• Korean Journal of Poultry Science
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• v.14 no.2
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• pp.89-96
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• 1987

The purpose of this paper to present morphological normal chick chromosomes and develope avian cytogenetic techniques including chromosome preparation and banding technique. The early chick embryos provide a consistent source of material with hish mitotic cells. Although chick embryo tissue gives excellent preparations, the 4-5 days embryo is somewhat incovenient materials, Most imp of ant for avian Chromosome analysis are the technical protocols to achieve adequate preservation, spreading, and staining of the full chromosome complement. To precise chromosome analysis, pro-metaphase states are required. Best results of banding will be obtained from air dried slides prepared from early chick embryos that have been aged at least 1 week. Good G-banding differentiation is achieved by adequate trypsin digestion fellowed by staining in Goe,sa dye. The results of C-banding is influenced by many factors including the conditions of Ba(OH)$_2$, HCl treatment, and state of rinsing. In addition to precisely interprets banding patterns, the densitometric analysis is recommended.

• Journal of Life Science
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• v.21 no.12
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• pp.1666-1677
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• 2011

The regulation of gene expression plays an important role in cell cycle controls. In this study, a novel gene, the $mas1^+$($\underline{mi}$tosis $\underline{as}$sociated protein) gene, a homolog of human CIP29/Hcc1, was isolated and characterized from fission yeast Schizosaccharomyces pombe (S. pombe) using a gene-specific polymerase chain reaction. The isolated gene contained a complete open reading frame capable of encoding 245 amino acid residues with a typical promoter, as judged by nucleotide sequence analysis. It was also found that a PCB ($\underline{p}$ombe cell $\underline{c}$ycle $\underline{b}$ox) is located in the promoter region, which controls M-$G_1$ specific transcription in S. pombe. The quantitative analysis of the $mas1^+$ transcript against $adh1^+$ showed that the pattern of expression is similar to that of the septation index. Cytokinesis of mas1 mutant was greatly delayed at $25^{\circ}C$ and $36^{\circ}C$, and a large number of multi-septate cells were produced. The mas1 mutant had 2C, 4C and 6C DNA contents, as determined by FACS analysis. In addition, the number of multi-septate cells significantly increased. When cells were cultured in nitrogen starvation medium to increase proliferation, the abnormal phenotypes of mas1 mutant dramatically increased. These phenotypes could be rescued by an overexpression of the $mas1^+$ gene. The mas1 protein localized in the nuclei of S. pombe and human HeLa cells, as evidenced by Mas1-EGFP signals. The abnormal growth pattern and the morphology of mas1 mutant were complemented by a plasmid carrying human CIP29/Hcc-1cDNA. In addition, CIP29 /Hcc-1 transcript level increased in active cell proliferation stages in the developing mouse embryos. These results indicate that the $mas1^+$ ishomologous to the human CIP29/Hcc1 gene and is involved in cytokinesis and cell shape control.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.255-262
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• 2008

The endemic Korean stumpy bullhead Pseudobagrus brevicorpus is a first-grade endangered wild fish as designated by the Ministry of Environment of Korea. As part of its restoration and proliferation effort, a histological study of this fish was carried out to investigate sex differentiation and gonadal development based on F1 generation individuals obtained by artificial breeding. On days 4~5 after hatching, a pair of genital ridges including clusters of primordial germ cells was observed between the gut and the mesonephric duct. On days 20 after hatching, the ovary began to initially differentiate and contained early oocytes with chromatin-nucleolus and peri-nucleolus stages on days 30~40 after hatching. As yolk material accumulated after day 80 from hatching, the oocytes grew increasingly large and were surrounded by a distinct follicular layer. On days 306 after hatching, the oocytes grew toward a mature ovum. In the males, the testis was distinguished by emergence of spermatogonium cells on 25 days after hatching, and day 40 after hatching it contained a small number of seminal lobes forming cysts. From 173 days after hatching, the testis consisted of numerous enlarged seminal lobes including spermatocytes and spermatids. Over 14 months after hatching, some seminal lumens were filled with spermatozoa.

• Journal of Life Science
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• v.27 no.6
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• pp.623-631
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• 2017

In the subventricular zone (SVZ) and the subgranular zone of the brain, neurogenesis occurs throughout one's lifespan. Neural stem cells (NSCs) in these regions divide to maintain their stem cell pools as well as differentiate into neurons and glial cells. To monitor cell division, a thymidine analogue such as 5-ethynyl-2'-deoxyuridine (EdU) has been used. In some cases, EdU was applied to label newly born neurons. Here, we report about the effects of EdU on the proliferation and differentiation of NSCs cultured from mouse SVZ. First, when NSCs were cultured in a proliferation medium containing EdU for 24 hr, they did not generate any neurons under the following differentiation conditions. When EdU was applied to the proliferating NSCs for 1 hr prior to differentiation, neurogenesis was still substantially reduced. Second, EdU decreased cell proliferation of NSCs in dose- and time-dependent manners. Finally, EdU inhibited differentiation into oligodendrocyte lineage, while the number of glial fibrillary acidic protein (GFAP)-positive astrocytes increased. To our knowledge, these findings are the first to show the effects of EdU on the differentiation of SVZ NSCs and suggest that cell division is necessary for differentiation into neurons and oligodendrocytes.

• Journal of Life Science
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• v.23 no.10
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• pp.1230-1238
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• 2013

The regulatory effect of the tumor-suppressor protein p53 on the apoptogenic activity of $17{\alpha}$-estradiol ($17{\alpha}-E_2$) was compared between HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells. When the HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells were treated with $2.5{\sim}10{\mu}M$ $17{\alpha}-E_2$ for 48 h or with $10{\mu}M$for various time periods, cytotoxicity and an apoptotic sub-$G_1$ peak were induced in the HCT116 ($p53^{+/+}$) cells in a dose- and time-dependent manner. However, the HCT116 ($p53^{-/-}$) cells were much less sensitive to the apoptotic effect of $17{\alpha}-E_2$. Although $17{\alpha}-E_2$ induced aberrant mitotic spindle organization and incomplete chromosome congregation at the equatorial plate, $G_2/M$ arrest was induced to a similar extent in both cell types. In addition, $17{\alpha}-E_2$-induced activation of Bak and Bax, ${\Delta}{\Psi}m$ loss, and PARP degradation were more dominant in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells. In accordance with enhancement of p53 phosphorylation (Ser-15) and p53 levels, p21 and Bax levels were elevated in the HCT116 ($p53^{+/+}$) cells treated with $17{\alpha}-E_2$. The HCT116 ($p53^{-/-}$) cells exhibited barely or undetectable levels of p21 and Bax, regardless of $17{\alpha}-E_2$ treatment. On the other hand, although the level of Bcl-2 was slightly lower in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells, it remained relatively constant after the $17{\alpha}-E_2$ treatment. Together, these results show that among the components of the $17{\alpha}-E_2$-induced apoptotic-signaling pathway, which proceeds through mitotic spindle defects causing mitotic arrest, subsequent activation of Bak and Bax and the mitochondria-dependent caspase cascade, leading to PARP degradation, $17{\alpha}-E_2$-induced activation of Bak and Bax is the upstream target of proapoptotic action of p53.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.4
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• pp.444-448
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• 1989

The division and circadian DNA-synthesis rtythm are studied in chick liver immediately after hatching. The vision function is tested by the mitotic and the $^3H-thymidine$ labelling index The DNA synthesis exhibited a cyclic variation of 12 hours immediately after hatching. The rhythmic changes of DNA synthesis was maintained in the liver of meal-fed chickens, but the DNA synthetic activities decreased gradually in the starved chicken liver. From this time, the rhythm of DNA synthesis was greatly afffected by lighting schedule, all these DNA synthesis of chicken liver was accompained by mitosis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.830-833
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• 2015

Schwann cells and neuron cells from dorsal root ganglion (DRG) of rat embryos (E16) were isolated and purified in vitro system. The purified DRG cells with anti-mitotic agents and purified Schwann cells, respectively, were cocultured and then consummated myelination processing. This myelination system was treated by M. leprae-specific phenolic glycolipid-1 (PGL-1) and then accomplished demyelination system. We compared with myelination and demyelination using neurofilament of monoclonal antibody.

• Journal of Plant Biology
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• v.28 no.1
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• pp.45-55
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• 1985

Observations on reproduction of Rhodochorton purpureum (Lightfoot) Rosenvinge (Acrochaetiaceae, Rhodophyta) was carried out with plants from Hokkaido, Japan. This species produces no monosporangia both in nature and culture, even though it does tetrasporangia commonly. The plants from Nemuro produce neither sporangia nor gametangia, and thus vegetative reproduction is the only known way to propagate themselves. It is suggested that the vegetative reproduction occurs in nature by fragmentation of vegetative filaments after development of a rhizoid. Several different modes of rhizoid production are described. The plants from Akkeshi and Oshoro (I) produce tetrasporangia that develop into plants producing only tetrasporangia. The plants from Muroran and Oshoro (II) produce tetrasporangia that develop into gametophytes. Gametophytes of R. purpureum from Muroran produce tetrasporangia as well as spermatangia or carpogonia. Such tetrasporangia on gametophytes are presumed to be mitotic.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.907-910
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• 1998

Primary leiomyosarcoma is an extremely rare tumor. We exprienced a case of 46-year-old man with a mass located in the left upper lobe bronchus which was discovered on a chest CT. Cytology of the sputum and bronchoscopic biopses did not reveal any malignant cells. The patient underwent a left sleeve upper lobectomy. The tumor was growing from the left upper lobe bronchus and had partially destroyed the lung parenchyme. The pathologic feature of the tumor was composed of fascicular arrayed cellular spindle cells with blunt-ended nuclei revealed mild to moderate pleomorphism and frequent mitoses (15/10HPF). The immunohistochemical staining was revealed positive reaction for antibody to smooth muscle actin and desmin. We conclude that the tumor is leiomyosarcoma of the lung and then report with a review of the literatures.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.232-236
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• 1997

It is known that septin gene encodes the filament in Saccharomyces cerevisiae and it has importants roles in bud formation and cytokinesis. Four septin genes have been cloned in S. cerevisiae and it was found in Drosophila melanogaster and mouse. In this study, we cloned the septin gene in Schizosaccahromyces pombe by use of PCR technique. The septin gene in S. pombe has an 1,143 bp open reading frame and encodes a protein of 380 amino acids with a molecular weight of 42 kd. Comparison of the predicted amano acid sequences between the septin gene in S. pombe and CDC12 gene in S. cerevisiae reveals the 51.8% of simility.