185 NONSURGICAL EMBRYO TRANSFER FOR PRODUCTION OF PIGS BY IN VITRO FERTILIZATION AND SOMATIC CELL NUCLEAR TRANSFER

2010 ◽  
Vol 22 (1) ◽  
pp. 251
Author(s):  
J.-G. Yoo ◽  
M.-R. Park ◽  
H.-N. Kim ◽  
Y.-G. Ko ◽  
J.-Y. Lee ◽  
...  

Instead of surgical embryo transfer (ET) in the pig, nonsurgical ET is a hopeful method to increase the efficiency of biotechnology applications such as cloning and transgenesis. In this study, we conducted surgical and nonsurgical ET methods after somatic cell nuclear transfer (SCNT) with MHC miniature pig cells to find out the best condition for production of cloned miniature pigs. Ovaries were obtained from prepubertal crossbred gilts at a local slaughterhouse. Oocytes were matured for 40 to 44 h at 38.5°C under 5% CO2 in air. As donor cells, fibroblast cells were cultured from ear skin tissue of 8-month-old MHC inbred miniature pigs. Fibroblast cells were cultured, passaged (3 to 8 passages), and used as donor cells for NT. After the enucleation and injection process, eggs were held in TCM-199. For fusion, 2 DC pulses of 1.2 kV cm-1 were applied for 30 μs. Both IVF and SCNT embryos were cultured in PZM-3 medium. After IVF, 84.9% (411/484) of embryos cleaved and 27.3% (132/484) of embryos reached the blastocyst stage. In the SCNT group, 80.8% (231/286) of eggs fused and 25.9% (60/286) of embryos developed to blastocysts. For surgical ET, approximately 200 SCNT embryos were transferred into oviducts of each synchronized recipient. For nonsurgical ET, embryos were cultured in PZM-3 for 6 days after SCNT and IVF, and then good quality blastocyst stage embryos were selected for ET. The pregnancy status of recipients at Day 30 was determined by ultrasound scanning. Using Day 30 of gestation as an endpoint, the nonsurgical ET method (47.3%, 9/19) had a similar pregnancy rate as the surgical ET method (56.5%, 13/23). Further study is needed to optimize the nonsurgical ET method especially for SCNT eggs. This work received grant support from the Agenda Program (no. 200901FHT010305535), Rural Development Administration, Republic of Korea.

2009 ◽  
Vol 21 (1) ◽  
pp. 198
Author(s):  
T. Xiang ◽  
S. Walker ◽  
K. Gregg ◽  
W. Zhou ◽  
V. Farrar ◽  
...  

Oct-4, a POU domain-containing transcription factor encoded by Pou5f1, is selectively expressed in pre-implantation embryos and pluripotent stem cells, but not in somatic cells. Because of such a unique expression feature, Oct-4 can serve as a useful reprogramming indicator in somatic cell nuclear transfer (SCNT). Compared with data of Oct-4 expression in mouse and bovine cloned embryos, little is known about this gene in equine nuclear transfer. In the present study, we investigated Oct-4 expression in donor cells, oocytes, and SCNT embryos to evaluate reprogramming of equine somatic cells following nuclear transfer. Horse ovaries were obtained from a local slaughterhouse and the oocytes collected from the ovaries were matured in vitro in an M199-based medium (Galli et al. 2003 Nature 424, 635) for 24 h. Donor cells were derived from biopsy tissue samples of adult horses and cultured for 1 to 5 passages. Standard nuclear transfer procedures (Zhou et al. 2008 Mol. Reprod. Dev. 75, 744–758) were performed to produce cloned embryos derived from equine adult somatic cells. Cloned blastocysts were obtained after 7 days of in vitro culture of reconstructed embryos. Total RNA were extracted using Absolutely RNA Miniprep/Nanoprep kits (Stratagen, La Jolla, CA) from oocytes (n = 200), donor cells, and embryos (n = 5). DNase I treatment was included in the procedure to prevent DNA contamination. Semiquantitative RT-PCR was performed with optimized cycling parameters to analyze Oct-4, GDF9, and β-actin in equine donor cells, oocytes, and cloned blastocysts. The RT-PCR products were sequenced to verify identity of the genes tested. The relative expression abundance was calculated by normalizing the band intensity of Oct-4 to that of β-actin in each analysis. No transcript of Oct-4 was detected in equine somatic cells used as donor nuclei, consistent with its expression patterns in other animal species, whereas Oct-4 was abundantly expressed in equine SCNT blastocysts derived from the same donor cell line. Oct-4 transcripts were also detected in equine oocytes and whether any maternally inherited Oct-4 mRNA persisted up to the blastocyst stage was unclear in this study. We selected GDF9 to address this question; GDF9 was abundantly detected in equine oocytes, consistent with its expression pattern in mouse and bovine, but not detected in donor cells and cloned blastocysts, suggesting that the GDF9 mRNA from the oocyte was degraded at least by the blastocyst stage. The results from this study imply occurrence of Oct-4 reprogramming in equine SCNT blastocysts, and future analysis for more developmentally important genes is needed to better understand reprogramming at molecular levels in this species.


2008 ◽  
Vol 14 (5) ◽  
pp. 418-432 ◽  
Author(s):  
Zhisheng Zhong ◽  
Yanhong Hao ◽  
Rongfeng Li ◽  
Lee Spate ◽  
David Wax ◽  
...  

AbstractWe previously reported that translocation of mitochondria from the oocyte cortex to the perinuclear area indicates positive developmental potential that was reduced in porcine somatic cell nuclear transfer (SCNT) embryos compared to in vitro–fertilized (IVF) embryos (Katayama, M., Zhong, Z.-S., Lai, L., Sutovsky, P., Prather, R.S. & Schatten, H. (2006). Dev Biol299, 206–220.). The present study is focused on distribution of donor cell mitochondria in intraspecies (pig oocytes; pig fetal fibroblast cells) and interspecies (pig oocytes; mouse fibroblast cells) reconstructed embryos by using either pig fibroblasts with mitochondria-stained MitoTracker CMXRos or YFP-mitochondria 3T3 cells (pPhi-Yellow-mito) as donor cells. Transmission electron microscopy was employed for ultrastructural analysis of pig oocyte and donor cell mitochondria. Our results revealed donor cell mitochondrial clusters around the donor nucleus that gradually dispersed into the ooplasm at 3 h after SCNT. Donor-derived mitochondria distributed into daughter blastomeres equally (82.8%) or unequally (17.2%) at first cleavage. Mitochondrial morphology was clearly different between donor cells and oocytes in which various complex shapes and configurations were seen. These data indicate that (1) unequal donor cell mitochondria distribution is observed in 17.2% of embryos, which may negatively influence development; and (2) complex mitochondrial morphologies are observed in IVF and SCNT embryos, which may influence mitochondrial translocation and affect development.


2006 ◽  
Vol 18 (2) ◽  
pp. 237
Author(s):  
J. Park ◽  
N. Minami ◽  
H. Imai

Developmental failure of a cloned animal using somatic cell nuclear transfer (SCNT) procedures is considered to be the result of abnormal expression of developmentally important genes caused by incomplete reprogramming of the donor cell nuclei. However, there are few reports about stage-specific gene expression during cleavage progression of cloned embryos. The aim of this study was to identify using fluorescein differential display method, the differentially expressed genes in cloned embryos at early developmental stages compared with those produced by in vitro fertilization. Bovine cumulus-oocytes complexes (COCs) were aspirated from follicles (2-8 mm in diameter) of slaughterhouse ovaries and cultured in TCM-199 supplemented with 10% fetal calf serum (FCS) for 18 h for somatic cell nuclear transfer (NT) or 24 h for in vitro fertilization (IVF) at 39�C. Removal of oocyte nuclei for NT was performed by squeezing out a small amount of the cytoplasm laying beneath the first polar body by means of a glass needle. Donor cells for NT were obtained from skin cells of an adult cow and cultured in DMEM supplemented with 10% FCS. After the transfer of somatic cell into enucleated oocytes, DC electric pulses at 200 V/mm for 2 � 10 �s were used for fusion, and the reconstructed embryos were treated with 10 �g/mL cycloheximide for 6 h. The embryos were then cultured for 120 h (morula stage) or 168 h (blastocyst stage) in modified SOF medium under 5% CO2, 5% O2 and 90% N2 at 39�C. Total RNA obtained from NT and IVF embryos were analyzed by differential display RT-PCR (DDRT-PCR) as previously described (Minami et al. 2001 Biol. Reprod. 64, 30-35). We obtained several differences in gene expression patterns between NT and IVF embryos at the morula and blastocyst stage. A total of 52 cDNA fragments were isolated and analyzed. Semiquantitative analysis revealed that some genes (NADH dehydrogenase subunit 1, SR rich protein, KIAA0107, ribosomal protein L19) were highly expressed in IVF embryos compared with NT embryos, whereas other genes (CASK) were highly expressed in NT embryos compared with IVF embryos. These results indicate that the differentially expressed genes observed in NT embryos may be representative of marker genes for the production of normal NT offspring and DDRT-PCR procedure is quite useful for identification of several genes that are differentially expressed between NT and IVF embryos.Although the detailed function of the genes and their products remains to be determined, it is likely that the reprogramming mechanisms can be elucidated genetically by the analysis of differentially expressed genes in the future.


2018 ◽  
Vol 24 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Shuang Liang ◽  
Zheng-Wen Nie ◽  
Jing Guo ◽  
Ying-Jie Niu ◽  
Kyung-Tae Shin ◽  
...  

AbstractMicroRNA (miR)-29b plays a crucial role during somatic cell reprogramming. The aim of the current study was to explore the effects of miR-29b on the developmental competence of bovine somatic cell nuclear transfer (SCNT) embryos, as well as the underlying mechanisms of action. The expression level of miR-29b was lower in bovine SCNT embryos at the pronuclear, 8-cell, and blastocyst stages compared within vitrofertilized embryos. In addition, miR-29b regulates the expression of DNA methyltransferases (Dnmt3a/3bandDnmt1) in bovine SCNT embryos. We further investigated SCNT embryo developmental competence and found that miR-29b overexpression during bovine SCNT embryonic development does not improve developmental potency and downregulation inhibits developmental potency. Nevertheless, the quality of bovine SCNT embryos at the blastocyst stage improved significantly. The expression of pluripotency factors and cellular proliferation were significantly higher in blastocysts from the miR-29b overexpression group than the control and downregulation groups. In addition, outgrowth potential in blastocysts after miR-29b overexpression was also significantly greater in the miR-29b overexpression group than in the control and downregulation groups. Taken together, these results demonstrated that miR-29b plays an important role in bovine SCNT embryo development.


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 < 0.05) in hDAF-MP (16%) than in LYD (9%) and MP (6%). MP showed higher (P < 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.


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).


2019 ◽  
Vol 86 (9) ◽  
pp. 1149-1167 ◽  
Author(s):  
Tanushri Jerath Sood ◽  
Swati Viviyan Lagah ◽  
Manishi Mukesh ◽  
Suresh Kumar Singla ◽  
Manmohan Singh Chauhan ◽  
...  

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