• The Korean Journal of Zoology
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• v.4 no.2
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• pp.13-19
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• 1961

Free amino acids at five different developemntal stages (Gastrulation-Hatching -out stage) of Hynobius leechi BOULENGER were analyzed qualitatively by the use of paper paitition chromatography. It was found that the number of free amino acids increased as the development proceeded. The free amino acids identified at each stages are as follows : Gastrulation stage : Alaninie, Aspartic acid, Glutamin acid, Histidine, Methionine. Neural plate formation stage : Alanine , Aspartic acid, Glutamic acid, Glycine, Histidine, MEthionine, Phenylalanine, Proline, Serine, Trypotophan. Middle tail-bud stage : Alanine, Arginine, Asparagine,Aspartic acid, Citrulline, Glutamic acid, Glycine, Histidie,Hydroxyproline, Proline, Leucine, Methionine, Ornithine, Phenylalanine, Serine, Threonine, Tryptophan. Late tail-bud stage : Alanine, Arginine, Asparagine, Aspartic acid, Citrulline, Glutamic acid. Glycine, Histidine, Hydroxyproline, Leucine, Methionine, Ornithine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Valine. Hatching -out stage : the same with the late tail-bud stage. It seems probable that the metabolic systems of amino acids before and after the middle tail-bud stage are quite different from each other. Before the middle tail=-bud stage, the reaction system of amino acids is thought not to be completed while after that stage the system has been completed , because in the former period of the development , the number of freeamino acids increased rapidly with the development , and after that stage, there is practically no change in the number of free amino acids.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.346-358
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• 2021

Secondary neurulation is a morphological process described since the second half of the 19th century; it accounts for the formation of the caudal spinal cord in mammals including humans. A similar process takes place in birds. This form of neurulation is caused by the growth of the tail bud region, the most caudal axial region of the embryo. Experimental work in different animal species leads to questioning dogmas widely disseminated in the medical literature. Thus, it is clearly established that the tail bud is not a mass of undifferentiated pluripotent cells but is made up of a juxtaposition of territories whose fate is different. The lumens of the two tubes generated by the two modes of neurulation are continuous. There seem to be multiple cavities in the human embryo, but discrepancies exist according to the authors. Finally, the tissues that generate the secondary neural tube are initially located in the most superficial layer of the embryo. These cells must undergo internalization to generate the secondary neurectoderm. A defect in internalization could lead to an open neural tube defect that contradicts the dogma that a secondary neurulation defect is closed by definition.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.367-373
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• 2021

Secondary neurulation (SN) is a critical process to form the neural tube in the posterior region of the body including the tail. SN is distinct from the anteriorly occurring primary neurulation (PN); whereas the PN proceeds by folding an epithelial neural plate, SN precursors arise from a specified epiblast by epithelial-to-mesenchymal transition (EMT), and undergo self-renewal in the tail bud. They finally differentiate into the neural tube through mesenchymal-to-epithelial transition (MET). We here overview recent progresses in the studies of SN with a particular focus on the regulation of cell lineage, self-renewal, and EMT/MET. Cellular mechanisms underlying SN help to understand the functional diversity of the tail in vertebrates.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.83-85
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• 2005

Ditylenchus acris was isolated from diseased strawberry plants. Frequently, D. acris and Aphelenchoides fragariae occur together in a strawberry plant. Both species appeared very similar in the shape, length, swimming behavior and causing symptoms, and difficult to distinguish them by a stereomicroscope. But they were easily distinguished under a compound microscope especially by their tail shape, median bulb, vulva position, and bursa.

• Journal of Plant Biology
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• v.39 no.1
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• pp.9-13
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• 1996

A clone, LCM1, which encodes calmodulin (CaM) was isolated and characterized from monocot lily (Lilium longiflorum Thunb.) plants. The clone is 681 bps and contains the 447 bp coding region, 8 bp leader sequence, 210 bp 3'-untraslated region, and a poly(A) tail. The coding region of 149 amino acids encodes a protein of predicted Mr 17 kD. Comparison of the LCM1 amino acid sequence with other CaMs revealed that the protein is highly conserved among various living organisms. The expression level of calmodulin gene in lily was studied by RNA blot analysis. The LCM1 mRNA was present in all tissues tested. However, a higher level of calmodulin was observed in anther and floral bud. The level of calmodulin mRNA in anther was about 10 times higher than that in anther was about 10 times higher than that in vegetative tissues. The anther preferential expression of CaM in lily is currently investigated in dicot plants.

• Animal cells and systems
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• v.7 no.3
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• pp.221-225
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• 2003

The tadpole larva of the ascidian Halocynthia roretzi has two sensory pigment cells in its brain vesicle. To elucidate the temporal requirement for FGF signaling in formation of the pigment cells, embryos were treated with an FGF receptor 1 inhibitor, SU5402, or an MEK inhibitor, U0126 during various embryonic stages. In the present study, it is shown that the embryos treated with SU5402 from the 16-cell stage to the early gastrula stage do not form pigment cells, whereas those treated after the early gastrula stage form pigment cells. In pigment cell formation, embryos suddenly exhibited the sensitivity to SU5402 only for 1 h at the neural plate stage(-4 h after the beginning of gastrulation). When U0126 treatment was carried out at various stages between the 8-cell and late neurula stages, the embryos scarcely formed pigment cells. Pigment cell formation occurred when the embryos were placed in U0126 at early tail bud stage. These results indicate that FGF signaling is involved in pigment cell formation at two separate processes during ascidian embryogenesis, whereas more prolonged period is required for MEK signaling.

• Toxicological Research
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• v.26 no.3
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• pp.209-216
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• 2010

Limb bud (LB) and central nerve system (CNS) cells were prepared from 12.5 day old pregnant female Crj:CD (SD) rats and treated with olaquindox and vitamin A. Cytotoxicity and inhibition on differentiation were measured in each cell. Three doses of olaquindox (4, 21 and 100 mgkg), and 0.2 and 75 mg/kg of vitamin A were administered to pregnant rat for 11 days from $6^{th}$ to $16^{th}$ of pregnancy. $IC_{50}$ values of olaquindox for proliferation and differentiation in CNS cell were 22.74 and $28.32\;{\mu}g/ml$ and 79.34 and $23.29\;{\mu}g/ml$ in LB cell and those values of vitamin A were 8.13 and $5.94\;{\mu}g/ml$ in CNS cell and 0.81 and $0.05\;{\mu}g/ml$ in LB cell, respectively. Mean body weights of pregnant rats were decreased at high dose of olaquindox (110 mg/kg) but relative ovary weight, number of corpus lutea, and number of implantation were not changed. Resorption and dead fetus were increased at high dose of olaquindox, and relative ovary weight, the number of corpus lutea and implantation, and sex ratio of male to female were not significantly changed in all dose of olaquindox. Mean fetal and placenta weights were significantly (p < 0.01) decreased in rats of high group. Seven fetuses out of 103 showed external anomaly like bent tail, and 10 out of 114 fetuses showed visceral anomalies at high group. The ossification of sternebrae and metacarpals were significantly (p < 0.01) increased by low and middle dose of olaquindox but it was significantly (p < 0.01) prohibited by high dose of olaquindox. In rats treated with vitamin A, the resorption and dead fetus were increased by high dose. Mean fetal weights were significantly (p < 0.01) increased by low dose but significantly (p < 0.01) decreased by high dose. Thirty four fetuses out of 52 showed external anomaly; bent tail (1), cranioarchschisis (14), exencephaly (14), dome shaped head (22), anophthalmia (15), brcahynathia (10) and others (19). Forty five fetuses out of 52 showed soft tissue anomaly; cleft palate (42/52) and anophthalmia (22/52) by high dose of vitamin A. Sixty one fetuses out of 61 (85.2%) showed skull anomaly; defect of frontal, partial and occipital bone (21/61), defect of palatine bone (52/61) and others (50/61). In summary, we support that vitamin A is strong teratogen based on our micromass and in vivo data, and olaquindox has a weak teratogenic potential in LB cell but not in CNS cell. We provide the in vivo evidence that a high dose of olaquindox could have weak embryotoxic potential in rats.

• The Research Journal of the Costume Culture
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• v.18 no.4
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• pp.741-754
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• 2010

The current study aims to link Korean tradition to modern culture; to re-produce patterns of lotus depicted in Minwha, The study also aims to discover the beauty of Korean tradition and to modernize it. The current study is based upon document searches(including research papers) and the Internet searches. Through these searches, it investigates the concept of Minhwa, the origin of lotus depiction and its symbolic meanings, the traits of such pattern. Based upon this investigation, the study attempts to modernize the patterns of lotus and apply the modernized patterns to designing shirts. The process which employs the lotus patterns illustrated in Minhwa to shirt design includes four sub-processes: selecting, allocating, coloring, and selecting production techniques. The sub- process of selecting patterns is two folded: the first stage covers carbon-copying the distinctive features of lotus, lotus leaf, lotus bud, lotus pip, and lotus stem; the second stage is making these features suitable to shirt sizes. For the process of coloring those shirts, Piccaso's work(Pablo Picasso, 1881~1973) has been selected and the colors in his work have been adopted to dye the rest of the shirts as well as the lotus features. The process of selecting production techniques includes ornament tail in order to modernize the patterns allocated in the shirts. Once these processes are completed, the shirts are made on a scale of real-life size. These processes of creating shirt design by modernizing traditional patterns will hopefully contribute to researchers expanding the domain of shirt design.

• Applied Microscopy
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• v.29 no.1
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• pp.105-124
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• 1999

Histological and ultrastructural differentiations of the neuroepithelial cells in the mouse embryo during neurulation were observed. The neural plates and grooves consisted of pseudostratified columnar epithelium in the embryonic day (ED) 8 embryo were developed. In the ED 9 embryo, the neural tube was developed in all body length of embryo except both the cephalic and caudal ends. Secondary neurulation was shown at the tail bud of the ED 10 embryo. In the ED 8 embryo, the primitive streak was shown in the posterior end of the embryonic disc. The neuroepithelium, notochord and mesenchyme were well differentiated in the cephalic and cervical portions. In the ED 9 and 10 embryos, the roof plates of neural tubes were constituted of the closing of the surface ectodermal cells in the hindbrain and the neuroepithelial cells in the spinal cord. The floor plate of neural tube were consisted of the low pseudostratified columnar epithelium. The spinal motor nerve fibers were initially differentiated in the ED 10 embryo. According to the electron density of the cell and the differentiation of tell organelles, the neuroepithelial cells in the ED 9 and 10 embryos were classified into three types: dark, intermediate and light types. All types in the ED 9 embryo were observed but the dark cell in the ED 10 embryo was not done. The free ribosomes and polysomes in all neuroepithelial cells were developed. The RER and lipid droplets in the dark cell and the Golgi complex in the intermediate and light cells were observed. Many microfilaments in the cytoplasmic processes of intermediate cell and the microfilaments and microtubules in the light cell processes were observed to be well differentiated.