• BMB Reports
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• v.39 no.6
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• pp.717-721
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• 2006

In vitro analyses of type I signal peptidase activities require protein precursors as substrates. Usually, these pre-proteins are expressed in vitro and cleavage of the signal sequence is followed by SDS polyacrylamide gel electrophoresis coupled with autoradiography. Radioactive amino acids have to be incorporated in the expressed protein, since the amount of the in vitro expressed protein is usually very low and processing of the signal peptide cannot be followed by SDS polyacrylamide gel electrophoresis alone. Here we describe a rapid and simple method to express large amounts of a protein precursor in E. coli. We have analyzed the effect of ionophors as well as of azide on the accumulation of expressed protein precursors. Azide blocks the function of SecA and the ionophors dissipate the electrochemical gradient across the cytoplasmic membrane of E. coli. Addition of azide ions resulted in the formation of inclusion bodies, highly enriched with pre-apo-plastocyanine. Plastocyanine is a soluble copper protein, which can be found in the periplasmic space of cyanobacteria as well as in the thylakoid lumen of cyanobacteria and chloroplasts, and the pre-protein contains a cleavable signal sequence at its N-terminus. After purification of cyanobacterial pre-apo-plastocyanine, its signal sequence can be cleaved off by the E. coli signal peptidase, and protein processing was followed on Coomassie stained SDS polyacrylamide gels. We are optimistic that the presented method can be further developed and applied.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.581-585
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• 1985

This study was carried out with blue mussels at Otsuchi Bay in Japan from August 1981 to May 1982, in order to investigate the effect of the parasitic pea crab (Pinnotheres pholadis) on the reproductive capacity of host blue mussels (Mytilus edulis galloprovincialis). The results show that pea crabs delay gonad development of host mussels about one month and lower their fatness rate by intercepting nutrients. The parasitization with pea crabs is thought not to prevent spawning activity itself, but to reduce the number of germ cell resulting in the reduced space of gonads.

• Reproductive and Developmental Biology
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• v.32 no.1
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• pp.15-20
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• 2008

Pronuclear DNA microinjection has been the most universal method in transgenic animal production but its success rate of transgenesis in mammals are extremely low. To address this long-standing problem, we used retrovirus- and lentivirus-based vectors carrying the enhanced green fluorescent protein (EGFP) gene under the control of ubiquitously active cytomegalovirus (CMV) promoter to deliver transgenes to bovine embryos. The rate of transgenesis was evaluated by counting EGFP positive blastocysts after injection of concentrated virus stock into the perivitelline space of the bovine oocytes in metaphase II. Among two different types of lentivirus vectors derived from FIV (feline immunodeficiency virus) and HIV (human immunodeficiency virus), the former scored the higher gene transfer efficiency; almost 100% of the blastocysts developed from the oocytes infected with FIV-based vector were EGFP positive. As for the vectors derived Com HIV lentivirus, the transgenesis rate of the blastocysts was reduced to 39%.

• Applied Microscopy
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• v.46 no.3
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• pp.150-154
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• 2016

The ultrastructure of fertilized egg envelope from Pseudobagrus fulvidraco belongs to Bagridae was investigated using light and electron microscopes. The fertilized egg was compressed spherical, light-yellowish, demersal, and adhesive. The size of fertilized egg is about $1.85{\pm}0.13mm$, perivitelline space is not well developed, and there were no appendicular structures on the outer surface of egg envelope and oil droplets in vitelline membrane under light microscope. The micropyle was located in the animal pole of fertilized egg. Adhesive reticular fiber was covered fertilized egg envelope. The thickness of egg envelope was about $3.7{\sim}4.2{\mu}m$, and the egg envelope consisted of two layers: an outer, electron-dense adhesive fibers layer and an simple inner layer with pore. Therefore, the ultrastructure of cross section of the fertilized egg envelope showed species specificity, but studies on the other species belongs to Bagridae were need to get correct information about common traits in family.

• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.63-67
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• 2014

BACKGROUND: The present study is an exploratory research to establish national biosafety regulation systems through a survey on the recognition of safety regulation systems for the living modified organism(LMO). METHODS AND RESULTS: We have conducted a survey on an awareness of LMO safety regulation systems in scientific working groups. The data of 235 respondents were analyzed using various statistical methods. As a result, 72.8% of the respondents were male; 27.2% were female, and 43.4% of them work in the university. A total of 33.2% of the respondents majored in general biology, and their most common job position was the laboratory safety manager. The difference of an awareness on LMO law and regulatory system was not statistically significant by either work places or job positions. CONCLUSION: For the rapid settlement and the efficient implementation of LMO safety management policy, we conclude that it is required to reduce the gap between the recognition and fulfillment of safety management. Furthermore, the mutual exchanges of information among researchers are needed with the settlement of the safety management system and the harmony of policy with improvement of the absurd regulations. The ongoing and specialized training, inspections, and the strengthening of public relations are also required along with the efforts to improve the absurd regulations.

• Journal of Information Management
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• v.43 no.3
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• pp.97-115
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• 2012

This paper derives determining factor for the management of oceanographic data in two ways. 1) The type of oceanographic observation and the raw data which were collected from marine physics, marine chemistry, marine biology, marine geology area were analyzed. 2) The services of the KODC(Korea Oceangraphic Data Center), NFRDI(National Fisheries Research & Development Institute), KHOA(Korea Hydrographic and Oceanographic Administration) were analyzed to derive metadata elements for retrieval. After analyze, the 42 deciding factor were derived in the 9 areas (general, Observer, satellites, observation instruments, observatories, space, information, projects, and observational data, data processing).

• Animal cells and systems
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• v.10 no.1
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• pp.27-40
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• 2006

Tree of heaven (Ailanthus altissima Swingle) as an invasive alien plant, appeared usually in the disturbed locations such as road-side, incised slope, and trampling path-side. They appeared abundantly in the trampling pathside but they did not appear or were rare in the interior of forest. Density and importance value of tree of heaven were proportionate to the relative light intensity measured according to distance from the trampling path toward forest interior and closely related to the breadth of trampling path as well. They were associated with annual, other exotic species or ruderal plants well. Distributional pattern of mature trees of them in the study area and its surrounding environments implied that they were introduced intentionally. Size class distribution of them showed that they are in expansion and artificial interferences such as, installing physical training space and developing hiking course functioned as trigger factors in their invasion and expansion. The results support the facts known generally in relation to invasion and expansion of the invasive alien plants. In this viewpoint, we suggest a management plan that applies ecological restoration principles to address ecosystems infected with tree of heaven by restoring the integral feature of the degraded nature and conserving the remained nature more thoroughly.

• Molecules and Cells
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• v.20 no.3
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• pp.361-363
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• 2005

Plasmid Achromobacter secretion (PAS) factor is a putative secretion factor that induces the secretion of periplasmic proteins. PAS factor from Vibrio vulnificus was crystallized at 294 K by the hanging drop vapor-diffusion method. It was isolated as a monomer during the purification procedures. The native crystal belongs to the F222 space group with unit cell parameters a = 56.1, b = 74.4, $c=80.0{\AA}$, ${\alpha}={\beta}={\gamma}=90^{\circ}$. The crystal was soaked in cryoprotectant containing 1 M NaBr for 1 h for MAD phasing. The diffraction limit of the Br-MAD data set was $1.9{\AA}$ using synchrotron X-ray irradiation at beam line BL-18B at the Photon Factory, Japan.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.235-243
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• 2010

For decades, traditional mutation breeding technologies using spontaneous mutation, chemicals, or conventional radiation sources have contributed greatly to the improvement of crops and microorganisms of agricultural and industrial importance. However, new mutagens that can generate more diverse mutation spectra with minimal damage to the original organism are always in need. In this regard, ion beam irradiation, including proton-, helium-, and heavier-charged particle irradiation, is considered to be superior to traditional radiation mutagenesis. In particular, it has been suggested that ion beams predominantly produce strand breaks that often lead to mutations, which is not a situation frequently observed in mutagenesis induced by gamma-ray exposure. In this review, we briefly describe the general principles and history of particle accelerators, and then introduce their successful application in ion beam technology for the improvement of crops and microbes. In particular, a 100-MeV proton beam accelerator currently under construction by the Proton Engineering Frontier Project (PEFP) is discussed. The PEFP accelerator will hopefully prompt the utilization of ion beam technology for strain improvement, as well as for use in nuclear physics, medical science, biology, space technology, radiation technology and basic sciences.

• 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.