• 한국산림과학회지
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• 제3권1호
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• pp.1-4
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• 1963

개나리 단주화개체(短柱花個體)를 사용(使用)하여 자성배우체발육(雌性配偶體發育)의 지연(遲延) 및 이상(異常), 임성(稔性)과의 관계(關係)를 조사(調査)한바 그 결과(結果)를 요약(要略)하면 다음과 같다. 1. 도생배주(倒生胚珠)의 주피(珠皮)는 대단(大端)히 두텁고 주심(珠心)은 반대(反對)로 극(極)히 작다. 2. 소포자모세포(小胞子母細胞)의 감수분열(減數分裂)은 9월하순(月下旬)~10월초순경(月初旬頃)인데 대포자모세포(大胞子母細胞)는 3월중하순경(月中下旬頃)에야 일어 난다. 3. 대포자모세포기(大胞子母細胞期)는 대단(大端)히 길다. 4. 성열배낭(成熱胚囊)은 개화약(開花約) 1개월후(個月後)인 5월초(月初)에 형성(形成)된다. 5. 정상배낭(正常胚囊)은 많지 않고 대부분(大部分)의 경우 배낭(胚囊)이 없는 공허(空虛)한 주심조직(珠心組織)만 생(生)긴다.

• 한국발생생물학회지:발생과생식
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• 제22권4호
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• pp.297-307
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• 2018

The objective of this study was to evaluate the effects of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on cumulus expansion, nuclear maturation, fertilization capacity and subsequent development in porcine oocytes. The oocytes were incubated with 0, 25, 50, and $100{\mu}M$ ALA. Cumulus expansion was measured at 22 h, and gene expresison and nuclear maturation were analyzed at 44 h after maturation. Then, mature oocytes with ALA were inseminated, and fertilization parameters and embryo development were evaluated. In results, both of cumulus expansion and nuclear maturation were increased in $50{\mu}M$ ALA groups compared to control groups (p<0.05). However, expression of gap junction protein alpha 1 (GJA1, cumulus expansion-related gene), delta-6 desaturase (FADS1, fatty acid metabolism-related gene), and delta-5 desaturase (FADS2) mRNA in cumulus cells were reduced by $50{\mu}M$ ALA treatment (p<0.05). Cleavage rate was enhanced in 25 and $50{\mu}M$ ALA groups (p<0.05), especially, treatment of $50{\mu}M$ ALA promoted early embryo develop to 4 and 8 cell stages (p<0.05). However, blastocyst formation and number of cells in blastocyst were not differ in 25 and $50{\mu}M$ ALA groups. Our findings show that ALA treatment during maturation could improve nuclear maturation, fertilization, and early embryo development through enhancing of cumulus expansion, however, fatty acid metabolism- and cumulus expansion-related genes were down-regulated. Therefore, addition of ALA during IVM of oocytes could improve fertilization and developmental competence, and further studies regarding with the mechanism of ALA metabolism are needed.

• Molecules and Cells
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• 제44권8호
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• pp.602-612
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• 2021

DNA methylation is an important epigenetic mechanism affecting genome structure, gene regulation, and the silencing of transposable elements. Cell- and tissue-specific methylation patterns are critical for differentiation and development in eukaryotes. Dynamic spatiotemporal methylation data in these cells or tissues is, therefore, of great interest. However, the construction of bisulfite sequencing libraries can be challenging if the starting material is limited or the genome size is small, such as in Arabidopsis. Here, we describe detailed methods for the purification of Arabidopsis embryos at all stages, and the construction of comprehensive bisulfite libraries from small quantities of input. We constructed bisulfite libraries by releasing embryos from intact seeds, using a different approach for each developmental stage, and manually picking single-embryo with microcapillaries. From these libraries, reliable Arabidopsis methylome data were collected allowing, on average, 11-fold coverage of the genome using as few as five globular, heart, and torpedo embryos as raw input material without the need for DNA purification step. On the other hand, purified DNA from as few as eight bending torpedo embryos or a single mature embryo is sufficient for library construction when RNase A is treated before DNA extraction. This method can be broadly applied to cells from different tissues or cells from other model organisms. Methylome construction can be achieved using a minimal amount of input material using our method; thereby, it has the potential to increase our understanding of dynamic spatiotemporal methylation patterns in model organisms.

• Molecules and Cells
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• 제26권2호
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• pp.186-192
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• 2008

NELL2, a neural tissue-enriched protein, is produced in the embryo, and postembryonically in the mammalian brain, with a broad distribution. Although its synthesis is required for neuronal differentiation in chicks, not much is known about its function in the adult mammalian brain. We investigated the distribution of NELL2 in various regions of the adult rat brain to study its potential functions in brain physiology. Consistent with previous reports, NELL2-immunoreactivity (ir) was found in the cytoplasm of neurons, but not in glial fibrillary acidic protein (GFAP)-positive glial cells. The highest levels of NELL2 were detected in the hippocampus and the cerebellum. Interestingly, in the cerebellar cortex NELL2 was observed only in the GABAergic Purkinje cells not in the excitatory granular cells. In contrast, it was found mainly in the hippocampal dentate gyrus and pyramidal cell layer that contains mainly glutamatergic neurons. In the dentate gyrus, NELL2 was not detected in the GFAP-positive neural precursor cells, but was generally present in mature neurons of the subgranular zone, suggesting a role in this region restricted to mature neurons.

• 한국산림과학회지
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• 제97권5호
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• pp.547-551
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• 2008

The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.

• 한국환경보건학회지
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• 제33권5호
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• pp.392-396
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• 2007

Aquatic ecotoxicity of bisphenol A, a well-known endocrine disrupter in mammals, was studied using laboratory-reared Daphnia magna as a test organism. The static acute 48 h $EC_{50}$ of bisphenol A for daphnid neonates(<24 hold) was 12.9 mg/l and 110 h $LC_{50}$ values of bisphenol A for daphnid embryos of different ages after deposition into the brood chamber increase with ages in the range of 1.55 mg/l-8.91 mg/l. Also, 48 h $EC_{50}s$ generally increase with daphnid's ages in the range of 12.9 mg/l-19.8 mg/l. In the acute toxicity tests using mature daphnids, the lethal response and immobility all showed good concentration-response relationship with exposure concentration and exposure time, showing little difference between lethality and immobility. These results clarify that acute toxicity tests, using daphnid and its embryo, could also be useful tools easily available for the assessment of ecotoxicity of various harmful chemicals.

• Plant Biotechnology Reports
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• 제3권3호
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• pp.251-257
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• 2009

Embryogenic callus was obtained from bulb segments of Iris pseudacorus on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with kinetin. When early globular somatic embryos were subcultured onto MS medium with $4.52{\mu}M$ 2,4-D, high frequency of somatic embryogenesis was obtained. Deprivation of 2,4-D was required for maturation. Mature somatic embryos had an elongated scutellum with a notch on the base of scutellum. Separation of embryos from embryo clusters was necessary to enhance the frequency of germination. Germination was stimulated by separation of embryos from embryo clusters and transfer onto fresh half-strength MS medium with 3% sucrose. After acclimation in artificial soil in greenhouse for 2 months, 96.4% of plantlets survived.

• Clinical and Experimental Reproductive Medicine
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• 제44권2호
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• pp.79-84
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• 2017

Objective: Optimizing in vitro maturation (IVM) media to achieve better outcomes has been a matter of interest in recent years. The aim of this prospective clinical trial was to investigate the effects of different media on the IVM outcomes of immature oocytes at the germinal vesicle (GV) stage. Methods: A total of 400 immature oocytes at the GV stage with normal morphology were retrieved from 320 infertile women aged $31{\pm}4.63years$ during stimulated intracytoplasmic sperm injection (ICSI) cycles. They were divided into groups of homemade IVM medium (I, n = 100), cleavage medium (II, n = 100), blastocyst medium (III, n = 100), and Sage IVM medium (IV, n = 100) and cultured for 24 to 48 hours at $37^{\circ}C$. ICSI was performed, and the rates of fertilization and embryo formation were compared across the four groups. Results: In the 400 retrieved GV oocytes, the total maturation rates showed significant differences in groups I to IV (55%, 53%, 78%, and 68%, respectively, p<0.001). However, there were no significant differences in the fertilization, embryo formation, or arrest rates of metaphase II oocytes across these groups. In all groups, GV maturation was mostly completed after 24 hours, with fewer oocytes requiring 48 hours to mature (p<0.01). Moreover, the rate of high-quality embryos was higher in group IV than in the other groups (p=0.01). Conclusion: The quality of the IVM medium was found to affect clinical IVM outcomes. Additionally, blastocyst medium may be a good choice in IVM/ICSI cycles as an alternative IVM medium.

• Journal of Ginseng Research
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• 제23권2호
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• pp.74-80
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• 1999

인삼 접합자배의 자엽을 식물호르몬이 전혀 첨가되지 않은 MS기본배지에 배양한 결과 자엽의 기부에서 높은 빈도의 체세포배가 유기되었다. 체세포배의 형성 빈도는 접합자배 자엽의 성숙도에 따라서 차이가 있었는데 미숙배에서 성숙배로 진행됨에 따라 감소되는 경향을 보였다. 미숙자엽의 경우에는 표피세포의 윗 아래층들이 모두 성숙자엽의 세포보다 더 적거나 더 촘촘하였으며, 많은 세포들이 체세포배의 형성에 관여하였으나 뿌리의 형성이 어려운 다배상태로 유기되었다. 그러나 발아직적의 성숙자엽은 표피세포의 윗층만이 촘촘한 세포로 이루워 졌으며 뿌리의 형성이 가능한 체세포 단일배로 유기되었다. 이런 결과는 체세포배의 기원과 발육이 배발생시 사용한 자엽의 성숙도에 따라서 배발생에 관여한 세포들이 단일 혹은 다량상태인지에 따라서 결정된다는 것을 의미한다.

• 식물조직배양학회지
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• 제25권1호
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• pp.51-56
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• 1998

강활(Ostericum koreanum Kitagawa)의 잎절편배양으로부터 체세포배 형성을 통한 식물체 재생, 체세포배의 이상자엽에 관한 NAA와 싸이토카이닌(kinetin, BA)의 영향 및 체세포배의 자엽수와 발아와의 관계을 밝히기 위하여 본 연구를 시도하였다. 배발생능캘러스는 여러 가지 농도의(0, 0.1, 0.5, 1, 2mg/L) NAA와 싸이토카이닌(kinetin, BA)이 첨가된 MS배지에서 배양된 캘러스는 희고 물기가 많고 부드러웠으며 배양중에 갈변하면서 연노랑색의 배발생능 캘러스로 되었으며 이로부터로 체세포배가 형성되었다. 1mg/L NAA+0.1mg/L BA가 첨가된 MS 배지상에서 계대배양 없이 60일간 배양하여 고빈도 체세포배를 얻을 수 있었다. 성숙한 체세포배는 계대배양없이 동일 배지상에서 2주후 발아하여 소식물체로 되었다. 성숙한 체세포배는 2개 자엽을 갖는 정상적인 자엽배가 39.8%이었고, 주발모양, 1개, 3개 및 4개자엽배 등은 3.1% 33.6%, 15.3% 및 8.2%이었다. 정상적인 2개 자엽 체세포배의 발아율은 97.4% 이었고 주방모양의 자엽을 갖는 체세포배를 제외하고(33.3%) 비정상 자엽배에서도 정상자엽체세포배의 발아율과 거의 비슷하였다.