• 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.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.4
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• pp.334-340
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• 2002

This paper proposes a self-organizing fuzzy modeling which can create a new hyperplane-shaped cluster by applying multiple regression to input/output data with relatively large fuzzy entropy, add the new cluster to fuzzy rule base and adjust parameters of the fuzzy model in repetition. Tn the coarse tuning, weighted recursive least squared algorithm and fuzzy C-regression model clustering are used and in the fine tuning, gradient descent algorithm is used to adjust parameters of the fuzzy model precisely And learning rates are optimized by utilizing meiosis-genetic algorithm. To check the effectiveness and feasibility of the suggested algorithm, four representative examples for system identification are examined and the performance of the identified fuzzy model is demonstrated in comparison with that of the conventional fuzzy models.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.71-78
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• 1995

Cobitis sinensis - longicorpus complex were commonly found in the upper stream of the Nakdong River in Korea and consisted of mostly with diploid and triploid karyotype forms. Among them, the triploid females of C. sinensis - longicorpus were artificially crossed with diploid males from C. sinensis and diploid males from C. longicorpus, respectively. The progenies from each cross produced the diploid individuals that possessed the paternal characters in their karyotypes and their body color patterns. Based on this results, we can assume that the triploid females, C. sinensis - longicorpus have a peculiar reproductive mode eliminating an uneven genome by the primary meiotic division and then producing a haploid ovum by secondary meiosis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.359-367
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• 1985

This experiment was conducted to study effect of cold water damage on some growth characters related to source and sink at reproductive growth stage in Jinan (sea level 303m). The cold water irrigation duration had irrigated 4, 8 and 12 days at panicle formation stage and reproduction division stage compared to perennial water irrigation. Cold water irrigation shortened culm length and panicle length and degree of panicle exsertion. The shortening effect appeared great at lower internodes when treated at panicle formation stage but at higher internodes when treated at reduction division stage. Cold water irrigation decreased the number of secondary branches and spikelets per panicle, and increased the number of degenerated spikelets being high degeneration when treated at panicle formation stage. Spikelet sterility and impediment of grain filling were affected by duration of cold water irrigation being great when treated at spikelet primodium differentiation stage and reduction division stage in particular. Grain weight was also reduced. Significant relationship existed between spikelets sterility, grain filling and yield. The degeneration of secondary branches and spikelets correlated with leaf area but spikelet sterility and yield with culm length, panicle length and panicle exsertion.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.347-356
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• 2000

포유동물의 난소 내에는 많은 수의 primordial follicles 과 preantral follicles 이 존재하고 있으며, 이것은 수정란을 체외생산하기 위한 잠재적인 난자의 공급원이 될 수 있다. 생쥐 preantral follicles 내에 존재하는 난자의 체외성장과 발달을 위하여 몇몇 배양체계가 개발이 되었으며, 적당한 배양조건에서 감수분열 능력이 없는 preantral follicles 내의 난자가 체외배양을 통하여 난자 직경이 증가하고 완전한 핵성숙을 하는 것으로 나타났다. 또한, 체외성장 및 성숙된 난자로부터 생쥐 산자의 성공적인 생산은 preantral follicles 내의 난자가 체외배양을 통해서도 완전한 발달능력을 얻을 수 있음을 입증하였다. 그렇지만, 생쥐 preantral follicle로부터 수정란의 체외생산능력은 매우 낮은 것으로 보고되고 있다. 한편 사람을 비롯한 돼지, 소와 같은 중ㆍ대가축의 경우에는 pre antral follicle의 체외배양을 통하여 감수분열능이 있는 단계의 난자로까지의 발달이 아직 보고가 되지 않고 있다. 따라서 지금까지의 연구결과들을 종합해 볼 때, preantral follicles의 체외배양조건을 개선하거나 새로운 배양체계를 개발에 대한 많은 연구가 요구되고 있다. 사람과 중ㆍ대가축의 preantral follicles의 체외배양체계의 확립은 우수한 형질을 가진 동물의 확장, 희귀동물 혹은 멸종위기 동물의 보존에 이용될 수 있을 것이며, 그리고 암치료를 위하여 화학적, 방사선 치료를 받아야 하는 여성에게서 향후에 불입치료를 위한 방법으로 활용될 수 있을 것으로 기대된다.

• Journal of Plant Biology
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• v.30 no.4
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• pp.225-247
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• 1987

Meiosis and postmeiotic mitosis in Boletus rubinellus were examined ultrastructurally. Meriosis occurred at the apex of the basidium. A sausage-shaped spindle pole body(SPB) was observed along with the presence of synaptonemal complexes during pachytene and a diglobular SPB was present on late pachytene or diplotene nuclei. During metaphase I, the monoglobular SPB at the spindle pole was surrounded bya membrane and the nuclear enveloope was discontinuous. At anaphase I, the chromosomes became better defined and formed a central spindle. The nucleolus was extruded from the nucleus. During anaphase I, the SPB was excluded from the chromosomal region by a membrane and both poles were fully separated to opposite sides of the basidial wall. In meiosis II, the two nuclei divided synchronously and the spindles were parallel. The spindles were smaller than in meiosis I, while the SPB was approximately the same size as that of the similar stage in meiosis I. During anaphasetelophase II, the SPB was surrounded by a cap of endoplasmic reticulum (ER) that delimited it from the spindle. The postmeiotic interphase nuclei migrated to the mid-region of the basidium before migration to the spores. The SPB at this stage was diglobular. A postmeiotic mitosis occurred within the basidiospore, and the plane of the spindle was obique to the long axis of the spore. The spindle and SPB were smaller than at meiosis I and there were fewer nonchromosomal microtubules. At anaphase, the nucleolus was present inside the nuclear envelope but lateral to the spindle.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.366-370
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• 1992

Salient chromosomal variations during the first meiotic division in primary spermatocyLes of the three brown planthopper, Nilaparvata lugens (Stal) , biotypes were observed. The meiotic index was highest in biotype 3 (58.6), followed by biotype 1 (39.4) and biotype 2 (23.6). Total chromosomal aberration including agmatoploidy, aneuploidy, loose pairings of sex chromosomes, and cytoplasmic shrinkage was found high in the order of biotype 1 (60.6%),2 (47.9 %), and 3 (38.1 %). However, percent agmatoploidy was highest in biotype 2 (19.6%) whereas in biotypes 3 and 1, it was 9.5% and 2.5%, respectively. The number of cells with isolated sex chrosomomes was observed highest in biotype 2.

• Korean Journal of Plant Taxonomy
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• v.35 no.1
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• pp.47-55
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• 2005

During the course of the field trip to Mt. Baekdu and Manchurian region especially along the border of North Korea, young flower buds were collected and fixed to analyze the meiotic configuration of chromosomes and to discuss the cytotaxonomic characteristics of these areas. A total of 29 taxa with 31 populations of vascular plants were analyzed chromosomally. Among them, 26 taxa with 28 populations were collected from Mt. Baekdu which include Papaver radicata var. pseudoradicata, Bupleurum euphorbioides, Oplopanax elatus, Silene jenisseensis, and Gentiana jamesii and three taxa collected from Manchurian region which include Scrophularia buergeriana, Ostericum grosseserratum and Callistephus chinensis. The first report of chromosome numbers were provided here for those species of Artemisia lagocephala as 2n = 9II, Cacalia komaroviana as 2n = 30II, Chrysanthemum zawadskii var. alpinum as 2n = 27II and Rodiola rosea as 2n = 11II,

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.231-242
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• 2005

연구목적: 본 연구는 아직 그 기능이 파악되지 않은 탈유비퀴틴효소 중 하나인 HIDE에 대한 기본적인 생화학적 특징과 고환에서의 발현 양상을 파악하고 있다. 연구재료 및 방법: 인간의 HIDE 유전자를 클로닝하여 효소활성이 있는지 세포 외 실험을 통해 확인하였고, 아미노산 서열을 분석하여 진화상 보존된 부분을 찾아 그 기능을 파악한 다음 HSP90과의 상호작용을 공동면역침전반응으로 확인하였다. HIDE의 조직별 발현양상을 파악하기 위해서 인간과 쥐의 RNA 블롯과 쥐의 단백질 블롯을 이용하여 각각 노던 블롯팅과 웨스턴 블롯팅을 수행하여 고환에서 많이 발현된다는 것을 알았고 이 사실을 바탕으로 쥐의 고환을 절개하여 면역조직화학반응으로써 고환 내의 HIDE 단백질의 발현양상을 파악하였다. 결　과: HIDE는 세포 외에서 유비퀴틴 잔기를 제거하는 탈유비퀴틴 활성이 있으나 세포 내에서 전체적인 유비퀴틴 복합체를 줄여주는 효과는 없었다. HIDE는 HSP90이라는 분자 샤페론과 상호작용한다. HIDE의 전사체는 고환에서 가장 많이 발현되며 다른 조직에서도 소량 발현된다. HIDE의 단백질은 웨스턴 블롯상에서 고환에서만 확인되었다. 고환 내에서의 HIDE의 발현양상은 왕성한 감수분열을 하는 정모세포에서 높았으며 지지세포나 정조세포에는 발현되지 않았다. 결　론: HIDE는 분자 샤페론 HSP90과 상호작용하며 고환 내의 감수분열 중인 세포에서 많이 발현되는 것으로 보아 감수분열이나 정자형성에 관여하는 것으로 보인다.

• Journal of Plant Biology
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• v.1 no.2
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• pp.1-4
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• 1958

1. A vernalized Korean rye was exposed to Co60 in dose of 150r (dose rate was 7r per minute) and pollen mother cells were examined for cytological study. 2. According to the observation, it is quite clear that scraping of chromosomes soon after irradiation and surface stickiness at the period of 6 hours after irradiation were followed by structural changes at the period of 12 hours after irradiation.