• Applied Microscopy
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• v.39 no.2
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• pp.185-189
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• 2009

Studies about the structure of Drosophila melanogaster retinal cell using electron microscopy have been carried out in details since 1960s. However, these results can have limitations in functional research because of two-dimensional structure. In this study, the adult retina of Drosophila melanogaster was investigated by employing high pressure freezing method, serial sections, high voltage electron microscopy, and 3-dimensional reconstruction method. From there results, mitochondria, microtubules, and nuclei were reconstructed as 3-dimensional structure using IMOD program. The 3D structure of these organelles showed that mitochondira mainly located in distal region near lens, and microtubule mainly located in distal and basal region. The 3D reconstruction of these organelles can be used for a critical evaluation in the dynamic change of cellular organelles caused by functional abnormality like retinal degeneration.

• BMB Reports
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• v.51 no.1
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• pp.1-2
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• 2018

Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.

• The Korean Journal of Zoology
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• v.1 no.2
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• pp.25-26
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• 1958

31 species, 5 genera of Drosophilidae had been obtained on 11 localities of Seoul and its adjacent and during the period of May ∼October, 1957. The species which distributed widely were Drosophila (Sophophora) quraria, D.(drosophila) angularis D.(D.) brachiynephros, D/(D.) nigromaculata, Scaptomyza disticha and D.(Sophophora) melanogaster. The localities where relatively many species of Drosophilidae were collected were Kwang Neung (25 species, 4 genera) and Sosa(13 species, 2 genera)

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.82-88
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• 2023

Genomic analysis indicated that the genome of Drosophila melanogaster contains more than 80 cytochrome P450 genes. To date, the enzymatic activity of these P450s has not been extensively studied. Here, the biochemical properties of CYP6A8 were characterized. CYP6A8 was cloned into the pCW vector, and its recombinant enzyme was expressed in Escherichia coli and purified using Ni²⁺-nitrilotriacetate affinity chromatography. Its expression level was approximately 130 nmol per liter of culture. Purified CYP6A8 exhibited a low-spin state in the absolute spectra of the ferric forms. Binding titration analysis indicated that lauric acid and capric acid produced type I spectral changes, with K_d values 28 ± 4 and 144 ± 20 µM, respectively. Ultra-performance liquid chromatography-mass spectrometry analysis showed that the oxidation reaction of lauric acid produced (ω-1)-hydroxylated lauric acid as a major product and ω-hydroxy-lauric acid as a minor product. Steady-state kinetic analysis of lauric acid hydroxylation yielded a k_cat value of 0.038 ± 0.002 min^-1 and a K_m value of 10 ± 2 µM. In addition, capric acid hydroxylation of CYP6A8 yielded kinetic parameters with a k_cat value of 0.135 ± 0.007 min^-1 and a K_m value of 21 ± 4 µM. Because of the importance of various lipids as carbon sources, the metabolic analysis of fatty acids using CYP6A8 in this study can provide an understanding of the biochemical roles of P450 enzymes in many insects, including Drosophila melanogaster.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.135-142
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• 1998

The mutagenicity of three external colorants, lake red CBA (D&C Red No.9, R-9), rhodamine B stearate (D&C Red No.37, R-37) and permanent orange (D&C Orange No.17, O-17) was evaluated. In this study, the genetic toxicity of the these dyes was examined by in vitro chromosome aberration test in cultured mammalian cells, in vivo micronucleus test in ddY mice, and somatic mutation and recombination test (SMART) in Drosophila melanogaster. Three dyes did not induce mutagenicity in chromosome aberration test and micronucleus test. But Red No.9 and Red No. 37 showed slight increase of abnormal wing spots in Drosophila melanogaster.

• 한국전자현미경학회:학술대회논문집
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• 2003.11a
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• pp.24-25
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• 2003

• The Korean Journal of Zoology
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• v.12 no.1
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• pp.22-28
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• 1969

In order to see if any suppressor system for the SD action was involved in natural populations of D. melanogaster samples from the populations of nine localities in Korea, Choonchun, Yusoo, Namhai, Shinchon(Seoul), Kwangjoo(Kyunggi), Koonsan, Kwangjoo(Chunnam), Jejoo and Pusan were analyzed by using the mating scheme for locating the suppressor on chromosome pairs. And also two kinds of recombinant SD lines R-1, the American line and $R(SD^NH -1)-1$, the Japanese one were used in order to see any difference of the response of the suppressor for differently originated SD. The results of the experiment are given below. (1) The suppressor system was involved in all lines of natural populations from nine localities of Korea. (2) Most of the suppressors were found to be located on the X chromosome and only a few lines from three populations showed to carry the suppressors on the second chromosome and on the third or fourth chromosoem. (3) The response of the suppressor for differently originated SD lines showed no significant difference.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.340-347
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• 1995

We have used two kinds of P element constructs, Pc[(ry+)B] and p[(ry+)$\Delta$SX9], for genetic transformation by microinjection of D. melanogaster. Pc[(ry+)B] construct carrying the rosy gene within an autonomous P element was injected into a true M strain caring the ry506. mutation. The source of transposase for microinjection and transformation was provided by a P element helper plasmid designated p-$\Delta$2-3hs$\pi$, which was co-injected with nonautonomous P[(ry+)$\Delta$SX9] construct into same ry506 M strains. A dechorination method was adopted and 35 independent transformed lines were obtained froin 1143 G0 Injected (35/1143). About 20% of the injected embryos eclosed as adults. Among G0 eclosed flies, approximately 40% exhibited eye color that was similar to wild-type (ry+), but about 60% of fertile G0 transformed lines appeared to have no G1 transformants. Therefore it is unlikely that G0 expression requires integration of the rosy transposon into chromosomes. Pc[(ry+)B] and P[(ry+)$\Delta$SX9] constructs were found to be nearly same in the frequency of element-mediated transformation. On the basis of these results, nonautonomous P elements constructs could he used as same effective vectors in P element-mediated transformation for introducing and fixing genes in insect populations.

• Journal of Environmental Science International
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• v.6 no.1
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• pp.45-52
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• 1997

Methyl methanesulfonate (MMS) was fed to Drosophila melnogaster in order to investigate its toxic capability at developmental and adult stages, and the hereditary effect of toxicity and the potency for induction of sex-linked lethal mutation during the slyer-matogenesis by the means of an attached-X method. In the control group, the egg to adult viability of D. melnogaster was 95.2%, while 3. 5mM and 5.0mM treated groups were 90.0% and 84.1%, respectively. In the case of their progenies (Fl), the viability was 96.9% in the control group, while 3.5mM and 5.0mM treated groups were 54.5% and 1.6%, respectively. Therefore, these differences between two generations show significant physiological toxic effects in the next generation. In the parental generation, the developmental time was calculated 11.05 days in the control group, 12.43 days In 3.5%mM treated group, and 13.23 days in 5.0mM. In the case of Fl it was estimated 10.35 days in the control group, and 11.43 days In 3.5mM treated group. Compared with the control groups In two generations, the developmental time generally delayed as the dose of MMS increased. As to the sex-ratio, there was no differences between the control and MMS treated groups. The toxic values of adult stage showed which increased the frequency of mortality with MMS concentrations. The mortality at 120hr In the control group was 1.67% and it in 0.5mM MMS treated group 3.33%. In 2.5mM MMS treated group, it was 33.3% at 72hr, and it 95% at 120hr The increase of the morality was shown from 72hr in 4.0mM treated group which was 100% at 96hr. There was the concentration-dependent induction of sex-linked lethal mutation during the spermatogenesis by means of an attached-X method, MMS had more pronounced effect in sperm and spermaid stages in D. melnogaster.

• KSBB Journal
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• v.27 no.5
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• pp.313-318
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• 2012

Dimethyl sulfoxide (DMSO) increased the intracellular calcium ion concentration in stably transfected Drosophila melanogaster S2 cells expressing recombinant cyclooxygenase 1 (COX-1). DMSO did not increase the Drosophila NOS (dNOS) transcript level in calcium chelator-treated cells. Expression of recombinant COX-1 due to DMSO was diminished in cells treated with calcium chelators or channel blockers. Our results indicate that an increased intracellular calcium ion concentration due to DMSO is associated with up-regulation of the dNOS gene, leading to enhanced expression of COX-1.