• Journal of Korean Society of Forest Science
• /
• v.78 no.1
• /
• pp.42-54
• /
• 1989

These studies were carried out to examine the anatomical, karyological characteristics, the variation of isozymes in needle and the frost damage of tissue for the purpose of investigating the relationships among the three natural Torreya nucifera populations of Cheju-do, Namhae, and Mt. Naejang in Korea. The results obtained can be summed up as follows : 1. The numbers of endodermal cells and inner layer cells of mucilage canal of needle conductive tissue were different in each population. The number of those of Cheju-do population was the largest. 2. In somatic chromosome, Namhae population showed one more secondary constriction. The values of $b^{arm}/a^{arm}$ were the same in all the three populations, but Cheju-do population particularly showed a different minimum value. And the karyotype formulas of each population showed difference. 3. During the meiosis, each population showed no significant difference in the irregular phenomena of chromosome. 4. In isoperoxidase and esterase variations of needle, each population showed its particular number and variation of bands. Cheju-do population showed the largest number and greatest variation of bands. 5. Under the same freeging conditions, the frost damage of Mt. Naejang population was comparatively slight, and Cheju-do population suffered from a greater frost damage than the others.

• Journal of Plant Biotechnology
• /
• v.33 no.1
• /
• pp.39-43
• /
• 2006

A detailed karyotype analysis was carried out in five Korean native Iridaceae species; Iris pseudoacorus, I. pallasii. var. chinensis, I. tectrum, I. dichotoma and Belamcanda chinensis. Chromosome compositions of the five species showed that they have different karyotypic formulae; I. pseudoacorus 2n=34=10m+16smn+8st including two pairs of satellite chromosomes, I. pallasii var. chinensis 2n=40=26m+12sm+2st including two pairs of satellite chromosomes, I. tectrum 2n=30=14m+16sm including five pairs of satellite chromosomes, I. dichotoma 2n=32=22m+10sm including two pairs of satellite chromosomes, and B. chinensis 2n=32=20m+10sm+2st including one pair of satellite chromosomes. These results will supplement the previous cytogenetic reports in Iridaceae species and enhance our understanding on the genetic structure, which will be useful in clarifying the unique characteristics of each species for practical breeding programs for horticultural and pharmaceutical purposes.

• Journal of Preventive Medicine and Public Health
• /
• v.23 no.1 s.29
• /
• pp.1-10
• /
• 1990

The protective effect of sodium selenite($Na_2SeO_3$) against the cytogenetic toxicity of heavy metals was investigated on human whole-blood cultures in relation to induction of sister chromatid exchange (SCE) in secondary metaphase chromosome. Methylmercury chloride($CH_3HgCl$), cadmium chloride($CdCl_2$), potassium dichromate($K_2Cr_2O_7$), and sodium selenite caused to the typically dose-dependent increase in sister chromatid exchanges (SCEs) by the concentrations ranging from $0.3{\mu}M\;to\;10{mu}M$. However, the inductions of sister chromatid exchanges by methylmercury chloride or cadmium chloride were inhibited by the simultaneous addition of sodium selenite $1.2{mu}M$. The frequencies of SCE were decreased to the level of control in the molar ratios as 2:1, 1:1, 1:2, and 1:4 of selenium selenite vs. methylmercury chloride, and as 1:1 and 1:2 of selenium selenite vs. cadmium chloride, while the frequencies of SCE induced by potassium dichromate were not changed by the addition of sodium selenite in culture condition. Mitotic indices were decreased in the higher concentrations of chemicals and not significantly changed by the simultaneous addition of sodium selenite to the culture condition containing each chemicals.

• Clinical and Experimental Reproductive Medicine
• /
• v.30 no.3
• /
• pp.223-231
• /
• 2003

Objective: The aim of the present study was to evaluate the clinical efficiency of fluorescent in situ hybridization (FISH) in the prenatal diagnosis of chromosomal aneuploidy. Methods: We reviewed data of 268 cases to identify women undergoing genetic amniocentesis at cytogenetic laboratory, from January 2000 to December 2002. Amniotic fluid was submitted for both rapid FISH on uncultured interphase amniocytes using a commercially available DNA probe for chromosome 13, 18, 21, X, Y and standard karyotyping on cultured metaphase amniocytes. Results from FISH and full karyotype were compared. Results: There were 251 cases (84%) normal and 17 cases (16%) abnormal in FISH results. All 17 cases of trisomy 13, 18, 21 including two cases of mosaicism and sex chromosome aneuploidies which are detected by FISH were confirmed with conventional cytogenetics and there was no false positive result. Twenty two cases had karyotypically proven abnormalities that could not have been detected by the targeted FISH. Conclusion: Interphase FISH analysis of uncultured amniotic fluid cells has been shown to be an effective and reliable technique for rapid fetal aneuploidy screening during pregnancy as an adjunctive test to conventional cytogenetics.

• Journal of Genetic Medicine
• /
• v.5 no.2
• /
• pp.125-130
• /
• 2008

Propose: To analyze the indications and cytogenetic results of midtrimester amniocentesis. Material and Methods: This study reviewed 2,523 cases of midtrimester prenatal genetic amniocentesis performed at MizMedi Hospital between January 2000 and December 2007. Results: The most frequent indication for midtrimester amniocentesis was advanced maternal age (45.9%), followed by positive serum markers (29.9%). Chromosomal aberrations were diagnosed in 110 cases (4.4%), for which numerical aberration accounted for 38 cases (34.5%), structural aberration accounted for 65 cases (59.1%), and mosaicism accounted for 7 cases (6.4%). Among the autosomal aberrations, there were 20 cases of trisomy 21 and 8 cases of trisomy 18. With respect to structural aberrations, there were 14 cases of reciprocal translocation and 8 cases of robertsonian translocation. The frequencies of chromosomal aberrations according to the indication were highest in individuals with a family history of chromosome abnormality 14.0% (8/57) followed by previous congenital anomaly 5.9% (2/34). Conclusion: Midtrimester amniocentesis is an effective tool for prenatal diagnosis. Indications such as advanced maternal age, maternal serum markers, and ultrasound are important for predicting abnormal fetal karyotypes.

• Journal of Genetic Medicine
• /
• v.5 no.1
• /
• pp.55-60
• /
• 2008

Purpose : The ability to perform chromosome analysis of cryopreserved cord blood mononuclear cells is important for future retrospective studies. We compared the karyotypes of cryopreserved cells with cells before cryopreservation. Methods : One cord blood (CB) sample was obtained from normal healthy volunteer. Karyotype analysis was performed before cryopreservation. After mononuclear cell separation with Ficoll-Hypaque, the mononuclear cells were cryopreserved by programmed controlled-rate freezer and then transferred into the liquid nitrogen ($-196^{\circ}C$) for 3 days. After rapid thawing, cytogenetic analysis was performed as the same method for each sample by different conditions. The samples were divided by three groups. The first group was no culture before cryopreservation, the second group was 72 hours culture before cryopreservation, but no 24 hours culture after thawing and the third group was 72 hours culture before cryopreservation and 24 hours culture after thawing. Results : The chromosome analysis was successful in the second and third groups of CB sample. Conclusion : The successful result from CB samples may suggest the usefulness of long-term cryopreservation for retrospective study in various clinical settings including hematologic malignancies.

• Journal of Genetic Medicine
• /
• v.5 no.1
• /
• pp.65-68
• /
• 2008

Molecular cytogenetics allows the identification of unknown chromosome rearrangements, which is clinically useful in patients with mental retardation and/or development delay. We report on a 31-year-old woman with severe mental retardation, behavior development delay, and verbal performance delay. Conventional cytogenetic analysis showed a 46,XX,add(8)(p23.3) karyotype. To determine the origin of this unbalanced translocation, we performed array CGH and subtelomeric FISH. The results showed that the distal region of chromosome 8p was added to the terminal of chromosome 13q. This was confirmed the final result of 46,XX,der(8)t(8:13)(p23.3;q32.1)dn.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.1
• /
• pp.57-65
• /
• 1997

Cytogenetic observations of loss of the distal portion of the Y chromosome long arm were found to be associated with disrupted spermatogenesis. The existence of a gene involved in the regulation of spermatogenesis, the azoospermia factor (AZF), was postulated. In this study, we screened the AZF region including DAZ and DAZH genes and observed the expression pattern of DAZ and DAZH transcript in infertile men with azoospermia and oligospermia by using a sequence-tagged site (STS)-based PCR method. PCR primers were synthesized for 11 STSs that span Yq interval 6, SRY, DAZ, and DAZH, functional DAZ homologue on chromosome 3. Microdeletions were detected in 4/32 (12.5%) azoospermic men and 1/11 (9%) severe oligospermic men. Only 2 of 5 patients had microdeletions of Yq that contained the DAZ gene, whereas the other 3 patients had deletions extending from intervals 5L-6F proximal to the DAZ gene on Yq. Testis biopsies of the azoospermic patients revealed a variety from Sertoli cell-only syndrome to testicular maturation arrest. Of 4 men with clinical data available, average testis size was R: 13.8 cc, L: 13.8 cc, serum T was $4.0{\pm}1.25$ ng/ml, LH was $3.63{\pm}1.90$ mIU/ml, and FSH was $8.85{\pm}5.13$ mIU/ml. These values did not differ significantly from the remainder of the patients tested. We could not observed the DAZ transcript in 2 patients, who have no mature spermatozoa. In 11.6% of patients microdeletions of the AZF could be detected. These deletions in the AZF region seem to be involved causing spermatogenic failure. But the frequency of microdeletions proximal to DAZ suggests that DAZ is not the only gene associated with spermatogenic failure.

• Journal of Aquaculture
• /
• v.10 no.3
• /
• pp.363-371
• /
• 1997

Backcross hybridization between female cyprinid loach(Misgurnus anguillicaudatus) any male mud loach (M. mizolepis)$\times$cyjprinid loach hybrid were made, and its effect on early survival, cytogenetic traits, and gonad development were examined. Mean fertilization rate and hatching success of backcross hybrids were similar to those found in the maternal species, the cyprinid loach. However, the backcross hybrids revealed significantly improved early survival up to yolk sac absorption (86.0%) compared to cyprinid loach (0%) under low culture temperature ($15^{\circ}C$). the erythrocytic size and DNA content of backcross hybrids were nearly intermediate to those of the parents. Karyological analysis of backcross hybrids displayed two kinds of modal chromosome number of 2n=48 or 2n=49. Growth of backcross hybrids over 6 months after hatching was proven to be intermediate between their parental species. Although backcross hybrids had intermediate values between those of thier parents in most morphometric traits, overall external morphology of backcross hybrids was morer simlar to cyprinid loach than mud loach$\times$cyprinid loach hybrid. Histological examination of gonads at 2 and 4 months of age revealed that no female was obseved in backcross hybrid groups, suggesting the possibility of production of monosex male population.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.2
• /
• pp.172-177
• /
• 1999

Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by Tc-99m-methylene diphosphonate (Tc-99m-MDP) in peripheral lymphocytes of patients undergoing bone scintigraphy. Materials and Methods: Lymphocytes from 22 patients (6 males, 16 females, mean age $50{\pm}14$ years) were collected before and after bone scintigraphy using 740 MBq Tc-99m-MDP Lymphocytes from 10 controls (6 males, 4 females, mean age $43{\pm}7$ years) were also collected. They were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Number of ring-form and dicentric chromosomes per 600 cells (chromosomal aberrations) was counted under the light microscope. Results: Chromosomal aberrations in patients before bone scintigraphy ($385.1{\pm}30.5$) was not different from that of controls ($367.8{\pm}36.6$). However, chromosomal aberrations in patients after bone scintigraphy was significantly decreased to $192.6{\pm}22.1$ (p=0.0001). Conclusion: Low dose gamma-irradiation by Tc-99m-MDP used for bone scintigraphy induces a cytogenetic adaptive response in peripheral lymphocytes.