Biodegradation of polyethylene by the marine fungus Parengyodontium album

Plastic pollution in the marine realm is a severe environmental problem. Nevertheless, plastic may also serve as a potential carbon and energy source for microbes, yet the contribution of marine microbes, especially marine fungi to plastic degradation is not well constrained. We isolated the fungus Parengyodontium album from floating plastic debris in the North Pacific Subtropical Gyre and measured fungal-mediated mineralization rates (conversion to CO2) of polyethylene (PE) by applying stable isotope probing assays with 13C-PE over 9 days of incubation. When the PE was pretreated with UV light, the biodegradation rate of the initially added PE was 0.044 %/day. Furthermore, we traced the incorporation of PE-derived 13C‑carbon into P. album biomass using nanoSIMS and fatty acid analysis. Despite the high mineralization rate of the UV-treated 13C-PE, incorporation of PE-derived 13C into fungal cells was minor, and 13C incorporation was not detectable for the non-treated PE. Together, our results reveal the potential of P. album to degrade PE in the marine environment and to mineralize it to CO2. However, the initial photodegradation of PE is crucial for P. album to metabolize the PE-derived carbon.

Discovery and quantification of a widespread methane ebullition event in a coastal inlet (Baltic Sea) using a novel sonar strategy

How much of the greenhouse gas methane is transported from the seafloor to the atmosphere is unclear. Here, we present data describing an extensive ebullition event that occurred in Eckernförde Bay, a shallow gas-hosting coastal inlet in the Baltic Sea, in the fall of 2014. A weak storm induced hydrostatic pressure fluctuations that in turn stimulated gas ebullition from the seabed. In a finely tuned sonar survey of the bay, we obtained a hydroacoustic dataset with exceptionally high sensitivity for bubble detection. This allowed us to identify 2849 bubble seeps rising within 28 h from the seafloor across the 90 km² study site. Based on our calculations, the estimated bubble-driven episodic methane flux from the seafloor across the bay is 1,900 μMol m⁻² d⁻¹. Our study demonstrates that storm-associated fluctuations of hydrostatic pressure induce bulk gas-driven ebullitions. Given the extensive occurrence of shallow gas-hosting sediments in coastal seas, similar ebullition events probably take place in many parts of the Western Baltic Sea. However, these are likely to be missed during field investigations, due to the lack of high-quality data acquisition during storms, such that atmospheric inputs of marine-derived methane will be highly underestimated.

First Observation of a Stable Highly Dissipative Divertor Plasma Regime on the Wendelstein 7-X Stellarator

For the first time, the optimized stellarator Wendelstein 7-X has operated with an island divertor. An operation regime in hydrogen was found in which the total plasma radiation approached the absorbed heating power without noticeable loss of stored energy. The divertor thermography recorded simultaneously a strong reduction of the heat load on all divertor targets, indicating almost complete power detachment. This operation regime was stably sustained over several energy confinement times until the preprogrammed end of the discharge. The plasma radiation is mainly due to oxygen and is located at the plasma edge. This plasma scenario is reproducible and robust at various heating powers, plasma densities, and gas fueling locations. These experimental results show that the island divertor concept actually works and displays good power dissipation potential, producing a promising exhaust concept for the stellarator reactor line.

182 Establishment of expanded potential embryonic stem cell lines from porcine embryos

The domestic pig is an excellent large animal in biomedical medicine and holds great potential for testing the clinical safety and efficacy of stem cell therapies. Previously, numerous studies reported the derivation of porcine embryonic stem cell (ESC)-like lines, but none of these lines fulfilled the stringent criteria for true pluripotent germline competent ESC. Here, we report the first establishment of porcine expanded potential stem cells (pEPSC) from parthenogenetic and in vivo-derived blastocysts. A total of 12 cell lines from parthenogenetic blastocysts from Day 7 (12/24) and 26 cell lines from in vivo-derived blastocysts from Day 5 (26/27) were established using defined stem cell culture conditions. These cells closely resembled mouse ESC with regard to morphology, formed compact colonies with high nuclear/cytoplasmic ratios, and could be maintained in vitro for more than 40 passages with a normal karyotype. The pEPSC expressed key pluripotency genes, including OCT4, NANOG, SOX2, and SALL4 at similar levels as porcine blastocysts. Immunostaining analysis confirmed expression of critical cell surface markers SSEA-1 and SSEA-4 in pEPSC. The EPSC differentiated in vitro into tissues expressing markers of the 3 germ layers: SOX7, AFP, T, DES, CRABP2, α-SMA, β-tubulin, PAX6, and, notably, the trophoblast markers HAND1, GATA3, PGF, and KRT7. After injection into immunocompromised mice, the pEPSC formed teratomas with derivatives of the 3 germ layers and placental lactogen-1 (PL-1)-positive trophoblast-like cells. Additionally, pEPSC cultured in vitro under conditions specific for germ cells formed embryoid bodies, which contained ~9% primordial germ cell (PGC)-like cells (PGCLC) that expressed PGC-specific genes, including NANOS3, BLIMP1, TFAP2C, CD38, DND1, KIT, and OCT4 as detected by quantitative RT-PCR and immunostaining. Next, we examined the in vivo differentiation potential of pEPSC and injected pEPSC stably expressing the CAG-H2B-mCherry transgene reporter into porcine embryos. The donor cells proliferated and were localised in both the trophectoderm and inner cell mass of the blastocysts cultured in vitro. After transfer to 3 recipient sows, chimeric embryos implanted and a total of 45 fetuses were recovered on Days 26 to 28. Flow cytometry of single cells collected from embryonic and extraembryonic tissues of the fetuses revealed mCherry+ cells in 7 conceptuses, in both the placenta and embryonic tissues; in 3 chimeric conceptuses, mCherry+ cells were exclusively found in embryonic tissues; and in 2 conceptuses, mCherry+ cells were exclusively localised in the placenta. The contribution of the mCherry+ cells was low (0.4-1.7%), but they were found and co-detected in multiple porcine embryonic tissues using tissue lineage-specific markers, including SOX2, TUJ1, GATA4, SOX17, AFP, α-SMA, and trophoblast markers PL-1 and KRT7 in the placental cells. The successful establishment of pEPSC represents a major step forward in stem cell research and provides cell lines with the unique state of cellular potency useful for genetic engineering and unravelling pluripotency regulation in pigs.

Towards a new image processing system at Wendelstein 7-X: From spatial calibration to characterization of thermal events

Wendelstein 7-X (W7-X) is the most advanced fusion experiment in the stellarator line and is aimed at proving that the stellarator concept is suitable for a fusion reactor. One of the most important issues for fusion reactors is the monitoring of plasma facing components when exposed to very high heat loads, through the use of visible and infrared (IR) cameras. In this paper, a new image processing system for the analysis of the strike lines on the inboard limiters from the first W7-X experimental campaign is presented. This system builds a model of the IR cameras through the use of spatial calibration techniques, helping to characterize the strike lines by using the information given by real spatial coordinates of each pixel. The characterization of the strike lines is made in terms of position, size, and shape, after projecting the camera image in a 2D grid which tries to preserve the curvilinear surface distances between points. The description of the strike-line shape is made by means of the Fourier Descriptors.

A divertor scraper observation system for the Wendelstein 7-X stellarator

Two graphite divertor elements called scrapers have been installed on the Wendelstein 7-X stellarator in the throat of the magnetic island divertor. To diagnose one, we have designed, built, calibrated, and installed a new infrared/visible imaging endoscope system to enable detailed observations of the plasma interactions and heat loads at one of the scrapers and the nearby divertor surfaces. The new system uses a shuttered pinhole-protected pair of 90° off-axis 228 mm focal length aluminum parabolic mirrors, and two flat turning metal mirrors, to send light to a sapphire vacuum window 1.6 meters away, beyond which we have co-located telephoto lens-based infrared and visible cameras. The back-to-back off-axis parabolas serve to cancel out most aberrations, enabling the use of off-the-shelf commercial optics outside of the vessel. For the infrared, we use a 3-5 μm 1-megapixel FLIR SC8303HD camera and for the visible, a 5-megapixel CMOS PCO 5.5 edge camera. A short 1-m quartz pickoff fiber is used to send 200-1100 nm light to a compact spectrometer, also located in the same iron shield box as the cameras. The camera field of view covers the 700 mm length of the scraper, and includes locations monitored by thermocouples and Langmuir probes embedded in some of the scraper tiles. Predicted and actual optical test performances of the overall system are compared.

Gene-specific profiling of DNA methylation and mRNA expression in bovine oocytes derived from follicles of different size categories

Epigenetic changes, such as DNA methylation, play an essential role in the acquisition of full developmental competence by mammalian oocytes during the late follicular growth phase. Here we used the bovine model to investigate the DNA methylation profiles of seven candidate genes (imprinted: bH19, bSNRPN; non-imprinted: bZAR1, bDNMT3A, bOCT4, bDNMT3 Lo and bDNMT3 Ls) and the mRNA expression of nine candidate genes (imprinted: bSNRPN, bPEG3, bIGF2R; non-imprinted: bPRDX1, bDNMT1B, bDNMT3A, bZAR1, bHSF1 and bNLRP9) in oocytes from antral follicles of three different size classes (≤2mm, 3-5mm, ≥6mm) to unravel the epigenetic contribution to this process. We observed an increased number of aberrantly methylated alleles in bH19, bSNRPN and bDNMT3 Lo of oocytes from small antral follicles (≤2mm), correlating with lower developmental competence. Furthermore, we detected an increased frequency of CpG sites with an unclear methylation status for DNMT3 Ls, specifically in oocytes from follicles ≥6mm, predominantly at three CpG positions (CpG2, CpG7 and CpG8), of which CpG7 is a potential regulatory site. No major differences in mRNA expression were observed, indicating that the transcriptional machinery may not yet be active during the follicular growth phase. Our results support the notion that a follicle diameter of ~2mm is a critical stage for establishing DNA methylation profiles and indicate a link between DNA methylation and the acquisition of oocyte developmental competence.

Successful knock-in of Hypertrophic Cardiomyopathy-mutation R723G into the MYH7 gene mimics HCM pathology in pigs

Familial Hypertrophic Cardiomyopathy (HCM) is the most common inherited cardiac disease. About 30% of the patients are heterozygous for mutations in the MYH7 gene encoding the ß-myosin heavy chain (MyHC). Hallmarks of HCM are cardiomyocyte disarray and hypertrophy of the left ventricle, the symptoms range from slight arrhythmias to sudden cardiac death or heart failure. To gain insight into the underlying mechanisms of the diseases' etiology we aimed to generate genome edited pigs with an HCM-mutation. We used TALEN-mediated genome editing and successfully introduced the HCM-point mutation R723G into the MYH7 gene of porcine fibroblasts and subsequently cloned pigs that were heterozygous for the HCM-mutation R723G. No off-target effects were determined in the R723G-pigs. Surprisingly, the animals died within 24 h post partem, probably due to heart failure as indicated by a shift in the a/ß-MyHC ratio in the left ventricle. Most interestingly, the neonatal pigs displayed features of HCM, including mild myocyte disarray, malformed nuclei, and MYH7-overexpression. The finding of HCM-specific pathology in neonatal R723G-piglets suggests a very early onset of the disease and highlights the importance of novel large animal models for studying causative mechanisms and long-term progression of human cardiac diseases.

Evaluation of Computer-assisted Image Enhancement in Minimal Invasive Endoscopic Surgery

Objectives: This paper focusses on the evaluation of the usage of computer-aided image processing methods for minimal invasive surgery. During video endoscopy of visceral cavities the images are displayed directly on the monitor without further processing. In the course of the operation the former good quality of the images decreases due to typical disturbances like bleeding, smoke or flying particles. These disturbances can be reduced by using image processing methods like color normalization, temporal filtering or equalization.

Methods: In this double-blinded analysis, 14 surgeons with different levels of experience evaluated 120 image pairs and 5 image sequences, directly comparing original and processed images or movies.

Results: Color normalization and equalization proved to significantly enhance video endoscopic images. With regard to temporal filtering, an improvement could be seen in the image sequences with filter size 5 being a greater enhancement than filter size 3. Comparing the state of experience and its influence on the results, it occurred that the experienced surgeons preferred the original color while altogether agreeing that the color-normalized images were better.

Conclusions: The results obtained in the present evaluation show that the image processing methods which were used can significantly improve the quality of video endoscopic images. As a result of this, necessary lavages of the operated area are reduced and a better overview and orientation for the surgeon can be reached.

Light Fields for Minimal Invasive Surgery Using an Endoscope Positioning Robot

Objectives: To generate a fast and robust 3-D visualization of the operation site during minimal invasive surgery.

Methods: Light fields are used to model and visualize the 3-D operation site during minimal invasive surgery. An endoscope positioning robot provides the position and orientation of the endoscope. The a priori unknown transformation from the endoscope plug to the endoscope tip (hand-eye transformation) can either be determined by a three-step algorithm, which includes measuring the endoscope length by hand or by using an automatic hand-eye calibration algorithm. Both methods are described in this paper and their respective computation times and accuracies are compared.

Results: Light fields were generated during real operations and in the laboratory. The comparison of the two methods to determine the unknown hand-eye transformation was done in the laboratory. The results which are being presented in this paper are: rendered images from the generated light fields, the calculated extrinsic camera parameters and their accuracies with respect to the applied hand-eye calibration method, and computation times.

Conclusion: Using an endoscope positioning robot and knowing the hand-eye transformation, the fast and robust generation of light fields for minimal invasive surgery is possible.

122 A New Maturation Medium Improves Porcine Embryo Production In Vitro

Recently (Spate et al. 2017 Reprod. Fertil. Dev. 29, 150), a new medium [TCM-199 supplemented with hCG 10 IU, pregnant mare serum gonadotropin (PMSG) 10 IU mL−1, fibroblast growth factor (FGF) 40 ng mL−1, leukemia inhibitory factor (LIF) 2000 U mL−1, IGF-1 20 ng mL−1, epidermal growth factor (EGF) 10 ng mL−1], termed FLI medium, was demonstrated to improve porcine oocyte maturation in vitro. The effects on embryo development and quality have not yet been investigated. The purpose of the present study was to compare the FLI medium in porcine in vitro embryo production (IVP) with our standard maturation medium (DMEM supplemented with 10 IU mL−1 PMSG and hCG, 50 ng mL−1 EGF, 100 ng mL−1 IGF1, and 5 ng mL−1 FGF). Briefly, gilt oocytes were collected via aspiration of follicles from abattoir ovaries and matured for 44 h in either FLI or standard DMEM medium at 39°C, 5% CO2 in humidified air. In vitro fertilization was performed with freshly ejaculated sperm (250,000 mL−1) of a multi-transgenic boar (GGTA1-KO/hCD46/hCD55/hCD59/hHO-1/hA20) by co-incubation with the matured oocytes in PGMTac4 medium for 4 h. Zygotes were washed twice and then cultured for 6 days in PZM3 medium. Development to the blastocyst stage was recorded at Day 6 of culture. Blastocysts were fixed and Hoechst33342 stained for counting the nuclei. Each of the experiments was repeated 3 times. In a second step, Day 5 blastocysts derived from the FLI medium were transferred to synchronized pubertal gilts to test the in vivo developmental competence of the IVF embryos. Maturation of oocytes in FLI medium resulted in a significantly higher blastocyst rate (49.3 vs. 13.5; P ≤ 0.001, Chi-squared test) and nuclei number (41.3 ± 12.2 vs. 35.3 ± 10.8; P ≤ 0.001, one-way ANOVA) compared with the standard medium, whereas the cleavage rate was not affected. Transfer of Day 5 blastocysts (average 35 embryos/recipient) derived from the FLI system using 8 recipients resulted in 7 pregnancies (87.5%) as determined by ultrasound scanning on Day 25 of gestation. At the time of writing, one recipient had delivered 5 healthy piglets after a gestation length of 114 days. Results indicate that the FLI medium significantly improves blastocyst rates and the cell number of the resulting blastocysts (Table 1) and yields pig IVF embryos with a high developmental capacity in vivo. By producing high-quality porcine embryos, this FLI-based IVF system provides an efficient method to modify the porcine genome by cytoplasmic microinjection of CRISPR/Cas molecules into IVF-derived zygotes. Table 1.Results of maturation of oocytes in FLI medium compared with DMEM

198 Germline-Specific Expression of the Murine Oct4-EGFP Transgene in the Pig

The Oct4 gene is crucial for undisturbed early embryonic development and maintenance of pluripotency in the mouse. It is found in mouse pre-implantation embryos after embryonic genome activation. After gastrulation, expression is restricted to germ cells. Limited research has been performed on OCT4 expression in the domestic pig, which is a valuable large animal model in biomedicine. Previously, we generated Oct4-EGFP reporter pigs carrying the genomic sequence of the murine Oct4 gene fused to the EGFP cDNA (Nowak-Imialek et al. 2011 Stem Cells Dev. 20, 1563-1575, 10.1089/scd.2010.0399). In the present study, we used this animal model to analyse the expression profile of the murine Oct4-EGFP transgene in porcine oocytes, in vivo-derived embryos (4-cell embryos, 8- to 16-cell embryos, morulae, and blastocysts) and ovaries. We studied whether the murine Oct4-EGFP transgene mimics the expression pattern of the endogenous OCT4 protein in transgenic pigs. Immature oocytes were isolated from ovaries of Oct4-EGFP transgenic sows (n = 5) using slicing methods. For collection of porcine embryos, wild-type sows were inseminated with sperm from an Oct4-EGFP transgenic boar. Sows were sacrificed 3, 4, and 5 days after insemination, and embryos were recovered by flushing oviducts and uterus and analysed by confocal microscopy. Ovaries obtained from female animals (5–12 months) were enzymatically dissociated and analysed using flow cytometry. Immature oocytes (n = 19) showed a very low, diffuse EGFP signal in cytoplasm. Embryos up to the 4-cell stage (n = 45) did not show Oct4-EGFP transgene expression. For the first time, EGFP fluorescence was detected at the 8-cell stage (n = 29) and a strong EGFP signal was observed in 16-cell stages and morulae (n = 53). In blastocysts from Day 5 (n = 40) EGFP fluorescence was not restricted to the inner cell mass (ICM), but was also seen in the trophectoderm (TE). Expression of EGFP was not detected in ovarian cells (n = 12). Thereafter, we analysed the expression pattern of endogenous OCT4 protein by immunostaining in nontransgenic porcine oocytes and pre-implantation embryos. As in Oct4-EGFP transgenic embryos, no expression of OCT4 was observed in 4-cell embryos (n = 12). Nuclear staining first became visible at the 8-cell stage (n = 12), with a strong signal observed in 16-cell stages and morulae (n = 18). In blastocysts from Day 5 (n = 26), both ICM and TE cell nuclei showed expression of OCT4 protein. These results demonstrate that the Oct4-EGFP transgene expression pattern reproduces the endogenous OCT4 protein expression profile in porcine oocytes and pre-implantation embryos. The Oct4-EGFP transgene was first detected at the 8-cell stage, consistent with embryonic genome activation, which is initiated at the 4-cell stage. However, Oct4-EGFP expression was not detected in ovarian cells. This might be related to the very low expression pattern of the Oct4-EGFP transgene in primary oocytes. In summary, the Oct4-EGFP transgene in the pig provides a useful marker for monitoring pluripotency in pre-implantation embryos after embryonic genome activation. In ongoing experiments, we are analysing the expression profile of the Oct4-EGFP transgene and endogenous OCT4 protein in porcine pre-implantation embryos from Days 8 and 11.

148 EFFECTS OF CAFFEINE SUPPLEMENTATION ON BOVINE OOCYTE DEVELOPMENTAL CAPACITY

Oocyte culture in the presence of the nonspecific competitive phosphodiesterase inhibitor caffeine has been reported to increase developmental capacity of oocytes in different mammalian species. Here, we evaluated the effects of caffeine supplementation during the final phase of in vitro maturation (IVM) on developmental rates and blastocyst cell numbers. Bovine ovaries were collected from a local abattoir. A total of 1142 cumulus-oocyte-complexes were obtained by slicing. Cumulus-oocyte complexes were either in vitro matured for 24 h (Standard) or matured for 20 h followed by additional culture for 6 h in fresh IVM medium supplemented with 10 mM caffeine (Caffeine 6 h). In vitro fertilization was performed for 19 h using frozen-thawed sperm from 2 different bulls. After IVF, presumptive zygotes were cultured in vitro for 8 days until the blastocyst stage. Cleavage and blastocyst rates were evaluated 3 and 8 days after IVF, respectively. Expanded blastocysts from the different treatments were submitted to differential staining. SAS/STAT software (SAS Institute Inc., Cary, NC, USA) was used to evaluate cleavage and blastocyst rates using the Glimmix procedure and blastocyst cell numbers were compared using the linear model procedure. Cleavage rates were lower using caffeine for bull B and blastocyst production decreased for bull A. Caffeine treatment increased inner cell mass (ICM) number for bull B and decreased trophectoderm (TE) and total cell numbers for bull A. However, similar TE and total cells were obtained for bull B (Table 1; P < 0.05). Results show that developmental competence can be affected by caffeine supplementation at the final phase of IVM probably due to oocyte-sperm interaction changes. Table 1. In vitro developmental competence of oocytes cultured with caffeine at the end of IVM

3 SIRT1—A POSSIBLE MARKER FOR REPRODUCTIVE AGING OF IN VIVO-DERIVED BOVINE OOCYTES?

Maternal aging-associated reduction of oocyte viability is a common feature in mammals. Effective measures to counteract this process have not yet been developed. Cows are commonly used as a model of early human development, including maternal aging, because both species share a very high degree of similarity, including follicle selection, cleavage and blastocyst formation and a long reproductive lifespan. SIRT1, a member of the Sirtuin family, deacetylates transcriptional regulators localised in the nucleus and cytoplasm by a NAD+-dependent mechanism. Resveratrol (3,4′,5-trihydroxystilbene) is an antioxidant identified in various plant species and red wine which enhances SIRT1 activity. Based on these observations, the goal of the present study was to examine, if SIRT1 gene and protein expression is either affected by maternal age and/or can be modulated by resveratrol. Cumulus-oocyte-complexes of prepubertal (5–6 months old) and adult/aged (2 to 8 lactation) cows were collected by ovum pick-up twice a week. Medium for in vitro maturation (TCM 199) and in vitro fertilization (FertTalp) was supplemented with 20 µL of Resveratrol® (Sigma-Aldrich, Buchs, Switzerland) to get a final concentration of 2 µM Resveratrol respectively. Standard (TCM 199 and FertTalp) media without Resveratol were used as control. Cleavage rates and blastocyst formation were evaluated. Comprehensive gene expression assays of germinal vesicle and metaphase II (MII)-stage oocytes and blastocyst were conducted using next-generation sequencing technology. Finally, SIRT1 protein expression in oocytes and blastocysts were analysed by fluorescence immunostaining under a confocal microscope (LSM510, Zeiss, Germany) and relative fluorescent intensity was calculated. The cleavage rates of adult and prepubertal donors did not differ significantly among the treatments (standard protocol: 56.5 ± 5.4% for adult and 53.0 ± 4.7% for prepubertal donors, Resveratrol supplemented protocol: 62.1 ± 4.3% for cows and 63.6 ± 3.9% for calves). The blastocyst rates were slightly enhanced in the Resveratrol supplemented groups (cows: 34.2 ± 3.8% and calves: 33.1 ± 4.2%) compared to those of standard protocol (cows: 27.5 ± 4.8% and calves: 26.4 ± 3.3%). Relative mRNA abundance levels of SIRT1 were lower in oocytes and blastocysts derived from cows than in those derived from their younger counterparts (2.8-fold change; P = 0.05), but did not differ significantly among treatment groups. Protein expression profiles revealed that bovine SIRT1 was localised in the nucleus. The relative fluorescence levels of SIRT1 were significantly lower (221 ± 34 FIU) in control groups compared to the resveratrol treated groups (865 ± 45 FIU, respectively; P = 0.05). Additionally, SIRT1 protein levels were significantly higher in MII-oocytes (1255 ± 56 FIU) and blastocysts (984 ± 26 FIU) derived from calves compared with their older counterparts (442 ± 37 FIU and 310 ± 23 FIU, respectively, P = 0.05). In conclusion, these results indicate that resveratrol affects SIRT1 protein expression in oocytes and blastocysts of donors in different age. Thus, we hypothesise that SIRT1 is a reliable marker for reproductive aging, which could also be useful for better understanding of human infertility caused by aging.

Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X (invited)

Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters in December 2015. At the end of the 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were in operation, allowing detailed studies of many interesting plasma phenomena. For example, fast neutral gas manometers supported by video cameras (including one fast-frame camera with frame rates of tens of kHz) as well as visible cameras with different interference filters, with field of views covering all ten half-modules of the stellarator, discovered a MARFE-like radiation zone on the inboard side of machine module 4. This structure is presumably triggered by an inadvertent plasma-wall interaction in module 4 resulting in a high impurity influx that terminates some discharges by radiation cooling. The main plasma parameters achieved in OP1.1 exceeded predicted values in discharges of a length reaching 6 s. Although OP1.1 is characterized by short pulses, many of the diagnostics are already designed for quasi-steady state operation of 30 min discharges heated at 10 MW of ECRH. An overview of diagnostic performance for OP1.1 is given, including some highlights from the physics campaigns.

Synthetic plasma edge diagnostics for EMC3-EIRENE, highlighted for Wendelstein 7-X

Interpretation of spectroscopic measurements in the edge region of high-temperature plasmas can be a challenge since line of sight integration effects make direct interpretation in terms of quantitative, local emission strengths often impossible. The EMC3-EIRENE code-a 3D fluid edge plasma and kinetic neutral gas transport code-is a suitable tool for full 3D reconstruction of such signals. A versatile synthetic diagnostic module has been developed recently which allows the realistic 3D setup of various plasma edge diagnostics to be captured. We highlight these capabilities with two examples for Wendelstein 7-X (W7-X): a visible camera for the analysis of recycling, and a coherent-imaging system for velocity measurements.

Efficient edition of the bovine PRNP prion gene in somatic cells and IVF embryos using the CRISPR/Cas9 system

The recently developed engineered nucleases, such as zinc-finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease (Cas) 9, provide new opportunities for gene editing in a straightforward manner. However, few reports are available regarding CRISPR application and efficiency in cattle. Here, the CRISPR/Cas9 system was used with the aim of inducing knockout and knock-in alleles of the bovine PRNP gene, responsible for mad cow disease, both in bovine fetal fibroblasts and in IVF embryos. Five single-guide RNAs were designed to target 875 bp of PRNP exon 3, and all five were codelivered with Cas9. The feasibility of inducing homologous recombination (HR) was evaluated with a reporter vector carrying EGFP flanked by 1 kbp PRNP regions (pHRegfp). For somatic cells, plasmids coding for Cas9 and for each of the five single-guide RNAs (pCMVCas9 and pSPgRNAs) were transfected under two different conditions (1X and 2X). For IVF zygotes, cytoplasmic injection was conducted with either plasmids or mRNA. For plasmid injection groups, 1 pg pCMVCas9 + 0.1 pg of each pSPgRNA (DNA2X) was used per zygote. In the case of RNA, two amounts (RNA1X and RNA2X) were compared. To assess the occurrence of HR, a group additionally cotransfected or coinjected with pHRegfp plasmid was included. Somatic cell lysates were analyzed by polymerase chain reaction and surveyor assay. In the case of embryos, the in vitro development and the genotype of blastocysts were evaluated by polymerase chain reaction and sequencing. In somatic cells, 2X transfection resulted in indels and large deletions of the targeted PRNP region. Regarding embryo injection, higher blastocyst rates were obtained for RNA injected groups (46/103 [44.6%] and 55/116 [47.4%] for RNA1X and RNA2X) than for the DNA2X group (26/140 [18.6%], P < 0.05). In 46% (26/56) of the total sequenced blastocysts, specific gene editing was detected. The total number of genetic modifications (29) was higher than the total number of gene-edited embryos, as three blastocysts from the group RNA2X reported more than one type of modification. The modifications included indels (10/56; 17.9%) and large deletions (19/56; 33.9%). Moreover, it was possible to detect HR in 1/8 (12.5%) embryos treated with RNA2X. These results report that the CRISPR/Cas9 system can be applied for site-specific edition of the bovine genome, which could have a great impact on the development of large animals resistant to important zoonotic diseases.

243 EFFICIENT EDITION OF THE BOVINE PRNP PRION GENE IN SOMATIC CELLS AND IVF EMBRYOS USING THE CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)/Cas9 SYSTEM

The rapid introduction of engineered nucleases technologies, such as zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR), provides new opportunities for editing genes in a targeted and rather simple fashion. Few reports are available regarding CRISPR efficiency in domestic species. Here, the CRISPR/Cas9 system was employed to develop knockout and knock-in alleles of the bovine PRNP gene, responsible for bovine spongiform encephalopathy (mad cow disease), both in bovine fetal fibroblasts and in IVF embryos. Five sgRNAs were designed to target a 875-bp region within prnp exon 3; all 5 were co-delivered with hCas9 and a homologous recombination vector carrying gfp (pHRegfp). For cells, 3 transfection conditions were compared: 2 μg of hCas9 + 1 μg of sgRNAs mix ± 2 μg pHREGFP (1X) versus 4 μg of hCas9 + 2 μg of sgRNAs mix ± 4 μg of pHREGFP (2X). For IVF zygotes, cytoplasmic injection was conducted with 2 RNA concentrations: (a) 50 ng μL–1 hCas9 RNA + 25 ng μL–1 sgRNAs mix (RNA1X), ±50 ng μL–1 pHREGFP, and (b) 100 ng μL–1 hCas9 + 50 ng μL–1 sgRNAs mix (RNA2X), ±100 ng μL–1 pHREGFP, which were compared with plasmid injections with 100 ng μL–1 pCMVCas9 + 50 ng μL–1 pU6sgRNAs mix (DNA2X), ±100 ng μL–1 pHREGFP. The pHREGFP was always injected as plasmid, under the same conditions as hCas9. DNA from cells was subjected to PCR, Surveyor assay, and sequence analysis. Embryo analysis was conducted on whole-genome-amplified DNA from blastocysts, followed by PCR assays and sequencing. In cells, 2X transfection resulted in indels and amplification of PCR products of lower MW than the wild-type, indicative of the deletion of a part of the targeted PRNP region. However, it was not possible to detect an effect for 1X transfection. For the group transfected with pHREGFP, insertion of a partial EGFP sequence was detected (383 bp). Regarding embryo injection, higher blastocyst rates were obtained in all groups injected with RNA (Table 1). In 48% (21/43) of the sequenced blastocysts specific gene editing was detected (Table 1). Modifications varied among single base pair shift (3/43; 7%), high level of mismatches all over the targeted sequence and vicinity (12/43; 27.9%), full deletion of the 875-bp region (1/43; 2.3%), and partial insertion of 100–498 bp pHREGFP fragments between the HR arms (5/24; 20.8%). Most of these modifications occurred in a mosaic fashion (76%). Results demonstrate that CRISPR/Cas can be efficiently applied for site-specific edition of domestic species genomes. Table 1.In vitro development and gene editing efficiency of embryos injected with plasmids or RNA coding for CRISPR/Cas9 system targeting PRNP

197 EFFECTS OF PRE-IN VITRO MATURATION WITH CAFFEINE ON BOVINE OOCYTE DEVELOPMENTAL CAPACITY

High cyclic adenosine monophosphate (cAMP) concentrations are critical for maintaining oocyte meiotic arrest in vivo. For in vitro maturation (IVM), the oocyte is released mechanically from the follicle, which induces a significant drop in intra-oocyte cAMP levels, triggering non-physiological meiotic resumption. It has been proposed that modulation of cAMP before IVM can increase bovine blastocyst rates in vitro. Caffeine is a nonspecific competitive phosphodiesterases (PDE) inhibitor and can inhibit meiotic resumption of oocytes due to maintenance of cAMP levels. It has been reported that gamete treatment with caffeine can increase developmental potential. The current study evaluated the effects of pre-in vitro maturation culture with different concentrations of caffeine on meiotic progress, developmental rates and blastocyst cell numbers. Bovine ovaries were collected from a local abattoir. A total of 6648 cumulus-oocyte complexes were obtained by slicing. Caffeine was used in 5 different concentrations (1, 5, 10, 20, and 30 mM) during slicing, searching, and 2 h pre-IVM culture. A control group, with 2 h pre-IVM without caffeine (0 mM) and a standard control were also included. Oocytes were washed either after standard or pre-IVM treatments and cultured for 24 h in vitro without caffeine. After IVM, oocytes were fertilised in vitro for 19 h, and zygotes were cultured in vitro for 8 days until the blastocyst stage. Subsets of oocytes were fixed in 2% glutaraldehyde at 9, 20, and 24 h after IVM. Hoechst staining was performed to evaluate nuclear status of matured oocytes. Cleavage and blastocyst formation rates were evaluated at Days 3 and 8 after IVF. Expanded blastocysts from all treatments were submitted to differential staining. One-way ANOVA from R software was applied to evaluate differences in cleavage and blastocysts rates and blastocyst cell numbers. Fisher’s exact test complemented by Bonferroni correction was used to determine meiotic progress. Caffeine maintained oocytes in meiotic arrest after 9 h of IVM in a concentration-dependent manner (germinal vesicle: 79.0%, 92.2%, 66.7%, 55.1%, 56.9%, 43.9%, 30.2%, respectively, for 30, 20, 10, 5, 1, 0 mM and standard; P < 0.016). Cleavage rates were similar in all treatments; however 30 mM caffeine decreased blastocyst rates (Table 1; P < 0.05). The number of cells did not differ significantly among in vitro treatments (Table 1; P > 0.05). Developmental competence was not affected by 2 h pre-IVM culture. Caffeine supplementation before IVM delayed resumption of meiosis and affected embryo development. Table 1.In vitro developmental competence of oocytes treated with different caffeine concentrations before IVM

15 HISTONE ACETYLATION PROFILE OF PORCINE EMBRYOS PRODUCED BY 2 CLONING METHODS WITH OR WITHOUT IN VITRO CULTURE

Conventional “Dolly”-based cloned (CNT) embryos maintain zona pellucida and can be transferred early in development. Handmade cloned (HMC) embryos are zona free and are cultured to later stages for transfer. We have shown differences between HMC and CNT embryos (Rep. Fert. Dev. 26, 123), and both in vitro culture and cloning method (NT) are associated with alterations in histone acetylation. More studies are needed to clarify whether CNT and HMC embryos differ in epigenetic profiles due to NT method or culture condition. Here we investigated histone acetylation profile of NT embryos produced by CNT or HMC with or without 5 to 6 days in vitro culture, emphasising quality and gene expression in resulting embryos. Both NT methods were performed on Day 0 (D0) with same oocyte batch, donor cells, and culture medium (CNT in group, HMC in well of well). On D0, 5, and 6 after CNT (Clon. Stem Cells 10, 355) or HMC (Zygote 20, 61), all developed embryos of all morphological qualities were collected for immunostaining of H3K18ac, and on D0 and 6 for mRNA expression of the genes KAT2A/2B, EP300, HDAC1/2, DNMT1o/s, and GAPDH. Embryo quality was evaluated normal (clear inner cell mass, high cell number, no fragments) or bad (no clear inner cell mass, low cell number, fragments). Cell numbers per blastocyst were counted on D5 and 6. Differences in cell number and H3K18ac level between different groups and days were analysed by ANOVA; gene expression data were analysed by GLM (SAS version 9.3, SAS Institute Inc., Cary, NC, USA). Embryo development rates of both NT methods were reported previously (Rep. Fert. Dev. 26, 123). On D5 and 6, all HMC embryos were evaluated as normal, but the CNT group contained both normal and bad embryos. Regarding cell numbers (Table 1), on D5 there was no difference between normal CNT and HMC embryos, but numbers were lower in CNT bad embryos. On D6 the blastocyst cell number was lower in both normal and bad CNT embryos compared with HMC. Regarding H3K18ac levels (Table 1), no differences were found on D5 between normal CNT and HMC embryos, but on D6 both CNT normal and bad embryos had higher H3K18ac level compared with HMC. On D0, no difference was found in mRNA expression of all 8 genes. On D6, KAT2A expression was slight increased (1.8-fold) in CNT compared with HMC embryos (P < 0.05). In conclusion, no differences were found between CNT and HMC embryos after completed NT procedure (D0) or after 5 days in vitro culture. However, differences in quality (cell number and H3K18ac) and gene expression between the 2 NT methods were observed when blastocyst expansion was initiated (D6). Thus, the 2 NT methods seem to produce embryos of similar quality, which is maintained over 5 days in vitro culture, but thereafter gene expression and histone acetylation are more active in CNT embryos. Table 1.Cell number and H3K18ac level1

223 GENERATION OF INTERSPECIES CHIMERAS BETWEEN PRIMATE INDUCED PLURIPOTENT STEM CELLS AND PORCINE PARTHENOGENETIC EMBRYOS

The availability of human induced pluripotent stem cell (hiPSC) paves the way to generate regenerative tissue or organs from patient’s own stem cells. The production of chimeric piglets carrying organs that are entirely derived from human stem cells, or at least have a high contribution of human cells or tissues, could be used as a new tissue or an organ replacement in the future treatment of the patients. Here, we produced porcine-nonhuman primate chimeric embryos to assess the feasibility of the potential use of human iPSC for production of human stem cell-derived organs in pigs. Because in vitro culture conditions for cynomolgus monkey iPSC and porcine blastocysts are different, we first identified an effective in vitro culture system for porcine blastocysts and monkey iPSC. We compared blastocyst rates (Days 7 and 8) and number of cells of porcine parthenogenetic blastocysts (Day 8) cultured in 8 different monkey iPSC media and in porcine zygote medium 3 (PZM-3). The best developmental rates of porcine blastocysts were achieved in Knockout DMEM+20% serum replacement monkey medium (iPS 20% medium; N = 65, n = 3). The number of blastocysts on Day 8 cultured in iPS 20% medium was significantly higher (91%; P < 0.05) than in the commonly used porcine PZM-3 medium (65%). We found significantly fewer (P < 0.05) degenerate porcine embryos on Day 8 after culture in iPS 20% medium (9%) compared to PZM-3 (35%). The number of nuclei per blastocyst in iPS 20% medium (88 nuclei; N = 30, n = 3) was significantly higher (P < 0.0001) than in the PZM-3 medium (57 nuclei; N = 54, n = 3). Therefore, we decided to use iPS 20% medium for culture of porcine blastocysts injected with monkey iPSC. Thereafter, we injected clusters of 10 to 15 monkey iPSC transgenic with AAVS1-CAG-Venus into porcine parthenogenetic embryos from Days 4 and 6. Interspecies chimeras were cultured in iPS 20% medium for 24 (for Day 6 embryos) or 48 h (for Day 4 embryos) and observed by confocal microscopy to determine the proportion of Venus-expressing monkey iPSC in porcine embryos. Approximately 37% of blastocysts contained Venus-positive cells after injection of Day 6 embryos (N = 133, n = 4). In contrast, injection into porcine embryos from Day 4 resulted in 73% of Venus-positive blastocysts (N = 69, n = 3). Finally, we investigated proliferation and survival of monkey iPSC in interspecies chimeras after blastocyst plating onto murine fibroblasts. Chimeric blastocyst outgrowth resulted in Venus-expressing monkey iPSC proliferating over 1 week in culture. Outgrowths of all chimeric blastocysts established distinct but separate monkey and porcine stem cell colonies. Here, we optimized the culture conditions for an in vitro interspecies chimera assay in which monkey iPSC are able to survive in porcine embryos. Integration of monkey iPSC to host inner cell mass is relevant for the further contribution to the embryo development. Therefore, to verify this, analysis of cell-cell connection between monkey iPSC and porcine blastocysts and experiments using vivo-derived embryos are currently underway.

101 TOWARDS OPTIMAL IN VITRO CULTURE CONDITIONS FOR PIG-MONKEY AGGREGATION CHIMERAS

Induced pluripotent stem cells (iPSCs) are promising for developing novel cell-based medical treatments. One potential use of iPSCs is for xenotransplantation via production of chimeric organisms. The generation of organs originated from the iPSCs of one individual in a foreign organism could allow the production of immune compatible organ transplants. One of the major problems down this road is to define the different nutrient needs of chimeric embryos (i.e. iPSCs and the host embryos). Here, we evaluated different media for supporting development of chimeric embryos consisting of parthenogenetic porcine embryos and iPS cells, either from pig or nonhuman primate, to identify the optimal medium conditions for pig-monkey aggregation chimeras. First, we cultured 3-day-old porcine parthenogenetic embryos in porcine zygote medium (PZM), iPSC-medium, and mixtures of the two media to identify the most suitable culture conditions. Three-day-old parthenogenetic embryos developed poorly in pure iPSC-medium (6.3% blastocyst rate), but grew in a mixture of PZM and iPSC medium. The best results were achieved with PZM and PZM with 10% or 25% iPSC medium (38.8% and 30% blastocyst rates, respectively). Next, we checked aggregation results of chimeric embryos produced with two different iPSC lines in the respective media (PZM, PZM+10% iPSC medium, PZM+25% iPSC medium). The porcine iPSC line (piPSC) and cynomolgus monkey iPSC line (ciPSC) carry fluorescent markers (piPSC: GFP, ciPSC: venus), thus facilitating detection of integration into the host embryos. After aggregation of iPS cells between two Day-3 parthenogenetic embryos (sandwich technique), blastocyst rates at Day 6 were determined (see Table 1). While culture in PZM allowed for the highest blastocyst rate (>40%), the iPS cell participation was very low (0–11.1%). Cultivation in PZM+25% iPS medium was compatible with a high rate of embryo-iPSC chimeras (50–100%), but with a low blastocyst rate (7.7–16.7%). Possibly, the iPS cells proliferate more rapidly than blastomeres and the embryo is overgrown. The best results were obtained in medium mixture PZM+10% iPSC medium (25–40% blastocyst rate with 66.7–100% iPS cell participation). These results show that supplementation of the basic culture medium with 10% iPSC medium yields high blastocyst rates for chimeric embryos, and also ensures much higher iPS cell participation. This improves the use of 3-day-old embryos in aggregation chimeras. Table 1.Development of parthenogenetic porcine embryo aggregates with porcine (p) or cynomolgus monkey (c) iPS cells

198 RESVERATROL SUPPLEMENTATION DURING IN VITRO MATURATION AND FERTILISATION ENHANCES DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES

Resveratrol (3,4′,5-trihydroxystilbene) is a phytoalexin identified in various plant species, particularly in grapevine peel. It is a strong antioxidant, induces mitochondrial biogenesis and enhances Sirtuin 1 (SIRT1) activity by inhibiting phosphodiesterase. SIRT1 belongs to the family of NAD+-dependent histone deacetylates and has been shown to regulate several key cellular processes, including transcriptional silencing, aging, chromatin remodeling, and genomic stability, via deacetylation of p53, FoxO transcription factors, and nuclear factor kappa B (NF-κB). The aim of this study was to determine whether supplementation of the maturation and fertilisation medium with resveratrol influences bovine oocyte maturation and subsequent embryonic development and whether these effects are mediated via SIRT1 pathway. Three different resveratrol concentrations were used during in vitro maturation (IVM) and IVF. Cumulus-oocyte complexes (n = 2878) were collected from slaughterhouse ovaries and subjected to IVM medium supplemented with 0.2 µM, 1 µM, or 20 µM resveratrol® (Sigma-Aldrich, Buchs, Switzerland) for 24 h followed by IVF with the same concentrations of resveratrol for 19 h. The IVM and IVF medium without resveratrol (controls) and dimethyl sulfoxide supplementation as vehicle control were also included. Presumptive zygotes were cultured in vitro until Day 8 to assess embryo development, and maturation rates, cleavage, and blastocyst formation were evaluated. Maturation rates as determined by polar body extrusion (0.2 µM: 64.2% ± 7; 1 µM: 82.3% ± 4; 20 µM: 68.8% ± 2; control: 74.6% ± 5 and vehicle control: 70.2% ± 6, respectively; P ≤ 0.05) did not differ dramatically. Oocytes in 1 µM resveratrol supplemented maturation medium showed distinct detachment of cumulus cells in comparison with those in the other treatment and control groups. Cleavage rates were reduced in the 0.2 µM and 20 µM group compared with controls (0.2 µM: 44.21% ± 2; 1 µM: 58.4% ± 3; 20 µM: 40.9% ± 5; control: 56.6% ± 2 and vehicle control: 55.2% ± 6, respectively; P ≤ 0.05). Blastocyst rates were impaired in the low and high resveratrol concentration groups compared to all other groups (0.2 µM: 11.3% ± 1; 1 µM: 33.4% ± 3; 20 µM: 8.2% ± 4; control: 26.7% ± 4 and vehicle control: 20.8% ± 2, respectively; P ≤ 0.05). Relative mRNA abundance of SIRT1 in matured oocytes from the 1 µM group did not differ significantly compared to the controls. Results so far indicate that very low and high concentrations of resveratrol impair development to the blastocyst stage. In conclusion, a 1 µM resveratrol supplementation during IVM and IVF seems to improve the developmental competence of oocytes, which is reflected not only in the elevated blastocyst rates but also in higher degree of expansion of cumulus cells after IVM and maturation rates.

siRNA mediated knockdown of tissue factor expression in pigs for xenotransplantation

Acute vascular rejection (AVR), in particular microvascular thrombosis, is an important barrier to successful pig-to-primate xenotransplantation. Here, we report the generation of pigs with decreased tissue factor (TF) levels induced by small interfering (si)RNA-mediated gene silencing. Porcine fibroblasts were transfected with TF-targeting small hairpin (sh)RNA and used for somatic cell nuclear transfer. Offspring were analyzed for siRNA, TF mRNA and TF protein level. Functionality of TF downregulation was investigated by a whole blood clotting test and a flow chamber assay. TF siRNA was expressed in all twelve liveborn piglets. TF mRNA expression was reduced by 94.1 ± 4.7% in TF knockdown (TFkd) fibroblasts compared to wild-type (WT). TF protein expression in PAEC stimulated with 50 ng/mL TNF-α was significantly lower in TFkd pigs (mean fluorescence intensity TFkd: 7136 ± 136 vs. WT: 13 038 ± 1672). TF downregulation significantly increased clotting time (TFkd: 73.3 ± 8.8 min, WT: 45.8 ± 7.7 min, p < 0.0001) and significantly decreased thrombus formation compared to WT (mean thrombus coverage per viewing field in %; WT: 23.5 ± 13.0, TFkd: 2.6 ± 3.7, p < 0.0001). Our data show that a functional knockdown of TF is compatible with normal development and survival of pigs. TF knockdown could be a valuable component in the generation of multi-transgenic pigs for xenotransplantation.

338 IN VITRO GENERATION OF LENTOID BODIES FROM INDUCED PLURIPOTENT STEM CELLS OF TRANSGENIC MICE

Pluripotent cells have the developmental potential to generate all adult cell types, so ocular diseases resulting from the failure of specific cell types could be potentially treatable through the transplantation of differentiated cells derived from stem cells. The present study was conducted with the aim of generating a cataract model. We attempted to derive the induced pluripotent stem (iPS) cells from fibroblast cells of transgenic (crytom) mice carrying a transgenic construct-alphaA crystallin promoter driving the tandem dimer (td) Tomato marker transgene, integrated in the genome. The 4- to 6-week-old female crytom mice were selected, superovulated, and mated. The fetuses were recovered and examined on various different days (10.5 to 15.5 days postfertilization), and the reporter expression was found to be initiated 12.5 days postfertilization and the intensity was increased thereafter. The expression of tdTomato was confirmed in the fetuses by Western blotting. Murine embryonic fibroblast (MEF) cultures were generated and electroporated with a reprogramming transposon cassette carrying Yamanaka factors (OCT4, SOX2, KLF4, and MYC) and Sleeping Beauty transposase to generate iPS cells which were picked up and clonally expanded. The cells were confirmed by PCR for tdTomato in the genome and characterised for the expression of Oct4 and cryAB by immunofluorescence. The iPS cells were also injected into the nude CD1 mice to test for teratoma formation. The generated cells were allowed to differentiate spontaneously on 3 different types (viz. P19, NTERA, and STO) of cell lines as feeders, in the absence of LIF, and cells were expected to fluoresce if differentiated to eye lens lineage. After long-term cultures, the iPS cells were found to differentiate and form lentoid bodies which expressed tdTomato. Thus, alphaA crystallin-tdTomato construct was allowed following lens cell formation by specific fluorescence excitation in a spatial and temporal manner. The employment of cell type-specific reporters for establishing and optimizing targeted differentiation in vitro seems to be an efficient and generally applicable approach for developing differentiation protocols for desired cell populations. Hence a transgenic murine iPS cell line was generated which exhibited potential to be used as a model for eye cataracts and other eye abnormalities.

332 DERIVATION OF BOVINE-INDUCED PLURIPOTENT STEM CELLS BY piggyBac-MEDIATED REPROGRAMMING

Induced pluripotent stem (iPS) cells are a seminal breakthrough in stem cell research and are promising for the development of advanced regenerative therapies and farm animal biotechnology. Considering the potential of this technology for both basic and clinical research, it is tempting to extend this research to important livestock species, such as cattle, in which authentic embryonic stem cell lines are yet not available. The first attempts to produce iPS cells from livestock species were made using retro- and lentiviral vectors, which are associated with an increased risk of insertional mutagenesis and which are not removable after reprogramming. Here, we describe a nonviral method for the derivation of bovine iPS cells, employing a piggyBac (PB) transposon system. The reprogramming PB transposon encodes the primate cDNA of 6 core reprogramming factors, OCT4, SOX2, KLF4, MYC, LIN28, and NANOG, separated by self-cleaving 2A peptide sequences and driven by the chimeric CAGGS promoter. The derived bovine iPS line expressed typical endogenous genes (OCT4, SOX2, c-MYC, KLF4, NANOG, REX1, and ALP) by RT-PCR and OCT-4 as well as SSEA-1 and 4 pluripotency-related markers by immunostaining, and it exhibited silencing of exogenous reprograming factors. Moreover, the iPS line showed long-term proliferation (until the 40th passage) under feeder-free culture conditions, differentiated into derivatives of the 3 germ layers in vitro, and formed teratomas (4/6) after subcutaneous injection into immunodeficient nude mice. These results are a major step towards the derivation of authentic bovine iPS cells, and thus facilitate the genetic modifications of the bovine genome.

286 DEVELOPMENTAL CAPACITY OF PREPUBERTAL BOVINE OOCYTES CULTURED WITH CYCLIC AMP MODULATORS

Prepubertal bovine donors are currently used for commercial breeding to accelerate the genetic gain and decrease the generation interval. Nevertheless, it has been reported that their oocyte developmental competence is lower than in adult females. Addition of cAMP regulators during in vitro maturation (IVM) has been suggested to enhance blastocysts rates (Albuz et al. 2010 Hum. Reprod. 25, 2999–3011). Here, we evaluated the effects of the cAMP modulators forskolin, 3-Isobutyl-1-methylxanthine (IBMX), and cilostamide during extended IVM on the developmental capacity of oocytes from prepubertal and adult bovine females. A total of 1851 oocytes from 24 lactating cows (>2 lactations) and 24 prepubertal donors (6–10 mo old) were collected by transvaginal oocyte recovery (OPU) twice per week and divided into 3 experiment groups: (1) TCM24 (OPU medium: PBS; 24 h of IVM; standard protocol/control); (2) cAMP30 [OPU medium: PBS-IBMX (500 μM); 2 h pre-IVM culture using forskolin (100 μM)-IBMX (500 μM) and 30 h of IVM adding cilostamide (20 μM)], and (3) DMSO30 [cAMP modulators are diluted in DMSO)/vehicle control; OPU medium: PBS-DMSO (46.3 mM); 2 h pre-IVM culture (280 mM DMSO) and 30 h IVM (5.6 mM DMSO)]. Following IVM, oocytes were either submitted to in vitro fertilization and embryo culture or fixed in 1% glutaraldehyde at 9, 20, 24, and 30 h after IVM and stained with Hoechst to evaluate their nuclear status. One-way ANOVA was implemented to evaluate recovered oocytes and meiotic stages. The Glimmix procedure from SAS/STAT was performed to compare blastocyst and cleavage rates. Total number of oocytes and IVM-suitable oocytes per donor per OPU session were similar in adult and prepubertal donors (total number/IVM suitable; prepubertal donors: 6.7/4.2, 6.4/4.0, 6.5/3.8; cows: 6.2/4.7, 6.2/4.4, 6.2/4.5 for TCM24, cAMP30 and DMSO30, respectively). At 9 h, cAMP regulators were able to maintain meiotic arrest in prepubertal and adult donors (GV: 80.0 and 40.9%, respectively) compared to standard IVM (GV: 61.1 and 31.2%) and DMSO30 (GV: 40.0 and 26.6%) protocols (P < 0.05). Using the cAMP30 protocol, the percentage of oocytes that reached MII stage at 20 h was lower in adult (4.5%) and prepubertal donors (5.26%) compared to the DMSO30 (50.0 and 42.8%, respectively) and TCM24 (56.2 and 44.4% respectively) protocols. Metaphase II rates after either 24 or 30 h were similar among treatments (prepubertal donors: 88.2, 70.5, and 84.2%; cows: 71.4, 85.7, and 81.2% for TCM24, cAMP30, and DMSO30, respectively; P > 0.05). Cleavage rates (prepubertal donors: 63.4, 54.9, and 52.1%, cows: 56.1, 57.8, and 51.6% for TCM24, cAMP30, and DMSO30, respectively) and blastocysts/presumptive zygotes rates (prepubertal donors: 26.2, 19.6, and 16.2%; cows: 27.5, 28.1, and 21.5% for TCM24, cAMP30, and DMSO30, respectively) did not show significant differences (P > 0.05). Although cAMP modulators delayed the progression through meiosis in adult and prepubertal oocytes, similar blastocysts rates were obtained. Our results suggest so far that oocyte retrieval and competence in prepubertal donors can be similar to that of the adult donors with and without addition of cAMP modulators.

Xenotransplantation of porcine islet cells as a potential option for the treatment of type 1 diabetes in the future

Solid organ and cell transplantation, including pancreatic islets constitute the treatment of choice for chronic terminal diseases. However, the clinical use of allogeneic transplantation is limited by the growing shortage of human organs. This has prompted us to initiate a unique multi-center and multi-team effort to promote translational research in xenotransplantation to bring xenotransplantation to the clinical setting. Supported by the German Research Foundation, an interdisciplinary group of surgeons, internal medicine doctors, diabetologists, material sciences experts, immunologists, cell biologists, virologists, veterinarians, and geneticists have established a collaborative research center (CRC) focusing on the biology of xenogeneic cell, tissue, and organ transplantation. A major strength of this consortium is the inclusion of members of the regulatory bodies, including the Paul-Ehrlich Institute (PEI), infection specialists from the Robert Koch Institute and PEI, veterinarians from the German Primate Center, and representatives of influential ethical and religious institutions. A major goal of this consortium is to promote islet xenotransplantation, based on the extensive expertise and experience of the existing clinical islet transplantation program. Besides comprehensive approaches to understand and prevent inflammation-mediated islet xenotransplant dysfunction [immediate blood-mediated inflammatory reaction (IBMIR)], we also take advantage of the availability of and experience with islet macroencapsulation, with the goal to improve graft survival and function. This consortium harbors a unique group of scientists with complementary expertise under a cohesive program aiming at developing new therapeutic approaches for islet replacement and solid organ xenotransplantation.

324 TESTIS-SPECIFIC EXPRESSION OF Oct4-EGFP TRANSGENE IN PIG

Oct4 is a transcription factor essential for establishment and maintenance of pluripotency in mammalian stem cells. Oct4 expression was found in early embryos and germ cells throughout fetal development. In male mice, Oct4 expression is found in mitotically arrested prospermatogonia until birth. After onset of spermatogenesis, expression is maintained in type A spermatogonia, but is downregulated in type B spermatogonia and in spermatocytes (Pesce et al. 1998 Mech. Dev). Previously, we successfully generated Oct4-EGFP reporter pigs carrying the entire 18-kb genomic sequence of the murine Oct4 gene fused to the enhanced green fluorescent protein (EGFP) cDNA (Nowak-Imialek et al. 2011 Stem Cells Dev.). This animal model is unique because it allows in vivo and in vitro visualisation of Oct4-positive cells. Germ line specific Oct4-EGFP expression was analysed in testis isolated from young (<1 week) and adult (>7 months) pigs. Squash preparation of testicular tissue isolated from adult transgenic boars revealed high amounts of EGFP-positive cells compared to young piglets. We confirmed Oct4 and EGFP expression in the testis from young and adult transgenic animals using Northern blot analysis. Specific expression of Oct4 and EGFP in testis could be observed in blots as a single band of 1.5 kb. As a loading control, the blot was rehybridized with a β-actin probe. Mammalian testes contain different cell types, including germ cells, Sertoli cells, Leydig cells, and peritubular cells. To define the cellular origin of EGFP-expressing cells, we isolated these cells from adult transgenic testis using fluorescence-activated cell sorting (FACS)-based techniques. Analysis of isolated EGFP positive cells with qRT-PCR demonstrated the presence of marker genes specific for undifferentiated (Oct4, UTF1, FGFR3, PGP 9.5, THY-1, SALL4, and GFRα1) and differentiated (BOLL and PRM2) germ cells. Markers specific for Sertoli cells (vimentin) and Leydig cells (LHCGR) were not observed. To verify the localization of EGFP-positive cells in seminiferous tubules, we performed immunohistochemical detection of GFP in adult pig testis. Unlike the Oct4-EGFP reporter mouse model, GFP protein was not found in spermatogonia attached to the basement membrane of seminiferous tubules, but instead were found in differentiated germ cells, including spermatocytes and spermatids. These results show that the Oct4-EGFP expression in testis differs between mouse and porcine Oct4-EGFP transgenic models. To verify that the EGFP expression driven by the mouse Oct4 promoter in porcine testis reflects the endogenous Oct4 expression profile, Western blot and histochemical analyses are currently underway.

70 INCORPORATING MULTIPLE STAGES OF MASS SPECTROMETRY INTO LIPID PROFILING OF OOCYTES AND PRE-IMPLANTATION EMBRYOS

Lipid profiling by mass spectrometry (MS) is increasingly used for the analysis of oocytes, embryos, and other reproductive cells. This analytical approach has several advantages, such as simple preparation (no need to perform extraction or separation), low detection limits (no need of sample pooling), and detection of structurally intact and diverse lipids. Many degrees of freedom are ensured by MS techniques (e.g. with the adoption of diverse ionization sources, mass analyzers, data acquisition systems), and this broadens the classes of lipids that can be detected and identified. Tandem or high-resolution MS experiments are normally performed for chemical characterisation. However, the use of novel approaches is a constant need to obtain deeper structural insights into lipids of biological interest, resulting in an information-rich dataset. Here we propose the use of multiple stages of MS for lipid profiling, specifically MS/MS data domain (i.e. ion mapping) experiments, so that comprehensive structural and relationship information (i.e. classes) can be extracted from a dataset. Indeed, the data generated have 2 dimensions of mass (i.e. precursor and product ions) and one of ion intensity, resulting in a datacube structure. Cutting through the datacube in different ways allows the extrapolation of (i) chemical composition of specific compounds (i.e. product scans) and (ii) pattern recognition for compounds that share identical neutral or charged fragments loss (i.e. neutral loss and precursor scans, respectively). The global chemical information enclosed into the datacube can be also processed by means of multiway statistical analyses to chemically characterise cells and cellular compartments. Preliminary data have been acquired, and the development of statistical tools for data processing is ongoing. Bovine and rat embryos were used for the experiments and analysed by extraction spray ambient MS. Experiments were performed with a Thermo Finnigan LTQ linear ion trap. Dimethylformamide-acetonitrile (1 : 1 v/v) was used as spray solvent. The ion mapping experiment was configured to scan ions of mass-to-charge (m/z) ratio 700 to 900 and perform MS/MS every m/z 1.5 window with a collision energy of 25 (arbitrary units). Fragments were detected in the m/z range of 150 to 900. Chemical differences are present between bovine and rat embryos, of note are palmitic, oleic, and stearic acids. The application of ion mapping to characterise species-specific and developmental dynamics regarding lipid composition is currently under investigation.

337 PROMOTER-DEPENDENT SILENCING OF REPROGRAMMING TRANSCRIPTION FACTORS IN MOUSE INDUCED PLURIPOTENT STEM CELLS PRODUCED WITH SLEEPING BEAUTY TRANSPOSON VECTORS

Epigenetic silencing of the transgenes has been considered a prerequisite for complete reprogramming of mouse somatic cells to induced pluripotent stem cells (miPSC). Here, we examined the activity status of the reprogramming transcription factors in miPSC produced with Sleeping Beauty (SB) transposon vectors carrying expression cassettes with the porcine OCT4, SOX2, c-MYC, and KLF4 (pOSMK) under the control of doxycycline (DOX)-inducible (TetO) or constitutive (CAG) promoters. Mouse embryo fibroblasts (MEF) were electroporated with SB-TetO-rTA-SV40pA-TetO-pOSMK-IRES-tdTomato-bGHpA (TetO group) or with SB-loxP-CAG-pOSMK-IRES-tdTomato-SV40pA-loxP (CAG group) together with SB100x (SB transposase). The cells were cultured on mitotically inactivated MEF feeders with DMEM supplemented with 20% knockout serum replacement, 2 mM l-glutamine, penicillin-streptomycin, nonessential amino acids, 0.1 mM 2-mercaptoethanol, 1000 U mL–1 of ESGRO, and 5 µg mL–1 of DOX. The miPSC colonies were individually picked, disaggregated to single cells, and propagated further under the same culture conditions. Three cell lines from each experimental group were examined for pluripotency characteristics, and the activity of the transgenes was monitored by the presence of tdTomato fluorescence and by RT-PCR. The miPSC produced with TetO vector silenced the transgene expression within 11 days post-transfection (in the presence of DOX) and upregulated the endogenous pluripotency genes Oct4, Sox2, Nanog, Rex1, and Utf1. These cells showed typical miPSC morphology and ability to differentiate into cells from the 3 primary germ layers in vitro and in vivo (teratomas). At the same time, the miPSC from the CAG group did not silence the transgenes even after 20 passages of continuous propagation, although they upregulated the endogenous pluripotency genes similarly to the TetO group. Moreover, these cells also showed ability to differentiate in vitro into cells from the 3 germ layers (contracting cardiac myocytes, neurons, epithelia) expressing differentiation markers Afp, Sox17, Gata4, Gata6, cardiac troponin, nestin, and PGP 9.5. Following Cre-mediated excision of the reprogramming cassette, the miPSC from the CAG group continued to self-renew and the expression of pluripotency markers Oct4, Sox2, Nanog, and Rex1 did not change significantly, as evidenced by real-time RT PCR (all P > 0.1), showing that these cells were not dependent on the transgenes for maintaining their pluripotency characteristics. Currently, we are investigating the ability of the miPSC from the CAG group to differentiate in vivo by producing teratomas and chimeras. The results from our preliminary investigations suggest that porcine transcription factors can be used for production of miPSC and that the silencing of the reprogramming transcription factors in miPSC is promoter-dependent, but may not be absolutely necessary for complete reprogramming to pluripotency.

Residential traffic and incidence of Type 2 diabetes: the German Health Interview and Examination Surveys

AIMS

To investigate whether an indicator of overall traffic intensity is related to the risk of Type 2 diabetes in a nationwide cohort.

METHODS

The study population comprised 3604 adults aged 18-79 years and without diabetes from the German National Health Interview and Examination Survey (GNHIES98, 1997-1999) who participated again in a follow-up survey (DEGS1, 2008-2011). The association between the participants' reported traffic intensity at their residential address and Type 2 diabetes incidence was examined using logistic regression models.

RESULTS

During a mean of 12.1 years of follow-up, 252 of the participants included in the study developed Type 2 diabetes. Compared with people living in traffic-calmed areas, odds ratios were 1.15 (95% CI 0.80-1.67) for people living on moderately busy side streets, 1.11 (95% CI 0.69-1.80) for people living on considerably busy side streets, 1.41 (95% CI 0.96-2.08) for people living on heavily busy roads, and 1.97 (95% CI 1.07-3.64) for people living on extremely busy roads, after adjusting for age, sex, active and passive smoking, type of heating, education, BMI, waist circumference, sport activity and parental diabetes history.

CONCLUSIONS

The twofold higher risk of Type 2 diabetes observed for people exposed to intense traffic in this nationwide cohort extends the limited evidence from previous selected populations. Although the underlying traffic-related components and their biological mechanisms still need to be unravelled, traffic exposure control should be considered in public health strategies to reduce the global burden of diabetes.

Strategies for the derivation of pluripotent cells from farm animals

Recent experiments demonstrated that forced expression of few critical genes drives conversion of a somatic into a pluripotent cell state. These induced pluripotent cells (iPS) were first generated from murine fibroblasts by Shinya Yamanaka's laboratory in 2006. By using retroviral vectors to express combinations of stemness genes, they identified Oct4, Sox2, Krueppel-like factor 4 and c-Myc as essential factors for reprogramming of somatic cells. Subsequent experiments applied this technology to human and rat fibroblasts, as well as other cell types and several groups showed that iPS can be generated by an even smaller number of transcription factors. The efficiency of conversion and maintenance of a pluripotent state can be supported by small molecules, such as valproic acid and specific pharmacological inhibitors. This technology is a milestone for a basic understanding of cell potency, cell fate and pathogenesis, as well as for development of cell therapies and potential applications in animal breeding.

18 DEVELOPMENTAL COMPETENCE OF CLONED PORCINE EMBRYOS PRODUCED WITH DIFFERENT CLONING PROCEDURES

Two nuclear transfer (NT) techniques are routinely used to produce cloned animals, traditional cloning (TC) and handmade cloning (HMC). The TC embryos keep their zona and can be transferred at early stages, whereas HMC embryos are zona-free and must be cultured to the morula/blastocyst stage before transfer. Some studies have shown that in vitro culture reduces embryo development and quality, but it is not known whether embryos produced by TC or HMC differ because of the NT method or the in vitro culture. Therefore, we investigated the developmental competence and histone acetylation (H3K18ac) of porcine NT embryos produced by TC and HMC with (Day 5 and 6) or without (Day 0) in vitro culture. Nuclear transfer experiments were performed on same day (Day 0), using same batch of porcine oocytes and donor cells and same in vitro culture conditions. Cloning procedures were previously described (TC : Cloning Stem Cells 10 : 355; HMC : Zygote 20 : 61). Parthenogenetically activated embryos (PA) were used as control of activation and culture conditions. Embryos from all groups were collected for immunostaining of H3K18ac on Days 0, 5, and 6. The normalized H3K18ac level was calculated as previously described (Epigenetics 6 : 177). Cell numbers per blastocyst in each group were counted on Days 5 and 6. The cleavage rate (Day 2) and blastocyst rates (Days 5 and 6) between groups were analysed by Chi-squared test, whereas cell number per blastocysts and H3K18ac level between groups and days were analysed by ANOVA (SAS version 9.2; SAS Institute Inc., Cary, NC, USA). Cleavage rate of HMC embryos was lower than that of TC embryos, but blastocyst rate and cell number per blastocyst were higher in the HMC group compared with TC (Table 1). Differences of H3K18ac level between HMC, TC, and PA groups were only observed on Day 6 but not on Day 0 or Day 5. Within HMC and TC groups, there was no difference in H3K18ac level between Day 0 and Day 5, but the level was lower on Day 6 compared with Day 5 in the HMC group, whereas the TC group displayed the opposite pattern. In conclusion, NT embryos produced by HMC show higher blastocyst rate and cell number per blastocyst compared with TC embryos. Both in vitro culture and the NT method result in differences of the normalized H3K18ac levels. Further study is needed to investigate putative differences between NT embryos produced by HMC and TC compared to in vivo embryos also after transfer to recipients. Table 1.Cleavage and blastocyst rate, cell numbers, and normalized H3K18ac level for handmade cloning (HMC), traditional cloning (TC), and parthenogenetically activated (PA) embryos1

192 IDENTIFICATION AND CHARACTERIZATION OF Oct4-EGFP EXPRESSING CELLS IN TRANSGENIC PIG TESTIS

We have produced germ line transgenic pigs carrying the entire 18-kb genomic sequence of the murine Oct4 gene fused to the enhanced green fluorescent protein (EGFP) cDNA (OG2 construct; Nowak-Imialek et al., 2011 Stem Cells Dev.). Expression of the EGFP reporter construct is confined to germ line cells, the inner cell mass, and trophectoderm of blastocysts, and testicular germ cells, including putative spermatogonial stem cells (SSC). SSC are unique among stem cells because they can both self-renew and differentiate into spermatozoa. In-depth knowledge on porcine SSC has been hampered by the inability to isolate these cells from the complex cell population of the testis. In the Oct4-EGFP transgenic mouse, SSC are the only adult stem cells that express Oct4. Fluorescence microscopy of testicular tissue isolated from transgenic piglets revealed minimum numbers of EGFP-positive cells, whereas testicular tissue isolated from adult transgenic boars contained a high amount of EGFP fluorescent cells. Northern blot analysis confirmed stronger EGFP expression in the testis of adult transgenic pigs than in the testis from transgenic piglets. Time course and the signal intensity of EGFP expression in Oct4-EGFP testis paralleled mRNA expression of the endogenous Oct4 gene. Here, we used adult Oct4-EGFP transgenic pigs as a model for fluorescence-activated cell sorting (FACS)-based isolation of EGFP-expressing cells from testes. To obtain a single-cell suspension, the testes were enzymatically dissociated using two digestion steps. Thereafter, FACS based on EGFP expression was successfully used to purify specific testicular cell populations. Two cell populations, i.e. EGFP+ (14%) and EGFP– (45%) could be isolated. Subsequently, qualitative PCR analyses were performed on EGFP+, EGFP–, and unsorted cell populations using marker genes specific for pluripotency and undifferentiated germ cells (OCT4, FGFR3, UTF1, PGP9.5, GFRα1, CD90, SALL4), differentiating germ cells (c-KIT), meiosis (BOLL), spermatids (PRM2), and somatic cells (VIM, LHCGR). All of the genes, including OCT4, UTF1, FGFR3, PGP9.5, CD90, SALL4, and GFRα1 were expressed at least 3-fold and up to 12-fold greater in the EGFP-positive population. Vimentin, which is mainly expressed in Sertoli cells and LHCGR, which is mainly expressed in Leydig cells, were expressed in unsorted and EGFP– cell populations and at very low level in EGFP+ cells. Moreover, expression of the c-KIT and PRM2 markers were detected also in EGFP+ cell population, indicating that these cells contain also differentiating spermatogonia. To explore the characteristics of the Oct4-EGFP expressing cells in greater detail, localization in the porcine testis sections and analysis of co-expression with germ cell markers using immunohistochemistry is currently underway.

2 SPECIFIC FATTY ACID FOLLOW-UP REVEALS RUMEN-PROTECTED FAT SUPPLEMENTATION EFFECTS ON BOVINE OOCYTE QUALITY AND EMBRYO DEVELOPMENT

Information on how supplementation of high-yield dairy cows with rumen-protected fat affects fertility in cattle herds is scarce. Here, Holstein-Friesian heifers (n = 84) received a supplement consisting of either rumen-protected conjugated linoleic acid (CLA; cis-9,trans-11-CLA and trans-10,cis-12-CLA) or stearic acid 18 : 0 (SA) on top of an isocaloric grass silage diet. Two supplementation doses were used (100 and 200 g d–1). Blood and follicular fluid were collected at the start and end of the supplementation period for analysis of cholesterol, insulin-like growth factor (IGF), and nonesterified fatty acids (NEFA), and for fatty acid profiling. Although cholesterol, IGF, and NEFA levels did not differ among experimental groups, lipid profiles in blood and follicular fluid were affected in a dose-dependent manner by both supplements. After 45 days of supplementation, oocytes were collected by ovum pick-up (OPU). The mRNA relative abundance of target genes (IGF1r, GJA1, FASN, SREBP1, and SCAP) was analysed in single in vitro- (24 h IVM) and in vivo-matured (collected by OPU 20 h after GnRH injection) oocytes and in vitro-produced blastocysts (Day 8) by qPCR (n = 6/group). Lipid profiling of individual oocytes from the CLA-supplemented (n = 37) and the SA-supplemented (n = 50) was performed by desorption electrospray ionization mass spectrometry (DESI-MS). Oocytes from the CLA-supplemented (n = 413) and the SA-supplemented (n = 350) groups were used for assessing maturation and blastocysts development rates. In immature oocytes, CLA supplementation led to an increase of triacylglycerol 52 : 3 [TAG (52 : 3)] and TAG (52 : 2), squalene, palmitic acid 16 : 0, and oleic acid 18 : 1, and decreased abundance of TAG (56 : 3), TAG (50 : 2) and TAG (48 : 1). In vitro-matured oocytes showed different lipid profiles, with increased abundances of TAG (52 : 3), and TAG (52 : 2) as well as phosphatidylinositol 34 : 1 [Plo (34 : 1)], whereas phosphatidylglycerol (34 : 1) [PG (34 : 1)] and palmitic acid 16 : 0 were less abundant in in vitro-matured oocytes. SCAP was significantly down-regulated in in vitro-matured oocytes from supplemented heifers compared with their in vivo-matured counterparts. Maturation (CLA = 74% v. SA = 67%) and blastocyst rates (CLA = 22.4% v. SA = 12.7%) were different among experimental groups. One-way ANOVA and the Tukey-Kramer test were applied for a multiple comparison of means (P-value ≤ 0.05 was considered as statistically significant). In conclusion, we demonstrate here that fatty acid monitoring along different compartments (i.e. blood system, follicular fluid, and intra-oocyte) after rumen-protected fat supplementation of dairy heifer diet reveals nutritional footprints on oocyte quality and embryo development. These results demonstrate the close relationship between nutrition and cattle herd's fertility and, at the same time, support the role of the bovine model for understanding nutritional-dependent fertility impairments.

189 SMALL MOLECULE INHIBITORS PD0325901 AND CHIR99021 CAUSE REDUCED EXPRESSION OF PLURIPOTENCY GENES IN PUTATIVE PORCINE INDUCED PLURIPOTENT STEM CELLS

Small molecule inhibitors acting on the MEK and Wnt signalling pathways (PD0325901 and CHIR99021, respectively) have been used successfully for the maintenance of murine and rat pluripotent stem cells in the in vitro culture. The effects of these compounds in other species have not been conclusively determined, and some reports suggest that they may actually cause loss of pluripotency in human embryonic stem cells and decrease of OCT4 expression levels in porcine induced pluripotent stem cells (piPSC). In our experiments, putative piPSC lines derived from transgenic porcine fetal fibroblasts (pFF) and adipose mesenchymal stem cells (pAMSC) that harbor the OCT4-EGFP reporter construct were maintained in piPSC culture medium [DMEM supplemented with 10% Knockout Serum Replacement (Life Technologies, Carlsbad, CA, USA), 10% fetal bovine serum, nonessential amino acids, L-glutamine, penicillin-streptomycin, and 1000 U mL–1 murine leukemia inhibitory factor (LIF)], with or without addition of 1 μM PD0325901 and 3 μM CHIR99021. After five passages in the two experimental culture conditions, three pFF-derived putative piPSC lines were evaluated morphologically and the expression of various pluripotency genes was analysed by real-time quantitative PCR. The results showed decrease of OCT4-EGFP expression and loss of compact colony morphology of the cells cultured in the presence of PD0325901 and CHIR99021. Moreover, the transcriptional expression levels of OCT4, SOX2, NANOG, REX1, UTF1, and TDH were reduced by 12-, 9-, 10-, 3-, 5-, and 20-fold, respectively, compared with the cells cultured without these inhibitors. When putative piPSC derived from pAMSC were cultured in medium supplemented with small molecule inhibitors, the OCT4-EGFP expression was completely lost within a few days. The cells also lost their iPSC-like colony morphology and were further propagated as single, mesenchymal-like cells. The same effects were observed when the cells were cultured with CHIR99021 alone, whereas there were no such changes when we used only PD0325901. This suggests that, similarly to human embryonic stem cells (ESC), the activation of the Wnt pathway in pAMSC-derived iPSC may lead to differentiation in these cells. The effects of the CHIR99021 alone on the pFF-derived piPSC-like cells are still to be determined. In conclusion, the results of our preliminary investigations call into question the effectiveness of PD0325901 and CHIR99021 in the maintenance of piPSC in culture.

163 EFFECTS OF DIFFERENT IN VITRO MATURATION SYSTEMS ON EMBRYO DEVELOPMENT IN BOVINE PREPUBERTAL AND ADULT DONORS

Prepubertal bovine females have been suggested as a source of oocytes in order to accelerate genetic gain and decrease the generation interval. However, prepubertal oocytes have a lower developmental competence than their adult counterparts. In vitro maturation (IVM) systems using cyclic AMP (cAMP) regulators and 30-h culture have been suggested to improve blastocyst in vitro production rates from bovine oocytes (Albuz et al., 2010). The present study evaluated the effects of an addition of the cAMP modulators forskolin, 3-isobutyl-1-methylxanthine (IBMX), and cilostamide during extended IVM on blastocyst yields and gene expression in prepubertal and adult bovine females. Holstein-Friesian donors were submitted to ovum pick-up twice per week. Oocytes from groups of 12 animals, including lactating cows (>2 lactations) and prepubertal donors (6–10 months old) were used in the following treatment groups: TCM24 (24-h IVM, routine protocol/control), cAMP30 (2-h pre-IVM culture using forskolin-IBMX and 30-h IVM adding cilostamide), DMSO30 [2-h pre-IVM culture and 30-h IVM with dimethyl sulfoxide (DMSO)/vehicle control]. In vitro-matured oocytes were fertilized and presumptive zygotes were cultured in vitro to assess embryo development. In vivo blastocysts were produced from superovulated cows and used for gene expression analysis. Cleavage rates, blastocyst formation, and mRNA abundance of selected genes were evaluated. The Glimmix procedure from SAS/STAT (SAS Institute Inc., Cary, NC, USA) was performed to compare blastocyst and cleavage rates. One-way ANOVA was implemented to evaluate gene expression. A total of 793 oocytes from the different sources were submitted to the IVM treatments. Cleavage rates (prepubertal donors: 64.6 ± 4%, 59.1 ± 6.4%, 53 ± 4.4%, cows: 55.1 ± 4.3%, 59 ± 6.5%, 50.8 ± 4.4%, for TCM24, cAMP30, and DMSO30, respectively; P > 0.05) and blastocyst/zygotes rates (prepubertal donors: 27 ± 6%; 21.8 ± 3.5%; 17.6 ± 2.4%; cows: 28 ± 3.3%; 27.7 ± 2.9%; 22.7 ± 3.2% for TCM24, cAMP30, and DMSO30, respectively; P > 0.05) did not differ among in vitro treatments. The mRNA relative abundance of the EGR1 gene was down-regulated 6-fold in all in vitro-produced blastocysts compared with their in vivo counterparts (P < 0.05). Gene expression profiles for SLC2A8, DNMT3B, BCL-XL, and PRDX1 were similar in in vitro and in vivo blastocysts. These results show similar embryo production patterns in prepubertal and adult donors. Furthermore, DMSO did not show effects on embryo developmental rates when used during IVM. The gene expression levels of EGR1 confirm our recent findings in blastocysts obtained from oocytes from slaughterhouse ovaries (data not presented), showing its usefulness as an embryo quality marker. These preliminary results indicate that oocyte developmental capacity in prepubertal donors can be similar to that of the adult donors without addition of cAMP modulators.