• The Korean Journal of Zoology
• /
• v.14 no.2
• /
• pp.75-84
• /
• 1971

Genetic analysis of a new wing mutant, Surf wings (Srf), was performed. Mutant flies were extracted from a wild population of Drosophila melanogaster at the vicinity of Atomic Energy Research Institute, Seoul in August-September 1969. 1. The distal half of wings of heterozygotes (Srf/+) turned upwards about 40 degree from body axis, but flying ability was not disturbed. They overlap Cy in low frequency when they are grown below $22^{\circ}C$. This resembles with Si or j series, but wing margins are not rolled and diversed. Postscutellars are erected slightly, but they, in general, are not crossed. Any other external pleiotropic effects were not observed. 2. Penetrance and expressivity of both sexes are not complete. Their extents are variable with sex and temperature. These characters show maximum tendencies when the development is made at $22^{\circ}C$ (female: P = 0.996, E = 0.932, male:P = 0.961, E = 0.698). 3. The preliminary locus of Srf was determined to be 66.8 on the right arm of second chromosome by using recessive maker gene cn bw. 4. The homozygous flies(Srf/Srf) have shown perfect lethality. The heterozygotes (Srf/+), on the other hand, have shown to be viable and fertile. Srf chromosomes are kept in a balanced lethal system with Pm chromosomes which are associated with inversions. Hence, it is partially reasonable to suppose that Srf may persist in a natural population by the same mechanism. 5. Allelism test with Cy was also conducted. The fact that combination with Cy in the trans-phase (+ Srf/Cy +) is viable in contrast to the lethality of Srf/Srf and Pm/Pm indicates that Srf and Cy are not functionally allelic.

• Korean Journal of Agricultural Science
• /
• v.39 no.2
• /
• pp.219-226
• /
• 2012

The acyl-CoA dehydrogenase, C-2 to C-3 short chain (ACADS) gene is known to be related with fat metabolism, especially coverts the fat to the energy sources in cattle. In human, the mutations in this gene cause SCAD deficiency, which is one of the fatty acid metabolism disorders. The ACADS gene is located on bovine chromosome 17. The objective of this study was to identify SNPs in Hanwoo ACADS gene and identify the relationships with economic traits. In this study, two SNPs, T1570G SNP in exon 2 and G13917A SNP in exon 4, were observed. Moreover, in the coding region, 2 missense mutations, T (Cys) ${\rightarrow}$ G (Trp) mutation at 1570 bp and G (Arg) ${\rightarrow}$ A (Gln) mutation at 13917 bp, were observed. These mutations were subjected to the PCR-RFLP for typing 198 Hanwoo animals. The observed genotype frequency for T1570G was 0.135 (TT), 0.860 (TG) and 0.005 (GG), respectively. Also, 0.900 (GG) and 0.100 (GA) were observed for the G13917A mutation. The association of these SNPs with four economic traits, CW (Carcass Weight), BF (Backfat Thickness), LMA (Longissimus Muscle Area), MS (Marbling Score), were also observed. The results indicated that no significant results were observed in all four traits (P>0.05). This might indicate that further studies are ultimately needed to use the SNPs in ACADS gene in lager populations for effectively used for the marker assisted selection.

• Molecules and Cells
• /
• v.19 no.1
• /
• pp.46-53
• /
• 2005

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.

• Korean Journal of Microbiology
• /
• v.29 no.1
• /
• pp.16-24
• /
• 1991

The yeast gene THR1 encodes the homoserine kinase (EC 2.7.1.39: HKase) which catalyses the first step of the threonine specific arm at the end of the common pathway for methionine and threonine biosynthesis. A recombinant plasmid pMC3 (12.6 kilobase pairs, vector YCp50) has been cloned into E. coli HB101 from a yeast genomic library through its complementing activity of a thr1 mutation in a yeast recipient strain M39-1D. When subcloned into pMC32 (8.6kbp, vector YRp7) and pMC35 (8.3 kbp, vector YIp5), the HindIII fragment (2.7 kbp) of pMC3 insery was positive in the thrI complementing activity in both yeast and E. coli auxotrophic strains. The linearized pMC35 was introduced into the original recipient yeast strain and the mitotically stable chromosomal integrant was identified among the transformants. Through the tetrad analysis, the integration site of the pMC35 was localized to the region of THR1 structural gene at an expected genetic distance of approximately 11.1 cM from the ARG4 locus on the right arm of the yeast chromosome VIII. When episomically introduced into the auxotrophic cells and cultured in Thr omission liquid medium, the cloned gene overexpressed the HKase in the order of thirteen to fifteenfold, as compared with a wildtype. HKase levels are repressed by addition of threonine at the amount of 300 mg/l and 1, 190 mg/l for pMC32 and pMC3, respectively. Data from genetic analysis and HKase response thus support that the cloned HindIII yeast DNA fragment contains the yeast thr1 structural gene, along with necessary regulatory components for control of its proper expression.

• KSBB Journal
• /
• v.5 no.2
• /
• pp.175-182
• /
• 1990

Protoplasts, isolated from leaf of N. tabacum NR-/SR+ and N. glottnosa were electrofused and divided with a plating efficiency of 30∼35% in AAPI 9M medium. Green callus lines were selected in protoplast-derived colonies on MSNO3 selection medium with 1.2mg/ml streptomycin sulfate on the basis of nitrate reductase proficiency and streptomycin resistance. Four putative hybrid plant lines regenerated from the green callus lines had intermediate morphology between that of parents with respect to floral shape, corolla length and ovate leaf blade. Zymograms of leaf peroxidase and esterase from these putative hybrid plant lines showed isozyme profiles derived from both parents and also, they exhibited additional and lost bands. Cytological analysis of two putative hybrid plant lines gave chromosome counts of 2n=66 in L22 and 2n=54 in L44 which were less than the expected number of N. tabacum(2n=48) and N. glutinosa(2n=24).

• Journal of Life Science
• /
• v.16 no.7 s.80
• /
• pp.1195-1198
• /
• 2006

The importance of wild plant resources along with the development of high biotecyhnology is highlighted for exploitation of new materials which can make the added value. The goal of this study is providing fundamental data bases for developing new materials through the analyses of morphological characteristics, antibiotics and molecular cytogenetics in Baegseon (Dictamnus dasycarpus Turcz.). Baegseon has several characteristics; there are two types of flower color, pink and white, the seed germination starts about February 20th, the maximum flowering season is around May 17th in southern Korea, the growth period is about 60 days. The number of chromosomes are 2n=2x=36, the size of chromosomes in metaphase is $4.2{\sim}8.1{\mu}m$. The amount of 2C nuclear DNA is 1.93pg, and there is no variation of genome size amoung varieties. The extraction juice of baegseon young roots has the excellent antibiotic activity against the mold (Botrytis cinerea).

• Journal of Microbiology
• /
• v.33 no.4
• /
• pp.339-343
• /
• 1995

We isolated a 10 kb Bam HI fragment originated from the chromosome of a $H_2O$$^2$-resistant mutant strain of Streptomyces coelicolor, which confer $H_2O$$^2$-resistance to S. lividance upon transformation. Among various subclones ot 10kb Bam HI fragment tested for their $H_2O$$^2$-resistant phenotype in S. lividans, a subclone containing 5.2 kb Bam HI-BglII fragment was found to be responsible for $H_2O$$^2$-resistance. The plasmid containing this 5.2 kb fragment was then transformed into S. coellicolor A3(2) at early and tested for their phenotype of $H_2O$$^2$-resistance and the change in various enzymes whose activity can be stained in the gel. We found out that the 5.2 kb insert DNA conferred $H_2O$$^2$-resisstance in S. coelicolor A3(2) at early phase of cell growth. The presence of this DNA also resulted in higher level of peroxidase compared with the wild type cell containing parental vector (pIJ702) only. Esterase activity was also higher in this clone. However, alcohol dehydrogenase activity decreased compared with the wild type. These results suggest that the presence of a gene in 5.2 kb BamHI-BglII DNA fragment causes multiple changes in S. coelicolor related to its response against hydrogen peroxide. The result also implies that not only peroxidase but also esterase may function in the defencse meahsnism agianst $H_2O$$^2$-.

• Korean Journal of Microbiology
• /
• v.26 no.4
• /
• pp.305-311
• /
• 1988

The spectinomycin resistant strain of slow growing R. japonicum R-168 was selected to be participated in conjugation with E. coli WA803/pGS9. Tn5 was introduced from suicide vector pGS9 into R. japonicum R-168 $spr^{r}$ chromosome at the frequency of $1.0\times 10^{-5}-5.0\times 10^{-7}$ and the transconjugante were selected on the yeast extract-mannitol plate containing kanamycin ($50{\mu}$g/ml) and spectinomycin ($100{\mu}$g/ml) after 8-9 days incubation. All transconjugants we tested were found to contain Tn 5 DNA on their genome, which was confirmed by Southern hybridization experiments. R. japonicum RNa75, which had been selected through plant test, was found to be defective in symbiotic nitrogen fixing ability and the production of leghemoglobin in soybean nodules formed by the inoculation of this mutant. In addition, this mutant strain hardly developed nitrogenase activity asymbiotically in contrast with the wild type strain, indicating that some nitrogen fixing gene might be blocked in this strain and the production of leghemoglobin could be decreased by the interference in nitrogen fixing genes.

• KSBB Journal
• /
• v.10 no.5
• /
• pp.575-581
• /
• 1995

A plasmid pTTY2, containing the lipase-producing gene, was used to transform an E. coli phage lysogen, P90c/$\phi$434, into the lipase-producing lysogen, P90c/$\phi$434/pTTY2. After the overproduction of lipase by the isopropylthio-${\beta}$-D-galactoside induction, the prophage $\phi$434 in the chromosome of the host cell was induced by the milomycin C addition or ultraviolet irradiation to lyse the host cell. The optimum operating conditions, such as the isopropylthio-${\beta}$-D-galactoside induction period and the phage induction timing, were sought for the efficient cell lysis in the same fermenter. Effective cell lysis occurred at the earlier exponential growth phase with the isopropylthio-${\beta}$-D-galactoside induction period of 1 hour. The amount of the lipase production was qualitatively measured by the halo size in Luria-Bertani agar medium containing tributyrin and Rhodamine B plate.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.2
• /
• pp.105-110
• /
• 2010

This study was conducted to analyze the relationships between resistance of brown planthopper and traits related to the lodging in rice. For the linkage analysis of traits tested in this study, a genetic linkage map was created with 162 DNA markers spanning 12 rice chromosomes based on 120 doubled haploid (DH) lines, which were derived from a cross between Samgang', a Tongil type cultivar with BPH resistance, and ‘Nagdong’, a japonica cultivar. QTLs were identified to analyze the agronomic traits including lodging by composite interval mapping. Thirteen QTLs were detected for five traits comprised of plant length (PL), 3rd internode length (3rdIL), moments (Mo), lodging index (LI), and breaking weight (BW). The relationships between the BPH resistance and agronomic traits including lodging revealed that two QTLs (qBPR7, qBPR8) were linked to traits related to lodging. Two QTLs, qBPR7 and qBPR8 on chromosome 7 (RM531-7042) and 8 (RM1148- RM544) showed associations with moments and 3rd internode length, respectively.