Due to their anatomical, physiological and genetic similarities, pig is attractive animal model in biomedical research. In the recent stem cell research era, porcine derived stem cells also gain attention due to its use for the preclinical application of human. Mesenchymal stem cells (MSCs) have been studied by many researchers over decade, and their prospect for clinical application is recognized. Although porcine derived MSCs (pMSCs) have confirmed to be differentiated into various types of cells, such as osteocyte, chondrocyte, neuronal cell, cardiomyocyte and pancreatic β cell, few report has been studied regarding hepatocyte differentiation in vitro. The present study was therefore aimed for bone marrow MSCs derived from pig femur to differentiate into hepatocyte. The cells were confirmed as MSCs by characterizing their morphology, lineage differentiation capacity and surface phenotype. They showed spindle like morphology and adipocytic, osteoblastic, and chondrocytic differentiation potentials and displayed positive expression of mesenchymal markers CD29, CD44 and CD90 while lacked the expression of hematopoietic marker CD45. Under appropriate differentiation conditions, MSCs displayed hepatocyte-like morphology depending on duration of differentiation. The differentiated MSCs into hepatocyte expressed hepatocyte-specific genes including hepatocyte nuclear factor 4 (HNF4), albumin (ALB), alpha fetoprotein (AFP), alpha-1-anti trypsin (A1AT). They also showed hepatocyte-like function, glycogen storage which is identified by PAS staining. Taken together, it concluded that the bone marrow MSCs have the potential to differentiate into hepatocyte. Further studies are needed on additional hepatocytic functional assays, such as low density lipoprotein (LDL) uptake and urea synthesis of differentiated MSC.

Serum amyloid A (SAA) is an acute phase protein with pro-inflammatory cytokine-like properties. Recent studies have revealed that SAA promotes γδT cell to produce IL-17 and T helper 17 (Th17) cells differentiation and function. In this study, we established the hepatic SAA1 overexpressed transgenic mice (TG). In this mouse, IL-17 was significantly increased in conditional state by γδT cell. We revealed that SAA1 mediated IL-17 producing from γδT cell is dependent on TLR2. Moreover we immunized SAA1 TG mice with Complete Freund’s adjuvant (CFA), which is well-known inducer of Th1 response and IFN-γ. We observed increased IL-17 secretion with increased Th17 cells and decreased IFN-γ, which is contrast to wild type mice (WT). In addition, we showed that locally increased transforming growth factor- β (TGF-β) followed by Th17 cells polarization might involve in Th17 cell maintenance by suppressing the expression of T-bet, a key transcription factor for the differentiation of T helper 1 (Th1) cells. These data demonstrate that SAA1 represent potent endogenous protein that drives IL-17 induced inflammation by γδT cell partially through TLR2 and by Th17 cell. Also these increased IL-17 response maintained by TGF-β Smad2/3 signaling. Therefore we could say that SAA is central player in IL-17 related inflammatory response.

To investigated the mechanism, induced pluripotent stem cells(iPSC) is important for clinical application and stem cell research. It is well known that hMAGEA2 expression pattern and effect on differentiation in embryonic stem cell but their specific role in iPS cells are unclear. The present study was schemed to understand the function of hMAGEA2 gene in iPS cells and to elucidate its characteristic. Although overexpression of hMAGEA2 in iPS cells are not different on morphology, their pluripotency and self-renewal capacity are significantly strengthened. And hMAGEA2 contributed to promote the cell cycle progression, this cell cycle changes induced proliferation acceleration. Through embryoid body formation in vitro and teratoma formation in vivo, we found that hMAGEA2 critically decreases the differentiation ability in iPS cells. Our results demonstrate that hMAGEA2 intensified the self-renewal, pluripotency, proliferation degree but efficiency of differentiaton is significantly repressed. Our findings provided that hMAGEA2 play a key role of iPS cells.

노화와 재해 등으로 인한 인간의 치명적인 간 부전 문제를 해결하기 위한 대안 중의 한 축으로 교차분화 기법을 적용한 induced hepatocyte (iHep)연구가 진행되고 있지만, 분화효율은 극히 낮다. 본 연구에서는 돼지 섬유아세포에 교차분화기법을 사용하여 piHep을 만들고, 소분자 화합물(A83-01)의 첨가에 따른 교차분화의 효율개선을 시도 하 였다. piHep의 유도를 위해서 세가지 간 전사 인자를 [human hepatocyte nuclear factor 1 alpha (hHNF1A), human hepatocyte nuclear factor 4 alpha (hHNF4A), human forkhead box protein A3 (hFOXA3)]를 렌티바이러스를 이용하여 체세포에 도입하였다. 3가지 유전자가 도입된 세포는 기본 배양액으로 hepatocyte induction medium (HIM)을 사용하였고, 여기에 A83-01을 첨가군과 미 첨가군(대조군)으로 나누어 교차분화를 유도 하였다. 그 결과 대조군에서 4주 후에 불완전한 간세포의 형태가 낮은 빈도로 나타났지 만, A83-01 처리군은 도입 2주 후부터 epithelial-like cell의 형성을 통해 점점 다핵을 가 지는 성숙한 piHep(명확한 핵, 다각형의 세포질)의 특성이 확인되었다. 간세포로의 기능 적 분화를 검증하기 위해 albumin (ALB)과 transferrin (TF)의 mRNA의 발현을 real-time PCR을 통해 분석하였다. A83-01 처리군에서 ALB와 TF의 발현이 교차분화 4 주차까지 증가되었다. 섬유아세포 표지 인자인 vimentin의 발현은 A83-01의 처리와 상관 없이 모두 감소되었다. 대조군과 달리 A83-01처리군은 piHep의 유도를 위해 사용된 3가 지 간 전사인자들 중 HNF4Α와 FOXA3에서 교차분화 후 4주차까지 endogenic expression 을 보였다. 결론적으로 간세포 교차 분화의 효율 개선을 위해 사용된 A83-01은 돼지 섬 유아세포의 내재된 간 특이적 전사 인자들을 활성화시켜 간세포의 분화를 촉진함을 확인 할 수 있었다.

최근 조직공학 기술의 발달로 재해와 질병으로 인한 손상된 조직과 장기의 대체연구들 이 진행되고 있다. 장기 대체 연구의 핵심 요소 중 하나는 재건된 조직이나 장기가 혈관 망을 형성하여 host tissue로부터 양분과 산소의 전달이다. 본 연구는 조직공학 기법을 이용하여 장기 재건에 필수적인 혈관 재건을 위해 혈관을 구성하는 주세포인 endothelial cell을 체외에서 배양하는 것이다. Endothelial cell(EC)배양을 위해서는 세포지지체인 세 포외 기질(External cellular metrics, ECM)을 필요로 하기 때문에 ECM중에 대표적인 collagen과 gelatin을 사용하여 지지체에 따른 체외배양능을 비교하였다. 실험 동물로는 돼지 대동맥을 채취하여, 대동맥 속에 collagenase type I을 주입하고, 혈관의 입·출구를 봉합한 상태로 10분 간 37℃에서 처리하였다. 관류된 용액은 10% FBS가 함유된 기본배 양액(EGM-2 media)을 사용하여 2번 수세한 후 회수된 세포를 각각의 ECM이 처리된 dish위에서 배양 하였다. EC세포인지를 확인하기 위해서 EC표지 인자인 CD31과 vWF 항체의 발현을 flow cytometry로 확인 하였고, 회수된 세포에서 두 단백질이 모두 발현 되었다. ECM에 따른 EC의 세포 형태를 비교하였을 때 형태학적 차이는 없었다. Basement Membrane Extract위에서 calcein-AM으로 염색된 EC는 ECM의 종류와 상관 없이 2-6시간 사이에 Tube Formation을 보였다. 또한 endothelial cell의 표지 마크인 CD31, Flk1, vWF의 mRNA 발현양과 IHC에 의한 단백질 발현을 조사한 결과 collagen 지지체 위에서 배양된 endothelial cells에서 발현양이 더 높았다. 결론적으로 두 가지 ECM에서 모두 성공적으로 endothelial cell의 배양이 가능하지만 collagen위에서 배양된 endothelial cell이 더 우수한 maintenance능력을 가짐을 확인 할 수 있었다.

It is still challenging to establish pESCs due to differences in the genetic backgrounds of mouse, human, and pig. So it is required to find pig specific pluripotency markers and cellular signaling. In this experiments, doxycycline-inducible vectors carrying OCT4, SOX2, NANOG, KLF4 and MYC known as reprogramming factors, were infected into pig stem cells for analyzing gene expression pattern. When cultured without doxycycline, pig stem cells were stably maintained in bFGF supplemented media. However, when treated with doxycycline, pig stem cells lost alkaline phosphatase activity and were differentiated within two weeks. And then, we investigated the expression of genes related to pluripotency in doxycycline-treated pig stem cells by using qRT-PCR. The qRT-PCR data revealed that expression of OCT4, CDH1 and FUT4 were significantly increased by OCT4 overexpression and OCT4 and FUT4 were also upregulated in SOX2-infected group. When infected with combination of two factors including OCT4 or SOX2, some groups could stably maintain at LIF supplemented media, having alkaline phosphatase activity. Given these data, although ectopic gene expression induced differentiation in pig stem cells, ectopic expression of OCT4 and SOX2 could upregulate pluripotent genes and overexpreession of two factors help pig stem cells adapt LIF-contained media. This study could improve understanding of pluripotent networks as well as aid in establishing bona fide pluripotent stem cells in pig.

RNA Sendai virus (SeV) vector system has no risk of being integrated into the host genome. Sendai virus (SeV) vectors expressing pluripotent factors have been used to produce integration-free induced pluripotent stem cells (iPSCs) with high efficiency from various cell types in human and mouse. In this study, we generated iPSCs from pig ear fibroblast cells using the SeV vector expressing 4 human factors (POU5F1, SOX2, C-MYC, and KLF4). Colonies were emerged at Day 14 of transduction and expressed the classical pluripotency markers (POU5F1, NANOG, and SOX2) and surface marker (SSEA1). Furthermore, they showed a domed shape and could passage over 40 times under 2i (CHIR99021 and PD0325901)-LIF and MEF feeder culture condition having in vitro differentiation ability into 3 germ layers. Next, we examined the ability of six feeder free culture conditions to maintain piPSCs in a pluripotent state. piPSCs were plated on Matrigel coated dishes in different media: 1. CM: control media (LIF culture media); 2. CM-F: CM+100 ng Fetuin-A; 3. CM-N: CM+100 ng Nanog-TAT; 4. CM-2i: CM+3 uM CHIR99021+1 uM PD0325901; 5. CM-2iN: CM-2i+100 ng Nanog-TAT; 6. CM-2iN+100 ng Fetuin-A. However, piPSC could not maintain the typical self-renewal morphology on feeder free conditions regardless of culture media tested here. Further, expression of pluripotency-related genes (Oct4, Nanog and Klf4) of piPSCs cultured on feeder free conditions could not be compared with that of iPSCs cultured on MEF feeder plate. Our results suggest that integration free pluripotent stem cell from pigs could be generated by SeV vector system and maintained their pluripotency under 2i-LIF and MEF feeder culture condition, but further optimization of culture conditions may be required.

Abnormal epigenetic reprogramming of donor nuclei is supposed to be one of the factors that causes low development efficiency of mammalian somatic cell nuclear transfer (SCNT). Trichostatin A (TSA) is an inhibitor of histone acetylase, and so development of SCNT embryos could be increased by treatment with TSA. In the present study, we examined the effect of TSA on in vitro development of porcine embryos derived from NT (nuclear transfer) by investigating the status of histone acetylation in TSA-treated and control NT embryos and the expression of developmental related genes. In this study, we found that incubating　NT embryos with 40nM TSA for 24h after activation could improved the blastocyst formation rate from 13.7% to 32.5%. Thechange in histone acetylation level as a reslut of TSA treatment were validated using immunofluorescence and confocal microscopy. Immunofluorescence results indicated that the level of aetylation at histone 3 lysine 18 (AcH3K18) was increased at early embryo development stage after TSA treatment. furthermore, we compared the expression patterns of several genes (developmental related genes; Oct4, Sox2, Nanog, Cdx2, the imprinting genes; igf2r). TSA treatment improved the expression of development related genes such as Oct4, Cdx2, Nanog as well as the imprinted genes like igf2r. In conclusion, our results demonstrated that TSA treatment improves the in vitro development of porcine NT embryos, increased the global histone acetylation (AcH3K18) and enhances the expression of some developmentally important genes (Oct4, Cdx2, Nanog) at blastocyst stages.

Somatic cell nuclear transfer (SCNT) has been considered for preserving genetically valuable or endangered animals. Sapsaree is a Natianal Monument in Korea to maintian a pure pedigree. The aim of this study was to produce azoospermia Sapsaree using SCNT and identify normal reproductive ability of cloned azoospermia Sapsaree. Ear skin biopsy was performed on a thirteen-year-old azoospermia Sapsaree and ear skin fibroblasts were isolated for SCNT as donor cells. The fibroblasts were injected into enucleated in vivo matured oocytes, the couplets were electrical fused by two pulse of direct current (55 V for 15 μs) using titanium and platinum fusion needle and activated by calcium ionophore. Cloned embryos were surgically transferred into oviducts of natuarally estrus cycle synchronized recipient dogs. The fusion rate of platinum needle was 70%, which was higher than those of titanium needle (64.1%). Developmental rate to the 8 cells and 10 cell stages was higher in platinum needle group (24% and 16%, respectively) than those of platinum needle group (14.8% and 3.1%, respectively). Total 35 SCNT embryos were transferred into oviducts of 3 recipient dogs and one recipient finally delivered a puppy by caesarean section. As results, this study demonstrated that platinum fusion needle could be successfully make the reconstructed embryos and improve the efficiency of canine SCNT. Cloning azoospermia Sapsaree may contribute to conserve genetically valuable and unique pedigree. And further study should be confirm whether cloned live dog is azoospermia.

Value of excellent breeding animals is important in livestock industry, but their economic life time is limited. And, many countries have been trying procuration of genetic resource in good animals. Therefore, this study was conducted to determine embryo production and to test efficiency of embryo transfer via non-surgical artificial insemination (AI) in different breed of superior sows. A total of 17 sows were used in this experiment (Duroc, n=10; Landrace, n=4; Yorkshire, n=3). The sows were artificially inseminated by semen of same breed boars. After 4 or 5 days following the AI, the embryos were obtained from the sows and then transferred to Landrace and Yorkshire recipients (n=3, respectively) by non-surgical method. The corpora lutea tended to be increased in Yorkshire and Landrace than Duroc(28 and 26 vs. 17, respectively). The recovery of embryo was 78.8% in Landrace, 65.4% in Duroc and 51.4% in Yorkshire. Duroc showed lower morulaes and early blastocyst embryos than 2, 4 ,8 and 16 cell. The morula in Yorkshire was higher (P<0.05) than that of Duroc (4.7 vs. 3.4). Similarly, the morulaes and early blastocyst embryos presented greater (P<0.05) in Landrace compared with other breed sows. The recipient sows were pregnant in a Landrace only. This reason may be due to little embryos inserted in the recipients. In addition, pregnancy results were limited because of the little sows. In conclusion, ovulated ovum in sows can be affected by different breed. Also, further study needed pregnant test by using the many embryo in each breed.

CRISPRs(clustered regularly interspaced short palindromic repeats) / CRISPR - associated(CAS) system has been used genome editing technology. Genome stage modification using CRISPR/CAS9 system can be used to wide research for the gene functional study and therapeutics. However, improving of CRISPR/CAS9 system in efficiency is essential for application in various fields. Here, we treated various chemicals during the procine early embryo development to increase the mutation of target site by NHEJ(non-homologous end joining). Firstly, we confirmed the chemical toxicity after parthenogenetic activation and then check embryo puality using by counting of total cell number and TUNEL Assay in blastocyst satge. To check any improvement on mutation rate by NHEJ pathway. AZT(3′-Azido-3′-deoxythymidine, antiretroviral drug – 0.1 μM) was treated after injection of cas9 and sgRNA target to OCT4 exon 5 during the zygote stage, followed by PCR sequencing. As a result, AZT treated group shows a significantly increased in knock-out efficiency as a consequence of NHEJ. Nocodazole(anti-neoplastic agent – 200ng/ml), RO-3306 (specific inhibitor of CDK1 - 10 μM) and NU-7026(PKC signalling inhibitor - 50 μM) was treated after injection of cas9 and sgRNA with eGFP vector during the zygote stage(hpa8~hpa20) and checked a efficiency of knock-in by PCR sequencing. Interestingly, nocodazole treatment groups increased of insertion of eGFP sequence in blastocyst stage compared with non-treat group(control : 8.33%, nocodazole treatment : 16.67%). However, RO-3306 and NU-7026 made a no impact. In summary, CRISPR/CAS9 system with treatment of chemicals during porcine embryogenesis can be improving of site-specific mutation and enhancement of CRISPR genome editing.

The production of therapeutic proteins from transgenic animals is one of the most important successes of animal biotechnology. Endostatin is 20 KDa C-terminal fragment derived from type XVIII collagen and an endogenous inhibitor of tumor growth by inhibition of angiogenesis. In this study, we are developed knock-in vector consists of 5’ arm region (1.02 kb), human Endostatin cDNA, CMV-EGFP, and 3’ arm region (1.83 kb). To express Endostatin gene as transgene, the F2A sequence was fused to the 5’ terminal of Endostatin gene and inserted into exon 3 of the β -casein gene. If this knock-in vector is inserted into the porcine β-casein gene locus by homologous recombination, human Endostatin mRNA are expressed using the gene regulatory region of the β-casein. Also, the β-casein and Endostatin fusion protein is translated and Endostatin protein is separated by F2A self cleavage during translation. In conclusion, our knock-in vector may help to create transgenic pig expressing human Endostatin protein via the endogenous expression system of the porcine β-casein gene in the mammary gland.

Alzheimer's disease (AD) has caused by expression of amyloid precursor protein (APP), Tau and presenilin (PS) as known as plaques and tangle accumulation. AD transgenic porcine model is necessary for preclinical testing of therapeutic agent because of similar metabolic system between porcine and human. The objective of study was to generate AD transgenic pig by somatic cell nuclear transfer (SCNT) with multi-cistronic vector system. AD multi-cistronic vector was 6 well-known mutation on 3 AD related genes, hAPP (K670N/M671L, I716V, V717I), hTau (P301L) and hPS1 (M146V, L286P). Establishment of AD transgenic cell lines was used from Jeju black pig ear fibroblast cells (JB-PEFAD) with the AD multi-cistronic vector. The JB-PEFAD cell was confirmed on mRNA expression, protein synthesis of hAPP, hTau and hPS1 and identification of integration and karyotype. Although fusion rate was no difference in SCNT with JB-PEF AD (SCNTAD) embryos, cleavage and blastocyst formation rates were slightly lower than in SCNT with non-transgenic JB-PEF (SCNTnon-TG). Individual SCNTAD blastocysts were detected hAPP, hTau and hPS1 genomic integration which showed 93.2% (n=30) efficiency in genomic DNA (gDNA) level. It will give us a possibility to develop porcine animal model for AD study in the future.

Ribosomal protein L21 (RPL21) plays an important role in ribosome assembly. It is considered to be a major cause for the occurrence of the hypotrichosis simplex (HTS), a type of sustained hair loss from early childhood to adulthood. In this study, the full-length sequence of pig RPL21 gene (GenBank accession number: KU891824) was cloned and identified for the first time. We found it contains a 483-bp open reading frame (ORF) encoding 160 amino acids. It is located in the plus strand of chromosome 11, which spans 2,167 bp from 4,199,792 to 4,201,958. We found RPL21 expression level is closely related to cell proliferation and cell cycle arrest. In the knockdown group, the cell proliferation activity was significantly decreased (P<0.01) and an obvious accumulation of cells at the G2/M phase with a simultaneous up-regulation of p53 and p21 was observed. This likely due to knockdown of RPL21 triggered ribosomal stress, which affected the normal ribosome assembly and caused defective ribosome biogenesis. The unassembled RPs were released consequently from the nucleolus to the nucleoplasm where they can activate p53-dependent cell-cycle responsive factors and led to a G2/M arrest. We expect these results may provide valid information for further study on the pig RPL21 gene and the cause of hypo trichosis simplex.

The clustered regularly interspaced short plalindromic repeats(CRISPR)/CRISPR associated protein (Cas9) system can be applied to produce transgenic pigs. We applied CRISPR/Cas9 system to generate hG-CSF targeted pig parthenogenetic embryos. Using sigle guided RNA targeted to pig hG-CSF genes was injected into cytoplasm of in vitro matured oocyte before electrical activation. The CRISPR/Cas9 vector were diluted in Tris-EDTA buffer (TE buffer) and injected with different concentration of 0 (sham injection), 2.5 and 25 ng/ul. In results, regardless of the concentrations of vector, the cleavage and blastocyst rate were not significantly different among three groups. Since plasmid DNA was used for microinjection, we investigated whether DNA vectors were integrated into the genome. Genomic PCR of the coding sequence of Cas9 variants and hG-CSF was performed to detect genomic integrants. Each blastocysts were collected into a microtube, and then PCR was performed. Overall 32 embryos are not expressed targeted gene.

The CRISPR/Cas9 system is proved to be a powerful tool for knock-out and knock-in in various species. By introducing genetic materials of two components (Cas9 and small guide (sg) RNA) into cells or pronuclear of the fertilized embryo, gene editing occurs. Some studies reported that efficiency of gene editing would be increased as Cas9 was integrated into cells or animals since Cas9 is indispensable in the CRISPR/Cas9 system. Accordingly, the production of Cas9 expressing cattle may provide the broadly used gene editing platform in cattle. For this study, Cas9 and RFP genes were cloned into PiggyBac (PB) transposon system. PB-Cas9-RFP and transposase were microinjected into 1436 in vitro fertilized embryos and 241 blastocysts were formed. Blastocysts with RFP expression accounting for 14.1% of total formed blastocysts were selected and transferred into 5 recipient cow. After gestation periods, four transgenic cattle were delivered without any veterinary assistance. From a transgenic cattle, ear skin tissue was collected for primary culture. On those primary cells, sgRNAs in DNA form for various genes such as PRNP, RB1 and BLG were transfected as 2ug of sgRNA per 5x105 cells using Nucleo factor system (Neon®, invitrogen, program#16). As expected, every group of each sgRNA delivered was confirmed to be mutated by T7E1assay. Those data demonstrated that for the first time, transgenic cattle with Cas9 expression were born, grown up to date and will be avaluable resource for genome-editing in cattle. This work was supported by BK21PLUS Program for Creative Veterinary Science and Seoul Milk Coop (SNU550-20160004).

Many transgenic domestic animals have been developed to produce therapeutic proteins in the mammary gland. However, purification of therapeutic proteins from transgenic milk are very important for productivity of recombinant protein. Development of a knock-in vector system is needed to improve production of therapeutic proteins. In this study, we are develop Knock-in vector to express human Erythropoietin protein (hEPO) using Gluthathione S-transferase (GST) fusion system on mouse β-casein exon 3 locus. The knock-in vector consisted of the 5 homologous arm (1.02 kb), GST, PreScission protease site, hEPO cDNA, BGH polyA signal, CMV-EGFP, and 3homologous arm(1.81 kb). The analysis of nucleotide and amino acid sequence revealed that GST-hEPO mRNA is probably translated with the mouse β-casein sequence and the β-casein-GST-hEPO fusion protein is probably secreted by ER-Golgi pathway. After that, the hEPO protein can be cleaved to remove the GST from the fusion protein by PreScission protease during purification of recombinant protein. This knock-in vector may help to create transgenic mouse expressing human Erythropoietin protein via the endogenous expression system of the mouse β-casein gene in the mammary gland.

This study was performed to compare the healing quality of the allogenic acellular dermal matix (ADM) and xenogenic ADM combined with autologous skin graft. Xenogenic ADM was obtained from two GalT knock-out pigs. Allogenic ADM was obtained from cynomolgus monkeys. ADM was stored with lyophilization. Full-thickness skin wounds were made on the back of two cynomolgus monkeys. In one monkey, wounds were covered by xenogenic ADM combined with autologous skin graft or autologous skin graft only. In another monkey, wounds were covered by allogenic ADM combined with autologous skin graft or autologous skin graft only. Skin healing process was observed during 2 weeks and skin biopsies were performed on 3 months after skin transplantation. We obtained IACUC approval (ORIENT-IACUC-16053) Skin on the xenogenic ADM was necrotized 1 week after skin transplantation. Possibly due to the thickness of ADM, which block the blood supply from the subcutaneous tissue to the autologous skin graft. Skin biopsy revealed that less fibrotic change of the skin on the ADM compared with the skin without ADM. Xenogenic ADM can be used in high degree burn patients who can suffered from contracture after healing since it can reduce fibrotic change.

In the present study, using a MoMLV-based retrovirus vector, we successfully generated a new transgenic chicken line expressing high levels of hEPO. A replication-defective Moloney murine leukemia virus (MoMLV)-based vectors packaged with vesicular stomatitis virus G glycoprotein (VSV-G) was injected beneath the blastoderm of non-incubated chicken embryos (stage X). One rooster was mated to wild-type hens to produce 748 G1 progeny. PCR analysis of blood samples from these progeny revealed that there were seven G1 transgenic offspring, corresponding to a 0.9% germline transmission rate. Subsequently, Southern blot analysis of the genomic DNA from three G1 transgenic chickens was carried out to verify the stable genomic integration and copy number of the transgene in the genome. Quantitative analyses of the blood samples taken from G1 transgenic chickens resulted in 4,150 ～ 10,823 IU/㎖ (34.6 ～ 90.2 ㎍/㎖) of hEPO in the blood. The biological activity of the recombinant hEPO in transgenic chicken serum was comparable to its commercially available counterpart. Red blood cell numbers were more than three-fold higher in the transgenic chickens compared to the non-transgenic chickens. Successful germline transmission of the transgene was also confirmed in G2 transgenic chicks produced from crossing G1 transgenic roosters with non-transgenic hens. We confirmed that 13 transgenic chicks of 45 G2 progeny, corresponding to a 28.9% germline transmission rate. These results will help establish a useful transgenic chicken model system for studies of embryonic development and for efficient production of transgenic chickens as bioreactors. This work was supported by the Bio-industry Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea, and by a grant from the Next-Generation BioGreen 21 Program (No. PJ011178), Rural Development Administration, Republic of Korea.

Human interferon alpha 2b (hIFNα-2b) is an important immune regulator widely used in clinic, for the treatment of chronic hepatitis, hairy cell leukemia, chronic myelogenous leukemia and multiple myeloma, etc. The clinically used hIFNα-2b is generally produced by E. Coli, which lacks the post-translational O-glycosylation of naturally synthesized protein, and has a short serum half-life. In this study, we report the successful generation of transgenic chickens that produce hIFNα-2b in the egg white using a feline immunodeficiency virus (FIV)-based lentiviral vector. In preliminary in vitro study, the hIFNα-2b gene under the control of CMV promoter expressed as much as 2,650 ng/㎖ in CEF-LNC-hIFNα-2bW cell. A FIV vector packaged with vesicular stomatitis virus G glycoprotein (VSV-G) was injected underneath the blastoderm of freshly laid chicken eggs (stage X) to produce a hIFNα -2b transgenic chicken. Out of 187 injected eggs, 55 chicks were hatched after 21 days of incubation, and 27 of the G0 hatched chicks expressed the vector-encoded hIFNα-2b gene. The expression of recombinant hIFNα-2b in transgenic chickens constitutes an important step towards low-cost and full biological activity production of this protein drug in bioreactor. This work was supported by the Bio-industry Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea, and by a grant from the Next-Generation BioGreen 21 Program (No. PJ011178), Rural Development Administration, Republic of Korea.