• Korean Journal of Animal Reproduction
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• v.5 no.2
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• pp.49-55
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• 1981

This experiment was conducted to investigate the effects of temperature and time of sedimentation and dilutor on the a, pp.arance of B-body in top and bottom fractions at separation of X and Y- chromosome bearing spermatozoa in boar semen. 1. The top fraction showed higher a, pp.arence rate of B-body than the bottom. 2. Sixty minutes at 5 and 15$^{\circ}C$ and 90 min, at 25$^{\circ}C$ showed highest difference of B-body a, pp.arence rate between top and bottom fractions. The highest difference was shown in the treatments of Sg at 5$^{\circ}C$, C at 15$^{\circ}C$ and P at 25$^{\circ}C$. 3. The highest difference was shown in the treatments of 25$^{\circ}C$ and Sg for 30 min, 15$^{\circ}C$ and P for 60 min. and 25$^{\circ}C$ and P for 90 min. 4. Sixty minutes in C, P, S and Sg dilutors showed the highest difference. 5. 25$^{\circ}C$ of the temperature levels, 60 min of the time levels and P of the dilutor levels showed the highest difference. 6. The difference was given due to the individual boar.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.216-218
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• 2017

We here provide the complete genome sequence of Bacillus thuringiensis C25, the strain showing antagonistic effects on fungal phytopathogens. The genome comprised of 5,308,062 bp with 35.32% G+C content of a circular chromosome and a plasmid containing 308,946 bp with 32.23% G+C content. The chromosome and plasmid genome included 5,683 protein coding DNA sequences, 107 tRNA and 42 rRNA genes.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.227-235
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• 1997

Cytogenetic studies were performed in peripheral blood lymphocytes from hospital workers occupationally exposed to low doses of radiation (0.30 - 40.07mSv). The workers were divided into three groups according to their job area : 18 diagnostic radiology, 17 therapeutic radiology, and 16 nuclear medicine. The control group consisted of 49 non-radiation workers with no history of exposure to radiation. A higher percentage of cells with aberration(1.275%) was observed in the workers compared to the controls(0.677%) and the difference was statistically significant(p<0.001). The frequency of chromosomal aberration was $0.706{\times}10^{-2}$/cell in the exposed and $0.344{\times}10^{-2}$/cell in the control(p<0.05). Chromosomal exchange frequency was $0.083{\times}10^{-2}$/cell in the control vs $0.245{\times}10^{-2}$/cell in the workers. There was no evidence of significant increase of chromosome aberration related to age or to the duration of employment. The frequency of chromosomal exchange in workers of nuclear medicine was $0.313{\times}10^{-2}$/cell, which was significantly higher than in the control($0.083{\times}10^{-2}$/cell) or other working groups: therapeutic radiology($0.265{\times}10^{-2}$/cell), and diagnostic radiology($0.167{\times}10^{-2}$/cell). No dose-effect relation was found between chromosome aberration and total cumulative doses, recent 5 yr, recent 2 yr cumulative dose. But in case of last 1 yr cumulative dose, dose-dependant increase was observed when controls were considered(p<0.05). The radiation dose which workers have received was much lower than the maximum permissible dose, but there was a significant difference in the frequency of chromosome aberration between occupationally exposed workers and control. So, it is clear that chromosome aberration is a quite sensitive indicator of radiation exposure and it can be detected at very low dose level of occupational exposure.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.597-611
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• 2003

Background : Loss of the short arm of chromosome 16 is a frequent event in various cancers, which suggests the presence of tumor suppressor gene(s) there. To map precise tumor suppressor loci on the chromosome arm for further positional cloning efforts, we tested 23 primary small cell lung cancers. Method : The DNAs extracted from paraffin embedded tissue blocks with primary tumor and corresponding control tissue were investigated. Twenty polymorphic microsatellite markers located in the short arm of chromosome 16 were used in the microsatellite analysis. Results : We found that six (26.1%) of 23 tumors exhibited LOH in at least one of tested microsatellite markers. Two (8.7%) of 6 tumors exhibiting LOH lost a larger area in chromosome 16p. LOH was observed in five common deleted regions at 16p. Among those areas, LOH between D16S668 and D16S749 was most frequent (21.1%). LOH was also observed at four other regions, between D16S3024 and D16S748, D16S405, D16S420, and D16S753. Six of 23 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Shifted bands occurred in 3.3% (15 of 460) of the loci tested. Conclusion : Our data demonstrated that at least five tumor suppressor loci might exist in the short arm of chromosome 16 and that they may play an important role in small cell lung cancer tumorigenesis.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.223-232
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• 2000

Comparative study was performed for the assessment of DNA damage and Chromosomal aberration in human lymphocyte exposed to low dose radiation using fluorescence in situ hybridization(FISH) and single cell gel electrophoresis(SCGE). Chromosomal aberrations in human lymphocytes exposed to radiation at doses of 5, 10, 30 and 50cGy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. FISH with chromosome-specific probe has been used to be a valid and rapid method fer detection of chromosome rearrangements induced by low dose radiation. The frequencies of stable translocation per cell equivalents were 0.0116, 0.0375, 0.040f, 0.0727 and 0.0814 for 0, 5, 10, 30 and 50cGy, respectively, and those of dicentric were 0.00, 0.0125, 0.174, 0.0291 and 0.0407 respectively. Radiation induced DNA damage in human lymphocyte in a dose-dependent manner at low doses from 5cGy to 50cGy, which were analysed by single tell gel electrophoresis(SCGE). From above results, FISH seemed to be useful for radiation biodosimetry by which the frequencies of stable aberrations in human lymphocyte can be observed more easily than by conventional method and SCGE also seemed to be sensitive method f9r detecting DNA damage by low dose radiation exposure, so that those methods will improve our technique to perform meaningful biodosimetry for radiation at low doses.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.490-493
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• 2004

Karyotypes were established in five Pulsatilla species from Korea : P. cernua, P. davurica, P. koreana, P. chinensis and P. tongkangensis. The somatic chromosome numbers of five species were all 2n=2x=16 with the basic number of x=8. The chromosome complement of P. cernua consisted of 5 pairs of metacentric, 1 pair of submetacentric and 2 pairs of subtelocentric. P. davurica, P. koreana and P. chinensis consisted of 5 pairs of metacentric and 3 pairs of subtelocentric. P. tongkangensis consisted of 5 pairs of metacentric, 2 pairs of submetacentric, and 1 pair of subtelocentric. Karyotype formulas of P. davurica, P. koreana, and P. chinensis were the same as K (2n) = 2x = 16 = 10m + 6st, while those of P. cernua was K (2n) = 2x = 16 = 10m + 2sm + 4st and P. tongkangensis was K (2n) = 2x = 16 = 10m + 4sm + 2st, respectively.

• Plant Biotechnology Reports
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• v.5 no.2
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• pp.187-195
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• 2011

The gesneriaceous perennial plant Titanotrichum oldhamii has beautiful foliage and attractive bright yellow flowers. However, breeding of T. oldhamii by conventional sexual hybridization may be difficult because sexual reproduction of this species is very rare. In the present study, plant regeneration systems via both direct and indirect formation of adventitious shoots from leaf explants were established as the first step toward breeding T. oldhamii by using biotechnological techniques. Adventitious shoots were formed efficiently on medium containing $0.1mg\;l^{-1}$ benzyladenine. Histological observation showed that shoot formation on this medium occurred directly from leaf epidermal cells without callus formation. On the other hand, leaf explants formed calluses on medium containing $0.1mg\;l^{-1}$ 2,4-dichlorophenoxyacetic acid. The calluses could be maintained by monthly subculturing to fresh medium of the same composition. When the calluses were transferred to plant growth regulator-free medium, they formed adventitious shoots. Directly and indirectly formed shoots rooted well on medium containing $0.1mg\;l^{-1}$ indole-3-butyric acid. Plantlets thus obtained were successfully acclimatized and grew vigorously in the greenhouse. Flow cytometry analysis indicated that no variation in the ploidy level was observed in plants regenerated via direct shoot formation, whereas chromosome doubling occurred in several plants regenerated via indirect shoot formation. Regenerated plants with the same ploidy level as the mother plants showed almost the same phenotype as the mother plants, whereas chromosome-doubled plants showed apparent morphological alterations: they had small and crispate flowers, and round and deep green leaves.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.287-291
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• 2010

The purpose of this study was to detect quantitative trait loci (QTL) for growth and carcass quality traits on BTA6 in a population of Hanwoo cattle. Three hundred and sixty one steers were produced from 39 sires that were sired by 17 grandsires in the two Hanwoo farming branches of the National Livestock Research Institute of Korea, between Spring 2000 and Fall 2002. DNA samples were collected for all of the steers, sires and grandsires, and the phenotypes for six growth and carcass quality traits were measured at 24 months of age. Twelve microsatellite markers were chosen on BTA6 and a linkage map was constructed by using seven of the twelve markers. Then, a chromosome-wide QTL scan was performed by applying an Animal Model, in which effects of QTL alleles within the grand sires were fitted as a random term. Three QTL were detected at the 5% chromosome-wise level for backfat thickness, average daily gain, and final weight. The most likely positions for the QTL were in the proximal region, i.e. 0 cM, 35 cM, and 63 cM, respectively. Also, another QTL for longissimus dorsi muscle area was detected at the 10% chromosome-wise level at 67 cM. These results were, in general, consistent with our previous report, in which candidate gene analyses showed that a SNP near ILSTS035 flanked by BM4621 (62.5 cM) and BMS2460 (81.3 cM) was associated with final weight, carcass weight, average daily gain, and longissimus dorsi muscle area in the same Hanwoo population.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.1
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• pp.75-81
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• 2004

Objective: The purpose of this study was to evaluate the efficacy and effect of various cryopreservation method on the survival and the cytoskeletal stability of metaphase II mouse oocyte. Methods: Mouse ovulated oocytes were collected and cryopreserved by a modified slow-freezing method with 1.5 M 1, 2-propanediol (PrOH)+0.1 M sucrose or by vitrification using cryo loop and EM grid with 40% ethylene glycol+0.6 M sucrose. Four hours after thawing, intact oocytes were fixed and stained with fluorescein isothiocyanate (FITC)-conjugated monoclonal anti-$\beta$-tubulin antibody to visualize spindle and propidium iodide (PI) to visualize chromosome. Spindle morphology was classified as follows: normal (barrel-shaped), slightly and absolute abnormal (multipolar or absent). Results: Survival rate of the frozen-thawed oocytes in vitrification group was significantly higher than that of slow-freezing group (62.7% vs. 24.4%, p<0.01). Vitrification with cryo loop showed significantly higher survival rate than that with EM grid (67.7% vs. 53.5%, p<0.05). On the other hand, proportion of normal spindle and chromosome configurations of the frozen-thawed oocytes between two vitrification group was not significantly different. Conclusion: For mouse ovulated oocytes, vitrification with cryo loop may be a preferable procedure compared to slow-freezing method. Further study should be needed to investigate developmental competency of frozen-thawed mouse oocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.8-19
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• 2017

Objective: A whole genome association study was conducted to identify single nucleotide polymorphisms (SNPs) with additive and dominant effects for growth and carcass traits in Korean native cattle, Hanwoo. Methods: The data set comprised 61 sires and their 486 Hanwoo steers that were born between spring of 2005 and fall of 2007. The steers were genotyped with the 35,968 SNPs that were embedded in the Illumina bovine SNP 50K beadchip and six growth and carcass quality traits were measured for the steers. A series of lack-of-fit tests between the models was applied to classify gene expression pattern as additive or dominant. Results: A total of 18 (0), 15 (3), 12 (8), 15 (18), 11 (7), and 21 (1) SNPs were detected at the 5% chromosome (genome) - wise level for weaning weight (WWT), yearling weight (YWT), carcass weight (CWT), backfat thickness (BFT), longissimus dorsi muscle area (LMA) and marbling score, respectively. Among the significant 129 SNPs, 56 SNPs had additive effects, 20 SNPs dominance effects, and 53 SNPs both additive and dominance effects, suggesting that dominance inheritance mode be considered in genetic improvement for growth and carcass quality in Hanwoo. The significant SNPs were located at 33 quantitative trait locus (QTL) regions on 18 Bos Taurus chromosomes (i.e. BTA 3, 4, 5, 6, 7, 9, 11, 12, 13, 14, 16, 17, 18, 20, 23, 26, 28, and 29) were detected. There is strong evidence that BTA14 is the key chromosome affecting CWT. Also, BTA20 is the key chromosome for almost all traits measured (WWT, YWT, LMA). Conclusion: The application of various additive and dominance SNP models enabled better characterization of SNP inheritance mode for growth and carcass quality traits in Hanwoo, and many of the detected SNPs or QTL had dominance effects, suggesting that dominance be considered for the whole-genome SNPs data and implementation of successive molecular breeding schemes in Hanwoo.