• Korean Journal of Microbiology
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• v.52 no.4
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• pp.406-414
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• 2016

Among 6 leu codons, CUG is the most frequently used codon in E. coli. It is recognized by leu-tRNA(CAG) encoded by four genes scattered on two chromosomal loci (leuT and leuPQV ). In the process of constructing a strain with no functional leu-tRNA (CAG) gene on chromosome, we made two mutant strains separately, one on leuPQV locus (${\Delta}leuPQV$), and the other on leuT locus [$leuT^*$(GAG)], where the anticodon of leuT was changed from CAG to GAG, thereby altering its recognition codon from CUG to CUC. We attempted to combine these two mutations by transduction using $leuT^*$(GAG) strain as a donor and ${\Delta}leuPQV$ strain as a recipient. Large and small colonies appeared from this transduction. From PCR and DNA sequencing, large colony was confirmed to be the reciprocal recombinant as expected, but the small colonies contained both mutant $leuT^*$(GAG) and wild type leuT (CAG) genes in the cell. This heterozygous diploid strain did not show any unusual morphology under microscopic observation, but, interestingly, it showed a linear growth curve in rich medium with much slower growth rate than wild type cell. It always formed homogenous small colonies in the selection medium, but, when there was no selection, it readily segregated into $leuT^*$(GAG) and leuT (CAG). From these observations, we suggested that the strain with both $leuT^*$(GAG) and leuT (CAG) genes was not a partial diploid (merodiploid), but a full diploid cell having two different chromosomes. We proposed a model explaining how such a heterozygous diploid cell was formed and how and why its growth showed a linear growth curve.

• Journal of Plant Biology
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• v.18 no.3
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• pp.92-100
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• 1975

The present study demonstrates karyotype based on H-patterns of A.fistulosum and A. ascalonicum using Giemsa technique. The results obtained in this study are summarized as follows: I). Karyotypic analysis of A. fistulosum is 6VII＋$JII^t＋JII$ and that of A. ascalonicum collected from a local farm in the suberbs of Taegu city clearly heterozygous as $13V＋J_1^t＋J_2＋i. ii$). The heterochromatin of both species is generally located distally in both arms of chromosomes and each chromosome type possesses some variations on H-patterns. iii). The percentage of heterochromatin to total chromosome length in cell is about 14.6% in A. fistulosum, 12.8% in A. ascalonicum. The number of bands is revealed about 38 in A. fistulosum and 33 in A. ascalonicum. Also in the amounts of chromocenters per nucleus, the former is somewhat more than the latter.

• 한국약용작물학회:학술대회논문집
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• 2011.04a
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• pp.106-107
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• 2011

• Biomedical Science Letters
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• v.14 no.2
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• pp.123-126
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• 2008

Long QT Syndrome (LQT) is a congenital disease due to the failure of electrical system of the heart. We have analyzed KCNE1 gene which is known to be the cause of Type V LQT in Korean genome. Although SNPs of KCNE1 have been reported for Chinese and Malaysians no data are available for Korean people yet. PCR primers were prepared to investigate the sequences for normal and SNP at G30A, G112A, C162T. They were different only by 3' ends. Genomic DNAs were extracted from the people who were known to be normal clinically (35) or patients (20) with metabolic disease. As results, we were able to recognize several SNPs in these Korean samples. Some people were homozygous or heterozygous depending upon the type of SNP. This study should facilitate the research on the cause of Type VLQTs and to develop the further therapy at genetic level.

• Korean Journal of Microbiology
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• v.17 no.3
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• pp.137-151
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• 1979

Germinating conidia of Aspergillus nidulans diploid heterozygous for color and other genetic markers were used to direct and distinguish genetic events such as mutation, mitotic crossingover and nondisjunction in a single test after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NG), mitomycin C(MC), and chloral hydrate(CH). The following results were obtained : 1. NG reduced the survival of conidia and increased the frequencies of miototic segregants about sevenfoli over the control ; among the mitotic segregants the predominant genetic event was mitotic crossingover. NG also produced many abnormal colonies, which appeared to be of the types caused by induced semidominant lethals or chromosomal aberrations, and the aneuploid types found spontaneously. 2. After treatment with MC the survival of conidia was reduced but few abnormal colonies were produced. The frequencies of miotic segregants were increased about threefold over the control ; in the mitotic segeregants the induced genetic event was mitotic crossingover. 3. CH gave no apparent effect on the survival of conidia and the frequencies of mitotic segregants. However, CH generated abnormal colonies, very greatly, which turned out to be of the aneuploid types. This result suggests that CH interferes with the normal distribution of chromosomes in mitosis.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.11-15
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• 2014

Congenital central hypoventilation syndrome (CCHS) is a disorder of the autonomic nervous system characterized by a decreased response to hypercarbia. CCHS is frequently associated with congenital megacolon; the combination is called Haddad syndrome. CCHS is associated with dysfunction in respiratory features of the autonomic nervous system and with other disorders, including facial deformities, cardiovascular symptoms, and tumors. Patients with CCHS frequently have a mutation in the homeobox protein 2b (PHOX2B) gene. Most mutations involve heterozygous expansion of alanine repeats (GCN). Interestingly, a higher polyalanine repeat number is associated with a more severe clinical phenotype. To clarify the role of PHOX2B in disease pathogenesis, we introduce and review the clinical and molecular features of CCHS and Haddad syndrome.

• Clinical and Experimental Pediatrics
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• v.53 no.10
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• pp.909-912
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• 2010

Familial hypokalemic periodic paralysis is an autosomal-dominant channelopathy characterized by episodic muscle weakness with hypokalemia. The respiratory and cardiac muscles typically remain unaffected, but we report an atypical case of a family with hypokalemic periodic paralysis in which the affected members presented with frequent respiratory insufficiency during severe attacks. Molecular analysis revealed a heterozygous c.664 C>T transition in the sodium channel gene $SCN4A$, leading to an Arg222Trp mutation in the channel protein. The patients described here presented unusual clinical characteristics that included a severe respiratory phenotype, an incomplete penetrance in female carriers, and a different response to medications.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.157-160
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• 2016

Coexistence of paroxysmal kinesigenic dyskinesia (PKD) with benign infantile convulsion (BIC) and centrotemporal spikes (CTS) is very rare. A 10-year-old girl presented with a 3-year history of frequent attacks of staggering while laughing and of suddenly collapsing while walking. Interictal electroencephalogram (EEG) revealed bilateral CTS, but no changes in EEG were observed during movement. The patient's medical history showed afebrile seizures 6 months after birth, while the family history showed that the patient's mother and relatives on the mother's side had similar dyskinesia. Genetic testing demonstrated that the patient had a heterozygous mutation, c.649_650insC, in the PRRT2 gene. To our knowledge, this constitutes only the second report of a patient with PKD, BIC, CTS, and a PRRT2 mutation.

• Journal of Nutrition and Health
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• v.3 no.3
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• pp.161-166
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• 1970

One male in the former group of 2110 Korean males of the Republic of Korea Army stationed Taegu. And two males and one female in the later group of 4590 Korean school children and university students in Seoul and Taejuon were found to have a slow hemoglobin in addition to normal hemoglobin A. In all four subjects the slow component migrated at a rate characteristic of the G hemoglobin. The overall incidence of the variant in the present group of Koreans was low: 4 in 6700 or 0.06 percent. It appears significant that no insistence of hemoglobin E were found among these Korean subjects. Hemoglobin E has been found among numerous ethnic groups of Southeast Asia and the variant most frequently appeared in Chinese subject. By Urea-Starch-Gel Electrophoresis in Alkaline PH and A.I. Chernoff method was demonstrated that another 3 cases of abnormal hemoglobin also were beta-chain variants. This was reconfirmed by Hybridization Experiment with canine hemoglobin. And the results of family test of 3 case of abnormal hemoglobin were heterozygous carrier.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.12-16
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• 2001

In order to develop near isogenic lines (NILs) the heterozygous rice plants for alkali digestibility value(ADV) were selected and tested in every generation from $F_5$to $F_9$ of a cross, Seratus malam/Suwon 345. Finally several sets of NILs, which were six low ADV lines and four medium-high ADV lines, were selected among $F_{10}$ lines. No differences of the plant growth characteristics, amylose content and protein content of rice grain were found between low and medium-high ADV lines. Rice flour of low ADV lines showed longer gel length in gel consistency test than medium-high ADV lines, and also showed different gelatinization characteristics measured by rapid visco analyzer compared with medium-high ADV lines. The result of genetic analysis indicated that ADV-NILs developed were differed in a pair of major gene controlling ADV, and low ADV was dominant over medium-high ADV.