• Korean Journal of Plant Taxonomy
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• v.40 no.3
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• pp.153-156
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• 2010

The somatic chromosome number of four Korean species of Leontopodium were investigated. The chromosome number of L. leiolepis (2n = 24) is reported here as for the first time. The chromosome number of L. japonicum (2n = 28) is not varied among the 3 populations on the Korean Peninsula, but that condition is different from the previous reports for Korea (2n = 26) and Japan (2n = 21, 26). L. hallaisanense and L. japonicum, both of which are in sect. Nobilia and similar to each other in gross morphology, have the same chromosome number of 2n = 28. On the other hand the chromosome number of Korean L. leontopodioides (2n = 24) is different from that in Russian reports (2n = 26). The chromosome numbers of all Korean species of the genus Leontopodium could be inferred as tetraploid or aneuploid.

• Journal of Genetic Medicine
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• v.3 no.1
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• pp.5-10
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• 1999

This is a case report of 46,XY female phenotype (46,XY karyotype, no pubic hair, blind vagina and absence of uterus)in an 18-year-old patient. To confirm whether a Y chromosome has a structural abnormality, fluorescent in situ hybridization (FISH) with the chromosome X/Y cocktail probe was simultaneously performed, and the six loci [PABY, RPS4Y(sy16, sy17), ZFY, DYS14] on the short arm, one locus (DYZ3) on the centromere and one locus (DYZ1) on the long arm were amplified by polymerase chain reaction (PCR). The probes used FISH hybridized to centromere of the X chromosome and heterochromatin region (Yq12) of the Y chromosome, and all PCR related Y chromosome showed positive band like normal male. From the results obtained, it seemed that the Y chromosome from the 46,XY female was structurely normal. Especially, the SRY gene has been equated with the mammalian testis-determining factor, and absence or point mutation in the SRY gene causes XY female. To detect the point mutations of SRY sequences, single-strand conformation polymorphism (SSCP) assay was used. Our results confirm that this patient has no mutation in the SRY gene on the Y chromosome.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.221-221
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• 2022

Chromosome breakage occurred by DNA methylation inhibitor. Zebularine is known as DNA methylation inhibitor and suitable for water solubility among different DNA methylation inhibitors as 5-Azacytidine and 5-aza-2'-deoxycytidine. We used zebularine as mutagen according to different methods by roots absorption and seed imbibition. After zebularine treatment, DNA methylation inhibitor, we observed mitotic chromosome behavior what is different according to two different treatment methods. First, seed imbibition treatment in 1,000 μM of zebularine solution for 72 hours in dark conditions. The second treatment to seedlings of Keumkang was also treated in 1,000 μM of zebularine solution for 72 hours after germination. Root and shoot showed different elongations in each treatment. Root absorption treatment(3.01±0.48, 2.00±0.26) showed the shortest elongation in root and shoot than control(8.16±0.61, 4.03±0.48) and seed imbibition treatment(4.33±0.80, 2.48±0.36). It can be explained root tip meristematic cell activity was damaged by DNA methylation inhibitor. Primary root tips were collected in DW for 24 hours at low temperature(0℃) and fixed in fixation solution for 3 days to chromosome observation in mitosis. Mitotic index, chromosome structure and chromosome aberration were observed by phase-contrast microscope. Mitotic index of the control(0.29) showed twice mitotic cells as the treated groups(imbibition 0.15, absorption 0.14). Observation of chromosomes showed some short chromosomes and loosen chromosomes affected by zebularine. It is considered because of zebularine damage DNA in mitosis. We observed "gap by chromosome breakage" in chromosomes that have loose parts between centromere and telomere. It seems demethylation of zebularine occurs chromosome breakage.

• Journal of Plant Biology
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• v.14 no.4
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• pp.14-18
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• 1971

Lilium Miquelianum Makino is a species which originated in Korea. The Karyotype of the species was examined in materials collected at Mts. Kaya, Kasan, Chejung, and Kaji. The results are as follows: 1) The somatic chromosome number was found to be 2n=24. 2) The karyotype is described as: K=2Am＋2Bkm＋2Csst＋2Dsst＋2Ests＋2Fst＋2Gst＋2Hst＋2Ist＋2Jsst＋2Kst＋2Lst m: metacentric, sm: submetacentric st: subtelocentric, s: secondary constriction 3) A single subcentric supernumerary B-chromosome was found in some bulbs from Mt. Kasan. 4) The shape of the supernumerary B-chromosome was similar to that of the E chromosome which had separated at its secondary constriction and lost its lower chromosome fragment. 5) From three to eight nucleio of varying sizes were found in the telophase or interphase nucleus of root tip cells. The maximum number of eight nucleoli corresponds to the number of chromosomes that have a secondary constriction.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.2
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• pp.139-141
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• 2017

Chromosome 6p duplication is very rare and clinically characterized by short stature, mental retardation, and congenital heart diseases. Patients with mental retardation may present with poor oral health conditions. Dental treatment may need to be performed under general anesthesia in such patients. Our case report deals with induction of general anesthesia to a patient with chromosome 6p duplication, for dental treatment. The selection of a nasotracheal tube of an appropriate size, because of the patient's short stature, was especially important for airway management. In the present case, the patient with chromosome 6p duplication was intubated with a nasotracheal tube, which was not age-matched but adapted to the height and physique of the patient.

• Development and Reproduction
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• v.15 no.3
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• pp.187-195
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• 2011

X chromosome inactivation (XCI) is a process that enables mammalian females to ensure the dosage compensation for X-linked genes. Investigating the mechanism of XCI might provide deeper understandings of chromosomal silencing, epigenetic regulation of gene expressions, and even the course of evolution. Studies on mammalian XCI conducted with mice have revealed many fundamental findings on XCI. However, difference of murine and human XCI necessitates the further investigation in human XCI. Recent success in reprogramming of differentiated cells into pluripotent stem cells showed the reversibility of XCI in vitro, X chromosome reactivation (XCR), which provides another tool to study the change in X chromosome status. This review summarizes the current knowledge of XCI during early embryonic development and describes recent achievements in studies of XCI in reprogramming process.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.821-825
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• 2018

A copy number amplification system for yeast artificial chromosomes (YACs) was combined with simultaneous overexpression of genes integrated into a YAC. The chromosome VII (1,105 kb) was successfully split to 887 kb, 44 kb containing the element for copy number amplification, and a 184-kb split-YAC. The 44-kb split-mini YAC was amplified a maximum of 9-fold, and the activity of the reporter enzymes integrated into the split-mini YAC increased about 5-7-fold. These results demonstrate that the mini-YAC containing a targeted chromosome region can be readily amplified, and the specific genes in the mini-YAC could be overexpressed by increasing the copy number.

• Environmental Mutagens and Carcinogens
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• v.7 no.2
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• pp.103-111
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• 1987

The effects of LET (linear energy transfer) of radiation on the induction of somatic chromosome mutations or gene mutations of Drosophila melanogaster were studied. For detecting somatic chromosome mutations and gene mutations, Drosophila wing spot system and eye-color spot system were used, respectively. The frequencies of somatic chromosome mutations or gene mutations induced after third instar larval treatment with 23 MeV neutrons, thermal neutrons, X-rays were examined. From these data, the RBE(relative biological effectiveness) values of 23 MeV neutrons relative to X-rays for induction of somatic chromosome mutations or gene mutations were calculated. The present results suggest that high LET radiations are efficient than X-ray in producing not only somatic chromosome mutations but also gene mutations.

• Toxicological Research
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• v.19 no.1
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• pp.29-31
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• 2003

It has been reported that the genetic variations in the Y chromosome has influence the blood pressure in some Caucasian male populations, but the effect in non-Caucasian population is unclear. In the present study, we examined the relationship between blood pressure and a HindIII RFLP of Y chromosome in 152 unrelated male individuals of ethnically homogeneous Korean origin. There were no significant differences in systolic and diastolic blood pressures between genotype groups, respectively. However, the frequency of A genotype in Korean population was much higher than those of Caucasian populations (P＜0.05). Therefore, the results of this study will con-tribute the better understanding the genetic characteristics of Y chromosome in Korean population.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.207-214
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• 1994

This study was carried out to develop the methodology of chromosome preparation from blood cultures in mammals which included human, mouse, cattle and pig. For karyotyping, 0.5-5.0ml of peripheral blood were collected and cultured. The satisfactory results were obtained from macroculture and microculture in all species. In culture, the patterns of cell growth were no difference among media except serum concentration and mitogen supplement. The presence of mitogen and fetal bovine serum in medium significantly affected the mitotic index. The optimal culture condition was 37$^{\circ}C$ for 3 days. And the concentration of colcemid and reincubation time also affected the chromosome morphology. In harvest, chromosome patterns were mainly affected on hypotonic treatment which included treated time and temperature, dropwise of fixative solution, and drying after slide preparation.