• 미생물학회지
• /
• 제22권4호
• /
• pp.229-234
• /
• 1984

A modified E. coli trp operon, $trpL({\Delta}att)\;trpE^{FBR}$, was conjugally transfered into Klebsiella pneumoniae $KC_{100}\;(Phe^-,\;Tyr^-,\;Trp^-,\;Rif^r,\;Kam^r)$ by in vivo cloning using the hybrid plasmid $R_{6}K::$ Mucts 61 with a transfer frequency of $5.2{\times}10^{-7}$. Two K. pneumoniae transconjugants, $KUA_{701}\;and\;KUA_{702}$, were isolated. The characters of attenuation control-free and resistance to feedback-inhibition which are characteristics of donor C. coli trp operon were normally expressed in the $KUA_{701}.\;However,\;KUA_{702}$ retained only the feedback-inhibition resistant character. $Trp^+$ phenotype and ampicillin resistant character were completely stable in the transconjugants, but streptomycin resistant character was lost in the transconjugants.

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
• /
• pp.14-17
• /
• 2001

Positional clonging (map-based cloning) of mutations or genetic variations has been served as an invaluable tool to understand in-vivo functions of genes and to identify molecular components underlying phenotypes of interest. Mice homozygous for the cerebellar deficient folia (cdf) mutation are ataxic, with cerebellar hypoplasia and abnormal lobulation of the cerebellum. In the cdf mutant cerebellum approximately 40% of Purkinje cells are ectopically located within the white matter and the inner granule cell layer (IGL). To identify the cdf gene, a high-resolution genetic map for the cdf-gene-encompassing region was constructed using 1997 F2 mice generated from C3H/HeSnJ-cdf/cdf and CAST/Ei intercross. The cdf gene showed complete linkage disequilibrium with three tightly linked markers D6Mit208, D6Mit359, and D6Mit225. A contig using YAC, BAC, and P1 clones was constructed for the cdf critical region to identify the gene. A deletion in the cdf critical region on chromosome 6 that removes approximately 150 kb of DNA selection. cdf mutant mice with the transgenic copy of the identified gene restored the brain abnormalities of the mutant mice. The positional cloning of cdf gene provides a good example showing the identification of a gene could lead to finding a new component of important molecular pathways.

• 미생물학회지
• /
• 제21권4호
• /
• pp.229-237
• /
• 1983

Aspergillus nidulans의 tRNA 유전자의 구성과 발현기착을 연구하기 위하여 우선 Aspergillus의 총 tRNA 유전자를 cloning 하였다. Aspergillus의 핵 DNA롱 포자로 부터 분리해 내고 본질 형성에서 분리한 BamHI과 T4 DNA ligase를 사용하여 pBR322플라스미드에 재조합시켜서 cloning하였다. 15벤의 transformation을 하여 30,000개 의 transformants 얻었고, 이 중 Aspergillus DNA를 가지고 있는 colony는 5,300켜개였다. In vivo에 서 S2p로 표지 된 total tRNA를 probe로 하여 colony hybridization 실험 결과, 105개의 total tRNA유전자 clone을 얻었다. 위의 결과와 cohybridization 실험 결과를 분석해 보면, Asprgillus의 tRNA 유전자는 yeast의 그것보다는 좀 더 밀집되어 존재한다고 생각된다.

• 미생물학회지
• /
• 제30권2호
• /
• pp.134-140
• /
• 1992

Teh $polA^{+}$ gene can be transducted in a multicopy mini-Mu plasmid, but not cloned because the product of this gene is lethal when overproduced. Although, we obtained one surviving cell, in which the ColEl-derived mini-Mu plasmid suffered a spontaneous deletion exactly at the region where the $polA^{+}$ gene was cloned. The $PolA^{+}$ unstream flanking sequence containing the promoter and pribnow-box was delected in vivo ; consequently this gene is not able to be expressed.

• The Plant Pathology Journal
• /
• 제32권3호
• /
• pp.173-181
• /
• 2016

Gene disruption by homologous recombination is widely used to investigate and analyze the function of genes in Fusarium fujikuroi, a fungus that causes bakanae disease and root rot symptoms in rice. To generate gene deletion constructs, the use of conventional cloning methods, which rely on restriction enzymes and ligases, has had limited success due to a lack of unique restriction enzyme sites. Although strategies that avoid the use of restriction enzymes have been employed to overcome this issue, these methods require complicated PCR steps or are frequently inefficient. Here, we introduce a cloning system that utilizes multi-fragment assembly by In-Fusion to generate a gene disruption construct. This method utilizes DNA fragment fusion and requires only one PCR step and one reaction for construction. Using this strategy, a gene disruption construct for Fusarium cyclin C1 (FCC1), which is associated with fumonisin B1 bio-synthesis, was successfully created and used for fungal transformation. In vivo and in vitro experiments using confirmed fcc1 mutants suggest that fumonisin production is closely related to disease symptoms exhibited by F. fujikuroi strain B14. Taken together, this multi-fragment assembly method represents a simpler and a more convenient process for targeted gene disruption in fungi.

• 미생물학회지
• /
• 제28권1호
• /
• pp.41-46
• /
• 1990

자연환경으로부터 분리한 DJ-12 균주는 4CBA 및 4CB를 비롯하여 그 대사산물인 4OHBA와 PCA를 분해하여 단일 탄소원으로 이용하였다. DJ-12 균주에서 4CBA 및 4CB분해유전자는 약 65kb 크기의 plasmid인 pDJ121에 존재하였으며, 이 pDJ121은 ExoRI, HindIII, SalI 그리고 PslI의 절단부위를 각각 9, 11, 10 그리고 19개씩 가지고 있었다. EcoRI으로 처리한 pDJ121 절편을 pKT230에 ligation 시켜 재조합 vector인 pDK450을 만들었으며, 이를 Pseudomonas putida KT2440에 transformation 시켜 얻은 cloned cell 에서는 4CBA 분해유전자가 잘 발현되었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권4호
• /
• pp.487-495
• /
• 2007

The objectives of the present study were to initiate cloning of Korean native goat by somatic cell nuclear transfer (NT) and to examine whether unovulated (follicular) oocytes can support the same developmental ability of NT embryos as ovulated (oviductal) oocytes after hCG injection in stimulated cycles of the goat. The in vivo-matured and immature oocytes were collected from the oviducts and follicles of superovulated does, respectively, and the immature oocytes were maturated in vitro. Ear skin fibroblasts derived from a 3-yr-old female Korean native goat were used as the donors of nuclei or karyoplasts. Following fusion, activation and in vitro culture to a 2- to 4-cell stage, 49 in vitro-derived and 105 in vivo-derived embryos were transferred to 6 and 17 recipient does, respectively. One doe and three does of the respective groups were identified as pregnant by ultrasonography on day 30 after embryo transfer. However, only one doe, which had received in vivo-derived embryos, delivered a normal female kid of 1.9 kg on d 149. The cloned kid gained more weight than her age-matched females as much as 87% during the first 4 mo after birth (17.7 vs. $9.4{\pm}0.8$ kg) and reached puberty at 6-mo age a few months earlier than normal female does. The telomere length of the kid, which was similar to that of the donor fibroblast at 2-mo age, decreased 8% between 2- and 7-mo ages. Moreover, at 7-mo age, she had 21% shorter telomere than her age-matched goats. To our knowledge, this is the first case in which a cloned animal born with a normal weight exhibited accelerated growth and development. The unusually rapid growth and development of the cloned goat may have resulted from SCNT-associated epigenetic reprogramming involving telomere shortening.

• 한국수정란이식학회지
• /
• 제25권4호
• /
• pp.221-227
• /
• 2010

Early cleavage is a reliable prognostic tool for successful embryo transfer in assisted reproduction because early cleaved embryo show better pregnancy rate after transfer. There for, preparation of good embryo recipient is important factor to optimize efficiency of pig cloning. The present study was performed to evaluate the effect of early cleavage on the in vivo development of cloned embryos and to analyze breed, parity and estrous synchrony to optimize recipient for pig cloning. In vitro matured porcine oocytes derived from local slaughterhouse and fibroblasts derived from miniature pig fetuses were used for somatic cell nuclear transfer (SCNT). Reconstructed embryos were transferred to recipient pigs on the same day of SCNT or after 1~2 days of in vitro culture for selecting early cleaved embryos. Breed, parity and date of standing estrous of recipients were recorded for analysis. After 25~35 days after embryo transfer pregnancy was diagnosed using ultrasonography, and pregnant recipients were monitored till delivery. Between purebred and crossbred, no significant difference was founded in both pregnancy and delivery rates. However, early cleaved embryos showed significantly higher pregnancy (46.2%) and delivery (12.8%) rates compared to non-selectively transferred group (24.8% and 4.5%, respectively). The results also showed that the recipients showing standing estrous on the same day of SCNT and less than 4 parities were most suitable for pig cloning.

• Molecular & Cellular Toxicology
• /
• 제2권3호
• /
• pp.176-184
• /
• 2006

The controversy on genotoxicity of molinate, an herbicide, has been reported in bacterial system, and in vitro and in vivo mammalian systems. To clarify the genotoxicity of molinate, we performed bacterial gene mutation test, in vitro chromosome aberration and mouse lymphoma $tk^{+/-}$ gene assay, and in vivo micronucleus assay using bone marrow cells and peripheral reticulocytes of mice. In bacterial gene mutation assay, no mutagenicity of molinate ($12-185{\mu}g/plate$) was observed in Salmonella typhimurium TA 98, 100, 1535 and 1537 both in the absence and in the presence of S-9 metabolic activation system. The clastogenicity of molinate was observed in the presence ($102.1-408.2\;{\mu}g/mL$) of metabolic activation system in mammalian cell system using Chinese hamster lung fibroblast. However, no clastogenicity was observed in the absence ($13.6-54.3\;{\mu}g/mL$) of metabolic activation system. It is suggested that the genotoxicity of molinate was derived some metabolites by metabolic activation. Molinate was also subjected to mouse lymphoma L5178Y $tk^{+/-}$ cells using microtiter cloning technique. In the absence of S-9 mixture, mutation frequencies (MFs) were revealed $1.4-1.9{\times}10^{-4}$ with no statistical significance. However, MFs in the presence of metabolic activation system revealed $3.2-3.4{\times}10^{-4}$ with statistical significance (p<0.05). In vivo micronucleus (MN) assay using mouse bone marrow cells, molinate revealed genotoxic potential in the dose ranges of 100-398 mg/kg of molinate when administered orally. Molinate also subjected to acridine orange MN assay with mouse peripheral reticulocytes. The frequency of micronucleated reticulocytes (MNRETs) induced 48 hr after i.p. injection at a single dose of 91, 182 and 363 mg/kg of molinate was dose-dependently increased as $10.2{\pm}4.7,\;14.6{\pm}3.9\;and\;28.6{\pm}6.3\;(mean{\pm}SD\;of\;MNRETs/2,000\;reticulocytes)$ with statistical significance (p<0.05), respectively. Consequently, genotoxic potential of molinate was observed in in vitro mammalian mutagenicity systems only in the presence of metabolic activation system and in vivo MN assay using both bone marrow cells and peripheral reticulocytes in the dose ranges used in this experiment. These results suggest that metabolic activation plays a critical role to express the genotoxicity of molinate in in vitro and in vivo mammalian system.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권1호
• /
• pp.1-8
• /
• 2011

Large quantities of high-quality recipient oocytes with uniform cytoplasm are needed for research in the promising field of somatic cell nuclear transfer (SCNT) and embryonic stem cell research. In canines, however, it is difficult to obtain large quantities of oocytes because each donor produces a limited number of mature oocytes in vivo. Although in vitro maturation (IVM) is considered an alternative approach to oocyte production, this technique is still too rudimentary to be used for the production of highquality, uniform oocytes in large quantities. One technique for overcoming this difficulty is to use oocytes obtained from different species. This technique is known as interspecies SCNT (iSCNT). This review provides an overview of recent advances in canine - porcine interspecies SCNT.