• Reproductive and Developmental Biology
• /
• v.36 no.1
• /
• pp.21-26
• /
• 2012

Suspension culture is a useful tool for culturing embryonic stem (ES) cells in large-scale, but the stability of pluripotency and karyotype has to be maintained $in$ $vitro$ for clinical application. Therefore, we investigated whether the chromosomal abnormality of ES cells was induced in suspension culture or not. The ES cells were cultured in suspension as a form of aggregate with or without mouse embryonic fibroblasts (MEFs), and 0 or 1,000 U/ml leukemia inhibitory factor (LIF) was treated to suspended ES cells. After culturing ES cells in suspension, their karyotype, DNA content, and properties of pluripotency and differentiation were evaluated. As a result, the formation of tetraploid ES cell population was significantly increased in suspension culture in which ES cells were co-cultured with both MEFs and LIF. Tetraploid ES cell population was also generated when ES cells were cultured alone in suspension regardless of the existence of LIF. On the other hand, the formation of tetraploid ES cell population was not detected in LIF-free condition, in which MEFs were included. The origin of tetraploid ES cell population was turned out to be E14 ES cells and not MEFs by microsatellite analysis and the basic properties of them were still maintained despite ploidy-conversion to tetraploidy. Furthermore, we identified the ploidy shift from tetraploidy to near-triploidy as tetraploid ES cells were differentiated spontaneously. From these results, we demonstrated that suspension culture system could induce ploidy-conversion generating tetraploid ES cell population. Moreover, optimization of suspension culture system may make possible mass-production of ES cells.

• The Journal of the Korean Society for Microbiology
• /
• v.19 no.1
• /
• pp.85-108
• /
• 1984

In order to study the relationship between resistance of tumor cells to anticancer drugs and immunologic cytotoxicity and their chromosome number, a line of cancer cells (NS-1) was exposed to BCNU and CCNU in vitro. Characteristics of the distribution of chromosome number of the survived cells were then comparatively analyzed. Effect of immune mediated cytotoxicity, i.e. complement and cell-mediated cytotoxicity, on the ploidy characteristics was observed in the same way. NS-1 cells were found to be a population of neoplastic cells of heterogeneity having 5 to 115 chromosomes per cell in metaphase. The majority of the cells were belong to the class of chromosome number 56 to 60 which were considered as the stem cell line. Dramatic changes in the distribution of chromosome number following drug treatment were not observed. However the range of chromosome distribution was slightly changed. Characteristics of chromosomal distribution of drug treated cells were not significantly varied by different doses of drug treated. Changed chromosomal distribution patterns of drug treated cells were reversible, especially the cells having 56 to 60 chromosomes recovered rapidly. Cells having 41-60 and 61-80 chromosomes among cells treated with BCNU and cells with 41-60 chromosomes after CCNU treatment were the major population which regenerated continuously. Following BCNU treatment cells having 61-80 chromosomes were not varied much whereas CCNU treatment affects the population in the same class. Chromosomal aberrations were significantly enhanced by BCNU and CCNU treatment. The frequency of chromosomal aberrations was greater in cells having more than 40 chromosomes compared with that in cells having less than 40 chromosomes. Changes in ploidy characteristics of the cells following complement mediated and cell mediated cytotoxicity were not significant. Therefore it was tentatively concluded that association of numerical distribution pattern of NS-1 cells with the response to the treatment used in this experiment was not recognized.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.3
• /
• pp.175-181
• /
• 1997

Plants were regenerated from hypocotyl protoplast culture of cabbage (F$_1$hybrid Green Challenger) and were transplanted on fields. The ploidy level of regenerated and seed-grown plants was measured by flow cytometry. In total 125 regenerated plant, diploid (2n), tetraploid(4n), and mixoploid (2n+4n) were 72.8%, 25.6%, and 1.6%, respectively. Most of the regenerated plants had normal phenotype, whereas several plane showed abnormal phenotype such as heavy leaf incision, savoy, and wave. The regenerated plants with abnormal phenotype and different ploidy level were analysed by isozyme and RAPD, but no significant difference was found.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.7917-7922
• /
• 2015

DNA ploidy is an important prognostic parameter in paediatric B-ALL, but the significance of the S-phase fraction is unclear. In present study, DNA ploidy was assessed in 40 pediatric B-ALL cases by flow cytometry. The DI (DNA index) and percentage of cells in S-phase were calculated using Modfit software. Aneuploidy was noted in 26/40 (65%) cases. A DI of 1.10-1.6 (hyperdiploidy B) was noted in 20/40 (50%) and 6/40 (15%) had a DI>1.60 (triploid and tetraploid range). Some 14/40 (35%) cases had a diploid DI between 0.90-1.05. None of the cases had a DI <0.90 (hypodiploid) or in the 1.06-1.09 (hyperdiploid A) range. The mean S-phase fraction was 2.6%, with 24/40 (60%) having low and 16/40 (40%) high S-phase fractions. No correlation was noted with standard ALL risk and treatment response factors with DI values or S-phase data, except for a positive correlation of low S-phase with high NCI risk category (p=0.032). Overall frequency of hyperdiploidy in our cohort of B-ALL patients was very high (65%). No correlation between hyperdiploidy B and low TLC or common B-phenotype was observed in our study as 42% cases with DI 1.10-1.6 had TLC> $50{\times}10^9$ and 57.1% CD 10 negativity. The study also highlighted that S-phase fraction analysis does not add any prognostic information and is not a useful parameter for assessment in ALL cases. However, larger studies with long term outcome analysis are needed to derive definitive conclusions.

• Korean Journal of Head & Neck Oncology
• /
• v.12 no.2
• /
• pp.153-160
• /
• 1996

Regardless of the prognostic factors in papillary thyroid cancer, such as sex, age, size of tumor, extent of disease, and distant metastasis, the prognosis of papillary thyroid cancer is sometimes difficult to predict from clinical and microscopic analysis alone and additional prognostic indicators are needed. Recent studies of thyroid cancer have indicated that DNA aneuploidy may be correlated to the biological behavior of malignancy and inversely correlated to the prognosis, but it still remains contraversal. We performed this study to assess DNA ploidy patterns in relation with the previously known prognostic factors in AMES scoring system and lateral neck node metastasis in papillary thyroid cancer. A series of 132 patients with papillary thyroid cancer and 80 patients with benign thyroid tumor(27 follicular adenomas and 53 adenomatous goiters) as a control group from October 1993 to Feburary 1995 were analyzed and their nuclear DNA content was measured with flow cytometry using fresh tissue specimens. DNA aneuploidy was found in 8(6.1%) in papillary cancer and 8(10%) in benign tumor. S-phase traction(SFP) and proliferative index(PI) were higher in thyroid cancers, being 2.18$\pm$4.24%, 6.34$\pm$4.94% in the papillary thyroid cancers and 1.97$\pm$2.93%, 4.44$\pm$3.80% in the benign tumors, respectively. However there was no significant difference of values between two groups(p>0.05). Among variable prognostic factors studied(age, sex, size of tun or, extent of disease, distant metastasis in AMES scoring system and lateral neck node metastasis), DNA aneuploidy was found to be common in distant metastasis(p<0.001) and in lateral neck node metastasis(p>0.035), but there was no significant difference between the high risk and low risk group according to the AMES scoring system(p<0.08). In our study, DNA aneuploidy was not valuable in determining the presence of malignancy and did not correlate to the AMES scoring system. However, follow-up study of more cases will be needed for accurate information about the DNA ploidy as a independent prognostic factor.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.3
• /
• pp.193-200
• /
• 2010

Current rose cultivars are all composed of heterozygous genome due to long history of out crossing including interspecific hybridization. It has been adapted by artificial selection and crossing by breeders that mainly based on the crossing with fertile pollen derived from inter- or intra-specific hybridization. Pollen viability and germination ability tests provide valuable information for the designing of parentage for more successful breeding efficacy. In this study, we tested the pollen viability and germination ability in seven rose cultivars to find any relationship among several factors including pollen size, ploidy levels, and crossing compatibility. The pollen viability showed wide ranges from 39% 'Pinocchio' as minimum to 82% 'Scarlet Mimi' as maximum, whereas pollen germination rate were from 1% 'Mini Rosa' to 41% 'Scarlet Mimi' as a highest. Pollen size ranged from 41.3 to $45.4{\mu}m$ in large sized pollen and 30.7 to $37.4{\mu}m$ in small sized pollen. The mean diameter of large sized pollen is approximately 10-40% bigger than that of small sized pollen. There are positive relationships among ploidy level, total chromosome length, and pollen size. Crossing list showed that seed setting ratio and seed germination were related to pollen viability, pollen germination, and ploidy level.

• 대한두경부종양학회:학술대회논문집
• /
• 1990.11a
• /
• pp.24.2-26
• /
• 1990

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.40-40
• /
• 2003

DNA content of the sperm of tetraploid mud loach (Misgurnus mizolepis) males and the ploidy status of progenies generated by crossing tetraploid males with diploid females are described. Reproductive performance of the induced adult tetraploid males ranged from sterility to fertility. Of 48 tetraploid males tested, 12 were sterile but the other 36 produced functional sperm. Of these 36, 26 produced haploid sperm, which on fertilizing the haploid eggs, generated diploid progenies. Seven tetraploid males were mosaics in their sperm, as indicated by the production of diploid, aneuploid and/or triploid offspring. Only 3 males produced diploid sperm rendering the production of all-triploid progenies. The DNA content of sperm of a tested tetraploid male was consistent throughout the 3 progeny tests, i.e. the haploid sperm-producing 4n males persisted to produce the haploid sperm only likewise the diploid sperm producing4n males consistently produced the diploid sperm only, when progeny testing was extended to 3 successive but alternate years. Hence, a careful and direct examination of the DNA profile of sperm from tetraploid males is a pre-requisite for reproductive containment of genetically modified fish.

• Toxicological Research
• /
• v.14 no.2
• /
• pp.143-149
• /
• 1998

This study was carried out to evaluate the testicular toxicity of 2-bromopropane (2-BP), which recently caused occupational intoxication on the reproductive and hematopoietic system in Koreans, using light microscopy, immunohistochemistry and flow cytometry. 10 weeks old male Sprague-Dawley (SD) rats were treated with 0.5 g/㎏/day of 2-BP orally for 8 consecutive weeks. The testes of the rats were vascularly perfused with Karnovsky's solution or immersed in Bouin's solution, embedded in plastic and evaluated with light microscopy. And relative proportions of haploid, diploid, and tetra-ploid states of DNA ploidy in the testicular cell suspensions of the SD rats were examined by flow cytometry. 2-BP induced severe testicular atrophy, depletion and degeneration of spermatogonia, spermatocytes, and spermatids and mild hyperplasia of Leydig cells without significant morphological changes. The Leydig cell hyperplasia was confirmed by immunohistochemistry using proliferating cell nuclear antigen (PCNA). The immunopositive cells against PCNA were observed in the nuclei oj some interstitial cells. Relative proportions of haploid states of DNA ploidy decreased in the atrophic testicular cell suspensions comparing with those of the control. In conclusion, 2-BP induced testicular atrophy with Leydig cell hyperplasia as examined by histopathology, immunohistochemistry and DNA flow cytometry.

• Journal of Korea Foresty Energy
• /
• v.19 no.1
• /
• pp.38-48
• /
• 2000

This study was initiated to investigate similarity and intraspecific variation in pollen morphology of korean subgenus. lepidobalanus Endl, of the genus Quercus L. The parameters measured were polar axis length (PL), equatorial width (EW), colpus length (CL) and copus width (CW), and PE (PL/EW) retios were calculated. The cluster analysis based on these variables of this result showed that the similarity between Q. acutissima Carruther and Q. variabilis Blume was the highest. Wide variation in the pollen grain size of Quercus dentata Thunb. ex Murray might imply, the existence of polyploid and/or aneuploid forms. Studies of ploidy levels within species are recommended for Lepidobalanus species.