• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.22-22
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• 2001

To produce reconstituted rabbit embryos with fetal fibroblasts, the present study was evaluated the efficiencies of the different fusion and activation conditions as assessments of subsequent development and chromosome in the embryos. New Zealand White rabbits were used throughout the study. Fetal fibroblasts collected from 22-d of fetuses were cultured in DMEM ＋ 10% FBS in 5% $CO_2$ in air. The culture was maintained for 10 passages. In every passage half of cell suspension were kept In frozen. From rabbits treated with FSH in 30% PVP solution and hCG, oocytes were surgically collected from oviducts at 14 h post-hCG injection and stripped off their cumulus cells by re-pipetting in a 300 IU hyaluronidase solution. Oocytes with an extruded first polar body and dense cytoplasm were enucleated by micromanipulation in Ham's F-10 medium＋7.5 g/$m\ell$ cytochalasin B. Euncleation was confirmed under a fluorescence microscope after staining with 5 g/$m\ell$ bisbenzimide for 2 min. Each enucleated oocyte was injected with a fetal fibroblast into a perivitelline space. Reconstructed eggs were compared fusion rates either at 2.0 ㎸/cm or 1.6 ㎸/cm(60 sec, double pulses). After fusion, all eggs were activated with the combination of 5 M ionomycin (5 min) and 10 g/$m\ell$ cycloheximide (CHX, 3h), and cultured in CRlaa medium and transferred into TCM199＋10% FBS on day 3. Although there was not significantly differ in fusion rate between treatments (60%, 2.0 ㎸/cm vs. 79.4%, 1.6 ㎸/cm), none of them in the eggs fused with 2.0 ㎸/cm developed to blastocyst. In comparison of development and chromosome status between different activation treatments (Group 1; 5 M ionomycin/10 g/$m\ell$ CHX, Group 2; 5 M ionomycin/5 g/$m\ell$ CHX ＋ 2 mM DMAP after fusion with 1.6 ㎸/cm), there were not differ in cleavage and development rates (67.3% and 28.9% in Group 1; 67% and 33% in Group 2). All out of 8 embryos evaluated in Group 1 appeared a normal diploid chromosome sets and mean number of cells (Mean SEM) on day 4.5 of culture was 141.5 23.15 (n=8). It can be concluded that the use of cycloheximide has not happened in chromosome abnormalities, and fetal fibroblasts can be used for cloning in rabbit.

• Genomics & Informatics
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• v.6 no.1
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• pp.18-28
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• 2008

Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium (LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centre d'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes (frequency $\geq$ 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.457-462
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• 2011

The purpose of this study was to detect QTL for carcass quality on bovine chromosome (BTA) 6 using a high density SNP map in a Hanwoo population. The data set comprised 45 sires and their 427 Hanwoo steers that were born between spring of 2005 and fall of 2007. The steers that were used for progeny testing in the Hanwoo Improvement Center in Seosan, Korea, were genotyped with the 2,535SNPs on BTA6 that were embedded in the Illumina bovine SNP 50K chip. Four different linkage disequilibrium (LD) mapping models were applied to detect significant SNPs for carcass quality traits; the fixed model with a single marker, the random model with a single marker, the random model with haplotype effects using two adjacent markers, and the random model at hidden state. A total of twelve QTL were detected, for which four, one, three and four SNPs were detected on BTA6 under the respective models (p<0.001). Among the detected QTL, four, two, five and one QTL were associated with carcass weight, backfat thickness, longissimus dorsi muscle area, and marbling score, respectively (p<0.001). Our results suggest that the use of multiple LD mapping approaches may be beneficial in increasing power to detect QTL given a limited sample size and magnitude of QTL effect.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.371-378
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• 1999

Morphology and karyotype of Korean Convallaria majalis plants were observed for taxonomic studies. Most plants produced two leaves (70%) and some one leaf (30%), but rarely three leaves. Plant length averaged 34.4 $\pm$ 4.6 cm. Percentage of plants bearing flowers was very low with 3.7% (n=1,346) in the field. Raceme usually grew below leaves and rarely grew over leaves. Plant beared five to ten flowers on a single raceme. Chromosomes were x=19 and diploidy with 2n=38. The chromosomes were composed of 13 pairs of median and 6 pairs of submedian chromosomes. The number of chromosome and karyotype of Korean C. majalis plant agree with those of Japanese and European plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.133-133
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• 2017

Lodging is one of the important constraints in rice production. The lodging destroys the canopy structure, and sharply reduces the capacity of photosynthetic rate and dry matter production. In cereal crops, stem lodging can be classified into two types: stem breaking type and stem bending type. To improve stem lodging resistance, it is important to reveal strong culm traits of superior lodging resistant varieties. There are large varietal differences in parameters associated with the bending moment at breaking (M) and flexural rigidity (FR). The indica variety Takanari possesses large M due to its large section modulus (SM) despite of its small bending stress (BS), while Takanari also has large FR due to its large secondary moment of inertia (SMI) and Young's modulus (YM). To identify quantitative trait loci (QTLs) and the corresponding genes associated with the parameters for M ($=SM{\times}BS$) and FR ($=SM{\times}YM$) should enable to develop lodging resistant varieties, efficiently. In order to identify QTLs for cell wall materials such as cellulose, hemicellulose and lignin associated with BS and YM, a set of Chromosome Segment of Substitution Lines (CSSLs) consisted of 37 lines with chromosome segments of Koshihikari in the genetic background of Takanari were used. Takanari had large M and small BS as compared with Koshihikari. The QTLs for BS were estimated on chromosomes 3, 5, 6, 8, 9, 10, 11 and 12. Koshihikari alleles increased BS in these QTLs. Takanari had a large FR due to its large SMI and YM as compared with Koshihikari. The YM was increased by substitution of the Koshihikari chromosomal segments on chromosomes 2, 10 and 11. Other QTLs estimated on chromosomes 7 and 12 that Koshihikari alleles contributed to the decrease of YM. For lignin, only one major QTL for lignin density was detected on chromosome 11. Hollocellulose densities were increased by the substitution of Koshihikari segments on chromosomes 5 and 11. On the other hand, these were decreased on chromosomes 1 and 3 by substitution of Koshihikari segments. QTLs for cellulose density were estimated on chromosomes 1, 3 and 5 by substitution of Koshihikari segments. For hemicellulose, QTL on chromosome 3 showed that hemicellulose density decreased by the substitution of Koshihikari segment. However, hemicellulose densities on chromosomes 5, 8 and 11 showed the opposite effects. The QTLs for hemicellulose, cellulose, and hollocelulose densities identified on chromosome 5 overlapped with that for bending stress, indicating the positive effect of Koshihikari segment on increasing bending stress. These results suggest that some QTLs for the densities of cell wall materials contribute to increasing bending stress and Young's modulus, and could be utilized to improve the lodging resistance for both types of breaking and bending in rice varieties.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.683-687
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• 1998

We have examined in vitro and in vivo radioprotective effects of a well-known thiol-containing compound, dithiothreitol (DTT). The treatment of both 0.5 and 1mM of DTT significantly increased clonogenic survival of ${\gamma}$-ray irradiated Chinese hamster (V79-4) cells. In order to investigate the possible radioprotective mechanism of DTT, we measured gamma-ray induced chromosome aberration by micronucleus assay. In the presence of 0.5mM or 1mM DTT, the frequencies of micronuclei were greatly reduced in all dose range examined (1.5-8 GY). Slightly higher reduction in micronucleus formation was observed in 1mM DTT-treated cells than in 0.5mM DTT-treated cells. In addition, incubation with both 0.5 and 1mM of DTT prior to gamma-ray irradiation reduced nucleosomal DNA fragmentation at about same extent, this result suggests that treatment of DTT at concentrations of 0.5 and 1mM reduced radiation-induced apoptosis. In vivo experiments, we also observed that DTT treatment reduced the incidence of apoptotic cells in mouse small intestine crypts. In irradiated control group 4.4${\pm}$0.5 apoptotic cells per crypt were observed. In DTT-administered and irradiated mice, only 2.1${\pm}$0.4 apoptotic cells per crypt was observed. In vitro and in vivo data obtained in this study showed that DTT reduced radiation-induced damages and it seems that the possible radioprotective mechanisms of action of DTT are prevention of chromosome aberration.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.18-18
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• 2001

Despite of importance of integrated events of nucleus and microtubule remodeling in nuclear transferred embryos with somatic cells, little information is available on this subject. In this study we configured chromatin and microtubule organization following somatic cell nuclear transfer in pre- and non-activated bovine oocytes in order to clearify nuclear remodeling process and to demonstrate centrosome inheritance during nuclear transfer. The cumulus-oocyte complexes were collected from slaughterhouse and were matured in vitro for 20 h in TCM 199 supplemented hormone. Matured bovine oocytes were enucleated by aspirating the frist polar body and metaphase chromatin using a beveled pipette. Bovine fibroblast cells were fused into enucleated oocyte by electrical stimulation. Reconstructed oocytes were activated with ionomycine and 6-dimethylaminopurin, and then cultured in CRlaa medium. The organization of nuclear and microtubules were observed using laser-scanning confocal microscopy. At 1 hour after fusion, microtubule aster was seen near the transferred nucleus in most oocytes regardless activation condition. While most of fibroblast nuclei remodeled to premature chromosome condensation (PCC) and to the two masses of chromosome in non-activated oocytes, a few number of fibloblasts went to PCC and multiple pronuclear like structures in activated oocytes. Microtubular spindle was seen around condensed chromosome. Gamma-tubulin was detected in the vicinity of condensed chromosome, suggesting this is a transient spindle. The spindle seperated nucleus into two masses of chromatin which developed to the pronuclear like structures. Two pronuclear like structures were than apposed by microtubular aster and formed one syngamy like nuclear structure at 15 h following nuclear transfer. At 17 to 18 h after fusion, two centrosomes were seen near the nucleus, which nucleates micrtubules for two cell cleavage. While 31% of reconstructed oocytes in non-activated condition developed to morulae and blastocysts, a few reconstructed oocytes in pre-activated condition developed to the blastocyst. These results suggested introduction of foreign centrosome during nuclear transfer, which appeared to give an important role for somatic cell nuclear reprogramming.

• Genomics & Informatics
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• v.1 no.2
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• pp.101-107
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• 2003

Loss of heterozygosity (LOH) has been used to detect deleted regions of a specific chromosome in cancer cells. LOH on chromosome 16q has been reported to occur frequently in progressed hepatocellular carcinoma (HCC). Liver tissues from 37 Korean HCC patients were analyzed for LOH by using 25 polymorphic microsatellite markers distributed along 16q. Out of the 37 HCC patients studied, 21 patients (56.8%) showed LOH in various regions of 16q with at least one polymorphic marker. Puring the analysis of these 21 LOH cases, 6 patients showed interstitial LOHs in which the boundary of the LOH region was defined. With two rounds of LOH analysis, five commonly occurring interstitial LOH regions were identified; 16q21-22.1, 16q22.2 - 22.3, 16q22.3, 16q23.2 and 16q23.3 - 24.1. Among the five LOH regions the 16q23.3 - 24.1 region has been reported to be related with chromosome instability. A complete physical map, which covers the 3.2 Mb region of 16q23.3 - 24.1 (D16S402 and D16S486), was constructed to identify novel candidate tumor suppressor genes. We provide the minimally tiling path map consisting of 28 BAC clones. There was one gap between NT_10422.11 and NT_019609.9 of the human genome sequence contig (NCBI sequence build 33, April 29, 2003). This gap can be filled by sequencing the R-1425M20 clone which bridges these sequence contigs.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.4
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• pp.71-80
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• 1996

This paper presents stabilization and position control of the Inverted-Pendulum system with cart by using Evolution Strategies that is one of the Evolutionary Computation and is effective in searching real number. The control input of the Inverted-Pendulum is the element of chromosome corresponding to the divided space of Inverted-Pendulum state variable x, x, 0, 0 . In general, the larger the length of the chromosome is, the longer the time of evolution to search optimal solution is. So in this paper, we propose a scheme that reduce the state space by half by taking the method, that is, converting only the sign of the control input without obtaining separately for the symmetrical sections of the Inverted-Pendulum to improve the speed of Evolution, and improved the efficiency of the entire system in addition to the improvement of the chromosome's evolution time by carrying out the chromosome's evolutional process by two steps one of which is that cart is positioned near the control point and the other cart is positioned far from that point. We propose another method that is Neural Network-Evolution StrategiedNN-ES) Controller. We verify the effectiveness of the proposed control scheme by computer simulations.

• Korean Journal of Breeding Science
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• v.42 no.2
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• pp.163-168
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• 2010

This study was carried out to determine the chromosomal localization of the 5S and 18S-26S ribosomal DNA(rDNA) genes by means of fluorescence in situ hybridization(FISH) techniques, and the constitutive heterochromatin detected by means of Gimsa C-banding technique in rye(Secale cereale L.). The somatic chromosomes number was 2n=14. The karyotype consists of four pairs of metacentrics(chromosomes 1, 2, 3, and 7) and three pairs of submetacentrics(chromosomes 4, 5, and 6). Secondary constrictions appeared in the short arm of chromosome 1. The 5S rDNA genes have been located on two pairs of chromosomes 1 and 5, and 18S-26S rDNAs genes have been located on one pair of chromosome 1. 5S rDNA genes were detected on the distal region of the secondary constrictions in nucleolus organizer regions(NOR) in chromosome 1, and other detected on the intercalary region in the short arm of chromosome 5.