• 한국동물학회지
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• 제27권1호
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• pp.1-12
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• 1984

생쥐 난자 및 초기 배아의 alkaline phosphatase의 기능을 알아보기 위하여 생화학적인 방법으로 배아의 발생 단계에 따른 효소의 활성도를 측정하였으며, 동 효소의 저해제로 알려진 levamisole이 난자의 성숙분열 및 초기 배아의 발생에 미치는 영향을 관찰하였다. 1. 동 효소의 활성도는 4세포기에서 뚜렷이 나타나며, 각 발생단계에 따른 현저한 변화는 없는 것으로 나타났다. 2. Blastocyst의 alkaline phosphatase의 활성도는 1 mM 및 10 mM의 levamisole에 의해서 각각 40%와 70% 이상 억제되었다. 3. Levamisole은 0.5 mM 이상의 농도에서 난자의 극체 형성을 완전히 억제하였으며, 동일한 농도에서 2세포기 배아 및 morula의 퇴화현상을 일으켰다.

• 한국가축번식학회지
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• 제11권3호
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• pp.218-222
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• 1987

This study was conducted using inbred ICR mice to investigate the sex-ratio of preimplantation mouse embryos. For the investigation of sex-ratio of mouse embryos, the karyotype of embryos collected at 70-72, 74-76, 78-80 and 82-84 hr after HCG injection was analyzed by chromosomal analysis. Eight-cell embryos were cultrued up to blastocyst stage, then divided them into three groups(fast-, intermediate- and slow-) according to the blastocoel formation. The sex-ratio was also investigated by chromosomal analysis. 1. The highest apperance of eight-cell and morula was observed at the embryos collected respectively at 66-68 hr(84.6%) and 82-84 hr(79.3%) compared to any other group. 2. The successful rate of embryos sexing at 4-, 8-cell and morula stage were 23.1% (3/13), 42.1%(138/328) and 32.6%(47/141), respectively. The respective sex ratios (female vs male) of 4-, 8-cell and morula were 66.7:33.3, 49.3:50.7 and 39.5:60.5. 3. Of the 476 eight-cell embryos cultured in vitro, 427(89.7%) embryos were developed to the blastocysts and the number of fast-, intermediate- and show-developing embryos were 139, 144 and 144, respectively. 4. Female to male ratios fo fast-, intermediate- and slow-developing group were 23.0:77.0, 55.2:44.8 and 73.8:26.2, respectively. Significantly higher (P<0.05) number of female (48/65;73.8%) was observed in the group of slow-developing embryo than that out of total number of embryos(82/188;43.6%).

• 한국가축번식학회지
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• 제16권4호
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• pp.347-352
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• 1993

This study was designed to develop the in vitro culture systemof mammalian preimplantation embryos. We proposed mouse fetal fibroblast cells (MFFC) from 14∼15 day mouse fetus. Zygotes from superovulated female ICR mice were cultured 96 hrs in simple defined media (T6) or on the monolayer of MFFC. In addition, to evaluate the action of the co-culture of MFFC, various diluted superoxide dismutase antibody (SOD-Ab) was supplemented into the monolayer of MFFC and zygotes were cultrued in presence or absence of SOD-Ab. The developmental rates of zygotes were significantly increased in co-culture with MFFC compared to the control. The rates of zygotes to the 4-cell stage in media treated with EDTA were higher than those cultured in MFFC but the proportions of morula and blastocyst were not differ between EDTA and MFFC. Interestingly blastocysts in co-culture with MFFC possessed as many as blastomere as those developing in vivo, but blastocysts cultured with EDTA had significantly fewer blastomeres. In addition, the treatment of SOD-Ab suppressed the beneficial effect of MFFC. Therefore, our findings suggest that co-cultrue system using MFFC may have an advantage in the development of mouse zygotes as well as embryonic differentiation.

• 한국발생생물학회지:발생과생식
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• 제6권1호
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• pp.1-6
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• 2002

세포외기질(exrtracellular matrix, ECM)에 의한 생쥐 초기 배아의 발생 조절 현상의 기작 규명을 위한 연구의 일환으로 Engelbreth-Holm-Swarm(EHS) mouse sarcoma의 세포외기질로부터 추출한 ECM 복합체인 Matrigel의 성장인자 제거형(GFR-Matrigel)을 생쥐 포배에 처리한 후 mitogen activated protein kinase (MAPK, ERK1/2) 활성 의 변화를 조사하였다. Matrigel 처리 후 10분 이내에 배아의 MAPK 활성이 유의하게 증가하였고, 60분 후에도 유의하게 높은 활성을 유지하였다. 한편 MAPK cascade의 저해제인 PD098059를 전처리한 경우 Matrigel에 의한 MAPK 활성의 증가가 관찰되지 않았다. Matrigel 배양액 내에서 12시간 동안 배양한 포배의 MAPK 활성은 대조군과는 현격한 차이를 보였다. 이러한 결과로부터 ECM에 의한 생쥐초기 배아의 발생 촉진효과 발현기작에는 하위 신호전달 과정의 MAPK 활성화 과정이 관여하는 것으로 사료된다.

• 한국발생생물학회지:발생과생식
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• 제5권2호
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• pp.101-106
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• 2001

Insulin과 tumor necrosis factor alpha(TNF-$\alpha$)에 의한 초기 배아 발생의 조절기작을 알아보고자 생쥐의 상실배를 대상으로 이들이 첨가된 배양액에서 형태발생, 세포증식을 조사하고, 포배에서 mitogen activated protein kinase(MAPK, ERK1/2)의 활성 변화에 미치는 영향을 조사하였다. Insulin은 상실배의 체외발생 및 포배내 할구 수를 대조군에 비해 유의하게 증가시켰으며, TNF-$\alpha$는 발생율을 유의하게 감소시켰다. Insulin은 TNF- $\alpha$에 의한 배아 발생율 감소를 완화하였다. TNF-$\alpha$는 농도에 의존적으로 MAPK 활성을 감소시켰으며, insulin은 포배에서 MAPK의 활성을 유의하게 증가시킨 반면 TNF-$\alpha$는 처리농도에 의존적으로 MAPK 활성을 감소시켰다. 50 ng/ml 농도의 TNF-$\alpha$를 전처리한 포배에서는 insulin에 의한 MAPK 활성의 증가가 저해되었다. 이러한 결과로부터 생쥐의 착상전 초기 배아 발생조절에 insulin과 TNF-$\alpha$ 사이에 MAPK를 경유하는 cross talk이 존재함을 확인하였고 insulin은 TNF-$\alpha$ 에 의한 배아의 손상을 억제하는 것으로 사료된다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2005년도 제5회 발생공학 국제심포지엄 및 학술대회
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• pp.107-107
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• 2005

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2005년도 제5회 발생공학 국제심포지엄 및 학술대회
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• pp.107-107
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• 2005

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 공동 춘계학술대회
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• pp.78.1-78
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• 2000

No Abstract, See Full Text

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2002년도 제43차 추계학술대회
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• pp.94-95
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• 2002

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.81-81
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• 2003

DNA methylation is a covalent modification of DNA that can modulate gene expression and is now recognized as a major component of the epigenome. During evolution, the dinucleotide CpG has been progressively eliminated from the genome of higher eukaryotes and is present at only 5% to 10% of its predicted frequency. Approxymately 80% of the remaining CpG sites contain methylated cytosines in most vertebrates and they are distributed in a pattern that is unique in each tissue and is inversely correlated with gene expression. The pattern of methylation is faithfully maintained during cell division by the enzyme Dnmt1, the maintenance DNA methyltransferase, which catalyzes the transfer of a methyl group from S-adenosyl-methionine to the 5'-position of the cytosine ring. We have been identified bovine Dnmt1 cDNA full-length recently (AY173048) Little is known on the functions of Dnmt1 in bovine preimplantation embryos. Thus, we analyzed the specific pattern of Dnmt1 in in vitro derived/nuclear transfer bovine and in vivo derived mouse embryos to monitor the epigenetic reprogramming process. We investigated these process by using indirect immunofluresence with an antibody to Dnmt1. According to other studies, Dnmt1 accumulates in nuclei of early growing oocytes but is sequestered in the cytoplasm of mature oocytes. In 2-cell and 4-cell embryos, Dnmt1 is cytoplasmic, but at the 8-cell stage, it is present only in the nucleus. By the blastocyst stage, Dnmt1o is again found only in the cytoplasm. Thus, nuclear localization of Dnmt1o in preimplantation embryos is limited to the 8-cell stages After implantation, Dnmt1 is localized in the nucleus in mouse. However, we have found different patterns of Dnmt1 nuclear localization. Though we used the common antibody, immune-localization data revealed that Dnmt1 antibody have been detected at the nucleus in 1-cell to blastocyst embryos. Therefore, maybe we think that the functions of Dnmt1 between bovine and mice are different. In order to Identify the mechanisms that regulate DNA methylation in bovine preimplantation embryo, we have plans on using bovine oocyte and somatic specific Dnmt1 antibodies.