• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.293-300
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• 2009

The rate of fetus with abnormal chromosomes increase with maternal age. Nondisjunction of aging oocyte chromosome is a major reason for the increased rate of abnormalities. Telomeres are the ends of eukaryotic chromosome, which are essential for chromosome stability and are related in cell senescence. This study was carried out to analyze the chromosome aberration rate and amount of telomeric DNA in chick embryo along with maternal age. Fertilized eggs and blood were sampled from White Leghorn layers starting at 20 weeks through to 70 weeks age at 10 weeks interval. Chromosome aberration rate was analyzed by karyotyping. The amounts of telomeric DNA in embryonic cells and lymphocytes were quantified by Quantitative Fluorescence in situ Hybridization method. The chromosome aberration rate in chick embryos significantly differed with maternal age. The chromosome aberration rate increased at early laying period and beyond 70 weeks of maternal age. Therefore, chromosome aberration rate was affected by maternal age due to ovulated oocytes state. However, the amount of telomeric DNA on embryonic cells did not differ significantly with maternal age. Thus, maternal age does not affects telomere quantity in their embryos due to cellular reprograming at early embryonic stage after fertilization.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.1
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• pp.41-49
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• 1996

본 연구는 체외수정에 의해 생산된 생쥐 배반포기배를 vitrification 방법으로 동결보존하였을때 높은 생존율을 얻기 위한 적정조건을 검토하고자 실시하였다. 배반포기배를 생산하기 위하여, B6CBA F1 (C57BL/6, (표현불가)${\times}CBA/N$, (표현불가)) 계통의 생쥐 미수정란에 $1{\times}10^6$ spermatozoa/ml 농도의 정자로서 수정을 유도하였으며, 이후 $37^{\circ}C$, 5% $CO_2$배양기내에서 96시간동안 체외배양하였다. 배양 4일째의 배반포기배는 발달상태에 따라 early, middle 그리고 hatching blastocysts로 구분하였다. 본 실험에 사용된 동결보존액은 30% Ficoll과 0.5mol의 sucrose가 첨가된 mDPBS 용액에 40%의 ethylene glycol를 첨가한 EFS 40 (Zhu et al., 1993) 이었고, 수정란은 $25^{\circ}C$의 상온에서 먼저 20% ethylene glycol에 노출된 후 EFS 40 용액으로 옮겨 액체질소에 침지하는 2단계 동결법에 의해 동결보존되었으며, 급속융해하여 다음과 같은 결과를 얻었다. 1. 체외수정율과 배양 4일째 배반포기까지의 배발달율은 각각 89.4%와 86.1%였다. 2. 20% ethylene glycol에서 5분간 평형된 후 EFS 40 용액에 냉동보존된 후 융해된 난자의 생존율은 20% ethylene glycol에 0, 1, 3분간 평형된 난자의 생존율에 비해 유의하게 높았다. 3. 배반포기배를 20% ethylene glycol에서 5분간, EFS 40 용액에 1분간 차례로 노출한 다음 체와배양하였던 바, 배양 24시간째 생존율은 $82.9%{\sim}88.4%$ 였다. 본 연구 결과, 체외수정, 배양된 생쥐 배반포기배는 20% ethylene glycol과 EFS40에 대한 노출만으로는 난자의 생존성에 나쁜 영향을 미치지 않는 것으로 미루어 보아 배반포기배의 초자화 동결이 가능함을 시사하였다. 따라서 동결 융해 후 높은 생존율은 상온에서 난자를 2단계 즉, 20% ethylene glycol에 5분간 평형시킨 후 EFS 40 용액에 노출하여 1분내에 LN2에 직접 침지하는 간편한 동결방법으로 얻을 수 있었다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.115-115
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• 2003

아미노산은 수정란의 체외생산에 있어서 배발달에 유효하게 작용한다. 이러한 이유로 체외배양 단계에 아미노산 첨가에 관한 보고는 많지만, 체외성숙 단계에서의 아미노산 효과와 관련된 보고는 소수이다. 본 실험에서는 먼저 체외성숙 배지에 NEAA와 EAA군들의 첨가 농도가 PB 출현율, 배발달율 그리고 생산된 배반포의 세포수에 미치는 영향과 더불어 새로운 아미노산원으로 LAH의 효과를 검토하였다. 체외성숙을 위한 난포란은 도축 한우 난소에서 2-8mm의 가시난포로부터 회수하였다. 체외성숙용 배지는 10% FBS가 첨가된 CRlaa 용액을 사용하였고, 실험1에서는 NEAA와 EAA(20$\mu l$/ml)군을 각각 $\times$l (NEAA:10$\mu l$/ml, EAA:20$\mu l$/ml), $\times$2 및 $\times$4를, 실험2에서는 LAH를 각각 1, 5 및 10 mg/ml를 첨가하였다. 체외수정은 fer-TALP 용액을, 체외배양은 CRlaa 용액을 배양 2일째까지는 0.3% BSA를, 그 이후에는 10% FBS와 난관상피세포를 첨가하여 사용하였다. 그리고 배양 8일째 확장배반포의 세포수를 조사하기 위하여 이중형광염색을 실시하였다. 통계분석은 $X^2$-test를 이용하였다. 실험 1에서 NEAA와 EAA 첨가 농도에 따른 PB 출현율은 $\times$l 첨가군(46.6%)이 대조군(29.9%)에 비하여 유의적으로 높았다. 수정을, 8세포기 및 배반포까지 발달율은 비슷한 경향이었으나, $\times$l 첨가군이 가장 높았다. 한편 ICM 세포수가 아미노산 첨가 농도의 높을수록 증가하는 경향이었고, 특히 $\times$4 첨가군($23.9 \mu 3.9$)이 대조군($14.8 \mu 2.5$)에 비하여 유의적(P<0.05)으로 높았다. 실험 2에서 LAH 첨가에 따른 핵성숙율은 5mg 첨가군, 배반포까지 발달율은 1mg 첨가군(25.9%)이 각각 가장 높았다. 배양 8일째 배반포의 세포수에 있어서 총세포수와 TE 세포수는 차이가 없었으나, ICM 세포수가 l0mg 첨가군에서 가장 높았다. 본 실험 결과에서 체외성숙 배지에 NEAA와 EAA 첨가가 배발달율에는 효과가 없었지만, 첨가농도의 증가에 따라 ICM 세포수가 증가하였다. 한편 체외성숙 배지에 LAH 첨가는 첨가 농도가 높을수록 배발달율은 낮았지만 ICM 세포수는 증가하였다.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.639-645
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• 1997

The objectives of the present study were improvements in the efficiency of developmental rates to morula and blastocyst stages to produce a large number of genetically identical nuclear transplanted embryos. The oocytes collected from slaughterhouse ovaries were matured 24h in TCM199+10% FBS and exposed to $39^{\circ}C$ or room temperature to allow cytoplasmic maturation and gain activation competence. Donor embryos were treated for 12h with $10{\mu}g/ml$ nocodazole or $0.05{\mu}g/ml$ demicolcine to synchronize the cell cycle stage at 26h after the onset of culture. The blastomeres and recipient oocytes were fused by electrofusion. The cloned embryos were then cultured in various conditions to allow further development. In the treatment of oocyte activation and cell cycle regulation of donor nuclei, the room temperature exposure and nocodazole treatment group had significant effect on the developmental rates to morula/blastocyst(21.7% vs 12.1~16.7%), but had no significant effect on the fusion rates between donor blastomeres and recipient oocytes. The developmental rates of bovine nuclear transplanted embryos appeared to be higher significantly in mTALP medium under 5% $O_2$ condition and in TCM199 with bovine oviduct epithelial cell under 20% $O_2$ condition(22.2%) than other groups. In embryo transfer of nuclear transplanted embryos, there were no significant differences in calving rates between the use of excellent and good grade donor embryos.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.369-375
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• 2011

The aim of this study was to evaluate the effect of ${\alpha}$-tocopherol on blastocysts development and subsequent cryosurvival of the vitrification. The ${\alpha}$-tocopherol(0, 100, 200, 400 ${\mu}M$) was added in to culture medium for the bovine embryos. The blasocysts from the ${\alpha}$-tocopherol and untreated control groups were then frozen-thawed, and their cryosurvival was assessed by in vitro culture for 48 h. There were no differences in the overall cleavage rate($56.14{\pm}4.66$, $58.18{\pm}4.70$, $62.97{\pm}6.86$ and $51.17{\pm}7.28$) among four treatment groups. However, in blastocyst development and total cell number were significantly higher in ${\alpha}$-tocopherol 200 ${\mu}M$ ($38.60{\pm}7.12$; $106.33{\pm}3.50$) to culture medium than other treatment groups($29.30{\pm}5.24$, $31.60{\pm}7.12$ and $26.37{\pm}4.18$; $101.36{\pm}5.12$, $97.27{\pm}2.87$, and $91.23{\pm}7.52$ respectively). Before and after vitrification, the total cell number and blastocyst development of embryo were significantly higher in July to August than September to October. In conclusion, addition of ${\alpha}$-tocopherol 200 ${\mu}M$ to in vitro bovine embryo culture medium was beneficial for improving embryo quality by decreasing the embryo damage blsstocysts cell number and improving the tolerance of the embryos to cryopreservation.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.339-347
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• 2001

Sperm-mediated DNA transfer has a potential to markedly simplify techniques for the generation of transgenic animals. The exogenous DNA transfer by intracytoplasmic sperm injection (ICSI) procedure has been recently introduced in the production of transgenic animals. In this study, the developmental competence and tile expression rates of transgene were investigated after injection of spermatozoon or sperm head with enhanced green fluorescent protein (EGFP) gene into the mature porcine oocytes. The porcine oocytes were injected with intact sperm, membrane-disrupted sperm or sperm head. After injection. embryos were cultured in NCSU23 medium up to the blastocyst stage, and the developmental competence and expression rates were studied. The developmental rate (67.0%) of sperm injection group was higher than that (59.7%) of sperm head injection group, and the rates of EGFP expression were also significantly different between sperm injection and sperm head injection groups (42.1 vs 20.0%) (F＜0.05). In the porcine oocytes injected with sperm treated with different methods of membrane disruption, the removal of sperm membrane did not alter the developmental competence of embryos. The rate of blastocysts at 7 days after injection with intact and membrane disrupted sperm were 15.0 and 14.2%, respectively. The EGFP expression rates, 38.4% in embryos injected with frozen-thawed sperm was higher than that, 22.4% of embryos injected with the Triton X-100 treated sperm. Prior to injection, sperm were cultured in different EGFP gene concentrations from 0.Ol to 1ng/u${mu}ell$. However, no significant difference in developmental rates of embryos among different concentrations of EGFP gene were observed. The highest expression rate of EGFP gene, 37.4% was obtained from the embryos injected with spermatozoa treated with 0.1 ng/${mu}ell$ EGFP gene. These results suggested that exogenous DNA could be attached to the membrane disrupted sperm, and that these sperm could be used as a vector carrying foreign DNA into embryos.

• Korean Journal of Animal Reproduction
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• v.19 no.2
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• pp.89-93
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• 1995

In this study was demonstrate that retrovirus-mediated gene transfer is one of the promising alternatives to the conventional pronuclear DNA microinjection approach, especially in transferring the exogenous genes into the boving embryos. By co-culturing of zona of zona-free one-cell stage embryos with the retrovirus-producing cells for 24 hours followed by 6 days of culture in virus-free medium, we could get morulae and blastocysts expressing the E. coli LacZ genes which were transferred by our retrovirus vector. The results obtained in this study are summarized as follows : 1. Addition of 5$\mu\textrm{g}$/ml of polybrene in the embryo and virus-producing cell co-culture medium did not affect development of zona-free one-cell embryo. 2. Compared with the intact embryos removal of zona at one-cell stage before co-culturing with the virus-producing cells for one day caused only slight decrease of embryo develpment. 3. Co-culture of 625 zona-free one-cell stage embryos with the virus-producing cells resulted in 65(10.4%) morulae or blastocysts, and 12.3%(8/65) of the morulae or blastocysts were E. coli LacZ positive.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.271-281
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• 1996

1960년대에 본격적인 연구가 시도된 난세포질내 정자직접주입법(Intracytoplasmic Sperm Injection ; ICSI)은 1976년에는 Uehara 등에 의한 hamster의 연구에서 최초로 전핵의 형성에까지 성공하였다. 이후 계속된 연구를 통하여 여러 동물종에서 이 방법에 의한 난자의 수정 및 배발달에 성공하여, 1988년에 토끼, 1991년에 소, 1995년에는 생쥐에서 산자의 생산에 성공하였다. 한편, 사람에 있어서는 1988년 Lanzendorf 등에 의해 최초로 사람난자가 난세포질내 정자직접주입법에 의해 수정에 성공한 것이 보고되었으며, 1992년에는 Palermo 등에 의해 이 방법에 의해 수정된 수정란 이식을 통한 임신 및 성공적인 분만이 보고되었다. 난세포질내 정자직접주입법에 있어서는 정자의 운동성 및 첨체반응 등의 유무가 수정에 관여하는 중요한 요인이 아닌 것으로 알려지고 있으며, 성숙한 정자가 아닌 정소상체(미부-두부)정자 혹은 정소내의 미성숙정자를 사용하여 난세포질내 정자직접주입법을 시행하여도 수정 및 임신이 가능한 것으로 보고되었다. 또한 정자세포(spematid)나 원형정자세포(round spermatid)를 수정과 배발달이 관찰되었으며 사람에 있어서는 분만까지 성공하였다. 현재까지 이 난세포질내 정자직접주입법은 학술적으로는 난자-정자가 결합하는 기전을 밝히는 연구에 이용되어 왔으며, 임상적으로는 시험관아기시술에 있어서 정자의 기능, 수 등이 문제가 되어 수정이 어려운 남성불임환자에게 적용하여 좋은 성과를 거두어 왔다. 향후 이 기술은 유전자진단이나 남성불임환자의 처치에 폭넓게 사용될 것으로 기대된다.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.209-218
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• 1983

A study on the function of the Laurer's canal of Clonorchis sinensis was conducted with help of the light microscope, the transmission electron microscope, and the scanning elctron microscope. Some selected sexual organs concerning with the passages of the spermatozoa and the eggs were observed in detail. The conclusion of this study is that the Laurer's canal may be the copulatory organ of the female reproductive system as Miyazaki et al. suggested in case of lung flukes.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.67-71
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• 2016

In order to obtain a large number of fertilized eggs for seedling production, experiment was carried out examine effects of serotonin on spawning of the Pacific oyster Crassostrea gigas. The shorter response time to initial spawning in case of serotonin injection showed, the higher serotonin injected with 7.6-27 min. The response time to initial sperm releasing showed the same tendency with female. The highest response rates and eggs amount spawned were showed in the highest concentration. The serotonin injection had no effect on frequency of germinal vesicle breakdown (GVBD), fertilization and hatching rate.