• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.40-46
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• 2001

The use of pluripotent stem cells has tremendous advantages for various purposes but these cell lines with proven germ-line transmission have been completely established only in the mouse. Embryonic germ (EG) cell lines are also pluripotent and undifferentiated stem cells established from primordial germ cells (PGCs). This study was conducted to establish and characterize the chicken EG cells derived from gonadal primordial germ cells. We isolated gonadal PGCs from 5.5-day-old (stage 28) White leghorn (WL) embryos and established chicken EG cells lines with EG culture medium supplemented with human stem cell factor (hSCF), murine leukemia inhibitory factor (mLIF), bovine basic fibroblast growth factor (bFGF), human interleukin-11 (hIL-11), and human insulin-like growth factor-I (hIGF-I). These cells grew continuously for 4 months (10 passages) on a feeder layer of mitotically active chicken embryonic fibroblasts. These cells were characterized by screening with the Periodic acid-Shiff＇s reaction, anti-SSEA-1 antibody, and a proliferation assay after several passages. As the results, the chicken EG cells maintained characteristics of undifferentiated stem cells as well as that of gonadal PGCs. When cultured in suspension, the chicken EG cells successfully formed an embryoid body and differentiated into a variety of cell types when re-seeded onto culture dish. The chicken EG cells were injected into blastodermal layer at stage X and dorsal aorta of recipient embryo at stage 14 (incubation of 53hrs) and produced chimeric chickens with various differentiated tissues derived from the EG cells. The germline chimeras were also successfully induced by using EG cells. Thus, Chicken EG cells will be useful for the production of transgenic chickena and for studies of germ cell differentiation and genomic imprinting.

• Molecules and Cells
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• 제38권10호
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• pp.895-903
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• 2015

Non-coding microRNAs (miRNAs) regulate the translation of target messenger RNAs (mRNAs) involved in the growth and development of a variety of cells, including primordial germ cells (PGCs) which play an essential role in germ cell development. However, the target mRNAs and the regulatory networks influenced by miRNAs in PGCs remain unclear. Here, we demonstrate a novel miRNAs control PGC development through targeting mRNAs involved in various cellular pathways. We reveal the PGC-enriched expression patterns of nine miRNAs, including miR-10b, -18a, -93, -106b, -126-3p, -127, -181a, -181b, and -301, using miRNA expression analysis along with mRNA microarray analysis in PGCs, embryonic gonads, and postnatal testes. These miRNAs are highly expressed in PGCs, as demonstrated by Northern blotting, miRNA in situ hybridization assay, and miRNA qPCR analysis. This integrative study utilizing mRNA microarray analysis and miRNA target prediction demonstrates the regulatory networks through which these miRNAs regulate their potential target genes during PGC development. The elucidated networks of miRNAs disclose a coordinated molecular mechanism by which these miRNAs regulate distinct cellular pathways in PGCs that determine germ cell development.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.276-276
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• 2004

Pluripotent stem cells have been generated from two embryonic sources. ES cells are generated from ICM of blastocyst stage embryos, and embryonic germ (EG) cells are generated from primordial germ cells (PGCs). Both ES and EG cells are pluripotent and present important characteristics such as high levels of alkaline phosphatase (AP) activity, multi-cellular colony formation, normal and stable karyotypes, continuously passaging ability, and the capability of differentiation into all three embryonic germ layers. (omitted)

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.22-23
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• 2003

Primordial germ cell (PGC) is the progenitor cell of the germ cell lineage and eventually give rise to gametes that are responsible for creating individual organisms via a fertilization process. This means that PGC is a unique cell that can be converted into individual fish. This advantage of PGCs would make it possible to develop various applications in the field of fish bioengineering. First, PGCs may make it easier to preserve the genetic resources of fish. Cryopreservation of fish eggs or embryos has not been successfully achieved so far. Therefore, the only possible method to preserve genetic resources of fishes is to raise fish as live individuals. If PGCs isolated from various fishes could be cryopresewed, these cells could be converted into live fishes via germ-line chimera production. This is particularly useful for preserving genetic materials of endangered species. Even if the species of interest were to become extinct, it could be recovered by the transplantation of cryopreserved PGCs into the embryos of a closely related species. Another application of this technology is in what could be termed "surrogate broodstock technology". (중략)

• 한국가축번식학회지
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• 제24권4호
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• pp.385-394
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• 2000

돼지 원시 생식세포를 미성숙 성선에서 분리하고 체외 배양하여 EG 세포를 얻으려 할 경우 , 상당수의 세포들이 배양초기에 손실을 입게 된다. 이러한 돼지 원시 생식세포의 체외 손실 원인을 규명하고자, 미성숙 성선에서 분리된 세포를 부유 배양을 하고 FACS (fluorescent activated cell sorter)를 이용한 DNA 절편 분석법으로 apoptosis를 관찰한 결과 체외 배양된 처리구에서 apoptosis가 증가되었다. 그러나, 미성숙 성선에서 분리된 세포는 원시 생식세포와 체세포가 혼합된 세포들이므로, apoptosis가 일어난 돼지 원시 생식세포를 다른 체세포들로부터 구분하기 위하여 0 시간부터 24 시간까지 배양된 세포를 대상으로 정량 TUNEL 분석을 시행하였다. 이 결과, alkaline phosphatase 활성과 in situ TUNEL 분석을 통하여 apoptosls 가 일어난 돼지 원시 생식세포가 시간이 경과함에 따라 증가되었다. 이러한 결과들을 종합하여 볼 때 apoptosis가 돼지 원시 생식세포의 체외 손실의 원인 중 하나임을 규명하였다.

• Animal Bioscience
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• 제37권3호
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• pp.471-480
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• 2024

Objective: The objective of this study was to investigate the regulation relationship of Ten-eleven translocation 1 (Tet1) in DNA demethylation and the proliferation of primordial germ cells (PGCs) in chickens. Methods: siRNA targeting Tet1 was used to transiently knockdown the expression of Tet1 in chicken PGCs, and the genomic DNA methylation status was measured. The proliferation of chicken PGCs was detected by flow cytometry analysis and cell counting kit-8 assay when activation or inhibition of Wnt4/β-catenin signaling pathway. And the level of DNA methylation and hisotne methylation was also tested. Results: Results revealed that knockdown of Tet1 inhibited the proliferation of chicken PGCs and downregulated the mRNA expression of Cyclin D1 and cyclin-dependent kinase 6 (CDK6), as well as pluripotency-associated genes (Nanog, PouV, and Sox2). Flow cytometry analysis confirmed that the population of PGCs in Tet1 knockdown group displayed a significant decrease in the proportion of S and G2 phase cells, which meant that there were less PGCs entered the mitosis process than that of control. Furthermore, Tet1 knockdown delayed the entrance to G1/S phase and this inhibition was rescued by treated with BIO. Consistent with these findings, Wnt/β-catenin signaling was inactivated in Tet1 knockdown PGCs, leading to aberrant proliferation. Further analysis showed that the methylation of the whole genome increased significantly after Tet1 downregulation, while hydroxyl-methylation obviously declined. Meanwhile, the level of H3K27me3 was upregulated and H3K9me2 was downregulated in Tet1 knockdown PGCs, which was achieved by regulating Wnt/β-catenin signaling pathway. Conclusion: These results suggested that the self-renewal of chicken PGCs and the maintenance of their characteristics were regulated by Tet1 mediating DNA demethylation through the activation of Wnt4/β-catenin signaling pathway.

• 한국가금학회지
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• 제26권2호
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• pp.119-129
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• 1999

In recent years, numerous researches have been carried out in author's laboratory to develop several kinds of methods for producing transgened chicken, leaving a lot of new findings. Some of them are very useful to search for new approaches necessary to improve the efficiency of hatchability and the survival rate of developing trasgened embryos. The results obtained hitherto might be summarized as follows: (1) foreign gene(Lac Z/ Miw Z) introduced into blastodermal cells of developing embryos was successfully transferred to embryos, leading to the production of primordial germ cells(PGCs) carrying foreign DNA. However, hatched hickens failed to show the incorporation of introduced gene into the gonads. (2) When foreign gene was introduced into germinal crescent region (GCR), the gene was also efficiently incorporated into germ cells, resulting in the production of transgened chickens(offspring) which produced fruther offspring having foreign gene in the gonads. In this case, 2nd and 3rd generations of chickens were obtained through the reproduction of transgened birds. (3) In another way, the gene was injected into blood vessels of developing embryos at stage 13∼15, creating PGCs having foreign gene, and produced some transgened chickens. In this work, the PGCs were transfered between embryos, resulting in the production of transgenic chickens. (4) in these experiments, PGCs were effectively employed for producing transgenic birds, developing some kinds of chimeric chickens from homo- or hetero-sexual transfer of the PGCs from embryos. This means that the gonads from donor PGCs developed in some degree to the stage of hatching. However, these gonads showed slightly abnormal tissues similar to ovotestis like organs through histological examination. (5) Avian Leukosis Virus(ALV) induced B cell line(DT40) successfully carried foreign genes into chicken embryos, suggesting the possibility of the cells as a vector in this field of study in the future. (6) Inter-embryonic transfer of the PGCs also gave us some.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.74-76
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• 2001

조류의 경우에는 포유류와 달리 수정란의 성별이 암컷에 의하여 결정된다. 수컷은 동일접합체로 ZZ 염색체를, 암컷의 경우에는 이형접합체로 Z W 염색체를 갖기 때문이다. 현재까지 조류에 있어서 염색체 분석 등에 의한 암 ·수의 세포 유전학적인 특성은 많은 연구가 되어 있으나, 배발달 초기의 원시생식세포 등에 대해서는 많은 연구가 진행되어 있지 않다. 따라서 본 연구는 암컷의 원시생식세포를 분리하여 숫컷의 초기 배자에 주입함으로써 수용체 배자의 원시생식기내로 이동이 가능한지를 검증하였으며, 또한 수컷의 원시생식기내로의 이동 후 정상적으로 분열 및 분화가 가능한지를 초기 배발달 과정에서 확인하였다. 본 연구 결과, 암컷의 원시생식세포는 수컷의 수용체 배자에 재주입시 정상적인 원시생식기내로의 이동 능력을 보여주었으며, 분열 ·분화함을 알 수있었다.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2004년도 제21차 정기총회 및 학술발표회
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• pp.9-10
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• 2004

형질전환 가금의 생산은 생체반응기(Bioreactor)가금에 의한 고부가가치의 생의약 물질을 저비용, 고효율로 생산할 수 있으며, 배 발달과정 및 유전자 조절기작 규명을 통한 학문적 이용성 등 다양한 분야에 응용될 수 있다. 형질전환 가금을 생산하기 위한 방법 중 닭의 배 발생 초기에 발생하는 성세포(정자 혹은 난자)의 전구세포인 원시생식세포를 이용한 연구가 활발하게 진행되고 있다. 그러나 이를 검증할 원시생식세포 특이적 마커의 부재로 많은 어려움을 겪고 있다. 따라서 본 연구는 원시생식세포의 특성 분석을 위해 PAS(Periodic acid-Schiff) 염색 및 특이항체 (SSEA-1,3,4 & Integrins $\alpha$6, $\beta$l) 그리고 lectins (STA, DBA, ConA, WGA)를 이용하였다. 이번 연구결과를 통한 닭 원시생식세포의 특이적 마커의 개발은 원시생식세포를 이용한 가금의 형질전환 연구에 기여할 것이다.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.427-434
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• 2013

귀중한 한국재래닭 (오계)의 원시생식세포를 냉동보존하고, 키메라 닭을 통한 재래종의 복원을 도모하는 방법을 실용화하기 위해서, 오계의 원시생식세포에 있어 최적의 동결방법에 대해 검토했다. 원시생식세포의 동결은, 세포를 분리한 후, 동결배지의 기초가 되는 혈청으로서 소 태아혈청 (FBS) 그리고 닭 혈청(CS)를 이용하고, 동결보호제로서는 EG 및 DMSO의 첨가량을 2.5, 5, 10, 15%로 설정하고, 300 ${\mu}L$의 동결배지 용량으로 동결 튜브 안에서 $-70^{\circ}C$로 동결했다. 융해 후에는 오계 PGC의 생존율을 확인 및 검토를 했다. 그 결과, FBS 처리군이 CS 처리군 보다 생존 PGC 회수율이 높은 경향을 나타냈다. 또한 항동해제로서 최적의 조건은 10% EG + FBS의 조합을 기초로 한 동결배지에서 가장 높은 오계원시 생식세포의 생존율을 확인했다. 이러한 결과들로부터 한국재래종(오계)의 원시생식세포의 동결보존의 실용화가 보다 더 향상 될 수 있는 또 하나의 방법이 될 수 있음을 시사한다.