• Journal of Embryo Transfer
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• v.16 no.3
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• pp.223-231
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• 2001

The success of nuclear transplantation with mammalian oocytes depends critically on the potential of oocytes activation, which mainly caused to prevent the re-accumulation of maturation promoting factor (MPF). This study was conducted to compare the effect of combined treatment of lonomycin with a Hl-histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on activation of bovine oocytes. In vitro matured bovine oocytes with the first polar body (PB) and dense cytoplasm were assigned to 3 experimental groups. For activation treatment, oocytcs were exposed to 5 $\mu$M lonomycin for 5 min (Group 1), and followed by 1.9 mM dimethylaminopurine (DMAP) for 3 h (Group 2) or followed by 2 mM sodium pyrophosphate (SPP) for 3 h (Group 3). The activation effects in the three treatments and the control group (untreated) were judged by the extrusion of the second PB and formation of a pronucleus (PN). Differences among groups were analysed using one-way ANOVA after arc-sine transformation of proportional data. All three treatments led to high activation rates (90% to 95%), with significant difference from the control. However, the extrusion of the second PB and the rate of PN formation differed remarkably among treatments. In Group I and 3, about 95% of the oocytes had extruded the second polar body, but one PN had formed in a higher proportion of oocytes in Group 3 than in Group 1 (90% vs. 5%). In experiment 2, the rates of cleavage and development into blastocysts in Group 1 were significantly lower than those of Group 2 and 3 (8.7% and 0% vs. 50.5% and 11.6%, and 44.6% and 7.2%, respectively, P<0.05). In experiment 3, ~80% of parthenotes in Group 1 were developed with haploid chromosomal sets. However, when ionomycin was followed immediately by DMAP (Group 2). only 20% of parthenotes were haploid. In Group 3, combined treatment with ionomycin and SPP, the appearance of abnormal chromosomal tracts was significantly (P〈0.05) reduced and the proportion of haploid parthenotes was increased to 85% (17/20) than in Group 2. These results demonstrate that SPP acted as a cdc2 kinase inhibitor and formed the haploidy in oocyte activation. Thus, the present study suggests that cdc2 kinase inhibitor, such as sodium pyrophosphate, may have an effective role in oocyte activation for the production of cloned embryos/animals by nuclear transplantation.

• Journal of Microbiology
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• v.39 no.1
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• pp.49-55
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• 2001

We have developed four chicken hybridomas secreting monoclonal antibodies to induce a protective immune response against the chicken disease avian coccidiosis, caused by the intestinal parasite Eimeria acervulina. Huwever, since the amount of antibodies secreted from these hybridomas is too low or sometimes they lost their ability to produce antibodies, the hybridoma method is not satisfactory in the production of large amounts of chicken monoclonal antibodies. To bypass these problems, we applied the antibody engineering technology using polymerase chain reaction. We cloned and determined the sequences of variable domains of the four chicken monoclonal antibodies, namely, 2-1, 5D11, 13C8 and 8C3. The sequences comparison to germline sequences skewed that the gene con version mechanism might contribute to developing diversification of heavy and λ-light chains in chicken antibodies. Several pseudogene families regarded as donors in gene conversion were identified at each framework region and the complementarily determining region of λ-light chains. In addition, as expected, numerous changes of nucleotide sequences such as nucleotide substitution, insertion and deletion were found predominantly in complementarity determining regions, which are likely to be somatic hypermutations as a result of affinity maturation in antibody-producing cells.

• Journal of Life Science
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• v.14 no.3
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• pp.521-524
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• 2004

This experiment was carried out to analyze genetic characteristics and to develop the breed specific DNA marker for Cheju-native horse. If this marker contains high repetitive sequences, it is possible to convert a RAPD marker of interest into a single-locus PCR marker called a sequence characterized amplified region(SCAR). Twenty six Cheju-native horse and Fifty thoroughbred genomic DNA were pooled and PCR. were accomplished using 800 random primers. Comparing the pooled DNA from Cheju-native horse and thoroughbred, we found 9 primers which identified markers present in the pooled DNA from breed but absent in the other breed. Among 9 random primers, 6 primers were thoroughbred specific and 3 primers were Cheju-native horse specific. Testing individual horse revealed that 5 marker showed the similar band pattern between Cheju-native horse and Thoroughbred. However, 4 marker were wholly absent in breed while present in the other breed. UBC $126_{3500bp}$, UBC $162_{500bp}$, and UBC $244_{1200bp}$ was detected only Thoroughbred and UBC $562_{560bp}$was detected Cheju-native horse, respectively. After determining of the cloned breed-specific fragment sequence, we designed the SCAR-primers and carried out PCR. Compared to random primer, RAPD-SCAR primer didn't show significantly higher specific band. However, RAPD analysis is useful for genetic characterization of Cheju-native horse.

• Journal of Animal Science and Technology
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• v.53 no.3
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• pp.203-209
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• 2011

Lysophosphatidic acid (LPA) is a small lipid molecule that plays an important role through LPA receptors (LPARs) in reproductive processes. Our previous study has shown maximal expression of LPAR3 in the uterine endometrium on day (D) 12 of pregnancy in pigs, the period when conceptus secretes various molecules such as estrogen and interleukin-$1{\beta}$ (IL1B) and initiates implantation. We determined that endometrial expression of LPAR3 was increased by conceptus estrogen in the previous study, but the effect of IL1B on LPAR3 expression has not been determined. Thus, in this study we examined whether LPAR3 expression was also affected by IL1B. Endometrial explant cultures from D12 of the estrous cycle showed that levels of endometrial LPAR3 expression did not changed in response to IL1B. We also investigated LPAR3 expression in the uterine endometrium on D12 and D30 of pregnancy from gilts with conceptuses derived from somatic cell nuclear transfer (SCNT). The expression of LPAR3 mRNA was lower in endometria from gilts with conceptuses resulting from SCNT compared with those from gilts with embryos resulting from natural mating on D12 of pregnancy, but it was not different between them on D30 of pregnancy. Our results indicate that estrogen of conceptus origin is responsible for induction of LPAR3 expression during the peri-implantation period and appropriate LPA signaling is impaired in the uterine endometrium with SCNT-derived conceptuses during the implantation period in pigs.

• Development and Reproduction
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• v.9 no.1
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• pp.33-41
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• 2005

Identification of differentially expressed genes at blastocyst stage embryos would provide insights into early development and differentiation. Here, we applied a new differential display reverse transcription polymerase chain reaction(DD RT-PCR) technology, called annealing control primers(ACP) system to identify the genes that are specifically or prominently expressed in mouse blastocysts compared to embryonic stem(ES) cells. Using 100 ACPs, 26 clones were perceived as differentially expressed genes in mouse blastocysts. A BLAST search revealed that cloned genes had significant sequence similarities with known genes in the GenBank/EMBL data base. Among them, 15 genes were selected and conformed by RT-PCR. This analysis suggests that the ACP system is a practical method for the identification of stage-specific genes using small numbers of mouse embryos.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.113-119
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• 1994

To improve nuclear transplantation(NT) efficiency and to produce a large scale genetically identical cloned calves, examined the in vitro development capacity after co-culture of bovine oviductal epithelial cells (BOEC) and granulosa cells in TCM-199 supplemented with 10% fetal calf serum (FCS) with early bovine embryos derived from in vitro matured fertilized(IVM-IVF) oocyte. In addition, the age dependence of IVM oocyte on electro-stimulation and the effective electric voltage on in ivtro development of bovine NT embryos were examined. The results obtained were summerized as follows; 1. The cleavage rates of IVM-IVF bovine embryos in co-culture with bovine oviductal epithelial cells and granulosa cells were not significantly different(P<0.05), but the developmental rate into morula and blastocyst stage were different showing 38.3 and 20.2%, respectively. 2. The activation (82.5%) and development in vitro(8.6%) into later embryo stages of the aging oocytes of 32 hours post-maturation (hpm) were significantly higher than those of 24 hpm at direct current (DC) voltage of 1.5kV/cm, 60$\mu$sec pulse duration and 1 pulse time. 3. The fusion rates of NT eggs of 32 hpm following to different DC voltages from range 0.75 to 1.5kV/cm were not differ, but the developmental rate into morula and blastocyst stages at DC voltages of 0.75 and 1.0kV/cm were higher(11.4 and 12.6%, respectively) than those of 1.5kV/cm(0%). From these results, it can be suggested the optimal culture system for in vitro culture of IVM-IVF bovine embryos is a co-culture system with BOEC in TCM-199 supplemented 10% FCS. The effective time and the DC voltage for activation, electrofusion and in vitro development of NT embryos derived from IVM-IVF bovine embryo are 32hpm and 0.75~1.0kV/cm. But to improve NT efficiency, the advanced research (cell cycle synchronization, micromanipulation, culture system, etc.) is needed.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1498-1504
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• 2005

Competitive direct ELISA was developed to detect gentamicin residues. Mice immunized with gentamicin-keyhole limpet hemocyanin (KLH) conjugate developed good antiserum titers, which gradually increased with booster injections, indicating immunization was successfully processed. Monoclonal antibody against gentamicin was prepared using hybridoma cells cloned by limit dilution of fused cells. IgG was purified from ascites fluid of hybridoma cell-injected mice through ammonium sulfate precipitation and Sephadex G-25 gel filtration. After the gel filtration, fractions of high antibody titer were further purified through affinity chromatography on protein A/G column. Monoclonal antibody against gentamicin was confirmed as IgG1, which has kappa light chain. Cross-reactivities ($CR_{50}$) of gentamicin monoclonal antibody to other aminoglycosides (kanamycin, neomycin, and streptomycin) were less than 0.005%, indicating the monoclonal antibody was highly specific for gentamicin. Standard curve constructed through competitive direct ELISA showed measurement range (from 80 to 20% of B/$B_0$ ratio) of gentamicin was between 1 and 40 ng/ml, and 50% of B/$B_0$ ratio was about 4 ng/ml. The gentamicin concentration rapidly increased to 1,300 ng/ml after the intramuscular administration up to 2 h, then sharply decreased to less than 300 ng/ml after 4 h of withdrawal, during which the elimination half-life ($t_{1/2}$) of gentamicin in the rabbit plasma was estimated to be 1.8 h. Competitive direct ELISA method developed in this study using the prepared monoclonal antibody is highly sensitive for gentamicin, and could be useful for detecting gentamicin residues in plasma of live animals.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.982-995
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• 2020

A putative multidrug efflux gene, yddA, was cloned from the Escherichia coli K-12 strain. A drug-sensitive strain of E. coli missing the main multidrug efflux pump AcrB was constructed as a host and the yddA gene was knocked out in wild-type (WT) and drug-sensitive E. coliΔacrB to study the yddA function. Sensitivity to different substrates of WT E.coli, E. coliΔyddA, E. coliΔacrB and E. coliΔacrBΔyddA strains was compared with minimal inhibitory concentration (MIC) assays and fluorescence tests. MIC assay and fluorescence test results showed that YddA protein was a multidrug efflux pump that exported multiple substrates. Three inhibitors, ortho-vanadate, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and reserpine, were used in fluorescence tests. Ortho-vanadate and reserpine significantly inhibited the efflux and increased accumulation of ethidium bromide and norfloxacin, while CCCP had no significant effect on YddA-regulated efflux. The results indicated that YddA relies on energy released from ATP hydrolysis to transfer the substrates and YddA is an ABC-type multidrug exporter. Functional study of unknown ATP-binding cassette (ABC) superfamily transporters in the model organism E. coli is conducive to discovering new multidrug resistance-reversal targets and providing references for studying other ABC proteins of unknown function.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.458-460
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• 2006

A 2-year-old female, 3.8kg weight, mixed-breed dog was presented for a 10-day history of vomiting and anorexia. The dog was diagnosed with pelvic fracture by vehicular accident at a local animal hospital before 2 months, but fracture did not reconstructed. After 2 months, the dog suffered from intermittent vomiting and anorexia. On barium contrast, we diagnosed the dog as intestinal obstruction. Consequently, we were found obstruction by strangulation and adhesion of intestine at the fracture site through the operation. At present after 18 months of surgery, general physical condition of the dog is good.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.576-584
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• 2002

Bovine PAS-4 is an integral membrane glycoprotein expressed in mammary epithelial cells. Complementary DNA (cDNA) cloning of PAS-4 was performed by reverse-transcriptase polymerase chain reaction (RT-PCR) with oligonucleotide probes based on it's amino terminal and internal tryptic-peptides. The cloned PAS-4 cDNA was 1,852 nucleotides (nt) long and its open reading frame (ORF) was encoded 1,413 base long. The deduced amino acid sequence indicated that PAS-4 consisted of 471 amino acid residues with molecular weight of 52,796, bearing 8 potential N-glycosylation sites and 9 cysteine residues. Partial bovine CD36 cDNA from liver also was sequenced and the homology of both nucleotide sequence was 94%. Most of the identical amino acid residues were in the luminal/extracellular domains. Contrary to PAS-4, bovine liver CD36 displays 6 potential N-glycosylation sites, which were located, except for those at positions 101 and 171, at same positions as PAS-4 cDNA. Cysteine residues of PAS-4 and CD36 were same at position and in numbers. Northern blot analysis showed that PAS-4 was widely expressed, although its mRNA steady-state levels vary considerably among the analyzed cell types. PAS-4 possessed hydrophobic amino acid segments near the amino- and carboxyl-termini. Two short cytoplasmic tails of the amino- and carboxyl-terminal ends constituted of a 5-7 and 8-11 amino acid residues, respectively.