• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.27-32
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• 2004

Using MLV (murine leukemia virus)-based retrovirus vectors encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein), we tried to make transgenic chickens carrying the transferred genes in their chromosomes. Twenty one days after virus injection beneath the blastoderms of unincubated chicken embryos (stage Ⅹ, at laying), DNA isolated from the hatched chicks were analyzed by PCR with two sets of primers specific for EGFP (enhanced green fluorescence protein) gene or $Neo^R$ (E. coli neomycin resistant) gene. Among sixty-seven embryos injected with retrovirus, four of them were identified to carry the EGFP genes in their genomes. Remarkably, one transgenic chick showed presence of the retrovirus vector sequences in all organs differentiated from one of endoderm, mesoderm, and ectoderm. Expression of EGFP gene was not detected, however, the stable germ line transmission of transgene was verified in spermatozoa from the founder chicken and 50% of $F_1$ progenies.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.163-169
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• 2001

Despite the high potency of the retrovirus vector system in gene transfer, one of the main drawbacks of has been difficulty in preparing highly concentrated virus stock. Numerous efforts to boost the virus titer have ended in unsatisfactory results mainly due to fragile property of retrovirus envelope protein. In this study, to overcome this problem, we constructed our own retrovirus vector system producing vector viruses encapsulated with VSV-G (vesicular stomatitis virus G glycoprotein). Concentration process of the virus stock by ultracentrifuge did not sacrifice the virus infectivity, resulting in more than 108 to 109 CFU (colony forming unit) per ml on most of the target cell lines tested. Application of this high-titer retrovirus vector system was tested on chicken embryos. Injection of virus stock beneath the blastoderms of pre-incubated fertilized eggs resulted in chick embryos expressing E. coli LacZ gene with 100% efficiency. Therefore, our results suggest that it is possible to transfer the foreign gene into chicken embryo using our high-titer retrovirus vector.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.359.2-359.2
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• 2002

In the previous study, we reported that 2'-hydroxy-4'-methxoychalcone, synthetic chalcone inhibited PGE2 production in TPA- stimulated rat peritoneal macrophages by inhibiting the induction of COX-2 protein. The present study was carried out to clarify whether 2'-hydroxy-4'-methoxychalcone inhibit angiogenesis by the experimental methods in vitro and in vivo. 2'-Hydroxy-4'-methoxychalcone decreased angiogenesis of both chick embryos in the chorioallantoic membrane assay and basic fibroblast growth factor-induced vessel formation inthe mouse Martigel plug assay. (omitted)

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.111-111
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• 2003

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.

• The Korean Journal of Zoology
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• v.25 no.2
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• pp.55-62
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• 1982

DNA synthesis, unscheduled DNA synthesis, excision of pyrimidine dimers and phtoreactivation were determined in UV-irradiated differentiating muscle cells at various times of primary culture of 12 day chick embryos and results obtained were as follows. The rates of UV-induced unscheduled DNA synthesis were increased as increase of UV dose. And the rates were gradually decreased as the increase of time after culture, but at higher doses the decreasing tendency was remarkable. The patterns of DNA replication were changed drastically as a function of time so that in the seven day cultures the rate of $^3$H-thymidine incorporation was found to be 0.2% of the original activity. The pattern of inhibition of DNA replication by UV damage demonstrated that in cells of earlier stages there were no remarkable changes, but in cells of later stages there was significant fluctuation. Photoreactivation and the excision of pyrimidine dimer in the one day cultures showed that photoreactivation occurred immediately after UV-irradiation, but excision of pyrimidine dimer was gradually and slowly occurred. These results indicate that the differentiation of embryonic muscle cells accompanies the gradual reduction of DNA replication and unscheduled DNA synthesis, and that the photoreactivation is rapid process compared to excision repair.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.1-12
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• 2003

The present study was carried out to establish the standard karyotype of the Korean Native Chicken and to find their chromosomal band markers using high-resolution banding technique. Chromosome analysis was performed on early chick embryos following in vitro culture of fertilized eggs of the yellow-brown and the red-brown lines of the Korean Native Chicken which had been established at National Livestock Research Institute. The high-resolution banding of the chromosome was achieved by treating the embryos with ethidium bromide and colchicine during culture. On GTG-banding, the Korean Native Chicken exhibited a typical chick banding pattern in all the macrochromosomes. Overall chromosomal morphology and positions of typical landmarks of the Korean Native Chicken were virtually identical to those of White Leghorn and International System for Standardized Avian Karyotypes(ISSAK). However, the lengths and G-band numbers of the Korean Native Chicken macrochromosomes were greater than those of White Leghorn and ISSAK. Especially in chromosomes 1 and Z, the Korean Native Chicken exhibited more separated bands in compared with ISSAK. In C-banding patterns, although a lot of observed cells had C-band polymorphic patterns, almost the Korean Native Chicken macrochromosomes had heterochromatic C-band on centromeres and/or near terminal part. However, the heterochromatic C-band was constantly observed at the end of q-arm of Z chromosomes and on the whole W chromosome. In addition, the Korean Native Chicken exhibited distinctive heteromorphic patterns of C-bands on the centromere of chromosome 3 and at the end of q-arm of Z chromosome between homologous chromosomes.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.781-787
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• 2009

The sense and antisense digoxigenin-labeled RNA probes of four genes, Cdc25A, Cdc25B, Sox2 and Mnb, were produced by using SP6 and T7 RNA polymerases, respectively, and in vitro transcription. Expression patterns of the four genes were detected by in situ hybridization in HH (Hamburger and Hamilton) stage 10 chick embryos. In general, expression patterns of the four genes were similar. mRNA of the four genes was mostly restricted to the entire CNS (central nervous system). All were confined to an identical region, neural tube, neural groove and caudal neural plate, corresponding to the notochord or spinal cord, but there was some distinction in specific region or in concentration, for example in somites. The overlap in expression at the same developmental stage in the CNS suggests that the four genes may be functional similar or related in CNS development. Expression patterns of the four genes support specific roles of these regulators in the developing CNS.

• BMB Reports
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• v.46 no.8
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• pp.404-409
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• 2013

Extracellular superoxide dismutase (EC-SOD) is a metallo-protein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.656-662
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• 2001

Angiogenesis is known as a crucial process in the growth and spreading of tumor cells. Accordingly, the effective inhibition of this process would appear to be a promising way to cure angiogenesis-related diseases, including cancer. This study demonstrates that acalycixenolide E (AX-E) from the marine organism Acalycigorgia inermis exhibits a potent anti-angiogenic activity both in vitro and in vivo. AX-E inhibits the bFGF-induced proliferation of HUVECs in a dose dependent manner, along with the bFGF-induced migration, invasion, and tube formation of HUVECs. Moreover, AX-E potently inhibits the in vivo neovascularization of the chorioallantoic membranes (CAMs) of growing chick embryos. interestingly, AX-E suppresses the expression of metalloproteases 2 and 9, yet shows no effect on their activities. The novel chemical structure and potent anti-angiogenic activity of AX-E will be of great value in elucidating the molecular mechanism of angiogenesis as well as in the development of a novel anti-angiogenic drug.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.201-207
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• 1989

This study was carried out to identify the chromosome morphological structure and G-, C-banding pattern of Korean native fowl. The samples used in this study were early chick embryos, and the method of chromosomal analysis quoted from the protocal of Ohio univ. with more or less modified. The results were summerized as follow as； 1. In each of macrochromosomal morphology, the arm-ratio, centromeric index, and relative length of Korean native fowl were more or less different from improved breeds, but the designations were the same. 2. The graphical pecks, by densitometric recordings, in each macrochromosome number of 1, 2, 3, 4, Z, and 5, numbered 21, 14, 12, 8, 11, and 4 in G-banded, and 16, 13, 9, 9, 9, and 4 in C-banded, respectively. Those pecks could be explained as a consequence of chromosome condensation during mitosis and of genetic material differences.