• 대한생식의학회:학술대회논문집
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• 1999.05a
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• pp.45-52
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• 1999

포유동물의 수정은 정자가 난자내로 침입함으로써 시작되는데 이때 정자는 부계의 유전물질 이외에도 다양한 후성적 요소들 (epigenetic factors), 즉 난활성 인자, 중심체, 부계 유래의 mitochondria 및 부계 특이 삽입 유전자 등을 난자에 전달해 준다. 하지만 수정 및 초기 배발달동안 정자에 의해 전달된 후성적 요소들의 역할과 기능적 발현 및 억제 기전에 관해서는 명확히 알려져 있지 않다. 수정보조기법인 ICSI 및 ROSI의 개발은 남성불임치료에 혁신적인 기술로 자리잡고 있을 뿐만 아니라 포유동물의 수정과정을 이해 하는데 많은 도움을 주고 있다. 본 연구실에서는 최근 몇 년간 돼지난자에 정자, 다양한 정자 구성 요소들, 정낭세포, 및 이종의 정자 등을 미세주입하여 수정을 유도한 후 핵질 및 세포질의 변화과정과 배 발달과정을 살펴 봄으로써, 수정시 정자에 의해 전달되는 후성적 요소들의 기능과 발현 기작을 규명하고자 하였다. 이러한 연구의 결과들은 체외수정, ICSI, ROSI 등의 임상치료기술의 개선에 기초자료로 활용될 수 있으리라 생각한다.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.596-602
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• 2016

Experiments were carried out examine short-term effects of human chorionic gonadotropin (hCG) and long-term effects of luteinising hormone releasing hormone analogue (LHRHa) on milt production of the tongue sole Cynoglossus semilaevis. In the first experiment, each fish was implanted with a blank cholesterol pellet (control), 100 and $200{\mu}g$ LHRHa per kg body weight. In the second experiment, fish were injected with either 100, 200, 400 and 800 IU hCG per kg body weight or same volume of marine fish Ringer's solution. In the first experiment, milt volume was increased in male implanted with $200{\mu}g$ LHRHa pellet compared with other groups at day 10. Injection of 400 and 800 IU hCG resulted in an increase in the milt volume at hour 96 after the treatment. Although statistical difference is unable to confirm because of small milt volume, compared with the control group, hormone pellet-treated groups had a reduction in the mean spermatocrit (Sct) and sperm concentration (Sc). The results suggest that the increase in milt volume is at least partially gonadotropin (GtH)-dependent and increased milt volume has a relationship with milt hydration.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.3
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• pp.119-124
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• 2019

Objective: It is widely accepted that aging decreases women's fertility capacity. The aim of this study was to assess correlations between maternal age and the morphokinetic parameters and cleavage pattern of embryos. Methods: The morphokinetics of embryos derived from women < 30, 30-35, 36-40, and > 40 years of age were compared retrospectively in terms of time of second polar body extrusion, time of pronuclei appearance, time of pronuclei fading, and time of two to eight discrete cells (t2-t8). Furthermore, abnormal cleavage patterns such as uneven blastomeres at the two-cell stage, cell fusion (Fu), and trichotomous mitoses (TM) were assessed. Results: Only t5 occurred later in women aged 36-40 and > 40 years when compared with those aged < 30 and 30-35 years (p< 0.001). Other morphokinetic timing parameters, as well the presence of uneven blastomeres, were comparable between the groups (p> 0.05). However, Fu and TM were more common in women aged > 40 years than in younger women (p< 0.001). Conclusion: Maternal age was correlated with the cleavage pattern of embryos. Therefore, evaluating embryo morphokinetics may contribute to optimal embryo selection, thereby increasing fertility in patients with advanced maternal age.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.4
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• pp.189-194
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• 2018

Objective: The aim of this study was to compare the rate of maturation, fertilization, and embryo development of in vitro-matured human oocytes derived from pregnant and non-pregnant women. Methods: Immature oocytes were obtained by needle aspiration from 49 pregnant women (group 1) who underwent a cesarean section at term and 77 non-pregnant women (group 2) who underwent a gynecological operation during the same period (8 months). Healthy immature oocytes (530 in group 1 and 539 in group 2) were cultured and assessed for maturation 36 hours later. Mature oocytes were inseminated by intracytoplasmic sperm injection and cultured up to 144 hours. Results: The percentage of degenerated oocytes was significantly higher (12.1% vs. 6.3%; p<0.001) in group 1 than in group 2. There was no significant difference in the maturation rate (66.8% vs. 68.1%; p=0.698), fertilization rate (66.7% vs. 67.6%; p=0.857), or the rate of formation of good-quality blastocysts (46.2% vs. 47.2%; p=0.898) in oocytes obtained from pregnant and non-pregnant women. Conclusion: The developmental competence of immature oocytes did not differ between pregnant and non-pregnant women.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.4
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• pp.362-367
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• 2021

Objective: The impact of early mechanical removal of cumulus cells on fertilization and embryonic development is not yet precisely known. This study aimed to investigate the effects of early and late cumulus cell removal on fertilization, polyspermy, embryonic development potential, blastocyst development, and clinical outcomes. Methods: A prospective study was conducted of patients who underwent in vitro fertilization between September 2019 and October 2020. Sibling oocytes were randomly allocated after insemination to early cumulus cell removal at 6 hours (group I) and late cumulus cell removal at 16-18 hours (group II). If total fertilization failure (TFF) was determined to have occurred at early cumulus cell removal, rescue intracytoplasmic sperm injection (ICSI) was performed. Fertilization, embryonic development, and pregnancy outcomes were compared. Results: A total of 912 oocytes were assigned to group I (458 oocytes) and group II (454 oocytes). Fertilization, polyspermy, embryo quality, and pregnancy outcomes were not significantly different between both groups. Rescue ICSI enabled fertilization of 79.2% of the TFF oocytes. Conclusion: Early cumulus cell removal at 6 hours had no significant difference in fertilization, polyspermy, embryo development, or obstetric and perinatal outcomes compared to late removal. Early cumulus cell removal combined with early rescue ICSI may have the potential to help couples with TFF.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.105-110
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• 2004

Objectives: Despite severe oligospermia, males with Y chromosome microdeletion can achieve conception through ICSI (Intracytoplasmic Sperm Injection). However, ICSI may not only result in the transmission of microdeletions but also the expansion of deletion to the offspring. The purpose of this study was to screen vertical transmission, expansion of microdeletions and de novo deletion in male fetuses conceived by ICSI. Materials and Methods: A total of 32 ICSI treated patients with their 33 (a case of twin) male fetuses conceived by ICSI were used to make this study group. Sequence-tagged sites (STSs)-based PCR analyses were performed on genomic DNA isolated from peripheral blood of fathers and from the amniocytes of male fetuses. Ten primer pairs namely, sY134, sY138, MK5, sY152, sY147, sY254, sY255, SPGY1, sY269 and sY158 were used. The samples with deletions were verified at least three times. Results: We detected a frequency of 12.5% (4 of the 32 patients) of microdeletions in ICSI patients. In 4 patients with detected deletions, two patients have proven deletions on single STS marker and their male fetuses have the identical deletion in this region. Another two patients have two and three deletions, but their male fetuses have more than 3 deletions which include deletions to their father's. Meanwhile, seven male fetuses, whose fathers were analyzed to have all 10 STS markers present, have deletions present in at least one or more of the markers. Conclusions: Although the majority of deletions on the Y chromosome are believed to arise de novo, in some cases a deletion has been transmitted from the fertile father to the infertile patient. In other cases the deletion was transmitted through ICSI treatment, it is likely that one sperm cell is injected through the oocyte's cytoplasm and fertilization can be obtained from spermatozoa. Our tests for deletion were determined by PCR and our results show that the ICSI treatment may lead to vertical transmission, expansion and de novo Y chromosome microdeletions in male fetuses. Because the sample group was relatively small, one should be cautious in analyzing these data. However, it is important to counsel infertile couples contemplating ICSI if the male carries Y chromosomal microdeletions.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.223-227
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• 2010

These study was carried out to investigate the effects of the recovery time, diameter of oocytes on in vitro fertilization or intracytoplasmic sperm injection (ICSI). The in vitro maturation rates to MII stage of oocytes recovered at the inactive, follicular and luteal stages matured for 72 h were $1.4{\pm}0.0%$, $43.4{\pm}3.2%$ and $10.8{\pm}2.7%$, respectively. The fertilization rates of in vitro cultured oocytes recovered from ovaries at the in active, follicular and luteal stages were $0.0{\pm}0.0%$, $15.7{\pm}3.4%$ and $7.6{\pm}3.5%$, respectively. The in vitro maturation rate of oocytes recovered from ovaries at the follicular stage of the reproductive cycle was significantly higher than those at the inactive and luteal stages (p<0.05). The penetration rate determined that the percentages of oocytes with diameters in the < $100\;{\mu}m$, 100 to $100\;{\mu}m$ and 110 to $120\;{\mu}m$ ranges were $17.5{\pm}4.7%$, $43.9{\pm}4.5%$, $21.3{\pm}3.4%$, respectively. The penetration rate of oocytes with diameters between 100 to $100\;{\mu}m$ was significantly higher than that of oocytes whose diameters were < $100\;{\mu}m$ and $110{\sim}120\;{\mu}m$ (p<0.05). The penetration rate of oocytes determined that the percentages of ovaries with diameters between 1 to 5 mm and 6 to 10 mm were $32.9{\pm}3.2%$ and $17.5{\pm}3.7%$, respectively. Thus, the diameters of the ovaries were significantly higher at 1 to 5 mm (p<0.05). A total of 264 oocytes were fixed and stained after co-incubation with sperm, of which 72 had identifiable nuclear material. After in vitro fertilization for 20 hrs, 27.3% of oocytes were penetrated by spermatozoas. Oocytes were fixed and stained after ICSI, of which 38 oocytes contained identifiable nuclear material. After in vitro fertilization and ICSI for 20 hrs, to 27.3% and 67.9% of oocytes were penetrated by spermatozoas. The in vitro fertilization rates by ICSI was significantly higher than that in vitro fertilization method (p<0.05).

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.171-177
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• 1998

The combination of testicular sperm extraction (TESE) with ICSI can achieve normal fertilization and pregnancy rate and is effective method in obstructive and non-obstructive azoospermic patients. But, when pregnancy was not occurred, repeated testicular biopsies are not evitable. Therefore, in this study, we observed the survival rate of testicular spemratozoa and spermatozoa extracted from the seminiferous tubules after cryopreserved-thawed used for next IVF cycle with ICSI. In a total of 23 cases, obstructive azoospermia was 17 cases and non-obstructive azoospermia was 6 cases. In obstructive azoospermia, after thawing, motile spermatozua was observed in 13 cases (76.5%). The fertilization rate with 2PN was 67.6% and 5 pregnancies (29.4%) were achieved. In non-obstructive azoospermia, motile spermatozoa was observed in 2 case (33.3%) after thawing. The fertilization rates with 2PN was 53.7% and 3 pregnancies (50.0%) were achieved. A comparison of the results of motile spermatozoa after thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section were 3 cases (60.0%) and 12 cases (66.6%), respectively. The fertilization and pregnancy rates of thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section were 69.4% and 20.0%, 62.5% and 38.8%, respectively. Conclusively, thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section can achieve normal fertilization and pregnancy and cryopreservation of testicular spermatozoa and seminiferous tubule may avoid repetition of testicular biopsies in azoospermic patients in whom the only source of spermatozoa is the testis.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.159-172
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• 1991

It has been investigated what could be the selective marker distinguishing the immature from mature spermatozoa and whether fi -glucuronidase and fi -glucosidase are dependent on androgen in the luminal fluid of the epididymis or not. The contents of hexose, hexosamine and sialic acid in the epithelial cells, luminal fluid and spermatozoa of the epididymis were examined and the patterns of protein bands were compared in each group of the luminal fluid by SDS-PAGE. Lactate dehydrogenase, glucose-6-phosphatase, Na+ -K+ -ATPase and MgNa-ATPase showed higher activities in the cauda than the caput epididymal spermatozoa but only $Mg^2$+-ATPase activity appeared to be changed significantly. When the contents of hexose, hexosamine and sialic acid were analyzed and compared quantitatively, those of hexose were significantly different in the luminal fluid of caput and cauda epididymis, those of hexosamine in the epithelial cells and those of sialic acid in the epithelial cells and luminal fluid. When SDS-PAGE has been performed in each group, the band of MW 33-37 KD which was absent in the luminal fluid of caput epididymis appeared obviously in the luminal fluid of cauda epididymis and ako apeared in the cauda sperm crude membrane fraction. In addition, $\beta$ -glucuronidase and $\beta$ -glucosidase activities and their dependence on androgen were measured and the SDS-PAGE patiems of proteins and/or glycoproteins in the luminal fluid were examined. The activities of these two enzymes in the luminal fluid of the epididymis decreased significantly from the 5th day after castration. When testosterone was injected, the activity of $\beta$ -glucuronidase began to increase significantly from the 5th day following injection and that of $\beta$ -glucosidase from the loth day. On the other hand, the band of about MW 21 KD was newly observed in the lumen of caput epididymis when testosterone was administered.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.239-249
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• 1999

The role of amino acids in culture media for IVF-ET was examined in a total of 76 cycles. Patients received clomiphene citrate (CC) followed by hMG or GnRH-a combined with gonadotropins (FSH/hMG) for controlled ovarian hyperstimulation. Severe male (<$4{\times}10^6$ motile sperm) or age factor (>39 y) patients were excluded in this study. Pregnancy was classified as clinical if a gestational sac or fetal cardiac activity was seen on ultrasound. No significant differences were found in age, duration of infertility, follicle size, the level of $E_2$ on the day of hCG injection, the mean number of oocytes retrieved, total motile sperm count, fertilization rate and the mean number of embryos transferred between bHTF (without amino acids) and mHTF (with amino acids) groups. However, total ampules of gonadotropins were higher (p<0.01) in mHTF group than bHTF group. Significantly (p<0.05) more clinical pregnancies were recorded in mHTF group (13/30) compared with bHTF group (9/46). The multiple pregnancy rates were 11.1% in bHTF group and 7.7% in mHTF group. There were one ectopic pregnancy in mHTF group and one heterotopic pregnancy in bHTF group. Abortion rates were 22.2% in bHTF group and 7.7% in mHTF, respectively. The ongoing pregnancy or livebirth rate was significantly (p<0.05) higher in mHTF group (12/30) than bHTF group (7/46). These results suggest that the addition of amino acids in culture media is essential for culture of zygotes in vitro and adjustment of energy substrates in phosphate-free culture media appears to be beneficial for human IVF-ET procedure.