• BMB Reports
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• v.40 no.3
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• pp.419-425
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• 2007

In vitro directed evolution through DNA shuffling is a powerful molecular tool for creation of new biological phenotypes. E. coli $\beta$-galactosidase and $\beta$-glucuronidase are widely used, and their biological function, catalytic mechanism, and molecular structures are well characterized. We applied an in vitro directed evolution strategy through DNA shuffling and obtained five mutants named YG6764, YG6768, YG6769, YG6770 and YG6771 after two rounds of DNA shuffling and screening, which exhibited more $\beta$-glucuronidase activity than wild-type $\beta$-galactosidase. These variants had mutations at fourteen nucleic acid sites, resulting in changes in ten amino acids: S193N, T266A, Q267R, V411A, D448G, G466A, L527I, M543I, Q626R and Q951R. We expressed and purified those mutant proteins. Compared to the wild-type protein, five mutant proteins exhibited high $\beta$-glucuronidase activity. The comparison of molecular models of the mutated and wildtype enzymes revealed the relationship between protein function and structural modification.

• Journal of Science and Technology Studies
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• v.16 no.2
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• pp.33-63
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• 2016

This paper compares and contrasts the concept of nature and the theory of evolution held by leading synthetic biologists and transhumanists in the post-genomic era. Synthetic biology, which emerged in the early 2000s, aims to design biological systems that perform specific functions with the two key concepts of "rational design" and "directed evolution". However, synthetic biology has also raised serious concerns about the creation of man-made biological materials and the manipulation of the direction and speed of evolution. It is no wonder that transhumanists, who dream of creating new, enhanced human species, have welcomed the arrival of synthetic biology. How, then, can we deal with the nature reinvented by synthetic biology? By what means can one justify research that may affect the process of evolution? What intellectual resources do synthetic biology and transhumanism share in common? What influence would the new trend of commercialization of science and technology exert upon the development of synthetic biology? Addressing those questions, this paper argues that the moral authority of nature can be restored in this post-genomic era.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.354-362
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• 2020

A common snapping turtle Chelydra serpentina inhabiting North America is internationally protected as an endangered species. It is known that the individuals of common snapping turtles were imported to South Korea as pets, and after being abandoned, some inhabit the natural ecosystem of South Korea like wild animals. No genetic survey has yet been performed for the common snapping turtles imported to South Korea. Hereby, cytochrome c oxidase subunit I (COI) information, which is 594 bp long, was determined for a total of 16 C. serpentina individuals, of which one was found in nature, twelve legally imported and their descendants, and the other three were provided from the Kansas Herpetological Society, USA. The obtained data were combined with thirteen COI sequences of C. serpentina retrieved from NCBI GenBank for the subsequent population genetic analyses. The results showed that there exist five haplotypes with high sequence similarity (only three parsimoniously informative sites). In the TCS and phylogenetic analyses, all the examined C. serpentina samples coincidently formed a strong monoclade with those collected mostly from Kansas State, USA, indicating that the imported ones to South Korea are from the central North America. In addition, there found the amino acid changes and the high degree of nucleotide sequence differences between C. serpentina and C. rossignoni with some important morphological characters. It is expected that the present results could provide an important framework for systematic management and control of exotic snapping turtles imported and released to nature of South Korea.

• BMB Reports
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• v.40 no.6
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• pp.1028-1038
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• 2007

Human plasma Hp is classified as 1-1, 2-1, and 2-2. They are inherited from two alleles Hp 1 and Hp 2, but there is only Hp 1 in almost all the animal species. Hp 2-2 molecule is extremely large and heterogeneous associated with the development of inflammatory-related diseases. In this study, we expressed entire bovine Hp in E. coli as a $\alpha\beta$ linear form. Interestingly, the antibodies prepared against this form could recognize the subunit of native Hp. In stead of a complicated column method, the antibody was able to isolate bovine Hp via immunoaffinity and gelfiltration columns. The isolated Hp is polymeric containing two major molecular forms (660 and 730 kDa). Their size and hemoglobin binding complex are significantly larger than that of human Hp 2-2. The amino-acid sequence deducted from the nucleotide sequence is similar to human Hp 2 containing a tandem repeat over the $\alpha$ chain. Thus, the Hp 2 allele is not unique in human. We also found that there is one additional -SH group (Cys-97) in bovine $\alpha$ chain with a total of 8 -SH groups, which may be responsible for the overall polymeric structure that is markedly different from human Hp 2-2. The significance of the finding and its relationship to structural evolution are also discussed.

• Rapid Communication in Photoscience
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• v.1 no.2
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• pp.42-42
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• 2012

• Korean journal of applied entomology
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• v.32 no.4
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• pp.373-381
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• 1993

Resistance evolution to organophosphate-based pesticides in apple and pear inhabiting arthropods of western North America extends to many classes of pest and some beneficial species. Resistance management programs to minimize resistance in pests while exploiting it in natural enemies have met with mixed success. Among beneficials, resistances have been exploited mostly among predators of pest mites. Evolution of resistant mites, leafminers, leafhopper, aphids, leafrollers and some internal fruit feeders have led to development of new monitoring methods and means to delay or avoid resistance. But it is resistance to azinphosmethyl in codling moth (Cydia pomonella) that is changing the pest control system and moving it from chemical to biologically-based means. Newly merging IPM system will depend more on use of biological, cultural, behavior and genetic controls. But more selective pesticides also will be needed to augment pheromones, resistant host plants and genetically altered organisms. These more biologically-based tactics will be prone to resistance evolution in pests as well, if used too unilaterally and/or too extensively.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.133-154
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• 2023

The Korean Peninsula is geographically located in the centre of Far Eastern Asia and has complex and various climate conditions following longitudinal topology, which would expect to be result in high diversity and endemism of millipede. In this study, the millipede fauna of the Korean Peninsula consists of 68 species plus 5 subspecies from 29 genera, 15 families and 7 orders. Of these species/subspecies, 29 and 12 are endemic in South Korea and North Korea, respectively; nine are recorded in both South Korea and North Korea. Each species has been provided comprehensive information including an original report, taxonomic changes, distribution, and remarks if necessary. Moreover, unsolved taxonomic uncertainty of some species included in this checklist should be investigated through further study.

• Animal Systematics, Evolution and Diversity
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• v.23 no.1
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• pp.103-105
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• 2007

A taxonomic study on Hoplophrys oatesii Henderson, 1893 was conducted with materials collected from Jejudo Island of Korea by SCUBA diving. H. oatesii is redescribed with some remarks on variations of dactylus and the number of segments of abdomen. The Korean Pisid fauna now consists of seven species of five genera.

• Animal Systematics, Evolution and Diversity
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• v.23 no.1
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• pp.91-93
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• 2007

A taxonomic study on the marine sponges was conducted with materials which were collected from Hongdo Island, Korea by SCUBA diving in September 2004. Among them, Higginsia mixta Hentschel, 1912 is newly recorded in the Korean fauna.

• Animal Systematics, Evolution and Diversity
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• v.23 no.1
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• pp.75-85
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• 2007

A taxonomic study was carried out on the Perinereis nuntia species group of Korea by using morphological and molecular data (mitochondrial cytochrome c oxidase subunit I: mtCOI). Two species, P. mictodonta (Marenzeller, 1879) and P. wilsoni (Glasby and Hsieh, 2006), are recognized and redescribed. In this study, mtCOI gene showed a good resolution as molecular marker for species identification of the P. nuntia species group of Korea.