• Reproductive and Developmental Biology
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• 제34권3호
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• pp.257-262
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• 2010

The purpose of this study is to establish a basic culture system enabling in vitro culture of chicken blastodermal cells and to test the feasibility of retrovirus-mediated gene transfer to the cultured cells. The blastodermal cells were isolated from freshly laid eggs of stage X and cultured with or without STO feeder layer cells. Stem cell-like morphology was maintained after multiple passages and RT-PCR analysis proved expression of several stem cell specific genes. Immunocytochemical analysis using antibodies of anti-EMA-1 and anti-SSEA-1 also showed the feature of stem cells. Infection of the cultured blastodermal cells with LNCGW retrovirus vector resulted in successful transfer of foreign genes. The results of this study may be useful in establishing stem cell-mediated transgenic chicken production.

• 한국가금학회지
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• 제27권1호
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• pp.73-78
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• 2000

Embryonic stem (ES) cells are pluripotent cell lines, which derived from preimplantation embryo. These cells have been used as a vehicle of foreign DNA for production of transgenic mammals. this experiment was performed to examined the possible use of blastodermal cells derived from hen's egg for germline manipulation. Stage X blsdtodermal cells isolated from fertilized eggs were cultured in DMEM containing 15% fetal calf serum. Blastodermal cells wre co-cultured on the chicken embryonic fibroblast (CEF) or mouse embryonic fibroblast(MEF) cells. to examine the effects of growth factors on stem cell growth, bFGF and LIF were added. There was no significant difference in colony formation of putative ES cells between CEF and MEF as a feederlayer, but the addition of growth factors enhanced the proliferation and inhibited differentiation of blastodermal cells. To characterize the cell colonies as a putative ES cells, putative embryonic cell colonies were stained by periodic acid Schiffs (PAS) reagent. The putative ES cell colonies showed intensive positive reaction similar to the property of undifferentiated PGC upto 20days in vitro, but not in other cell types. this result demonstrates that PAS-positive cell colonies may be used for the study of establishment of chicken ES cell lines for the production of transgenic chicken.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2002년도 가을 학술발표논문집
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• pp.96-97
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• 2002

Primordial germ cells (PGCs) are the progenitors of the sperms or eggs of adult. Evidence suggests that the specification of primordial germ cells (PGCs) in the mammalian embryo does not depend on maternal determinants. Recent previous studies in the mouse has shown that several bone morphogenetic proteins (BMPs) are required for the formation of PGCs. However, there is no study about the effect of BMPs on avian PGCs. Here, we studied the effects of recombinant human BMP-2 (rhBMP-2) and recombinant human BMP-4 (rhBMP-4) on chicken blastodermal cells in culture. As a results, the addition of rhBMP-2 and rhBMP-4 increased the number of SSEA-1 positive cells in dose-dependent manner. However, there is no synergic effect by using both rhBMP-2 and rhBMP-4.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.158-164
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• 2005

A practical approach was proposed to produce transgenic chimeric chickens using blastodermal cells (BCs). The chicken BCs were mechanically dissociated and transferred into the recipient eggs that had been exposed to 500 rads irradiation of$^{60}Co$ and windowed on the equatorial plane. Chimeric chickens were generated using two models: the crosses (MXL) from Black Minors (ii,EE,b/b) ♂${\times}$Barred Leghorns (ii,ee,B/-) ♀ as donors and White Leghorns (WL, II) as acceptors (Model 1), or the Black Heifengs (BH, ii,EE,bb) as donors and Hua-xing white (HW, II) as recipients (Model 2). The treated eggs were incubated in their original shells in normal conditions until hatching. Green fluorescent protein (GFP) gene was transferred into the BCs derived from MXL and BH via lipofectamine and the pEGFP-C1, and transfection efficiency into the BCs was examined under a fluorescent microscope. Potential transgenic chimeras were selected based on the proposed methods in this study. Using the fresh BCs, the best rate of phenotypic chimeras was 6.7% and 26.0% in model-1 groups, and model-2 groups, respectively. We also described the optimized conditions for transfection. Although 30% of the BCs transfected in vitro emitted green light under an inverted fluorescent microscope, no embryos injected with the transfected BCs expressed foreign GFP gene at 3-4 days.

• 한국가금학회지
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• 제27권2호
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• pp.155-161
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• 2000

Unfortunately, there is no technique which is stable and repetitive to produce transgenic chicken, although various ways of gene transfer including PGC-and embryonic cell-mediated gene transfer, DNA microinjection, virus inoculation and sperm cells have been employed. The aims of this study were 세 develop and establish such a stable, repetitive and efficient way of gene transfer giving a faithful gene expression during development after the reconstruction of embryo in an UV-irradiated egg. A dual reporter plasmid (pJJ9), a fusion gene containing lacZ and GFP driven by a CMV promoter was used to exploit either merits of both reporting markers. lacZ with strong signal or GFP with vital marking. Electroporated embryonic blastodermal cells (EBCs) in the presence of the pJJ9 DNA faithfully showed 377 bp PCR product and lacZ or GFP expressions in the identical cells in vitro of in vivo. Furthermore, analyses of expression pattern of the foreign DNA demonstrated that microinjected EBCs cells into the UV-irradiated recipient egg should participate in normal developmental process, for example, proliferation and differentiation into various tissues. Thirty percentages of the manipulated eggs showed lacZ expression in their tissues. These results together with the specific procedures used in this study should facilitate avian transgenesis.

• 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.

• 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.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.65-70
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• 2012

귀중한 한국재래닭의 배반엽세포를 냉동보존하고, 키메라 닭을 통한 재래종의 복원을 도모하는 방법을 실용화하기 위해서, 한국재래종의 배반엽세포에 있어 최적의 동결 방법에 대해 검토했다. 배반엽세포의 동결은 세포를 단리한 후, 항동해제와 소태아혈청(FBS)를 함유하고 있는 동결용액 중에 부유하고 수지성 동결용기 중에 넣고, $-7^{\circ}C$에서 동결시키고 나서 분당 $-1^{\circ}C$에서 $-35^{\circ}C$까지 냉각하고 액체질소 안에 침지시켜서 실험을 진행했다. 동결조작 중에서 (1) 동결 전의 세포의 단리 방법, (2) FBS 농도, (3)동결 시 세포밀도가 동결융해 후의 세포생존율에 미치는 영향을 조사했다. (1) 세포의 단리 방법을 피펫팅으로부터 시험관 믹서에 의한 단시간의 flushing으로 변경하면, 동결융해 후의 세포의 생존율이 29%부터 51%로 향상된다. (2) 동결용액 속 FBS 농도를 20%에서 80%로 증가시키면 동결융해 후의 생존율이 28%에서 35%로 증가한다. 또한, (3) 융해 후, 생존율은 (2개의 배자/0.5 ml) 처리군에서의 동결은 34%인 반면에, (20개의 배자/0.5 ml)에서는 44%였다. 더욱이, 이 세 가지 개선점을 조합함으로써 동결융해 후의 생존율은 60%로, 개선 전의 41%에 비하여 크게 개선이 될 수 있고, 한국재래종의 배반엽세포의 동결보존의 실용화가 보다 더 향상될 수 있는 방법이 될 수 있음을 시사한다.

• Reproductive and Developmental Biology
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• 제37권3호
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• pp.91-96
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• 2013

Transgenic chickens have been spotlighted as an highly potent bioreactor for their fecundity, short generation time, and eggs associated with mass production of protein. In this study, we generated transgenic chickens exhibiting oviduct specific expression of human growth hormone fused to human transferrin for oral administration. Gene of the modified growth hormone located at downstream ovalbumin promoter (~3.6 kb) was introduced to stage X blastodermal cell employing retrovirus vector system. Several transgenic chickens were successfully generated. However, genomic analyses showed unexpected deletion within the transgene. The modification of the transgene seemed to occur during germ cell formation because the deletion was detected only from the sperm DNA of the G0 founder animal. There was no evidence of deletion in the somatic cell DNA samples of the same chicken. Consequently, same pattern of the deletion was confirmed in both somatic and germ cells of the G1 progeny.