• Title/Summary/Keyword: 포유동물

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Nuclear and Cytoplasmic Dynamics in Mammalian Oocytes during Sexual and Asexual Developments (포유동물 난자의 유성 및 무성 발생과정 동안 핵 및 세포질의 변화)

  • Kim, Nam-Hyung
    • Development and Reproduction
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    • v.4 no.1
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    • pp.7-12
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    • 2000
  • At fertilization, sperm penetrates into oocyte, male and female pronuclei are fused together, and mitotic division follows. However, little information is available on the interactive roles and dynamic processes between cytoplasmic and nuclear components during the pronuclear formation, migration and cell division. The assisted reproductive technologies such as, intracytoplasmic sperm injection (ICSI) and round spermatid injection(ROSI) could provides new treatments for the male infertility as well as tools for the study of basic mechanism during fertilization. Nuclear transfer can also provide a mechanism on the interactive roles between nucleus and cytoplasm since the process includes nuclear reprogrammming of differentiated cells in the enucleated oocytes. Recently, I have investigated developmental processes in porcine oocytes following fertilization parthenogenesis, ICSI, ROSI and nuclear transfer using indirect immunocytochemical and electron microscopic studies. The results could provide an insight into biological questions related with epigenesis as well as strategies for the enhancement of embryology in general such as ICSI and nuclear transfer.

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Evaluation of the Genetic Toxicity of Synthetic Chemicals (Ⅸ) a Synthetic Selective Herbicide, Pretilachlor- (합성화학물질들의 유전독성평가(Ⅸ) -합성 제초제 Pretilachlor -)

  • Ryu Jae-Chun;Kim Youn-Jung
    • Environmental Analysis Health and Toxicology
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    • v.19 no.1
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    • pp.93-100
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    • 2004
  • Pretilachlor [2-chloro-N -(2, 6-diethylphenyl)-N-(2-propoxyethyl) acetamide, $C_{17}$H$_{26}$ClNo$_2$, M.W.=311.9, CAS No.51218-49-6]는 제초제의 일종으로 본 연구에서는 박테리아 복귀 돌연변이 시험과 포유동물 세포를 이용한 염색체 이상 시험 및 마우스를 이용한 in vivo소핵 시험을 수행하여 pretilachlor의 유전독성을 평가하였다. 박테리아 복귀 돌연변이 시험에서 pretilachlor는 Salmonella typhimurium TA98, TA 100, TA1535, TA1537 균주의 대사 활성계 존재 및 부재시 313-5,000$\mu\textrm{g}$/plate의 범위에서 농도 의존적인 돌연변이 율의 증가를 관찰할 수 없었다. 또한 포유동물 세포인 Chinese hamster lung (CHL) fibroblast를 이용한 염색체 이상 시험에서 pretilachlor는 대사 활성계 존재 및 부재시 1.56-6.24$\mu\textrm{g}$/mL의 농도에서 clastogenicity를 보이지 않았고, 137.5-550.1 mg/kg의 pretilachlor를 복강 주사한 마우스의 골수세포를 이용한 in vivo소핵 시험의 결과에서도 통계적으로 유의한 소핵 유발능을 관찰할 수 없었다었다

Biotransformation of Arylnitroso Compound by Mammalian 1,4-Benzoquinone Reductase (포유동물 1,4-벤조퀴논 환원효소에 의한 아릴니트로소 화합물의 생변환)

  • 김경순;신해용
    • Journal of Life Science
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    • v.12 no.3
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    • pp.281-287
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    • 2002
  • Quinone reductase was purified to homogeneity from bovine liver and the purified enzyme catalyzed the reduction of phenanthrenequinone as well as benzo- and naphthoquinones. The enzyme catalyzed the biotransformation of arylnitroso nitroso compound and the reaction product was identified by TLC, GC, CC-MS and NMR. The reaction was almost entirely inhibitable by Cibacron blue 3GA or dicumarol, potent inhibitors of mammalian quinone reductase.

Artificial Activation of Pig Oocytes Arrested at meiotic Metaphase II (제2감수분열 중기에서 발달정지된 돼지 난자의 인위적 난활성)

  • R. S. Prather;;Z. Mach ty
    • Korean Journal of Animal Reproduction
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    • v.20 no.4
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    • pp.395-412
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    • 1997
  • Mammalian eggs are ovulated arrested at meiotic metaphase II until fertilization. Generally in mammals, fertilization results in a series of intracellular calcium oscillations that are mediated by inositol triphosphate (IP$^3$) or cyclic adenosine diphosphoribose (cADPr). The high levels of maturation promotion factor (MPF) within the cell decrease, pronuclei form, the cytoskeleton is reorganized and proteins are post-translationally modified. If all is normal, the newly formed embryo initiates the developmental program specific to that species. Artificial methods of producing these effects in pig oocytes are discussed. One potential mechanism mediated via a signal transduction pathway is present in pig oocytes. Stimulation of this pathway leads to the early events following fertilization, and electrical stimulation leads to apparently normal de v velopment to day 12. Further studies are needed to determine which mechanism(s) the sperm uses to initiate development.

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