Species-specific challenges in dog cloning

Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.

Gaussian mixture model-based classification of dynamic contrast enhanced MRI data for identifying diverse tumor microenvironments: preliminary results

Tumor hypoxia develops heterogeneously, affects radiation sensitivity and the development of metastases. Prognostic information derived from the in vivo characterization of the spatial distribution of hypoxic areas in solid tumors can be of value for radiation therapy planning and for monitoring the early treatment response. Tumor hypoxia is caused by an imbalance between the supply and consumption of oxygen. The tumor oxygen supply is inherently linked to its vasculature and perfusion which can be evaluated by dynamic contrast enhanced (DCE-) MRI using the contrast agent Gd-DTPA. Thus, we hypothesize that DCE-MRI data may provide surrogate information regarding tumor hypoxia. In this study, DCE-MRI data from a rat prostate tumor model were analysed with a Gaussian mixture model (GMM)-based classification to identify perfused, hypoxic and necrotic areas for a total of ten tumor slices from six rats, of which one slice was used as training data for GMM classifications. The results of pattern recognition analyzes were validated by comparison to corresponding Akep maps defining the perfused area (0.84 ± 0.09 overlap), hematoxylin and eosin (H&E)-stained tissue sections defining necrosis (0.64 ± 0.15 overlap) and pimonidazole-stained sections defining hypoxia (0.72 ± 0.17 overlap), respectively. Our preliminary data indicate the feasibility of a GMM-based classification to identify tumor hypoxia, necrosis and perfusion/permeability from non-invasively acquired, in vivo DCE-MRI data alone, possibly obviating the need for invasive procedures, such as biopsies, or exposure to radioactivity, such as positron emission tomography (PET) exams.

Co-delivery of LETM1 and CTMP synergistically inhibits tumor growth in H-ras12V liver cancer model mice

As hepatocellular carcinoma (HCC) is one of the most common tumors worldwide, development of novel therapeutic approaches for HCC is urgently needed. Two different genes, LETM1 and CTMP, which target mitochondrial functions, were chosen and linked using 2A-peptide sequence. Successful self-cleavage of 2A-peptide induced synergistic antitumor effect in the liver of H-ras12V, the HCC model mice, by simultaneous activation of LETM1 (Leucine zipper/EF hand-containing transmembrane-1) and CTMP (carboxyl-terminal modulator protein). Overexpression of LETM1 and CTMP significantly reduced the incidence of tumorigenesis, which were confirmed by gross and microscopic observations. Morphological changes in mitochondria, such as swelling and loss of cristae, were significant, and the prolonged activation of defects in mitochondrial function led to mitochondria-mediated apoptosis. Furthermore, with CTMP as a direct binding partner of Akt1, and LETM1 as a binding partner of CTMP, LETM1-2A-CTMP downregulated the Akt1 pathway at both Ser473 and Thr308 sites of phosphorylation. Proliferation and angiogenesis, which are important in cancer prognosis, were reduced in tumor sites after introduction of LETM1-2A-CTMP. Taken together, the results indicate that introduction of the mitochondria-targeting genes, LETM1 and CTMP, and self-processing capacity of 2A-peptide sequence exerts an antitumor effect in liver of H-ras12V mice, suggesting its potential as a tool for gene therapy.

42 EFFECT OF S-ADENOSYLHOMOCYSTEINE, A NON-TOXIC EPIGENETIC MODIFYING REAGENT, ON PORCINE FEMALE DONOR CELLS AND CLONED EMBRYOS

Despite great advances in the field of cloning techniques, the efficiency of production of cloning animals is very low. Maybe the poor outcome of somatic cell nuclear transfer (SCNT) is thought to be a consequence of incomplete reprogramming of the donor cell or cloned embryos. The objective of this study was to investigate the effects of treatment with S-adenosylhomocysteine (SAH), the reversible nontoxic inhibitor of DNA methyltransferases (DNMT), on porcine female fibroblast donor cells and in vitro development of cloned embryos. We hypothesized that SAH targeting DNA methylation could alter chromatin configuration and turn it more amenable to reprogramming. Thus, the female fibroblast donor cells were cultured in media containing respective concentrations of SAH [0 (control), 0.1, 0.5, and 1 mM) for 2 passages. One-way ANOVA was used to determine significant differences in the data and a Tukey test was done to determine statistical differences among groups. Compared with nontreated controls, the cells treated with SAH, especially 1 mM, revealed significantly (P < 0.05) reduced global DNA methylation, proved by commercial kit and immunocytochemistry analysis, and elevation of transcript levels for X chromosome-linked genes (XIST and HPRT), estimated by real-time PCR analysis compared with the control group. It was suggested that treatment with SAH in female cells could make cells into more valuable donor cells for cloning. In another trial, cloned embryos using normal donor cells were cultured in media containing 1 mM SAH for 0 (control), 12, and 24 h after activation on different time interval of DNMT inhibition, transferred to PZM5 media, and subsequently cultured for 7 days. Treatment with SAH for 12 h resulted in 13.0 ± 1.9% blastocyst production, which was significantly greater than cloned embryos treated with SAH for 24 h (11.2 ± 2.1%) and control cloned embryos (9.1 ± 1.2%). It was suggested that the appropriate DNMT inhibition might have an important role in in vitro development of porcine SCNT, and improving effects on developmental competency of cloned embryos. We concluded that SAH induced global DNA demethylation that partially reactivated the X chromosome and that a hypomethylated genome may facilitate the nuclear reprogramming process. This study was supported by IPET (no. 311011-05-1-SB010), MKE (no. 10033839-2012-21), Institute for Veterinary Science, the BK21 program, and TS Corporation.

143 EFFECTS OF BOAR SEMINAL PLASMA IN IN VITRO CULTURE OF PORCINE EMBRYOS

Seminal plasma consisting of carbohydrates, proteins, and lipids not only serves as a nutritive and protective medium for sperm cells but also play a pivotal role in inducing the tolerance to pre-existing immune cells as well as improving the intra-uterine conditions for implantation of fertilized embryos (Guerin et al. 2009 Hum. Reprod. Update 15, 517–535). However, the effects of seminal plasma in in vitro culture of fertilized embryos are unknown. In the present study, the seminal plasma was separated from the second fraction of a normal farm boar (n = 1) by centrifugation and filtered seminal plasma was stored at –30°C until use. In a preliminary experiment, the optimal activity of seminal plasma was evaluated by incubating the embryos for different time intervals. To investigate the developmental rates, electrically (EA) (triplicates, n = 490) or chemically (CA) (quintuplicates, n = 599) activated 2-day-old porcine embryos were incubated for 3 h in PZM-5 medium (Funakoshi Co., Tokyo, Japan, Catalog no. IFP0410P) containing 0% (EA: n = 122 and CA: n = 152), 0.1% (EA: n = 123 and CA: n = 148), 0.5% (EA: n = 122 and CA: n = 150), or 1% (EA: n = 123 and CA: n = 149) seminal plasma. Similarly, the developmental rate of chemically activated 2-day-old somatic cell nuclear transferred porcine embryos (quadruplicates, n = 239) was studied after incubation with 0% (n = 119) or 0.1% (n = 120) seminal plasma for 3 h. A significant difference was noticed only in the rate of blastocyst formation in the chemically activated embryos treated with 0.1% seminal plasma (31.7 v. 24.8% in the 0% group, ANOVA; P < 0.05; Prism5, GraphPad Software Inc., La Jolla, CA, USA). None of the treatments showed a significant effect on the cleavage rate and cell numbers of blastocysts. In conclusion, the seminal plasma did not show any harmful effect on early embryos development. Furthermore, the seminal plasma (0.1%) improved the rate of blastocyst formation among the chemically activated nuclear transferred embryos. The results of this preliminary study suggest that the addition of seminal plasma during embryo transfer could increase the rate of pregnancy in pig. This study was supported by MKE (#10033839-2012-21), IPET (#311011-05-1-SB010), the Research Institute for Veterinary Science, and TS Corporation.

283 GENERATION AND CHARACTERIZATION OF BOVINE INDUCED PLURIPOTENT STEM CELLS

Stem cells in large animals are an excellent model for cell therapy research and fine resources for producing transgenic animals. However, there are only few reports of stem cells in large animals because of technical differences between species. In this report, we successfully generate bovine induced pluripotent stem cells (iPSC) using 4 human reprogramming factors (Oct4, Sox2, Klf4, and c-myc) under control of PiggyBac transposition vector. Fibroblasts derived from bovine fetuses were transfected using FugeneHD agent. After 21 days, colony-shaped structures on the culture plates were mechanically detached and then seeded on a mouse embryonic fibroblast (MEF) feeder layer pretreated with mitomycin C. The culture medium was DMEM/F12 supplemented with 20% serum replacement, 5 ng mL–1 basic fibroblast growth factor (bFGF), 0.1 mM β-mercaptoethanol, 1% NEAA, and 1% penicillin-streptomycin antibiotics. The iPSC colonies showed alkaline phosphatase activity and expressed several pluripotency markers (Oct4, Sox2, SSEA1, and SSEA4). To confirm differentiation potential, the iPSC were cultured as embryoid bodies and then plated again. βIII-tubulin (ectoderm) and GFAP or α-SMA (mesoderm) were well expressed on the attached cells. The results revealed that the bovine fibroblasts were well inducted to iPSC that had potential of multilineage differentiation. We hope this technology contributes to improving transgenic cattle production. This study was financially supported by IPET (grant # 109023-05-3-CG000, 111078-03-1-CG000) and the BK21 program for Veterinary Science.

52 IMPLANTATION OF TRANSGENIC BOVINE CLONED EMBRYOS DERIVED FROM TRANSFECTED CELLS BY PiggyBac TRANSPOSITION

A gene-delivery system, PiggyBac (PB) transposition, has been applied to transgene expression in mammalian cells or animals. In this study, to produce transgenic cattle, we used PB in bovine fibroblasts and then the transfected cells were microinjected into enucleated bovine oocytes to produce embryos and offspring. For this study, 2 different fluorescence genes (GFP, transcribed by constitutive promoter and RFP, transcribed by tetracycline-dependent promoter), which were flanked by PB sequences, were transfected into the bovine fetal fibroblasts by the FuGENE transfection protocol. The developmental rate of blastocysts among the cleaved embryos derived from GFP cells and doxycycline-induced RFP cells was developed at 23.1% (31/134) and 40.9% (442/1082), respectively. After transferring the GFP- or RFP-expressing blastocysts into recipient cows, pregnancies were detected by ultrasonography from both recipients of GFP or RFP. To know gene expression in fetal stage, embryonic sacs were collected surgically. The primary cells were successfully isolated from both embryonic sacs. Every cell from the GFP embryonic sac expressed GFP. When the cells from the RFP embryonic sac were treated with doxycycline, RFP was homogenously expressed. In conclusion, this study demonstrated that PB transposition could be applied to deliver genes into bovine somatic cells. Furthermore, transgenic embryos from transfected cells using the PB system were developed into blastocysts, implanted, and were able to form embryonic sacs. The PB system will be a useful method to produce transgenic cattle. This study was financially supported by IPET (grant no. 109023-05-3-CG000, 111078-03-1-CG000) and the BK21 Program for Veterinary Science.

158 EFFECTS OF AMINO ACIDS IN EMBRYO TRANSPORT MEDIA ON PORCINE EMBRYOS

Due to the distance from the laboratory to the recipient farm, several laboratories, including ours, carry somatic cell nuclear transfer (SCNT)-derived porcine embryos to the farm using a portable incubator for a few hours. If the embryos are nourished well during the transport, viability of embryos might be increased and cloning efficiency can be improved. TALP, which is widely used as a porcine embryo transport medium, lacks amino acids (AA). Proper supply of AA in the uterus is important for the development of pre-implantation embryos because AA have functions as osmolytes, metabolic regulators, or substrates and buffers of intracellular pH. Thus, supplementation of AA could affect the embryonic viability during the transport of SCNT-derived porcine embryos. The aim of this study is to determine whether the transport medium containing AAs affects the in vitro development of parthenogenetic embryos compared to TALP. Porcine zygote medium-5 (PZM-5) was chosen as transport medium containing AA due to its similarity in constituents with TALP except for the AA. Because PZM-5 contains sodium bicarbonate as a buffer system which can not cover wide variation of pH, 10 mM HEPES was added into PZM-5 (PZM+H) as it was normally done with TALP. Porcine cumulus–oocyte complexes (COC) were collected from ovaries of slaughtered pigs and cultured for 44 h using a two-step culture protocol. After denuded, matured oocytes were activated by thimerosal for 10 min followed by dithiothreitol for 30 min. The parthenogenetic embryos were cultured in PZM-5 for 2 days, monitored for cleavage, and loaded in a straw with TALP or PZM+H, respectively. Embryos were stored in a portable incubator (MTG, Bruckberg, Germany; no CO2) at 37°C for three hours and moved to PZM-5 drop for additional 5 days culture. The development was monitored on Day 7 after activation and blastocysts (BL) were collected for total cell number counts and RNA extraction. Ten BL from the TALP group and 11 BL from the PZM+H group were stained with 10 µg mL–1 bisbenzimide (Hoechst 33342) and were visualized for cell counting under fluorescence microscopy. Messenger RNA was extracted from 7 BL of the TALP and PZM+H groups and cDNA were synthesized. Quantitative real-time PCR were done to detect expression levels of apoptosis-related genes using the cDNA. The Bax/Bcl2 ratio was investigated as expression level of apoptosis-related genes and GAPDH was used as control. Each experiment was repeated at least 3 times. Data were analyzed by paired Student’s t-test using Graphpad Prism (version 5, Graphpad Software Inc., La Jolla, CA, USA). No difference was observed between the TALP and PZM+H groups with respect to blastocyst formation rate (22.46 ± 1.47% and 23.17 ± 2.13%, respectively) and total cell number (32.9 ± 2.22 and 37.09 ± 2.18, respectively). There was no significant difference between groups in the Bax/Bcl2 ratio. The use of PZM-5 media, which contains AA, did not affect the development and apoptosis of parthenogenetic embryos. This study was supported by MKE (#10033839-2012-21), IPET (#311011-05-1-SB010), the Research Institute for Veterinary Science, and TS Corporation.

64 USING PORCINE GRANULOSA CELLS AS FEEDERS FOR PORCINE AND BOVINE TROPHECTODERM CELL CULTURE

The trophectoderm cells, arising from the outer side of the blastomere in the blastocyst stage, are the first differentiated embryonic cells with specific potential as stem cells. The physiology of trophectoderm cells has been studied; however, their functions still remain unclear, because the lack of definitive information of cell lineages. Here, we aimed to establish in culture different feeder-dependent trophectoderm cell lines from 9-day, preimplantation, in vitro-produced porcine and bovine embryos. We used 2 different feeders: porcine granulosa cells (PGC) and mouse embryonic fibroblasts (MEF). Both cells were mitotically inactivated by mitomycin-C and then cultured with a density of 5 × 104 mL–1 on 0.1% (wt/vol) gelatin coated 4-well dishes in DMEM-199 medium supplemented with 10% (vol/vol) fetal bovine serum (FBS), nonessential amino acids (NEAA), β-mercaptoethanol and nucleosides (Talbot et al. 2000 Biol. Reprod. 62, 235–247). Trophectoderm cells were observed by light microscopy and characterised by reverse transcription-PCR using specific primers for both species. Different feeders and trophectoderm cells growth rates were compared after trypsinization using a hemocytometer. Data were analysed using 1-way ANOVA. In results, trophectoderm cells display epithelial characteristics, cuboidal morphology and express mRNA of homebox protein CDX2, cytokeratin 8 (KRT8) and interferon (IFN) gamma or tau for porcine or bovine cells, respectively. Moreover, oestrogen receptor (ESR1) and progesterone receptor (PGR) were expressed in trophectoderm cells of both species. Porcine granulosa cells were highly proliferative with doubling time of 24 h when compared to MEF (P ≤ 0.5), easy to recover and provided a reasonable source of steroids, 17β-oestradiol (E2; 31.21 ± 3.1 ng mL–1) and progesterone (P4; 6.36 ± 0.4 ng mL–1). Moreover, trophectoderm cell colonies of both species that cultured on PGC grew faster, with a doubling time of 48 h when compared to those cultured on MEF (P ≤ 0.5). We speculate that the continuous supplement of steroids and other cytokines during the co-culture of trophoblasts with granulosa cells might help the trophectoderm cells growth more than that of MEF. Further investigations are required in this regard. In conclusion, porcine granulosa cells can be good alternative feeders to culture porcine and bovine trophectoderm. This research was supported by MKE (Grant # 10033839-2011-13) and IPET.

32 NEURON-SPECIFIC EXPRESSION OF THE RED FLUORESCENCE PROTEIN IN CLONED DOGS

The pathogenesis of neuronal degenerative disease as Alzheimer's disease (AD) has been a subject of intensive research for the last few decades worldwide. But despite such effort, treatment or preventive measures for AD have so far made no breakthrough. One of the contributing factors that hindered the progress of research is the lack of appropriate AD models. Mouse models have limitations for AD research because the irreconcilable species gap between the rodent and human has impeded the research itself as well as the application of the findings from the rodent studies to human cases. As an alternative, here we performed a preliminary study to develop novel neuronal degenerative disease models using a canine transgenic somatic cell nuclear transfer (SCNT) technology. The aim of this study is to produce a transgenic dog that expresses neuron-specific transgene in the brain by SCNT. In this study, we chose human synapsin 1 promoter as primarily neuron selective, driving the red fluorescent protein transgene. For SCNT, synapsin 1-red fluorescence protein (SYN1-RFP) was introduced into female beagle adipose-derived stem cell via lentiviral vector infection. The SYN1-RFP cells were injected into enucleated in vivo-matured dog oocytes and fused by electric stimulation. The fused couplets (80/94, 85.1%) were chemically activated and transferred into the uterine tube of 5 naturally oestrus-synchronized surrogates. Three of them (60%) maintained pregnancy and subsequently gave birth to 3 cloned pups (SYN1-RFP A, SYN1-RFP B, SYN1-RFP C) by natural delivery or cesarean section. Birth weights of the offspring ranged from 120 to 280 g and SYN1-RFP C is still alive, healthy and does not show any abnormalities. The microsatellite analysis shows that all SYN1-RFP puppies originated from the SYN1-RFP cells used in SCNT and mitochondrial DNA analysis shows that the puppies had been derived from the oocyte donors. In order to investigate the result in multiple transgene insertions, SYN-RFP puppies were screened by Southern blot analysis using DNA extracted from skin biopsies. Transgene copy number was estimated by Southern blot analysis. The SYN-RFP A and B that died at 3 days after birth had approximately 5 and 2 copies of the transgene integrated, respectively, whereas the alive SYN-RFP C has 1 copy. SYN-RFP B was particular in that it did not express RFP in the entire body, but samples collected postmortem showed expression of the RFP transgene under the human synapsin 1 promoter in neural cells in the brain of SYN-RFP B. In conclusion, we report here that (1) the human synapsin promoter is functional in neural cells of dog brain and (2) a neural-specific-transgene-expressed dog was generated for the first time by transgenic SCNT technique. Furthermore, the SYN-RFP dog has great potential to understand the function of a neuronal degenerative disease model dog. This study was supported by MKE (Grant # 10033839-2011-13), RNL Bio, IPET and TS Corporation.

33 IN VITRO IMMUNOGENICITY OF SOMATIC CELL NUCLEAR TRANSFER-DERIVED TRANSGENIC CLONED DOGS

Histocompatible tissue has been generated by somatic cell nuclear transfer (SCNT) and the resultant tissues were not rejected by the immune system of the nucleus donors. In addition, many transgenic animals combined with SCNT have been produced. However, in vitro immunogenicity of transgenic cloned animals originated from the same donor cell with nontransgenic cloned animals has not been assessed until now. The objective of this study was to evaluate the in vitro immunogenicity of cloned dogs with each other, between cloned dogs and transgenic cloned dogs and between transgenic cloned dogs with each other by mixed lymphocyte reaction. In this study, we used cloned beagles (BG1, 2) derived from SCNT using fetal fibroblasts (BF3). Serially, 4 transgenic cloned beagles (Ruppy 1–3, 5) were also genetically engineered from the same donor cell, BF3, with red fluorescent protein (RFP) gene inserted into their genome. We used 2 age-matched healthy female beagle dogs as control dogs. They have different 3 DLA types with all cloned dogs. Peripheral blood mononuclear cells (PBMC) of 2 cloned beagles and 4 transgenic cloned beagles were isolated from whole bloods using Ficoll gradient solution. PBMC from each dog were mixed to auto PBMC, other transgenic cloned dogs and non-related control dogs under the experimental designs. All the mixtures were incubated at 37°C for 4 days, adding BrdU labeling reagent and re-incubated for 24 h. Results are expressed in absorbance mean value ± standard deviation of 450-nm wavelength read by microplate reader. Each cell combination was assayed in 8 replicates. In Experiment 1, PBMC of cloned beagles were combined with equal concentrations of another cloned beagle's PBMC. In Experiment 2, PBMC suspension of Ruppy 1–3, 5 were mixed with equal concentrations of another transgenic cloned beagle's PBMC suspension. In Experiment 3, PBMC suspensions of cloned beagles were mixed with PBMC suspensions of transgenic cloned beagles and reverse reaction was performed. Statistical analysis was performed by using Mann-Whitney U test. In Experiment 1, whereas the absorbance value of mixture of cloned dogs and control dogs shows apparent proliferation, auto mixture of each dog and allo-mixture of BG1 and BG2 show no proliferation (Table 1), indicating immunological factors exposed to PBMC in 2 cloned dogs were compatible. In Experiment 2 among transgenic cloned dogs, no evidence of proliferations in mixed allo-PBMC was shown (Table 1), suggesting in vitro immunogenicity between transgenic cloned dogs was also not shown. In Experiment 3 among cloned dogs and transgenic cloned dogs, no significant difference was found (Table 1). In conclusion, cloned dogs derived from SCNT shared immunological phenotype. Next, immunogenicity among transgenic cloned beagle dogs was not shown despite random insertion of a foreign gene. Lastly, cloned beagles and transgenic cloned beagles show lymphocyte antigen compatibility irrespective of having a foreign gene or not. Table 1.The absorbance values of mixed lymphocytes of 4 transgenic cloned dogs and 2 cloned dogs This study was supported by RNL BIO (#0468-20110001), IPET, MKE (#10033839-2011-13) and Natural Balance Korea.

Effect of roscovitine-treated donor cells on development of porcine cloned embryos

Synchronization of the donor cell cycle is an important factor for successful animal cloning by nuclear transfer. To improve the efficiency of porcine cloning, in the present report, we evaluated effects of contact inhibition, serum starvation and roscovitine treatment of donor cells on in vitro and in vivo developmental potency of cloned porcine embryos. Fibroblasts derived from a porcine foetus at day 30 of gestation were isolated and cultured to 70% confluency. Then, cells were either cultured to 100% confluency for contact inhibition, or cultured in 0.5% serum for 72 h for serum starvation or with 15 μM roscovitine for 24 h. Cells were most effectively synchronized at G0/G1 in the serum starvation group (87.5%) compared with the contact inhibition and roscovitine treatment groups (76.3% and 79.9% respectively p < 0.05). However, after somatic cell nuclear transfer followed by in vitro culture, the serum starvation group showed a significantly lower blastocyst formation rate (5.6%) compared with the contact inhibition and roscovitine treatment groups (11.6% and 20.0% respectively). Differential expression of apoptosis-related genes and the level of apoptosis in each treatment group explain the variation in developmental competence among the groups. Significantly higher level of apoptosis was observed in the serum starvation group. On the other hand, the roscovitine treatment group shows the lowest level of apoptosis and the best in vitro development among the groups. Cloned embryos derived from roscovitine-treated donor cells were transferred to surrogate pigs. Three healthy live piglets were produced. In conclusion, we suggest that roscovitine treatment of donor cells improves development of cloned porcine embryos and can raise the efficiency of cloned piglet production.

332 INDUCIBLE RED FLUORESCENT PROTEIN (RFP) EXPRESSION IN PORCINE FIBROBLASTS AND TRANSGENIC CLONED EMBRYOS USING piggyBac TRANSPOSITION

Transgenic pigs are promising animal resources for human disease models and organ donors for xenotransplantation, because they resemble humans anatomically and physiologically. Transgenic pigs have been produced from transfected donor cells using several gene delivery systems including retrovirus infection. Recently, it has been reported that piggyBac (PB) transposition is a highly efficient tool in producing transgenic mice. This study investigated the use of PB transposition to establish transgenic cells and produce transgenic cloned embryos in pigs. We constructed plasmid DNA with red fluorescence protein (RFP) expressed by tetracycline-dependent cassette (from Addgene) with PB site using gateway cloning. We co-transfected porcine fibroblasts with the structured plasmid vector (pB-TET-DsRed), pB-rtTA (from Addgene), and a transposase expression vector pCy43 (Sanger Insitute, Hinxton, UK) using Fugene HD. After 24 h, 2 μg mL–1 doxycycline was added to the culture medium to turn on RFP expression. After 48 h of culture, 1 mg mL–1 neomycin was added to select stable RFP transfectants. Selected fibroblasts were cultured for 9 days without doxycycline, thus reducing RFP expression. After establishment of inducible RFP-expressing cells, the cells were used for somatic cell nuclear transfer. Embryos were cultured in porcine zygote medium-3, and 2 μg mL–1 doxycycline was added 5 days later. As a result, RFP expression was detected in the blastocysts. In conclusion, this study demonstrated that the inducible RFP gene in porcine fibroblasts and embryos was controlled by PB transposition system. Furthermore, this system could be a means of delivering an exogenous gene into porcine somatic cells and embryos for transgenic research. This study was supported by grants from MKE (#2009-67-10033839, #2009-67-10033805), IPET (#109023-05-1-CG000), NRF (#M10625030005-10N250300510), and BK21 program.

331 BLOOD ANTIGEN-COMPATIBILITY BETWEEN CLONED BEAGLES AND TRANSGENIC CLONED BEAGLES

It is known that cloned animals produced by somatic cell nuclear transfer (SCNT) using the same donor cells show immunological compatibility for tissue transplantation. However, immunological compatibility for tissue transplantation or blood transfusion between cloned animals and transgenic cloned animals originating from the same donor cell has not been assessed until now. The objective of this study was to evaluate the compatibility of blood group antigens in cloned dogs with each other, in cloned dogs and transgenic cloned dogs, and in transgenic cloned dogs with each other by a crossmatching test. In Lee’s group, 2 cloned beagles (BG1, 2) were produced from fetal fibroblasts (BF3) using SCNT. Serially, 4 transgenic cloned beagles (Ruppy 1–3, 5) were also genetically engineered from the same donor cell, BF3, although with the transfection of the red fluorescent protein (RFP) gene. All 6 beagles shared the same genetic background except for RFP gene insertion in their genome. Canine blood antigen is labelled as dog erythrocyte antigen (DEA), a critical factor for determining blood antigen compatibility during a crossmatching test. Blood samples were collected from all tested dogs. Serum and red blood cells (RBC) were separated; RBC of all dogs were washed 3 times with 0.9% saline, and a 4% RBC suspension was made from the washed cells. They were mixed in the following experimental designs. In experiment 1, an RBC suspension of cloned beagles was combined with equal volumes of another cloned beagle’s serum. In experiment 2, an RBC suspension of Ruppy 1–3, 5 was mixed with an equal volume of another transgenic cloned beagle’s serum; the reverse reaction was also performed. In experiment 3, an RBC suspension of cloned beagles was mixed with the serum of transgenic cloned beagles and the reverse reaction was performed. All the mixtures were incubated at 37°C for 20 min, centrifuged, and then assessed for hemolysis or agglutination. In experiments 1 and 2, no samples showed any evidence of hemolysis. However, in contrast to the other experiments, experiment 3 showed a different pattern. Although the RBC of transgenic cloned dogs showed hemolysis when mixed with the serum of cloned dogs, the RBC of cloned dogs did not react with the serum of transgenic cloned dogs. From the results, we see that the 4 transgenic cloned beagles could not be donors for blood transfusion, but the 2 cloned dogs could be universal donors for all. In conclusion, cloned beagles and transgenic cloned beagles show blood antigen compatibility within themselves. However, the 4 transgenic cloned beagles showed blood antigen incompatibility with the 2 cloned beagles. This study was supported by Korean MEST, through NRF (grant #M10625030005-10N250300510), and BK21 program, SNU foundation (Benefactor; RNL BIO) and Natural Balance Korea.

56 ESTABLISHMENT OF TRANSGENIC RED FLUORESCENCE PROTEIN (RFP) CLONE DOGS THROUGH A STABLE TRANSMISSION OF RFP GENE TO NEXT GENERATION

Somatic cell nuclear transfer (SCNT) technology has been spotlighted not only for its advantage in producing unlimited numbers of genetically identical animals, but also the possibility of producing complex genetic modifications in animals. However, a few reports showed that mosaic expression of transgene in transgenic animals produced by SCNT (Park et al. 2002) and down-regulated gene expression is sometimes irreversible in their offspring (Bordignon et al. 2003). Therefore, we investigated reproductive ability by a breeding between female transgenic beagles and wild-type beagles. When female transgenic beagles (R1, R2, R3, and R5) expressing red fluorescence protein (RFP) gene reached puberty at 373, 353, 283, and 354 days after birth, serum progesterone concentration was monitored for detecting timing of ovulation. Approximately 72 to 79 h after ovulation, the beagles were naturally mated or artificially inseminated. Pregnancy was confirmed by ultrasonography at Day 30 after insemination. The transgenic bitches (R1, R2, R3, and R5) were then bred with wild-type male dogs, became pregnant, and successfully delivered 13 puppies (9 female and 4 male). In order to prove integration of RFP gene in all offspring, DNA was extracted from the blood of pups on Day 7 after birth. For PCR analysis, a primer pair for the RFP gene, forward primer (5′CGTGAAGCTGAAGGTGA-3′) and reverse primer (5′-CTCGTACTGCTCCACGA-3′), were used to amplify a 517-bp DNA fragment. The initial denaturation was performed at 94°C for 5 min, followed by 30 cycles at 94°C for 40 s (denaturation), 58°C for 40 s (annealing), and 72°C for 40 s (extension), and a final incubation at 72°C for 10 min to ensure complete strand extension. Presence of the RFP transgene in 7 of the puppies was confirmed by PCR and the puppies expressed RFP upon UV illumination. It was not different from the 53.8% expected Mendelian ratio. The present result demonstrated a stable transmission of the RFP gene into 5 female and 2 male offspring in the second generation. Among the second generation, 2 female puppies integrated with the RFP gene were in heat at ∼1-year-old. They were then bred with the semen of a wild-type beagle and bore 6 puppies. In the third generation, 3 puppies carried the RFP gene and results showed the expected Mendelian ratio. In conclusion, the present study demonstrates that female transgenic beagles have normal reproductive ability and a stable insertion of the transgene to the next generation. This study was financially supported by NRF (#M10625030005-508-10N25), SNU foundation (Benefactor; RNL BIO), BK 21 for Veterinary Science, and Purina Korea.

105 IN VIVO DEVELOPMENT OF CANINE PARTHENOTES AND THE EXPRESSION PATTERN OF Igf2/Igf2r GENES

Parthenogenesis is the process by which an oocyte develops without fertilization, resulting in parthenogenetic embryos carrying only maternal chromosomes. Until now, little information has been available on the post-activation development of parthenogenetic embryos, and there are no reports about canine post-implantation development of parthenogenetically activated oocytes. Thus, the objective of this study was to investigate the development of parthenogenetic canine embryos when implanted in vivo, and the subsequent post-implantation development of such canine parthenogenetic fetuses. Also, we examined expression patterns of Igf2 and its receptor (Igf2r), which are reciprocally imprinted and expressed from the paternal and maternal genomes, respectively, in other mammalians, to gain insight into the role of genomic imprinting during uniparental development. In vivo matured dog oocytes were obtained by flushing oviducts of mixed breed bitches ∼72 h after ovulation. The denuded oocytes (n = 48; 5 replicates) were subjected to chemical activation by incubation in a culture medium containing 10 μM calcium ionophore (Sigma, St. Louis, MO, USA) for 4 min and then in a culture medium supplemented with 1.9 mM of 6- dimethylaminopurine (Sigma) for 4 h at 39°C. Parthenogenetic embryos were surgically transferred to synchronized recipient female dogs. The implantation rate of parthenogenetic embryos was compared with that of artificially inseminated controls. Normal and parthenogenetic fetuses, obtained from recipients on Day 28, 30, and 32 of pregnancy, were analysed for gross external morphology and Igf2/Igf2r gene expression examined. Data were analysed using SAS and means compared by Student’s t-test. The in vivo development of canine parthenogenetic fetuses was observed after embryo transfer and the implantation rate of parthenotes was 56.3%, which was significantly lower than those of the control (79.5%; P < 0.05). The weight of parthenogenetic fetuses and placentae recovered from uteri at 28, 30, and 32 day of pregnancy were significantly lighter than those of the control (P < 0.05), whereas the appearance of recovered parthenogenetic fetuses were comparable to those of in vivo fertilized fetuses. We found that both Igf2 and Igf2r were expressed in canine parthenotes but the expression level of Igf2 in the parthenotes was significantly lower than the control (P < 0.05). The expression level of Igf2r in the parthenotes was comparable with the control. These results confirmed that the protocols used in our present study were suitable for activating the canine oocyte artificially and to support the viability and developmental potential of canine embryos up to the mid-gestation stage. It will provide an opportunity to determine the reason for developmental differences between parthenogenetic and fertilized embryos, and will be a useful model system for elucidating the roles of parental genomes in mammalian postimplantation development. This study was financially supported by NRF (#M10625030005-508-10N25), SNU foundation (Benefactor; RNL BIO), Institute for Veterinary Science, and Nature Balance Korea.

130 THE SYNERGIC EFFECT OF NERVE GROWTH FACTOR AND VASCULAR ENDOTHELIAL GROWTH FACTOR ON IN VITRO MATURATION AND DEVELOPMENTAL COMPETENCE IN BOVINE OOCYTES

Nerve growth factor (NGF) has been reported to increase the mRNA expression of vascular endothelial growth factor (VEGF) in granulose cells of human, rat via TrkA signaling; VEGF has been shown to exert beneficial effects during bovine in vitro maturation (IVM) as well as early embryonic development. The aims of this study were 1) to investigate not only the direct effect of NGF but also the collaborative effect of NGF and VEGF during bovine in vitro maturation (IVM), in vitro culture (IVC), or both; and 2) to validate the correlation among transcript abundance of 7 genes (VEGF164, VEGF120, Flt-1, Flk-1, TrkA, PTGS2, and CYP11A1) in bovine cumulus cells and the results of IVM or IVC among the differently treated groups. In Experiment 1, concentrations of 0, 10, and 100 ng mL–1 NGF were added to our established IVM medium without serum, and in Experiment 2, control and treatment groups (concentration of 0, 10, and 100 ng mL–1 NGF with VEGF 100 ng mL–1) were added into chemically defined media. The oocytes of each group in Experiments 1 and 2 were determined by the proportion of MII oocytes after 24 h, and embryos were assessed after parthenogenetic activation. Cumulus cells from the differently treated matured cumulus cell–oocyte complexes (COC) were separated and synthesised into cDNA for RT-PCR and real-time PCR in order to measure relative abundance of 7 genes in a dose-dependent manner or a time-dependent manner. In Experiment 1, the concentration of 10 ng mL–1 (57.40%) and 100 ng mL–1 (62.75%) NGF treatment groups did not significantly increase the proportion of MII oocytes compared with the control group (55.06%). In Experiment 2, both the NGF 10 ng mL–1 with VEGF 100 ng mL–1 treated group (67.69%; P ≤ 0.01) and the NGF 100 ng mL–1 with VEGF 100 ng mL–1 treated group (72.24%; P ≤ 0.001) had a significantly higher percentage of polar body extrusion than control group (51.77%) and the group which was treated with VEGF 100 ng mL–1 (56.39%). The NGF treatment group with VEGF increased transcriptional level of VEGF164 and VEGF120 compared with the control group and only NGF- or VEGF-treated groups. In addition, either the NGF-treated group or NGF plus VEGF showed significantly increased mRNA abundance in VEGF164, VEGF120, Flt-1, Flk-1, and TrkA genes, whereas the NGF plus VEGF-treated group indicated the up-regulation of VEGF164, VEGF120, CYP11A1, and PTGS2 genes. In conclusion, NGF and exogenous VEGF have a synergic effect during bovine IVM and the early stage of embryo development; the elevated VEGF mRNA abundance in cumulus cells might contribute to the viability of bovine oocytes and early embryonic development. This study was supported by grants from IPET (#109023-05-1-CG000), NRF (#M10625030005-10N250300510), MKE (#2009-67-10033839, #2009-67-10033805), and BK21 program.

129 DEVELOPMENTAL COMPETENCE OF PORCINE OOCYTES AFTER IN VITRO MATURATION AND IN VITRO CULTURE UNDER COMPARATIVE OXYGEN TENSION

The in vitro developmental abilities of porcine oocytes are generally increasing steadily at a similar ratio to those of in vivo embryos. However, it has been suggested that the in vitro culture system for the development of porcine embryos is not optimal. In this study, we investigated the effect of 2 oxygen concentrations (5 and 20%) on porcine embryo development during in vitro maturation and in vitro culture and analyzed differences in gene expression of resulting blastocysts. Oocytes were recovered by aspiration of slaughterhouse ovaries and then matured in tissue culture medium (TCM) 199 supplemented with 10% porcine follicular fluid (pFF), epidermal growth factor (EGF), insulin, pyruvate, cystine, and gonadotropin. Matured oocytes were then activated parthenogenetically, cultured in PZM-3 media for 7 days. In vitro maturation (M group) of oocytes was carried out under two oxygen concentration (5 and 20%) in terms of nuclear maturation (polar body extrusion; Exp. 1). The developmental differences between 5% oxygen culture group and 20% oxygen culture group during in vitro culture (C group) of embryos after parthenogenetic activation was investigated in terms of first cleavage and blastocyst formation (Exp. 2). Relative mRNA abundance of multiple genes in blastocysts was analyzed for transcript abundance of genes related with metabolism (GLUT1, LDHA), oxidative response (MnSOD, GPX1), apoptosis (BAX, Bcl2), and developmental competence (CCNB1, IGF2R; Exp. 3). The results show there were no significant differences in maturation rate between 2 oxygen concentrations during in vitro maturation (83 v. 86%). It was thought that cumulus cells surrounding oocytes might have attenuated oxidative stress, but number of resulting blastocysts were (P < 0.05) increased in 5% IVC group when compared with 20% IVC group (18.67 v. 14.09%, respectively). Moreover, the M20C5 group (23.01%) had a beneficial effect on in vitro culture compared with M5C5 (14.32%), M5C20 (10.30%), and M20C20 (17.88%) groups. Total cell numbers were not significantly different among groups. According to mRNA abundance data of multiple genes, each group altered the expression of genes in various patterns. Therefore, it could be concluded that high oxygen tension during in vitro maturation and low oxygen tension during in vitro culture might alter the expression of multiple genes related to oocyte competence and improve (P < 0.05) embryo development, but not blastocyst quality. This study was supported by MKE (#2009-67-10033839, #2009-67-10033805), NRF (#M10625030005-508-10N25), BK21 for Veterinary Science, IPET (#109023-05-1-CG000), and Hanhwa L&C.

58 ISOLATION OF BOVINE TROPHOBLAST AND ITS REPROGRAMMING BY NUCLEAR TRANSFER

Nuclear transfer (NT) has been used to produce many cloned offspring using several types of cells, including embryonic cells. Even though inner cell mass cells have been used as donor karyoplast for producing cloned animals, there are few studies using trophoblast. In mice, clones were born by nuclear transfer of trophoblasts from the expanded blastocyst into enucleated oocytes as a trial to show the totipotency of both inner cell mass and trophectoderm cells isolated from blastocysts (Tsunoda and Kato 1998 J. Reprod. Fertil. 113, 181–184). However, bovine trophoblast cell (TC) lines have not been used in NT to date. The purpose of this study was to elucidate whether TC as donor cell can be reprogrammed in bovine enucleated oocyte and determine the relative abundance of interferon tau (IFNτ) expression in the resulting cloned preimplantational embryos. Hatched blastocysts produced by IVF were used to isolate TCs on mouse embryonic fibroblasts treated with mitomycin C as feeder cells. TCs and adult fibroblasts (AF, control group for NT) were microinjected to perivitelline space of in vitro mature enucleated oocytes and electrically fused. Reconstructed embryos were chemically activated and cultured in a 2-step chemically defined medium. Levels of IFNτ expression in IVF-, TC-, and AF-derived blastocysts were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). IVF produced embryos were used as reference to analyze the linear progressive expression of IFNτ through mid-, expanded, and hatching blastocysts. As a result, TCs expressing IFNτ were successfully isolated and cultured on feeder layers. It grew as cell sheets of cuboidal epithelium with high proliferation capacity as a single colony originated from a small clump of cells measured 0.5 cm within 7 days of culture. TCs were reprogrammed in the enucleated oocytes to blastocyst with similar efficiency to AF (14.5% and 15.6%, respectively; P ≤ 0.05). RT-qPCR studies showed that IFNτ expression was higher in TC-derived blastocysts than IVF- and AF-derived blastocysts. Both IVF- and TC-derived blastocysts, showed progressive increase of IFNτ expression through the advancement of blastocyst development when it was compared to AF-derived blastocysts. In conclusion, using TCs expressing IFNτ as donor cell for bovine NT could increase the developmental competence of cloned embryos as indicated by progressive linear increase in IFNτ expression. This study was supported by grants from IPET (#109023-05-1-CG000), NRF (#M10625030005-10N250300510), MKE (#2009-67-10033839, #2009-67-10033805), and BK21 program. Saadeldin I. M. is supported by Islamic Development Bank (IDB) merit scholarship, Jeddah, Saudi Arabia.

Influence of oocyte donor and embryo recipient conditions on cloning efficiency in dogs

To determine factors that affect the efficiency of dog cloning by somatic cell nuclear transfer, the present study was performed to investigate 1) the effects of surgical history (non-operated/operated) and parity (nullipara/multipara) on the recovery of in vivo canine oocytes; 2) the effects of surgical history and parity of recipients on the pregnancy and delivery; and 3) the effects of synchronization state (AA, advanced asynchrony; SY, synchrony; RA, retarded asynchrony) between oocytes donor and recipient on the pregnancy and delivery. Oocyte recovery rate was significantly higher in non-operated dogs compared to operated dogs (93.8 vs. 89.6%, P < 0.05) and not different between nulliparous dogs and multiparous dogs. Delivery rate was also significantly higher in non-operated dogs compared to operated dogs (2.8 vs. 1.0%, P < 0.05) and in nulliparous dogs than multiparous dogs (3.0 vs. 1.7%, P < 0.05). Even though SY showed increased pregnancy and delivery rate (20.0% and 3.0%) compared to AA (15.0% and 2.0%) and RA (0.0% and 0.0%), there was no significant difference. In conclusion, we recommend non-operated dogs as experimental dogs and nulliparous dogs as recipient dogs to increase delivery rate after transfer of somatic cell nuclear transferred embryos, but further study is needed to find out appropriate synchrony status at the transfer.

342 EFFECTS OF MELATONIN ON PREIMPLANTATION DEVELOPMENT OF PORCINE PARTHENOGENETIC EMBRYOS

In mammalian species, melatonin is a multi-functional pineal gland hormone that regulates several circadian and seasonal rhythms including reproduction. However, the melatonin study was not common as to the oocytes in the pig. Recently, we reported that exogenous melatonin has beneficial effects on nuclear and cytoplasmic maturation during porcine oocyte IVM and we also reported an existence of melatonin receptor on the cumulus cells and granulose cells (Kang JT et al. 2009 J. Pineal Res. 46(1), 22-28). In this study, as adding further experiments rather than our previous study, we investigated effect of exogeneous melatonin (10 ng mL-1) on the porcine oocytes and analyzed possible factors which can be responsible for that results. Oocytes were recovered by aspiration of slaughterhouse ovaries, and then matured in TCM-199 supplemented with EGF, insulin, pyruvate, cystine, and gonadotropin. Expression of apoptosis-related genes mRNA in oocytes cultured with melatonin were evaluated by real-time PCR (Exp 1), cumulus cell expansion on COC was assessed on the microscopes during in vitro maturation (Exp 2), and developmental effects between melatonin treatement group and non-treatment group on the in vitro culture of parthenogenetically activated oocytes was investigated (Exp 3). In results, oocytes matured with melatonin were assessed for the expression of apoptosis-related genes Bcl-xl (anti-apoptotic gene) and Bax (proapoptotic gene) by real-time quantitative PCR. Analysis of data showed that the expression of Bcl-xl was higher compared to the control while the expression of Bax was decreased relative to the control (P < 0.05). Cumulus cell expansion was evaluated under a stereomicroscope at 22 h, 44 h during IVM. Representative photomicrographs of porcine COC at the start of the IVM, after 22 h and 44 h treatment with melatonin, are shown in Figure. After 22 h of melatonin treatment, cumulus cells were visually expanded compared with non-treatment group. We analyzed significantly greater proportion of parthenogenetically activated oocytes developed to blastocyst when the IVM medium was supplemented with melatonin. Melatonin treatment in the IVM has consequently beneficial effect on the blastocyst formation rates on the development of porcine parthenogenetic embryos (15.4%) compared to non-treatment group (10.7%, P < 0.05). However, cleavage frequency was not affectedby the treatment. In conclusion, the present study demonstrated that melatonin had a beneficial effect on the development of parthenogenetically activated porcine embryos, probably through decreased apoptosis rate and increased cumulus cell expansion. This study was supported by Korean MKE, MEST (BK21 program), and Hanhwa L&C