• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.24-24
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• 2019

Iris L. is a perennial genus comprising approximately 300 species worldwide, with the greatest number of endemic species occurring in Asia. Iris is one of the largest genera in the family Iridaceae and includes ca. 15 species native to Korea. Although chromosome number change, karyotype restructuring, and genome size variation play an important role in plant genome diversification, understanding the karyotype variation in Korean Iris species has been hampered by the wide range of base chromosome number (x = 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22) reported to date. This study documents the chromosome numbers, karyotype structure and genome size variation in Iris ruthenica K. Gawl., an endangered species in Korea obtained using classic Feulgen staining and flow cytometry. The chromosome number of all investigated plants from the nine populations was 2n = 42. All individuals studied possessed metacentric and submetacentric chromosomes. The genome size of the I. ruthenica in eight wild populations ranged from 2.39 pg/1C to 2.45 pg/1C ($2.42{\pm}0.02pg/1C$: $mean{\pm}SD$). This study provides the first report of genome size variation in Iris ruthenica in Korea. This study lays foundation for cytogenetic further analyses employing by fluorescence in situ hybridization (FISH) to better understand the chromosomal evolution in this species and in the whole genus.

• Animal Systematics, Evolution and Diversity
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• v.5 no.1
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• pp.1-12
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• 1989

Samples of striped field mice, Apodemus agrarius Pallas, from eight localities in s southwestern islands and coasts in Korea were collected and analyzed together with samples from the mainland and Jeju island. In chromosomal analyses no variation was revealed in karyotypes among samples from Korea. In morphometric analyses samples from Wan and Bogil islands formed a large-size g group (A. agrarius chejuensis) with those from Jeju island, whereas samples from Jin and H Hajo islands formed a small-size group (A. agrarius coreae) with those from the mainland including southwestern coasts It is supposed that small-size population of striped field mice in Wan and Bogil islands w were extinct and replaced by large-szie population of striped field mice immigrated from Jeju island by humans.

• Journal of Genetic Medicine
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• v.6 no.1
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• pp.62-66
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• 2009

Purpose: Chromosomal abnormalities of abortuses have been used to investigate common etiologies of spontaneous abortion, but the frequencies and types of spontaneous abortions have demonstrated considerable variation among different countries and races. Materials and Methods: A cytogenetic analysis of 75 abortuses was performed at GenDix, Inc. from January 2006 to December 2007. Results: The frequency of chromosome abnormalities in abortuses was 32.0% (24/75 cases). Among the chromosomal abnormalities, trisomy was present in 62.5% (15/24 cases) of cases and the most frequent trisomy was trisomy 21 with an occurrence rate of 26.6% (4/15 cases). The following was trisomy 22 (3/15 cases) and trisomy 20 (2/15 cases). The average maternal age for abnormal karyotypes was $34.3{\pm}3.3$. Conclusion: Cytogenetic analysis of abortus is important for diagnosis and genetic counseling of patients with spontaneous abortion.

• Journal of Gastric Cancer
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• v.22 no.4
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• pp.348-368
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• 2022

Purpose: Chromosomal instability is a hallmark of gastric cancer (GC). It can be driven by single nucleotide variants (SNVs) in cell cycle genes. We investigated the associations between SNVs in candidate genes, PLK2, PLK3, and ATM, and GC risk and clinicopathological features. Materials and Methods: The genotyping study included 542 patients with GC and healthy controls. Generalized linear models were used for the risk and clinicopathological association analyses. Survival analysis was performed using the Kaplan-Meier method. The binding of candidate miRs was analyzed using a luciferase reporter assay. Results: The PLK2 C_rs15009-C_rs963615 haplotype was under-represented in the GC group compared to that in the control group (P_corr=0.050). Male patients with the PLK2 rs963615 CT genotype had a lower risk of GC, whereas female patients had a higher risk (P=0.023; P=0.026). The PLK2 rs963615 CT genotype was associated with the absence of vascular invasion (P=0.012). The PLK3 rs12404160 AA genotype was associated with a higher risk of GC in the male population (P=0.015). The ATM T_rs228589-A_rs189037-G_rs4585 haplotype was associated with a higher risk of GC (P<0.001). The ATM rs228589, rs189037, and rs4585 genotypes TA+AA, AG+GG, and TG+GG were associated with the absence of perineural invasion (P=0.034). In vitro analysis showed that the cancer-associated miR-23b-5p mimic specifically bound to the PLK2 rs15009 G allele (P=0.0097). Moreover, low miR-23b expression predicted longer 10-year survival (P=0.0066) in patients with GC. Conclusions: PLK2, PLK3, and ATM SNVs could potentially be helpful for the prediction of GC risk and clinicopathological features. PLK2 rs15009 affects the binding of miR-23b-5p. MiR-23b-5p expression status could serve as a prognostic marker for survival in patients with GC.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.12-20
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• 1996

The spermatogenesis and chromosome number were investigated in the pupal testes of Helicouerpa assulta Guenee by light microscopy. During the spermatogenesis, each bundle of P8(256) sperms developed by 6 mitotic and 2 meiotic spermatogonial divisions. From the early stage of spermatogenesis, it was distinguishable between two kinds of sperm differentiation, eupyrene and apyrene spermatogenesis, which are characteristic in Lepidoptera, by the differences in nuclear shape and cell distribution in immature spermatocyst. Through the followed spermiogenesis, the spermatocysts were developed into two kinds of mature cyst, a streamline-shaped eupyrene cyst with nucleated sperms of thready head or a long spindle-shaped apyrene cyst with anucleated sperms of cylindrical head. As the results off chromosomal analysis at metaphase of the spermatogonial mitosis and spermatocytic meiosis, the chromosome number were 2n=6a/n=31, respectively, and no variation between individuals.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.11-16
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• 2000

The electrophoretic banding patterns of 6-phosphogluconate dehydrogenase (PGD) in the two different chromosomal ploidy groups of Gyraulus were compared. The monomeric or dimeric banding patterns or allelic variations in a locus of PGD were observed in four diploid populations (Osan, Sohre, Kimpo and Kangwha) of G. convexiusculus occurring in Korea, whereas the isozyme banding patterns encoded by at least 3 different loci were shown in the tetraploid populations of G. (Torquis) groups collected from Michigan, the U.S.A. Of 3 different tetraploid groups, G. (T.) circumstriatus group showed 3 monomorphic isozyme banding patterns, and the other 2 populations showed some allelic variations. Such results provided good evidence to differentiate tetraploid subgenus Torquis group from the diploid Gyraulus populations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.128-133
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• 1998

Analyses of now karyotypes using different maize (Zea mays L.) inbred lines have been performed. The accumulation and isolation of high quality and quantity metaphase chromosomes from root tips can be achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed with a now cytometry. The variations of experimental now karyotypes were detected among inbred lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among 8 inbred lines ranged from 5.09 to 5.52 pg. The variability of DNA content in maize chromosome 1 was 9.1 % ranging from 0.685 to 0.747 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.70-73
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• 1999

This study was conducted to ascertain the chromosomal locations and effect of quantitative trait loci (QTL) associated with the physical traits of rice (Oryza sativa L.) eating quality. One hundred sixty four recombinant inbred lines (MGRILs) of F$_{11}$ were derived from the cross between Milyang 23 (Tongil type) and Gihobyeo (japonica type). They were evaluated for six physical traits of cooked rice. Transgressive segregation was observed for all examined traits. Significant QTL were detected (LOD$\geq$2.0) in three traits, including single QTL for adhesiveness, gumminess, and chewiness of cooked rice, respectively. Phenotypic variation explained by each QTL ranged from 6.3% to 14.6%. However, no significant QTL was detected for hardness, cohesiveness, and elasticity of cooked rice. Pleiotropic effects of single QTL on different traits are observed.d.

• The Korean Journal of Zoology
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• v.30 no.4
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• pp.379-386
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• 1987

Karyotype of the ricessh Orygias latipes (Temminck et Schlegel) was investigated using 151 specimens of eleven populations in the southern Korea. Based on the karyotype analysis, two distinct chromosomal groups were found. One group, occurring in the Kum River, the Mankyong River, the Dongjin River, the Ysngsan River and the SEmjin River had a diploid chromosome number of 46 and arm number of 70, which contained one pair of "large" metacentric chromosomes. The other group, occurring in the Tamjin River, the Hyongsan River andthe all four island populations observed had a diploid chromosome number of 48 and arm number of 68. These results showed that 0. latipes of 6 inland populations was identical with the Chinese population in diploid number, arm number and presence of "large" metacentric chromosome, while the present species of island populations ana populations of the Tamjn R. and Hyongsan R. was similar to the Japanese population in chromosome number and arm number. The karyotype variation in populations indicated that karyotypes will probably provide useful information in studying zoogeography of this species.phy of this species.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.117-125
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• 2003

It was reported that radiopharamaceuticals induced radiation adaptive response (RAR) in patients undergoing nuclear medicine imaging studies. Individual variations of RAR were not studied well. The purpose of this study was to evaluate individual variation of RAR in patients undergoing nuclear medicine imaging studies. Peripheral lymphocytes were collected from 23 patients undergoing $^{99m}Tc-diethylenetriamine$ pentaacetic acid $(^{99m}Tc-DTPA)$ renal scintigraphy, 18 patients undergoing $^{99m}Tc-methylene$ diphosphonate $(^{99m}Tc-MDP)$ bone scintigraphy and 21 patients undergoing $^{99m}Tc-tetrofosmin\;(^{99m}Tc-TF)$ scintigraphy were collected before and 4 hours after injection of radiopharmaceuticals. The lymphocytes were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Numbers of ring-form (R) and dicentric (D) chromosomes were counted under the light microscope. and used to calculate the frequency of chromosomal aberration [Ydr=(D+R)/total number of counted lymphocytes]. Adaptation index (k) was defined 3s ratio of Ydr in conditioned lymphocytes over Ydr in unconditioned lymphocytes. Coefficients of variance of k in $^{99m}Tc-DTPA,\;^{99m}Tc-MDP\;and\;^{99m}Tc-TF$ were 35%, 34% and 21%, respectively k was not dependent upon age, sex, and underlying diseases. There was a wide variation of RAR induced by radiopharmaceuticals among patients undergoing nuclear medicine procedures. It remains to be determined for causes of such variation.