• The Korean Journal of Zoology
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• v.31 no.4
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• pp.327-333
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• 1988

계절에 따른 초파리 집단내 역위다형 현상의 변동상을 알기 위하여 전주근교의 과수원에서 1983년 1월부터 11월까지 격월로 여섯번 채집한 집단 표본을 분석하였다. 총 1071마리에서 얻은 15개형의 역위는 모두 편동원체역위(paracentric inversion)였으며, 이 중 7개형은 세계형91위(cosmopolitan inversion)였고, 나머지 8개형은 지역형역위(endemic inversion)였다. 개체당 역위의 평균 보유수는 0.639이고 역위를 보유한 개체의 빈도는 0.465였다. 7개의 세계형역위에 대한 표본집단을 분석한 결과 격월 집단간에서 유의한 차이를 보이는 반면 1월과 1 1월 표본간에서는 그 성황이 오히려 비숫해짐으로서 집단내 총역위빈도는 주기적으로 변동하고 있음이 암시된다. 역위와 환경변수와의 다중상관분석에서는 기온, 습도, 강수량이 역위빈도에 유의한 영향을 미치는 것으로 나타났고 역위 중 In(2L)t가 상기한 환경변수 모두에 대하여 유의한 상관관계를 보인 반면, In(3R)C와 In(3R)P는 어느 것과도 상관성을 보이지 않았다. 염색체내 그리고 염색체간의 연관 또는 조합의 검정결과 연관불평형혈상을 1월, 5월, 그리고 7월 표본의 제3염색체에서, 그리고 비균일조합은 1월과 7월 표본에서 역시 제3염색체에서만 산출 되었다. Seasonal changes of inversion frequencies in Chonju 0. melanogaster populations were studied. A total of 1071 males were collected six times with ho months intewal from January through November in 1983. to analyse diploid sets of chromosomes carried by males, each male was mated to several virgin females homoBvgous for cytologically standard sequence in all chromo-somes. From each mating, more than seven FL larvae were selected in random and tested to find chromosomal aberrations. In the present study, 15 different inversions were found and identified to be paracentric only In both second and third chromosomes; seven were cosmopolitan and the rest eight endemic types. The average frequency of inversions was 0.465 and the mean number of inversions carried by a single male was 0.639. The linkage disequilibria were detected between the leK and right arms of third chromosomes from the samples of January, May and Julv, Whereas nonrandom associations appeared also in the third chromosomes only in January and Julv samples. In multiple regression analysis among frequencies of inversions and environ-mental variables it appeared that mean temperature, relative humidity and total precipitation for a month skipped over 30 days before collected affect to change to frequencies of particular inver-sions. With respect to the behavior of inversions in the present samples, it is suggested, with the Friedman's analysis of variance by ranks of inversion frequency orders, that the frequencies of inversions change cyclically year to year.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.638-647
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• 2010

The genetic relationships in 5 species of $Ligularia$ were investigated using RAPD (Randomly Amplified Polymorphic DNA) and ITS (Internal Transcribed Spacer) sequences analyses. In RAPD analysis, sixty three of 196 arbitrary primers showed polymorphism. The amplified fragments ranged from 0.2 to 1.6 kb in size. The dendrogram was constructed by the UPGMA clustering algorithm based on genetic similarity of RAPD markers. A total of 16 accessions were classified into 5 major groups corresponding each species at the similarity coefficient value of 0.77. In the ITS sequence analysis, the size of ITS 1 was varied from 248 to 256 bp, while ITS 2 was varied from 220 to 222 bp. The 5.8S coding region was 164 bp in lengths. Forty nine sites (10.2%) of the 478 nucleotides were variable, and the G+C content of ITS region ranged from 49.4 to 53.5%. In the ITS tree, five species of $Ligularia$ were monophyletic, and $L.$ $taquetii$ was the first branching within the clade. $Ligularia$ $intermedia$ formed a clade with $L.$ $fischeri$ var. $spiciformis$ (BS=79), and $L.$ $stenocephala$ and $L.$ $fischeri$ were also claded. Two data sets were congruent, except of the position of $L.$ $fischeri$ var. $spiciformis$.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1916-1927
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• 2018

Corynebacterium glutamicum is an excellent platform for the production of amino acids, and is widely used in the fermentation industry. Most industrial strains are traditionally obtained by repeated processes of random mutation and selection, but the genotype of these strains is often unclear owing to the absence of genomic information. As such, it is difficult to improve the growth and amino acid production of these strains via metabolic engineering. In this study, we generated a complete genome map of an industrial L-valine-producing strain, C. glutamicum XV. In order to establish the relationship between genotypes and physiological characteristics, a comparative genomic analysis was performed to explore the core genome, structural variations, and gene mutations referring to an industrial L-leucine-producing strain, C. glutamicum CP, and the widely used C. glutamicum ATCC 13032. The results indicate that a 36,349 bp repeat sequence in the CP genome contained an additional copy each of lrp and brnFE genes, which benefited the export of L-leucine. However, in XV, the kgd and panB genes were disrupted by nucleotide insertion, which increase the availability of precursors to synthesize L-valine. Moreover, the specific amino acid substitutions in key enzymes increased their activities. Additionally, a novel strategy is proposed to remodel central carbon metabolism and reduce pyruvate consumption without having a negative impact on cell growth by introducing the CP-derived mutant $H^+$/citrate symporter. These results further our understanding regarding the metabolic networks in these strains and help to elucidate the influence of different genotypes on these processes.

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.76-82
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• 2003

To prepare evolved PHB depolymerase with increased activity for PHB or P(3HB-co-3HV) compared to the activity of the original PHB depolymerase from Alcaligenes faecalis T1, random mutation of the cloned PHB depolymerase gene was performed by using a DNA shuffling method. A library of mutated PHB depolymerase genes from A. faecalis T1 was fused to the ice nucleation protein (INP) gene from Pseudomonas syringae in pJHCl 1 and approximately 7,000 transformants were isolated. Using M9 minimal medium containing PHB or P(3HB-co-3HV) as the carbon source, mutants showing alteration in PHB depolymerase activity were selected from the transformants. The PHB depolymease activity of the transformants was confirmed by the formation of halo around colony and the turbidity decrease tests using culture supermatants. The catalytic activity of PHB depolymerase of the best mutant II-4 for PHB or P(3HB-co-13 mol% 3HV) was approximately 1.8-fold and 3.2-fold, respectively, higher than that of the original PHB depolymerase. DNA sequence analysis revealed that three amino acid residues (Ala209Val, Leu258Phe, and Asp263Thr) were substituted in II-4. From the mutational analysis, it was presumed that the substitution of amino acids near catalytic triad to more hydrophobic amino acids enhance the catalytic activity of PHB depolymerase from A. faecalis T1.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.82-94
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• 2015

In this paper, we propose hardware prefetch mechanism with an efficient cache replacement policy by giving priority to the trigger block in which a spatial region and producing a spatial region by using the displacement field. It could be taken into account the sequence of the program since a history is based on the trigger block of history record, and it could be quickly prefetching the instructions or data address by adding a stored value to the trigger address and displacement field since a history is stored as a displacement value. Also, we proposed a method of replacing at random by the cache replacement policy from the low priority block when the cache area is full after giving priority to the trigger block. We analyzed using the memory simulator program gem5 and PARSEC benchmark to assess the performance of the hardware prefetcher. As a result, compared to the existing hardware prefecture to generate the spatial region using a bit vector, L1 data cache miss rate was reduced about 44.5% on average and an average of 26.1% of L1 instruction misses occur. In addition, IPC (Instruction Per Cycle) showed an improvement of about 23.7% on average.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.72-80
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• 2010

The 1Gbps clock and data recovery (CDR) circuit using the proposed multi-point phase detector (PD) is presented. The proposed phase detector generates up/down signals comparing 3-point that is data transition point and clock rising/falling edge. The conventional PD uses the pulse width modulation (PWM) that controls the voltage controlled oscillator (VCO) using the width of a pulse period's multiple. However, the proposed PD uses the pulse number modulation (PNM) that regulates the VCO with the number of half clock cycle pulse. Therefore the proposed PD can controls VCO preciously and reduces the jitter. The CDR circuit is tested using 1Gbps $2^{31}-1$ pseudo random bit sequence (PRBS) input data. The designed CDR circuit shows that is capable of recovering clock and data at rates of 1Gbps. The recovered clock jitter is 7.36ps at 1GHz and the total power consumption is about 12mW. The proposed circuit is implemented using a 0.18um CMOS process under 1.8V supply.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.383-396
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• 2002

RAPD analyses were compared for 17 taxa of Korean Iris including the subgenus Sisyrinchium and Belamcanda. Eighty scorable RAPD markers were formed from the PCR reactions using 10 random oligoprimers. In this systematic analyses which used neighbor-joining methods including bootstrapping analyses with genetic coefficients, the Korean Iris were divided into three subgenera (Limniris, Crossiris, Pardanthopsis), or two genera (Limniris, Pardanthopsis). The molecular data agree with the previous classification system that recognized two sections and six series for the subgenus Limniris because the subgenus is comprised of four clades in the RAPD analyses. According to the molecula data, the series Chinensis should be divided into two groups. The minutoaurea group is composed of I. koreana, I. odaesanensis, and I. minitoaurea, while the rossi group is comprised of two varieties of I. rossi. The series Tripetalae is closely allied with the series Sibiricae, whereas the series Ensatae is recognized as a sister group to the series Ruthencae. The molecular phylogeny, which was based on RAPD analysis, for the most part agreed with the data proposed by previous authors. This is because the basis of morphological and ITS sequence data suggests that the RAPD markers should be very useful in addressing phylogenetic questions about the genus Iris.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.209-213
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• 2005

In order to provide the molecular genetic information necessary for conservation of bog whortleberry (Vaccinium uliginosum L), one of the rare species in Korea, I-SSR analysis was performed on two populations on Mt. Halla and Mt. Seorak. A total of 68 I-SSR products were observed, and higher level of genetic diversity was observed in Mt. Halla population (S.I.=0.539) than in the Mt. Seorak population (S.I,=0.401). Level of genetic diversity in this species was relatively higher than those in other rare species analysed with I-SSR marker. From the results of AMOVA, exceptionally large proportion of genetic diversity (33.5%) was resulted from genetic difference between two populations, and only 66.5% of the genetic variation was allocated in common among individuals within each population, compared with the results in other long-lived woody species. This remarkably high degree of genetic heterogeneity existed between Mt. Halla and Mt. Seorak populations might suggest that they might be originated from the independent progenitors before the post glacier ages, respectively, and/or that they undergone random genetic drift respectively due to geographical isolation resulted from dramatic changes in environmental conditions after the post glacier ages.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.162-172
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• 2002

Schizosaccharomyces pombe is suited for the study of cytokinesis as it divides by forming a septum in the middle of the cell at the end of mitosis. To enhance our understanding of the cytokinesis, we have carried out a genetic screen for temperature-sensitive S. pombe mutants that show defects in septum formation and cell division. Here we present the isolation and characterization of a new temperature-sensitive mutant, sun1(septum uncontrolled), which undergoes uncontrolled septation during cell division cycle at restrictive temperature $(37^{\circ}C)$. In sun1 mutant, actin ring and septum are positioned at random locations and angles, and nuclear division cycle continues. These observations suggest that the sun] gene product is required for the proper placement of the actin ring as well as precise septation. The sun] mutant is monogenic recessive mutation unlinked to previously known various cdc genes of S. pombe. In a screen for $sunl^+$ gene to complement the sun] mutant, we have cloned a gene, $susl^+$(suppressor of sun1 mutant), that encodes a protein of 689 amino acids. The predicted amino acid sequence of $susl^+$ gene is similar to the human hMadlp and Saccharomyces cerevisiae Mad1p, a component of the spindle checkpoint in eukaryotic cells. The null mutant of $susl^+$ gene grows normally at various temperatures and has the increased sensitivity to anti-microtubule drug, while $susl^+$ mutant shows no sensitivity to microtubule destabilizing drugs. The putative S. pombe Sus1p directly interacts with S. pombe Mad2p in yeast two-hybrid assays. These data suggest that the newly isolated susr gene encodes S. pombe Mad1p and suppresses sun] mutant defective in controlled septation in a cell division cycle.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.45-53
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• 1999

We examined the hepatitis G virus infections among 227 Koreans who were healthy or were suspected of hepatitis and determined the phylogenetic relationship based on a part of the NS-5 region of 5 positive samples. Viral RNA was extracted from sera and cDNA was synthesized and subsequently amplified by RT-PCR (reverse transcription-polymerase chain reaction) or RT-nested PCR using random hexamer and NS-5 specific primers (470-20-1-77F, 470-20-1-211R, HGVNESTFO, HGVNESTRE). Five positives were found to belong to samples of patients showing symptoms of viral hepatitis. Primers used for PCR or nested PCR were derived from the NS-5 region. On the other hand, no amplification was detected using primers derived from the 5'-NCR (G-146F, G-401R). We performed TA cloning and sequencing of 5 amplified fragments, and their sequences were compared with those of foreign isolates of HGV. The phylogenetic analysis using MegAlign programme of DNAstar has shown that the Korean isolates are clustered on the phylogenetic tree. In summary, we confirmed the hepatitis G virus infection in 5 cases out of 12 patients showing the symptoms of viral hepatitis. The phylogenetic analysis of sequences of 5 amplified fragments showed that their relations to each other were closer than those to the foreign HGV isolates reported.