• 한국수정란이식학회:학술대회논문집
• /
• 한국수정란이식학회 2003년도 제3회 발생공학 국제심포지움 및 학술대회
• /
• pp.29-48
• /
• 2003

It is remarkable that nuclear transfer using differentiated donor cells can produce physiologically normal cloned animals, but the process is inefficient and highly prone to epigenetic errors. Aberrant patterns of gene expression in clones contribute to the cumulative losses and abnormal phenotypes observed throughout development. Any long lasting effects from cloning, as revealed in some mouse studies, need to be comprehensively evaluated in cloned livestock. These issues raise animal welfare concerns that currently limit the acceptability and applicability of the technology. It is expected that improved reprogramming of the donor genome will increase cloning efficiencies realising a wide range of new agricultural and medical opportunities. Efficient cloning potentially enables rapid dissemination of elite genotypes from nucleus herds to commercial producers. Initial commercialisation will, however, focus on producing small numbers of high value animals for natural breeding especially clones of progeny-tested sires. The continual advances in animal genomics towards the identification of genes that influence livestock production traits and human health increase the ability to genetically modify animals to enhance agricultural efficiency and produce superior quality food and biomedical products for niche markets. The potential opportunities inanimal agriculture are more challenging than those in biomedicine as they require greater biological efficiency at reduced cost to be economically viable and because of the more difficult consumer acceptance issues. Nevertheless, cloning and transgenesis are being used together to increase the genetic merit of livestock; however, the integration of this technology into farming systems remains some distance in the future.

• 한국수정란이식학회지
• /
• 제19권3호
• /
• pp.239-244
• /
• 2004

본 연구는 체내, 체외 및 복제를 통하여 각각 생산된 배반포를 이식하여, 수란우의 수태율, 임신기간 및 유산율과 더불어 송아지의 생시 체중과 이후 생존율을 조사하였다. 그 결과, 수태 을은 체내수정란이 56.3%로서 복제 수정란의 19.4%에 비하여 유의하게 높았으나 (p<0.05), 체외수정란의 30.0%와는 유의성이 인정되지 않았다 유산율과 임신기간은 처리군 간에 유사한 경향이었다(유산을 0, 22.2 및 16.7%; 임신기간 278.8, 289.4 및 281.4일). 한편 송아지의 체중은 복제수정란에서 유래된 송아지의 평균 39.9kg은 체내수정란에서 유래된 송아지의 평균 25.5kg에 비하여 유의하게 높았다.(p<0.05). 체내수정란이 수태된 수란우(n=9)는 모두 정상 분만하였으며, 그 송아지 는 생후 60일령까지 모두 생존하였다. 한편 체외수정란이 수태된 수란우(n=7)도 모두 정상 분만하였으나, 그 송아지 가운데 1두는 생후 48일에 사망하였다. 복제 수정란이 수태된 수란우(n=5)는 정상 분만 3두 및 제왕절개 2두를 하였다. 정상 분만된 복제송아지(n=3) 중에서 2두는 분만 직후 사망하였으나, 제왕절개로 태어난 송아지는 생후 60일까지 모두 생존하였다.

• 한국수정란이식학회지
• /
• 제27권2호
• /
• pp.87-92
• /
• 2012

A study on estrus synchronized dairy cows using progesterone intravaginal device was done to classify each cow's reproductive status from calving to synchronization and to evaluate the reproductive performance according to ovarian and uterine status, and calving season. From calving to estrus synchronization, silent heat or error of estrus detection among ovarian status and endometritis among uterine disorders were exposed in the most distribution (75.4% and 48.3%, respectively). The pregnancy rate of cows with inactive ovaries was lower than those in the follicular and luteal phase. And according to the uterine status before estrus synchronization, the pregnancy rate was similar in three groups; normal, endometritis, and pyometra (70.9, 69.1 and 100%, respectively). The interval from calving to conception was shorter (p<0.05) in cows calved during autumn than in cows calved during spring and winter.

• 한국수정란이식학회:학술대회논문집
• /
• 한국수정란이식학회 2003년도 제3회 발생공학 국제심포지움 및 학술대회
• /
• pp.82-82
• /
• 2003

• Reproductive and Developmental Biology
• /
• 제41권2호
• /
• pp.33-40
• /
• 2017

X-chromosome inactivation is one of the most complex events observed in early embryo developments. The epigenetic changes occurred in female X-chromosome is essential to compensate dosages of X-linked genes between males and females. Because of the relevance of the epigenetic process to the normal embryo developments and stem cell studies, X-chromosome inactivation has been focused intensively for last 10 years. Initiation and regulation of the process is managed by diverse factors. Especially, proteins and non-coding RNAs encoded in X-chromosome inactivation center, and a couple of transcription factors have been reported to regulate the event. In this review, we introduce the reported factors, and how they regulate epigenetic inactivation of X-chromosomes.

• 한국수정란이식학회:학술대회논문집
• /
• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
• /
• pp.30-31
• /
• 2006

• 한국수정란이식학회지
• /
• 제6권2호
• /
• pp.47-51
• /
• 1991

This study investigated full-term development potential of ultrarap idly frozen and thawed mouse 2-cell embryos. Mouse 2-cell embryos, dehydrated by exposure to freezing medium, were directly immersed into liquid nitrogen and thawed in 37$^{\circ}C$ water. The embryos that were frozen and thawed were cultured in uitro and transferred to foster mothers to examine there developmental potential. As a result, the frozen-thawed 2-cell embryos developed to blastocysts in vitro as a similar rate as control 2-cell embryos did(in vitro 2-cell, 86.4%; in vivo 2-cell, 90.9%; solution control, 89.9%; control, 89.7%). Normal live young were obtained from transfer of frozen-thawed embryos to the oviduct and uterus of pseudopregnant recipients (3l.4~56.7%).

• 한국수정란이식학회지
• /
• 제25권4호
• /
• pp.287-290
• /
• 2010

On January 6, 2010, two months earlier than normal breeding season, a red fox vixen was implanted with synthetic GnRH analogue, Deslorelin. Blood was sampled every 2~3 days from the day of implant to identifying spermatozoa on stains of epithelial cells. Estradiol and progesterone were examined. Even though the vixen was in non-breeding season, she was mated by a male fox. Pregnancy was confirmed by canine pregnancy detection kit that detect relaxin released from placenta. Four healthy pups were born on March 9, 2010. This is the first report showing synthetic GnRH can activate ovarian function and lead to fertile estrus of red fox in non-breeding season.

• 한국동물학회지
• /
• 제34권3호
• /
• pp.389-393
• /
• 1991

To obtain monozygotic multiplets from 8-cell mouse embryos, we artificially constructed chimeric embryos by introducing one blastomere (donor) of 8-cell embryos of Fl hybrid (C57BL/6 X CBA) mice into 4-cell ICR mouse embryos (carrier) of which one blastomere had been previously removed with a micromanipulator. After 42 h of culture, the developmental frequency of chimeric embryos to normal morula and blastocyst was 95% (310/328). When chimeric embryos at morula or blastocvst stage were transferred to pseudopregnant mice,39%, (70/180) of them were born. Most of the offspring (56/70) were the carrier type in coat color, whereas only three of them were the donor type, of which ho were assumed to be derived from single 8-cell donor embryo. Because the two donor type mice Ivere the same sex and produced only the donor type offspring from a testcross, they are probably monozvgotic multiplets of 8-cell mouse embryos. However, since their internal chimerism was not able to be examined, it remains to be determined if their genetic constitutions are identical.

• 한국환경보건학회지
• /
• 제30권2호
• /
• pp.104-107
• /
• 2004

This study was conducted to evaluate the effects of pH, using gametes, embryos and early development system of three sea urchins species, Hemicentrotus pulcherrimus, Anthocidaris crassispina and Scaphechinus brevis. As the result of performing effects of pH on early embryo development, the conditions of appropriate pH on formation of normal pluteus were pH 7.0-8.0 for H. pulcherrimus, A. crassispina and S. brevis. Otherwise, the conditions of pH 5.0, pH 6.0, pH 9.0 and pH 10.0 damaged the development of early embryos of each testing animal moderately or strongly.