• BMB Reports
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• 제43권2호
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• pp.69-78
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• 2010

Asymmetric cell division is a fundamental mechanism for the generation of body axes and cell diversity during early embryogenesis in many organisms. During intrinsically asymmetric divisions, an axis of polarity is established within the cell and the division plane is oriented to ensure the differential segregation of developmental determinants to the daughter cells. Studies in the nematode Caenorhabditis elegans have contributed greatly to our understanding of the regulatory mechanisms underlying cell polarity and asymmetric division. However, much remains to be elucidated about the molecular machinery controlling the spatiotemporal distribution of key components. In this review we discuss recent findings that reveal intricate interactions between translational control and targeted proteolysis. These two mechanisms of regulation serve to carefully modulate protein levels and reinforce asymmetries, or to eliminate proteins from certain cells.

• 식물조직배양학회지
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• 제22권1호
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• pp.13-17
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• 1995

작약의 화분배양에 의한 반수체 식물을 유기시킬 목적으로 화분배양을 실시하여 배양중 소포자의 변화를 관찰하고 캘러스 및 배발생에 미치는 저온전처리(5$^{\circ}C$/10 days)의 효과와 배양화분의 생존율을 조사하였다. 작약의 화분배양시 캘러스 및 배발생에는 저온전처리의 효과가 다소 인정되었으나 약배양의 효과에는 미치지 못하였다. 화분를 첨가한 고체배지에 이식했을 때 구형배가 형성되었다. 화분의 생존율에는 저온전처리 및 배지조성간 의 영향이 미치지 않았으며 배양기간이 지남에 따라 화분의 생존율도 저하되었다.

• Reproductive and Developmental Biology
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• 제38권1호
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• pp.35-40
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• 2014

Beta-catenin (CTNNB1, catenin (cadherin-associated protein), beta 1) is involved in various biological processes, including embryogenesis, tumorigenesis, angiogenesis and progression of metastasis. CTNNB1, as a multifunctional and oncogenic protein, has important roles in adhesion between Sertoli cells through an N-cadherin-dependent manner and in various cancer types through its over-activation. In addition, CTNNB1 can interact with estrogen/estrogen receptor alpha complex, which regulates the transcription of WNT (wingless-type MMTV integration site family)/CTNNB1 target genes. Recently, we investigated the functional roles and expression pattern of CTNNB1 during the morphological changes of embryonic gonads of chickens and the estrogen-dependent regulation of CTNNB1 in oviduct development and potential functions as a biomarker of CTNNB1 in human epithelial ovarian cancer using the chicken as a biological research model. Therefore, in this review, we provide a new insight of potential role of CTNNB1 in the development of the female reproductive tract during early embryogenesis and ovarian carcinogenesis of laying hen models.

• Journal of Forest and Environmental Science
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• 제34권1호
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• pp.77-81
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• 2018

Mass production of forest medicinal plants is related to quality control of raw medicinal materials. Plant tissue culture is an important technology to produce high-quality plant materials. Numerous factors are reported to influence the success of in vitro regeneration of medicinal plants. Embryogenesis is known to be the most effective techniques and it has developed in some medicinal plant species. Various in vitro cultural condition for direct and/or indirect somatic embryogenesis systems have developed in Epimedium koreaum, Bupleurum falcatum, Paeonia lactiflora, Chrysanthemum zawadskii, Houttuynia cordata etc. In this study, we provide the present statue and information of in vitro propagation techniques that is able to apply as an efficient system for rootstock propagation system of forest medicinal plants.

• 대한의생명과학회지
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• 제12권4호
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• pp.343-348
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• 2006

Drosophila Sog and vertebrate Noggin play important roles during development. They function as antagonists against BMP4 signaling and induce neural ectoderm during embryogenesis. They are also engaged in appendage formation by inhibiting BMP4 signaling during late development. To understand further functions of Sog, Supersog, which is a more potent form of Sog, and Noggin BMP4 antagonists during development, I performed the molecular genetic analysis using Drosophila embryogenesis and wing formation as assay systems. In cellular blastoderm embryos, Sog inhibited Dpp signaling, Drosophila BMP4 signaling, whereas Supersog or Noggin did not block Dpp signaling. During wing formation, Sog inhibited Sax type I receptor of Dpp signaling whereas Noggin inhibited Tkv type I receptor of Dpp signaling. However, Supersog inhibited both Sax and Tkv type I receptors. These results suggest that functions of BMP4 antagonists are developmental stage dependent and indicate that each BMP4 antagonist inhibits BMP4 signaling by blocking different BMP4 receptors.

• 식물조직배양학회지
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• 제27권5호
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• pp.411-413
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• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.

• 한국작물학회지
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• 제56권3호
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.

• 한국동물학회지
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• 제34권3호
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• pp.394-402
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• 1991

Yolk protein-3 (YP3) was purified from the ovary of Hvpharatria cunea D. and the synthesis and fate during embryogenesis of WP3 were investisated by electrophoresis and fluorography. YP3 purified through gel slice and electrophoretic elution'was determined to have M. W. of 18 Kd and consist of one subunit. Haemolymph and fat body of male and female %were electrophoresed during vifellogenic stages to indentifv the vitellosenin in female. The result showed that there was no distinct difference in electrophoretic patterns betweerl male and female. However, tissue culture of fat body and maturing ovary indicated that YP3 was svuthesized by fat body. Aiso, vP3 in iaid eggs was maintained constant untii naut s artier oviposition and then decreased, indicating that YP3 was drastically used during late embryosenesis. However, a part of YP3 was present even in newly hatched first instar larvae.

• Animal cells and systems
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• 제4권3호
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• pp.239-243
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• 2000

Most space-related life science programs are expensive and time-consuming, requiring international cooperation and resources with trans-disciplinary expertise. A comprehensive future program in "life sciences in space" needs, therefore, well-defined research goals and strategies as well as a sound ground-based program. The first half of this review will describe four key aspects such as the environment in space, previous accomplishments in space (primarily focusing on amphibian embryogenesis), available resources, and recent advances in bioinformatics and biotechnology, whose clear understanding is imperative for defining future directions. The second half of this review will focus on a broad range of interdisciplinary research opportunities currently supported by the National Aeronautics and Space Administration (NASA), National Institute of Health (NIH), and National Science Foundation (NSF). By listing numerous research topics such as alterations in a diffusion-limited metabolic process, bone loss and skeletal) muscle weakness of astronauts, behavioral and cognitive ability in space, life in extreme environment, etc., we will attempt to suggest future opportunities.

• 한국동물학회지
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• 제30권4호
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• pp.432-444
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• 1987

Very early stage of chick embryo cultivated in the medium containing DLtryptophan by beaker method has been investigated in vitro morphologically using electron microscopy at cellular level and found that the development of tryptophan treated chick embryos corresponding to 18∼66 hrs incubation was impaired and york granule degradation was significantly delayed. It was also found that DNA, RNA and protein biosynthesis of tryptophan treated chick embryo was greatly lowered than those of control group. Conversion of L-tryptophan into serotonin was traced using 14C-L-tryptophan and found that 13.8cA of added radioactivity was recovered from serotonin formed during 18 hrs incubation and the amounts of serotonin formed were depend upon added amount of tryptophan in e99 yolk. It seemed that the serotonin formed from external tryptophan might inhibit the degradation of yolk granule by feedback mechanism, resulting in malformation of chick embryogenesis.