• Clinical and Experimental Reproductive Medicine
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• 제42권2호
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• pp.33-44
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• 2015

The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn.

• 한국가금학회지
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• 제17권1호
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• pp.1-6
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• 1990

닭에서 2배수성 배우자(gametes)의 생성을 통해서 4배수성 태아 생산을 위한 본 실험의 결과는 다음과 같다. 1. 2배수성 정자생산 TEM(Tri -ethyleneme-lamine) 0.37mg을 연속 3일 주사한 후 9일째(최초 TEM처리 후 12일째)에 11%로 가장 높았다. 2. 2배수성 배우자를 유도한 후 수정을 통하여 109개의 수정난 중 4배수성 태아를 3개(2.8%) 관찰할 수 있었다. 3. 4배수성 개체의 유전구조는 정상구조에서 변화가 없이 동일한 염색체가 4장으로 구성된 형태였다.

• 한국초지조사료학회지
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• 제17권1호
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• pp.1-10
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• 1997

Unreduced (2n) gametes are meiotic products (pollen or egg) having a sporophytic (somatic) chromosome number, resulting from abnormalities during either microsporogenesis or megasporogenesis. They occur naturally at a low frequency in many plant species. Unreduced (2n) gametes in plants can be identified for four possible ways as follow i) pollen size and/or shape differences between haploid (n) and diploid (2n) pollen, ii) ploidy analysis (chromosome number) of progeny or meiotic analysis (presence of dyads andlor triads at the microspore stage), iii) progeny performance and fertility and iv) dosage of isozyme and DNA markers. Unreduced (2n) gametes can be an effective breeding tool in synthesizing new cultivars, providing a unique method to maximizing heterozygosity, i.e., transferring a large proportion of the non-additive genetic effects (intra- and inter- locus interactions) h m parent to offspring and can also be used to overcome infertility of interploidy crosses. Sexual polyploidization through 2n gametes has been a major route to the formation of naturally occurring polyploids. The three mechanisms of 2n pollen formation in potato have been discovered as follow: i) parallel spindles (ps) or tripolar spindles (ts), ii) premature cytokinesis (pc-I, pc-2) and iii) synaptic mutants (sy-2, sy-3, sy-4). Genetic analysis indicated that the mechanisms of 2n gamete formation were controlled by single recessive gene in potato, alfalfa, red clover, etc., and by two recessive genes in wheat. The use of 2n gametes which can efficiently transfer germplasm fiom wild relatives to cultivated species, especially fiom diploid to tetraploid could make a contribution to the improvement of germplasm base in breeding programs.

• Journal of Plant Biology
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• 제13권2호
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• pp.1-10
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• 1970

This experiment surveys ecological and morphological phase on Prasiola sp. in the mountain torrent of Chodang-ri, Keunduck-myon, Samchuck-gun, Kangwon-do, Korea from November 1968 through January 1970 and the results obtained were summarized as follows. 1. The temperature of the surface water was 12.4$\pm$2.3$^{\circ}C$, and pH was 7.25$\pm$0.2. 2. The external forms of thallus are very variable, but its basic form likely lanceolated and ovated. 3. The length of thallus is 0.6cm-8.8cm (3.6$\pm$1.72cm), and the width, 0.2cm-5.5cm(1.7$\pm$0.92cm). (The inside of the parentheses the average for 500 individuals). 4. It is observed that thallus at the time of formation of a monospore is a monostratum cell whose thickness is 21$\pm$3.2$\mu$. 5. Thickness of thallus at the transveres section at the time of heteroplanogametes formation is 29.9$\pm$2.2$\mu$, and that of the female gametes cell is 6.3$\pm$1.7$\times$6.3$\pm$0.8$\mu$, and that of the male gametes cell is 2.8$\pm$0.6$\times$28.1$\pm$1.1$\mu$. 6. As for growth, it begins with apical growth, followed by marginal growth. It seems to grow, through cell division when microsopical papillae are produced in growth line cell of marginal rigion thus by fusioning microscopical papillae. 7. The two kinds of thallus, one produced from a monospore and other from a planozygotes, are both haplonts and observed as n-3. 8. It seems that a thallus sprouts in April and increases its number through a asexual reproduction by a monospore and begins a sexual reproduction in November by forming gametes. 9. Female gametes are produced 16 from one thallus cell, whose structure shows 8 cells in the surface view and 4 layers in transverse section. Male gametes are produced 128 from one thallus cell, 16 cells surface, 8 layers in transverse section.

• Journal of Plant Biotechnology
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• 제1권1호
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• pp.56-60
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• 1999

Sexual reproduction is an essential process in the propagation of flowering plants. Recent advances in plant cell biology and biotechnology have brought new and powerful methodologies to investigate and manipulate the reproductive processes of angiosperms including agronomically important crop plants. Successful cryopreservation of maize, rye and triticale pollen and young embryos of microspore-and zygote-origine contributes to long term preservation of important plant germ-lines in gene banks. Discovering morphogenetic characteristics of the different developmental pathways taking place in wheat and maize androgenesis in vitro helps to influence the procedure to produce genetically and phenotipically stable homozygous doubled haploid plants for breeding purposes. Detailed ultrastructural and cell-biological studies on the developmental sequences of male and female gametophyte development in wheat, experimental protocols developed to isolate and micromanipulate egg cell protoplasts, make it possible to use plant gametes and the sexual route itself to produce genetically improved organisms. Plant gametes can become useful tools for crop improvement in the near future. Recent achievements by our laboratory in this field are reviewed in the present paper

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2001년도 제2차 연수강좌
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• pp.221-228
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• 2001

• 대한생식의학회:학술대회논문집
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• 대한불임학회 1999년도 제38차 추계 학술대회
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• pp.25-30
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• 1999

• 한국환경과학회지
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• 제8권1호
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• pp.1-6
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• 1999

This study was carried out to evaluate off-shore water quality and to draw marine pollution map to Southern sea in Korea by bioassay using gametes and early development system of Asterias amurensis. From the bioassay, it was determined that the water qualites of Southern sea maintained the grade II, because development of A. amurensis were moderately inhibited. However, Sunchon, Kwangyang, and Jinhae Bay belonged to grade III, because development of A. amurensis were strongly inhibited. This could be due to the inflows of several river systems and poor water circulation. The water quality at Yosu island was the grade I, because A. amurensis were not inhibited in its early development.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 The 5th Biannual Meeting of Pacific Rim Society for Fertility and Sterility
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• pp.165.2-165.2
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• 2006

• 환경생물
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• 제22권3호
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• pp.376-380
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• 2004

In August 2003, the water quality of offshore waters along the Incheon coast of Korea was evaluated by biological evaluation using gametes, embryos and early development systems of a starfish species (Asterina pectinifera). As the result of performing biological evaluations on seawater samples from a total thirteen sites, the formation rate of normal larva was 16-68%. At seawater sample from site 5 and 13, formation rate of normal larva averaged 16%, the most abnormal rate hindering the early embryo development of the experimental animal, while that of site 3 averaged 68%, the highest formation rate of normal larva. At seawater sample from site 2, 4, 7, 9, 10, 11, 12, formation rate of normal larva averaged 33-54%, those which damage the development of early embryos slightly. At seawater sample from site 1, 5, 6, 8, 13, formation rate of normal larva averaged 16-28%, those which damage the development of early embryos strongly.