• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.1-12
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• 2003

The present study was carried out to establish the standard karyotype of the Korean Native Chicken and to find their chromosomal band markers using high-resolution banding technique. Chromosome analysis was performed on early chick embryos following in vitro culture of fertilized eggs of the yellow-brown and the red-brown lines of the Korean Native Chicken which had been established at National Livestock Research Institute. The high-resolution banding of the chromosome was achieved by treating the embryos with ethidium bromide and colchicine during culture. On GTG-banding, the Korean Native Chicken exhibited a typical chick banding pattern in all the macrochromosomes. Overall chromosomal morphology and positions of typical landmarks of the Korean Native Chicken were virtually identical to those of White Leghorn and International System for Standardized Avian Karyotypes(ISSAK). However, the lengths and G-band numbers of the Korean Native Chicken macrochromosomes were greater than those of White Leghorn and ISSAK. Especially in chromosomes 1 and Z, the Korean Native Chicken exhibited more separated bands in compared with ISSAK. In C-banding patterns, although a lot of observed cells had C-band polymorphic patterns, almost the Korean Native Chicken macrochromosomes had heterochromatic C-band on centromeres and/or near terminal part. However, the heterochromatic C-band was constantly observed at the end of q-arm of Z chromosomes and on the whole W chromosome. In addition, the Korean Native Chicken exhibited distinctive heteromorphic patterns of C-bands on the centromere of chromosome 3 and at the end of q-arm of Z chromosome between homologous chromosomes.

• BMB Reports
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• v.42 no.4
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• pp.227-231
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• 2009

The eukaryotic genome forms a chromatin structure that contains repeating nucleosome structures. Nucleosome packaging is regulated by chromatin remodeling factors such as histone chaperones. The Saccharomyces cerevisiae H3/H4 histone chaperones, CAF-1 and Asf1, regulate DNA replication and chromatin assembly. CAF-1 function is largely restricted to non-transcriptional processes in heterochromatin, whereas Asf1 regulates transcription together with another H3/H4 chaperone, HIR. This study examined the role of the yeast H3/H4 histone chaperones, Asf1, HIR, and CAF-1 in chromatin dynamics during transcription. Unexpectedly, CAF-1 was recruited to the actively transcribed region in a similar way to HIR and Asf1. In addition, the three histone chaperones genetically interacted with Set2-dependent H3 K36 methylation. Similar to histone chaperones, Set2 was required for tolerance to excess histone H3 but not to excess H2A, suggesting that CAF-1, Asf1, HIR, and Set2 function in a related pathway and target chromatin during transcription.

• The Korean Journal of Zoology
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• v.31 no.4
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• pp.309-317
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• 1988

내륙산 관박쥐와 제주산 관박쥐간의 동-종 여부를 조사하기 위하여 경남과 제주에서 채집한 이들 관박쥐들을 핵형분석하였다. 핵형분석의 결과, 2종 모두 염색체수는 2n=58이었으며 FN도 62였다. 상염색체에서는 중형의 2쌍과 미세형 1쌍이 중부염색체(metacentrics)였고, 대형에서 소형까지는 25쌍이 단부염색체facrocentrics)이었다. 성염색체에서 X염색체는 대형의 차중부염색체(submetacentrics)였고, Y염색체는 소형의 단부염색체(acrocentrics)이었다. 그리고 이들 염색체들은 동원체 부근에 이질염색체을 가지는 특이한 1쌍의 단부염색체(acrocentrics)가 존재하고 있었다. in this study, We analysed the karyotypes of the inland bat(Rhinolox)thus femequinum hora) and the Cheju-Island bat(Rhinorophus ferrumequinum quelpartis(\ulcorner)) collected in Kyungnam and Cheju provinces to identify the homogeneous between them. The results are as follows. The diploid number of chromosomes of them are equally 58 and the fundamental number 62. In the autosomes, metacentrics consist of two pairs of the middle form and a pair of the micro-form. And acrocentrics have 25 pairs of large and small form. In sex-chromosomes, X-chromosome is a large submetacentrics and Y is a small acrocentrics. And, these chromosomes possess a pair of particular acrocentrics having heterochromatin around centromere in both the inland bat(Rhinolophus fenmequinum korai ) and Cheju-Island bat(Rhinolophus fewmequinum querporis (\ulcorner)).

• The Korean Journal of Cytopathology
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• v.7 no.1
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• pp.23-30
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• 1996

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs, nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma, the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ in their chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.

• Applied Microscopy
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• v.9 no.1
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• pp.35-56
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• 1979

To investigate ultrastructural characteristics of cancer cells of the nervous system, 25 cases; i.e. astrocytoma(9), oligodendroglioma(1), medulloblastoma(1), meningioma(5), pinealoma(2) and pituitary adenomas(7). The common findings were marked irregularity of nuclear membrane with pronounced infoldings, clumping of heterochromatin along inner nuclear membrane, enlargement of nucleolus, and frequent observations of nuclear bodies and nuclear inclusions. But these findings are also the signs that can be observed in hyperactive cells. Thus, ultrastructural characteristics of cancerous nucleus are the great variability of nuclear size, shape and composition. but none of them appear to be specific. Among cytoplasmic organelles, massive fibrils are characteristic of astrocytoma and meningiomas, cytoplasmic protofibrils such as glial process and microvesicles in oligodendroglioma, secretory granules are characteristic in pituitary adenomas, and fine filamentous fibrils and desmosomes are characteristic of fibroblastic type of meningioma. Intercellular relationships and cell membrane specialization are important features in the differential diagnosis of various undifferentiated tumors. The frequent resolution of difficult diagnosis problems by electron microscopy outweighs the disadvantages of this technique, such as the expense and time required.

• Applied Microscopy
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• v.15 no.2
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• pp.69-79
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• 1985

Ultrastructural and cytochemical studies of the root hair cell and the trichoblast were undertaken with light and electron microscopes to clarify the type of root hair, fine structure and the activities of acid phosphatase and ATPase. The root hair was differentiated from the middle portion of the cell, and perpendicularly to the long axis of the cell. Consequently, the type of root hair comes under the panicoid type. In the trichoblast, nucleus and cytoplasm are located in the vicinity of cortex. On the contrary, after the root hair is formed, they migrate to the apical region of the root hair, and the basal region of the root hair is filled with numerous vacuoles. Cell walls of actively growing root hairs are subdivided into two layers on the basis of the arrangement of cellulose microfibrils. New cell wall of the root hair is presumptively formed from Golgi complex-derived vesicles. Activity of acid phosphatase appeared on tonoplast, plasma membrane, and nuclear envelope, whereas ATPase activity appeared on the plasma membrane, heterochromatin, and mitochondrial cristae.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.154-158
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• 1987

As a series of systematic classification of paramphistomes, the worms in the rumen and reticulum were collected on 214 Korean cattle slaughtered at Jeonju abattoir from January, 1986 to April, 1987 and were classified by means of morphology. Afterwards, the karyotype of Paramphistomum cervi(Zeder, 1790) was detected by means of modified air.drying method from germ cells of the worms. The results were summarized as follows: 1. In the chromosome number of 254 p. cervi, the haploid cell was n:9 and the diploid 2n=18. The meiotic divisions were observed frequently; 1,924 haploid and 32 diploid cells were reliable. Nine pairs of mitotic chromosomes were homologous in the metaphase stage, and the chromosomes were composed of five medium-sized metacentrics (m) , subtelocentrics(st) or submetacentrics(sm) and four small-siRed subtelocentrics(st) or submetacentrics(sm). Meiotic metaphase was composed of five medium and four small chromosomes in size. 2. As a series of C-banding method, C-band was showed in centromeric region from all of the haploid germ cells. Whereas chromosome No. 3 and 5 included heterochromatin on the tip region, chromosome No. 4 on the distal region and No. 6 proximal region. And chromosomes No. 2 and 8 showed a remarkable C-band distinguished from other chromosomes.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.109-112
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• 2001

Sieve element area and sieve pore formed generally from plasmodesmata. Sieve pore formed by the fusion of several tiny vesicles with plasmodesmata, or those with cell wall after the destruction of special region of newly formed cell wall or those finally with circular arranged form from tissure culture of Streptanthus. The tiny vesicles were produced from dispersed nucleolus or heterochromatin. The sieve area and sieve pore formed from tissue cultured cells were shown round tube form similar to those of natural plants. Sieve area and sieve pore were produced by various methods, and it suggested that the basic materials of the construction of sieve pore originated from the vesicles.

• Molecules and Cells
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• v.26 no.4
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• pp.356-361
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• 2008

In this work, we have studied the structural and functional linkage between lamin A/C, nuclear actin, and organization of chromosome territories (CTs) in mammary carcinoma MCF-7 cells. Selective down-regulation of lamin A/C expression led to disruption of the lamin A/C perinuclear layer and disorganization of lamin-bound emerin complexes at the inner nuclear membrane. The silencing of lamin A/C expression resulted in a decrease in the volume and surface area of chromosome territories, especially in chromosomes with high heterochromatin content. Inhibition of actin polymerization led to relaxation of the structure of chromosome territories, and an increase in the volumes and surface areas of the chromosome territories of human chromosomes 1, 2 and 13. The results show an important role of polymeric actin in the organization of the nuclei and the chromosome territories.

• Molecules and Cells
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• v.27 no.4
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• pp.481-490
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• 2009

Diverse posttranslational modifications of histones, such as acetylation and methylation, play important roles in controlling gene expression. Histone methylation in particular is involved in a broad range of biological processes, including heterochromatin formation, X-chromosome inactivation, genomic imprinting, and transcriptional regulation. Recently, it has been demonstrated that proteins containing the Jumonji (Jmj) C domain can demethylate histones. In Arabidopsis, twenty-one genes encode JmjC domain-containing proteins, which can be clustered into five clades. To address the biological roles of the Arabidopsis genes encoding JmjC-domain proteins, we analyzed the temporal and spatial expression patterns of nine genes. RT-PCR analyses indicate all nine Arabidopsis thaliana Jmj (AtJmj) genes studied are actively expressed in various tissues. Furthermore, studies of transgenic plants harboring AtJmj::${\beta}$-glucuronidase fusion constructs reveal that these nine AtJmj genes are expressed in a developmentally and spatially regulated manner.