12.0 ${\pm}$ 2.5% and 14.8 ${\pm}$ 2.8%) was decreased compared with that of the control group (28.0 ${\pm}$ 3.0%, p<0.05). The survival and in vitro developmental rate of oocytes vitrification-thawed with EDS and EDT + TCM-199 medium supplemented with 0.1% PVA were 46.3 ${\pm}$ 3.0%, 54.5 ${\pm}$ 3.8% and 14.8 ${\pm}$ 2.5%, 16.4 ${\pm}$ 2.7%, respectively. This results were lower than the control group (28.0 ${\pm}$ 3.5%). The in vitro developmental rate of embryos vitrified with EDS and EDT supplemented PVA did not have a significant difference. The survival and in vitro developmental rate of vitrified-thawed morula and blastocyst embryos were 44.2 ${\pm}$ 3.5%, 17.3 ${\pm}$ 3.0% and 48.1 ${\pm}$ 4.2%, 18.5 ${\pm}$ 3.5%, respectively. Vitrified morulae and blastcyst embryos had a lower survival and developmental rates than their control counterparts.

• 한국발생생물학회지:발생과생식
• /
• 제22권4호
• /
• pp.297-307
• /
• 2018

The objective of this study was to evaluate the effects of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on cumulus expansion, nuclear maturation, fertilization capacity and subsequent development in porcine oocytes. The oocytes were incubated with 0, 25, 50, and $100{\mu}M$ ALA. Cumulus expansion was measured at 22 h, and gene expresison and nuclear maturation were analyzed at 44 h after maturation. Then, mature oocytes with ALA were inseminated, and fertilization parameters and embryo development were evaluated. In results, both of cumulus expansion and nuclear maturation were increased in $50{\mu}M$ ALA groups compared to control groups (p<0.05). However, expression of gap junction protein alpha 1 (GJA1, cumulus expansion-related gene), delta-6 desaturase (FADS1, fatty acid metabolism-related gene), and delta-5 desaturase (FADS2) mRNA in cumulus cells were reduced by $50{\mu}M$ ALA treatment (p<0.05). Cleavage rate was enhanced in 25 and $50{\mu}M$ ALA groups (p<0.05), especially, treatment of $50{\mu}M$ ALA promoted early embryo develop to 4 and 8 cell stages (p<0.05). However, blastocyst formation and number of cells in blastocyst were not differ in 25 and $50{\mu}M$ ALA groups. Our findings show that ALA treatment during maturation could improve nuclear maturation, fertilization, and early embryo development through enhancing of cumulus expansion, however, fatty acid metabolism- and cumulus expansion-related genes were down-regulated. Therefore, addition of ALA during IVM of oocytes could improve fertilization and developmental competence, and further studies regarding with the mechanism of ALA metabolism are needed.

• Clinical and Experimental Reproductive Medicine
• /
• 제50권3호
• /
• pp.154-159
• /
• 2023

Monospermy occurs in the process of normal fertilization where a single sperm fuses with the egg, resulting in the formation of a diploid zygote. During the process of fertilization, the sperm must penetrate the zona pellucida (ZP), the outer layer of the egg, to reach the egg's plasma membrane. Once a sperm binds to the ZP, it undergoes an acrosomal reaction, which involves the release of enzymes from the sperm's acrosome that help it to penetrate the ZP. Ovastacin is one of the enzymes that is involved in breaking down the ZP. Studies have shown that ovastacin is necessary for the breakdown of the ZP and for successful fertilization to occur. However, the activity of ovastacin is tightly regulated to ensure that only one sperm can fertilize the egg. One way in which ovastacin helps to prevent polyspermy (the fertilization of an egg by more than one sperm) is by rapidly degrading the ZP after a sperm has penetrated it. This makes it difficult for additional sperm to penetrate the ZP and fertilize the egg. Ovastacin is also thought to play a role in the block to polyspermy, a mechanism that prevents additional sperm from fusing with the egg's plasma membrane after fertilization has occurred. In summary, the role of ovastacin in monospermic fertilization is to help ensure that only one sperm can fertilize the egg, while preventing polyspermy and ensuring successful fertilization.