• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.49-55
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• 2003

We describe the generation of transgenic silkworm that carrying the chimeric fibroin light chain (L-chain) gene. Previously, we have cloned the complete fibroin L-chain gene from the silkworm Baekok-Jam, Bombyx mori, and the complete fibroin gene from the oak silkworm, Antheraea yamamai. The 444 bp repetitive sequence of A. yamamai fibroin gene was inserted into the exon 6 of B. mori fibroin L-chain gene to produce chimeric fibroin L-chain gene. The chimeric fibroin L-chain gene was cloned into the polyhedrin gene site of Autographa californica nuclear polyhedrosis virus (AcNPV) to yield a recombinant baculovirus as a fibroin gene targeting vector, One-day-old fifth instar female silkworm larvae were injected with the recombinant baculovirus and then mated with normal male moths. Genomic DNA from their progenies was extracted and screened for the desired targeting event by using PCR and Southern blot analysis. The analysis showed that the chimeric fibroin gene had intergrated into the L-chain gene on the genome by homologous recombination and was transmitted through generations. The transgenic silkworm carrying the chimeric fibroin gene were approximately 43.2% in $F_2$ generation, and the silkworms synthesized the fusion protein in cocoons layer.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.77-77
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• 2003

Chimeric animals are referred to as an organism composed of tissues derived from more than one species. In order to examine if a pluripotency of embryonic stem cells can cross the limitation of a species, we tried to establish human-mouse chimeric animals. Human embryonic stem cells were genetically modified to express eGFP using eukaryonic expression vector pcDNA 3.1 (In Vitrogene) for an easy identification. After selection with neomycin, approximately 15 cells were implanted into mouse blastocoele cavity. Ten chimeric blastocysts were transferred to one of the uterine horn of 2.5 days pesudopregnent ICR female. Out of 272 blastocysts transferred to pseudopregnant recipients 20 live newborn were obtained after 20 days. When newborn were obtained, pups were quickly removed immersed into 4% PFA. By histological examination using fluorescent microscope, green fluorescence was observed from the liver, heart, and spleen in newborn mice. Three weeks after born, presence of eGFP sequence within mouse genome (tail and kidney) was reconfirmed by PCR. eGFP sequence was amplified from the progenies of the animal suggesting a genetic transmission of the transgene. These chimeric mice having human cells at the beginning of development, are expected to recognize human cells as “self”, therefore, human cells or tissues will be able to escape the immunological surveillance of the host if grafted into the animal. These animals will serve as a good model system for studying the graft rejection in tissue transplantation and the potential of the cells to work well in many human disease.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.121-124
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• 2002

This work was initiated to develope a recombinant oral poliovaccine (OPV), which is highly advanced in safety (minimizing VAPP) by introducing Type 2,3 poliovirus epitopes into our RPS-Vax system. We have introduced several potential vaccine epitopes of poliovirus Type 2, and 3 into RPS-Vax system, resulting in production of recombinant polioviruses. Any of these chimeric viruses, however, were not detected for their foreign gene expression by serotype-specific mouse antiserum. We have designed several folding units to stabilize the introduced vaccine protein and attached short epitope-concatamer or epitope-multimer to them, followed by production of chimeric viruses. Only those who have an HIV-1 Tat-mediated folding unit were nicely detected for the introduced foreign proteins by anti-Tat antiserum and type-specific peptide-induced antisera. Nevertheless, introduced epitopes were not detected in Western blot experiment with each serotype-specific antiserum. None of the mice inoculated with these chimeric viruses showed preventative immunity when challenged with Lansing and Leon wildtype 2 and 3 poliovirus, and the antiserum did not show neutralizing capacity in vitro. Conformational epitope covering B/C loop region of type 2 and 3 were newly designed by computer modeling, and introduced into the RPS-Vax vector system, followed by production of chimeric viruses. Introduced epitope regions were nicely detected by anti-Tag23 mAb or peptide antibody, but still not detected by poliovirus antiserum. Nevertheless, neutralizing antibody was detected in the Tg-PVR mice even when inoculated once with these chimeric viruses. Also, the immunized mice showed perfect preventative immunity against the wild Type poliovirus Lancing or Leon. When boosted appropriately, those chimeric virus-inoculated Tg-PVR mice produced equivalent amounts of neutralizing antibody to those in Sabin 2/3-immunized mice. These data strongly suggest that our recombinant poliovirus (RPS-PV2 and RPS-PV3) can be used as a safe and effective rec-OPV instead of any preexisting poliovaccine.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.597-604
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• 2009

Purpose: Compound tissue defects remain a challenge to reconstructive surgeons. The objective of this study was to introduce examples of successful reconstruction of compound defects of the head and neck and upper and lower limbs, using chimeric flaps based on the subscapular vascular system. Methods: We report 19 reconstruction cases using chimeric flaps based on the subscapular vascular system. The scapular flap, scapular fascia, scapular bone, parascapular flap, latissimus dorsi, latissimus dorsi perforator flap, latissimus dorsi myocutaneous perforator flap, serratus anterior, serratus anterior fascia, and rib bone were used as components for chimeric flaps. 12 cases had defects of the upper limb, three in the lower limb, three in the head and neck area, and one case had a defect of the thoracoabdominal wall. Results: Defect sizes ranged from $6{\times}8cm$ to $20{\times}22cm$. The component used most often for skin coverage was the latissimus dorsi perforator flap; for soft tissue bulk, the latissimus dorsi; for fascia coverage, the serratus anterior fascia flap; and for bone reconstruction, the scapular bone flap respectively. All cases were successfully reconstructed without additional operative procedures or flap necrosis. Conclusion: Because it is fairly easy to employ vascular pedicles of sufficient length and diameter, enabling the use of diverse types of tissue with various shapes and sizes, the use of chimeric flaps based on the subscapular vascular system allows one - stage reconstruction tailored to the characteristics of the defect area.

• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.24-31
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• 2020

Five genes (mxbDM, mxcQE and mxaB) are responsible for the transcription of methanol oxidation genes in Methylobacterium strains. Among these, MxbDM and MxcQE constitute the two-component system (TCS) regulating methanol metabolism. In this study, we integrated the methanol-sensing domain of MxbD and MxcQ with the EnvZ/OmpR from Escherichia coli. The domain-swapping strategy resulted in chimeric histidine kinases (HK's) MxbDZ and MxcQZ AM1 containing recombinant E. coli. Real-time quantitative PCR was used to monitor OmpC expression mediated by the chimeric HK and response regulator (RR) OmpR. Further, an ompC promoter based fluorescent biosensor for sensing methanol was developed. GFP fluorescence was studied both qualitatively and quantitatively in response to environmental methanol. GFP measurement also confirmed ompC expression. Maximum fluorescence was observed at 0.05% methanol and 0.01% methanol using MxbDZ and MxcQZ AM1, respectively. Thus the chimeric HK containing E. coli were found to be highly sensitive to methanol, resulting in a rapid response making them an ideal sensor.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.835-842
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• 2014

Haloperoxidase (HPO, E.C.1.11.1.7) is a metal-containing enzyme oxidizing halonium species, which can be used in the synthesis of halogenated organic compounds, for instance in the production of antimicrobial agents, cosmetics, etc., in the presence of halides and $H_2O_2$. To isolate and evaluate a novel non-metal HPO using a culture-independent method, a cassette PCR library was constructed from marine seawater in Japan. We first isolated a novel HPO gene from Pseudomonas putida ATCC11172 by PCR for constructing the chimeric HPO library (HPO11172). HPO11172 showed each single open-reading frame of 828 base pairs coding for 276 amino acids, respectively, and showed 87% similarity with P. putida IF-3 sequences. Approximately 600 transformants screened for chimeric genes between P. putida ATCC11173 and HPO central fragments were able to identify 113 active clones. Among them, we finally isolated 20 novel HPO genes. Sequence analyses of the obtained 20 clones showed higher homology genes with P. putida or Sinorhizobium or Streptomyces strains. Although the HPO A9 clone showed the lowest homology with HPO11172, clones in group B, including CS19, showed a relatively higher homology of 80%, with 70% identy. E. coli cells expressing these HPO chimeric genes were able to successfully bioconvert chlorodimedone with KBr or KCl as substrate.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.150-151
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• 1998

Drug delivery to the brain is facilitated by the synthesis of chimeric peptides, where in neuropharmaceuticals are linked to a vector such as an antibody to the transferrin receptor that mediates transcytosis through the blood-brain barrier (BBB). When disulfide linkers are used in the chimeric peptide, it is crucial that the S-S bridge is stable during transit and that cleavage does not occur prematurely within endothelial cells, as the peptide drug moiety would then be sequestered by the BBB instead of passing through it. The present study addressed that problem. As a model drug a metabolically stable opioid peptide, [$^3$H]DALDA (Tyr-dArg-Phe-Lys-NH$_2$), was used. It was monobiotinylated with NHS-SS-biotin to yield bio-[$^3$H]DALDA. The biotinylated peptide was bound to the vector OX26-SA which is a covalent conjugate of OX26 and streptavidin (molar ratio = 1: 1). In vitro treatment of the chimeric peptide, bio-[$^3$H]DALDA/OX26-SA, with a reducing agent, dithiothreitol, released the labeled peptide from the vector by conversion of bio-[$^3$H]DALDA to the desbiotinylated derivative, desbio-[$^3$H]DALDA.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.79-84
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• 1999

Oxidative stress is one of the major environmental stresses to plants. Reactive oxygen species (ROS) generated during metabolic processes damage cellular functions and consequently lead to cell death. Fortunately plants have in vivo defense system by which the ROS is scavenged by enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). In attempts to understand the protection mechanism of plant against oxidative stress, we developed transgenic tobacco (Nicotiana tabacum cv. Xanthi) plansts thet expressed both SOD and APX in chloroplast using Agrobacterum-mediated transformation and evaluated their protection capabilities against methyl viologen (MV, paraquat) -mediated oxidative damage. Three double transformants (CAI, CA2, and CA3) expressed the chimeric CuZnSOD and chimeric APX in chloroplast, and one transformant (AM) expressed the chimeric APX and chimeric MnSOD in chloroplast. In addition, we obtained three lines of transformants (C/Al, C/A2, and A/C) that expressed the APX and SOD than control plants, and more resistant to oxidative stress caused by MV. TRansformants (C/A and A/C) overexpressing MnSOD, CuZnSOD and APX at the same time showed the highest resistance to MV-mediated oxidative stress among the transformants.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.48-48
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• 2002

Chimerism has become an important tool for investigating fundamental aspects of early embryonic development and differentiation in mammals for producing transgenic animals. The objective of this study was to evaluate the developmental capacity of chimeric embryos reconstructed with parthenotes and IVF bovine embryos into empty zona pellucida. The MII oocytes were activated by two treatment groups [Group 1, 5 μM inomycin, 5min, ＋ 10 ㎍/㎖ cycloheximide (CHX)/5 ㎍/㎖ cytochalasin B (CCB), 3 h; Group 2, 5 μM ionomycin, 5 min ＋ 1.9 mM 6-dimetylaminopurine (6-DMAP), 3 h]. (omitted)

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.162-166
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• 2001

Helicobacter pylori is a major cause of gastric-associated diseases. In our previous study, the Adhesin/CTXA2B was expressed as insoluble recombinant chimeric protein derived from the H. pylori adhesin genetically coupled to CTXA2B subunit in Escherichia coli. Since it is very important to optimize IPTG concentration, culture temperature and composition of medium to maximize cell growth and productivity, these conditional growth factors were determined for increasing the productivity of the expressed Adhesin/CTXA2B chimeric protein in Escherichia coli JM101 carrying pTEDhpa/ctxa2b. Our data demonstrate that optimal medium for increased production of chimeric protein was a YCP/Glu medium composed of 2% yeast extract, 1% casamino acid, phosphate solution [0.3% $KH_2P0_4$, 0.4% $Na_2HP0_4$, 0.25% ($NH_4)_2HPO_4$], and 0.5% glucose. In addition, optimal concentration of IPTG was 1 mM and culture temperature, $37^{\circ}C$.