Using a nano-flare probe to detect RNA in live donor cells prior to somatic cell nuclear transfer

2015 ◽  
Vol 40 (1) ◽  
pp. 7-15
Author(s):  
Bo Fu ◽  
Liang Ren ◽  
Di Liu ◽  
Jian-zhang Ma ◽  
Tie-zhu An ◽  
...  
2013 ◽  
Vol 25 (8) ◽  
pp. 1142 ◽  
Author(s):  
Insung Hwang ◽  
Yeon Woo Jeong ◽  
Joung Joo Kim ◽  
Hyo Jeong Lee ◽  
Mina Kang ◽  
...  

Interspecies somatic cell nuclear transfer (iSCNT) is an emerging assisted reproductive technology (ART) for preserving Nature’s diversity. The scarcity of oocytes from some species makes utilisation of readily available oocytes inevitable. In the present study, we describe the successful cloning of coyotes (Canis latrans) through iSCNT using oocytes from domestic dogs (Canis lupus familiaris or dingo). Transfer of 320 interspecies-reconstructed embryos into 22 domestic dog recipients resulted in six pregnancies, from which eight viable offspring were delivered. Fusion rate and cloning efficiency during iSCNT cloning of coyotes were not significantly different from those observed during intraspecies cloning of domestic dogs. Using neonatal fibroblasts as donor cells significantly improved the cloning efficiency compared with cloning using adult fibroblast donor cells (P < 0.05). The use of domestic dog oocytes in the cloning of coyotes in the present study holds promise for cloning other endangered species in the Canidae family using similar techniques. However, there are still limitations of the iSCNT technology, as demonstrated by births of morphologically abnormal coyotes and the clones’ inheritance of maternal domestic dog mitochondrial DNA.


2007 ◽  
Vol 19 (1) ◽  
pp. 147
Author(s):  
E. Lee ◽  
K. Song ◽  
Y. Jeong ◽  
S. Hyun

Generally, blastocyst (BL) formation and embryo cell number are used as main parameters to evaluate the viability and quality of in vitro-produced somatic cell nuclear transfer (SCNT) embryos. We investigated whether in vitro development of SCNT pig embryos correlates with in vivo viability after transfer to surrogates. For SCNT, cumulus–oocyte complexes (COCs) were matured in TCM-199 supplemented with follicular fluid, hormones, EGF, cysteine, and insulin for the first 22 h and in a hormone-free medium for 18 h. Three sources of pig skin cells were used as nuclear donor: (1) skin fibroblasts of a cloned piglet that were produced by SCNT of fetal fibroblasts from a Landrace × Yorkshire × Duroc F1 hybrid (LYD), (2) skin fibroblasts of a miniature pig having the human decay accelerating factor gene (hDAF-MP), and (3) skin fibroblasts of a miniature pig with a different strain (MP). MII oocytes were enucleated, subjected to nuclear transfer from a donor cell, electrically fused, and activated 1 h after fusion. SCNT embryos were cultured in a modified NCSU-23 (Park Y et al. 2005 Zygote 13, 269–275) for 6 days or surgically transferred (110–150 fused embryos) into the oviduct of a surrogate that showed standing estrus on the same day as SCNT. Embryos were examined for cleavage and BL formation on Days 2 and 6, respectively (Day 0 = the day of SCNT). BLs were examined for their cell number after staining with Hoechst 33342. Pregnancy was diagnosed by ultrasound 30 and 60 days after embryo transfer. Embryo cleavage was not affected by donor cells (82, 81, and 72% for LYD, hDAF-MP, and MP, respectively), but BL formation was higher (P &lt; 0.05) in hDAF-MP (16%) than in LYD (9%) and MP (6%). MP showed higher (P &lt; 0.05) BL cell number (46 cells/BL) than hDAF-MP (34 cells) but did not show a difference from LYD (37 cells). LYD and MP showed higher pregnancy rates (Table 1) on Days 30 and 60, even though they showed lower BL formation in vitro. Due to a relatively small number of embryo transfers through a limited period, we could not exclude any possible effects by seasonal or operational differences. These results indicated that pregnancy did not correlate with in vitro BL formation of SCNT pig embryos but rather were affected by the source of donor cells. Table 1.In vivo development of somatic cell nuclear transfer pig embryos derived from different sources of donor cells This work was supported by the Research Project on the Production of Bio-organs (No. 200506020601), Ministry of Agriculture and Forestry, Republic of Korea.


2013 ◽  
Vol 25 (1) ◽  
pp. 308
Author(s):  
A. Wuensch ◽  
A. Richter ◽  
M. Kurome ◽  
B. Kessler ◽  
V. Zakhartchenko ◽  
...  

The generation of genetically tailored pig models for biomedical research using somatic cell nuclear transfer (SCNT) is an efficient and precise approach, whereas the outcome is crucially dependent on the source of nuclear donor cells. Especially for site-directed mutagenesis by homologous recombination, including the generation of single cell clones, the demands on the target cells are high. Different primary cells used for SCNT have been tested for their efficiency in SCNT experiments, but further characterisation of the specific cell types, their morphology, proliferation, lifespan, and stability of karyotype is mostly lacking. We have evaluated the potential of 2 primary porcine kidney cell lines (PKC) isolated from juvenile pigs by a simple collagenase digestion and culture in collagen-coated dishes as cell source for SCNT, including their morphology, proliferation capacity, transfection efficiency, and capacity to support full-term development of SCNT embryos after additive gene transfer or homologous recombination. Single cell clones generated by subcloning of PKC at passage 3 showed different morphologies, proliferation rates, and lifespan, indicating that PKC culture is a mixed population of different types of fibroblasts and/or other cells types. The PKC could be maintained in culture for up to 71 passages without signs of senescence and decreased proliferation, exhibiting a stable karyotype containing 74% normal chromosome numbers (2N = 38) determined from metaphase spreads. In contrast, porcine fetal fibroblasts (PFF) and porcine ear fibroblasts (PEF) could be not be passaged more than 20 times. The calculation of growth curves at passage 4 to 5 showed that PKC exhibited a higher proliferation rate with a population doubling time of 16.6 to 18.4 h compared with PFF (23.2. h) and PEF (32.9 h). Furthermore the determination of the developmental competence after SCNT using PKC at passage 4 in 3 independent experiments and in vitro cultivation for 7 days resulted in a higher blastocyst rate (21%) compared with that in PFF (9.1%) and PEF (4.3%). The comparison of different transfection methods (lipofection, nanofection, conventional electroporation, nucleofection), using an expression vector for green fluorescent protein (GFP), showed that the NucleofectorTM technology gave the best results with transfection efficiencies of 70 to 89%, high fluorescence intensity, low cytotoxicity, good cell proliferation, and almost no morphological signs of stress. So far, around 150 cloned piglets using 18 different gene constructs have been produced using stable transfected PKC after additive gene transfer and targeting of 3 different loci. These findings demonstrate that among the 3 tested types of donor cells, PKC, PFF, PEF, primary PKC have outstanding potential for the production of genetically modified pigs by SCNT. This work is supported by the DFG (FOR535, FOR793), the Bayerische Forschungsstiftung, and Mukoviszidose e.V.


2012 ◽  
Vol 24 (1) ◽  
pp. 126
Author(s):  
X. Yang ◽  
J. Mao ◽  
E. M. Walters ◽  
M. T. Zhao ◽  
K. Lee ◽  
...  

Somatic cell nuclear transfer (SCNT) efficiency in pigs and other species is still very low. This low efficiency and the occurrence of developmental abnormalities in offspring has been attributed to incomplete or incorrect reprogramming. Cytoplasmic extracts from both mammalian and amphibian oocytes can alter the epigenetic state of mammalian somatic nuclei as well as gene expression to more resemble that of pluripotent cells. Rathbone et al. (2010) has showed that pretreating somatic donor cells with frog oocyte extract (FOE) increased live birth in ovine. Liu et al. (2011) also reported that treating donor cells with FOE enhanced handmade clone embryo development in pigs. The aim of this study was to evaluate the early development of cloned embryos produced with porcine GFP fibroblasts pre-treated with a permeabilizing agent, digitonin and matured frog oocyte extract. Frog egg cytoplasmic extract was prepared from one frog's oocytes after being matured in vitro to MII stage. The experiment included 2 groups. In the FOE-treated group, GFP-tagged fetal fibroblasts were permeabilized by digitonin (15 ng mL–1) and incubated in FOE containing an ATP-regenerating system (2.5 mM ATP, 125 μM GTP, 62.5 μg mL–1 of creatine kinase, 25 mM phosphocreatine and 1 mM NTP) at room temperature (24°C) for 2 h; cell membranes were re-sealed by culturing in 10% FBS in DMEM media for 2.5 h at 38.5°C before used as donor cells. In the control group, the same donor cells were treated with digitonin, but without frog oocyte extract incubation. The SCNT embryos were produced by using the 2 groups of donor cells as described above. In total, 305 control and 492 FOE oocytes were enucleated from 8 biological replicates. Two hundred fifty control and 370 FOE couplets were fused and cultured in porcine zygote medium 3. Percent cleavage was recorded on Day 2 and the percent blastocyst formation was determined on Day 7 (SCNT day = 0). In addition, the number of nuclei in the blastocysts was recorded on Day 7. Percent fusion, cleavage, blastocyst formation and number of nuclei in blastocysts were analysed by using SAS software (v9.2), with day and treatment class as main effects. There was no difference in percent fusion (FOE, 76.2 ± 2.5% vs control, 80.8 ± 2.8%) or in cleavage (FOE: 74.8 ± 2.5% vs control: 74.6 ± 2.9%). Only green blastocysts with 16 or more nuclei were considered to be a true SCNT blastocyst. The percent blastocyst was higher in the FOE group than that in the control (13.9 ± 0.8% vs 9.5 ± 0.9%, P < 0.05), whereas the number of nuclei in the blastocysts was not different between the 2 groups (39.7 ± 2.4, 35.9 ± 3.8 for FOE and control, respectively). In conclusion, our study demonstrated that pre-treatment of donor cells with digitonin and Xenopus MII oocyte extract increased porcine SCNT embryo development to blastocyst and cloning efficiency. Funded by the National Natural Science Foundation of China (NO. 31071311), Natural Science Foundation of Fujian Province of China (No. 2009J06017) and NIH U42 RR18877.


2011 ◽  
Vol 23 (1) ◽  
pp. 120 ◽  
Author(s):  
H. K. Bae ◽  
J. Y. Kim ◽  
I. S. Hwang ◽  
C. K. Park ◽  
B. K. Yang ◽  
...  

The present study was conducted to examine the reactive oxygen species (ROS) generation levels in the donor cells, recipient oocytes, and somatic cell nuclear transfer (SCNT) embryos during nuclear transfer procedures. Bovine ear skin cells were classified by serum starvation, confluence, and cycling cells. Bovine metaphase II (MII) oocytes matured in vitro for 22 h and denuded by vortexing were enucleated and electrofused with serum-starved donor cells, then activated by a combination of Ca-ionophore and 6-dimethylaminopurine culture for 4 h. In vitro fertilization (IVF) was performed for controls. SCNT and IVF embryos were cultured in CR1aa supplemented with 3 mg mL–1 BSA for ∼36 h. Donor cells, recipient oocytes, and SCNT embryos were stained in 10 μM dichlorohydrofluorescein diacetate (DCHFDA) or 10 μM HPF dye each for 30 min at 39°C to measure the H2O2 or ·OH radical levels after various micromanipulation steps. SCNT and IVF embryos were also stained at the 1-, 2-, and 4-cell stages after 8, 24, and 42 h of fusion or insemination, respectively. The fluorescent emissions from the samples were recorded as JPEG file using a digital camera (F5.0, 4 s) attached to a fluorescent microscope with filters at 450 to 480 nm for excitation and at 515 nm for emission. The images were analysed using ImageJ software 1.37 (NIH) by the intensity of fluorescence (pixels) in each cell (total 70 to 75 cells in each group), oocyte and embryo (total 50 to 60 eggs or embryos in each group). 4 to 7 replicates were performed for each experiment, and data were analysed by Duncan′s multiple-range tests. H2O2 and ·OH radical levels of cultured somatic cells were high in confluence group and significantly low in serum starvation group (P < 0.05). During micromanipulation, H2O2 levels in recipient oocytes and SCNT embryos were increased by enucleation (37.2 pixels), electrofusion (49.7 pixels), and activation (40.6 pixels) treatments (P < 0.05) compared to that in MII oocytes (33.1 pixels), and the level of H2O2 was extremely increased immediately after electrofusion. ·OH radical levels were significantly higher during manipulation procedures (51.6 to 55.7 pixels; P < 0.05) compared to MII oocytes. During in vitro culture, the H2O2 and ·OH radical levels of SCNT embryos were significantly higher (P < 0.05) compared to IVF embryos at 1- (32.4 v. 17.3 and 52.0 v. 29.6 pixels, respectively), 2- (27.2 v. 22.0 and 33.4 v. 26.0 pixels, respectively), and 4-cell (25.1 v. 16.5 and 26.9 v. 20.7 pixels, respectively) stages. These results suggest that the culture type of donor cells can affect the ROS generation level and the cellular stress during micromanipulation procedures also can generate the ROS in bovine SCNT embryos, which may lead the cellular damages in bovine SCNT embryos. This work was supported by National Research Foundation of Korea Grant funded by the Korean Government (KRF-2008–313-F00067).


2017 ◽  
Vol 29 (1) ◽  
pp. 123
Author(s):  
S. Lee ◽  
M. H. Jung ◽  
H. J. Oh ◽  
O.-J. Koo ◽  
B. C. Lee

Pigs are useful models for studying human diseases because of the similarity of their anatomy and physiology. Recent advances in genome editing techniques such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeat-associated Cas9 system (CRISPR/Cas9) have made it possible to produce animals for specific purposes. Especially, recent application of the CRISPR/Cas9 system improved the efficiency of genome editing in pigs with higher targeting efficiency or percentage of desired mutation compared to other meganucleases (ZFNs and TALENs). The klotho deficiency in small animals such as mice is characterised by an extremely shortened life span with multiple aging-like phenotypes similar to human premature-aging syndromes. However, limited information is available on the function of klotho in large animals such as pigs. The objective of this study was to determine whether the use of non-selected porcine fibroblasts electroporated with Cas9/sgRNA ribonucleoproteins, targeting the klotho gene, for somatic cell nuclear transfer (SCNT) results in high mutation rates in embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and type 2 Cas9 RNPs (total 36 μg, 1:4 ratio, respectively) were transfected into porcine fibroblasts via Neon (Life Technologies) with a single DC pulse of 1400 V for 30 ms. Then, transfected fibroblasts were cultured for 1 day and used randomly for SCNT without selection. SCNT was performed by enucleation of in vitro-matured porcine oocyte, followed by injection of non-selected donor cells, fusion with a single DC pulse of 200 V/mm for 30 μs using an electro cell fusion generator (LF101; Nepa Gene Co.), and electrical activation with a single DC pulse of 150 V/mm for 60 μs using a BTX Electro-Cell Manipulator 2001 (BTX Inc.). The SCNT embryos were cultured in PZM5 culture medium to Day 7 and analysed for the presence of modifications to the klotho gene. Blastocysts were classified as modified if they contained an INDEL as measured by both T7E1 assay and deep sequencing of PCR amplicons spanning the targeted exon. The klotho modification rate was 65% (n = 13), of which 38.5% (n = 5) of the embryos contained biallelic modifications. In conclusion, SCNT with non-selected donor cells transfected with Cas9/sgRNA RNPs might be an efficient and simple tool to produce klotho deficient pigs as models for human diseases. Further studies are required to generate klotho deficient pigs by performing embryo transfer to the recipients. This study was supported by Korea Institute of Planning and Evaluation for Technology in food, agriculture, forestry and fisheries (#311011–05–5-SB010, #114059–03–2-SB010), Research Institute for Veterinary Science, TS Corporation and the BK21 plus program.


2015 ◽  
Vol 82 (11) ◽  
pp. 867-879 ◽  
Author(s):  
Huanhuan Chen ◽  
Lei Zhang ◽  
Zekun Guo ◽  
Yongsheng Wang ◽  
Rongjun He ◽  
...  

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