20 IMMUNOCYTOCHEMICAL CHARACTERIZATION OF DAYS 17 AND 19 OVINE IN VIVO AND SOMATIC CELL NUCLEAR TRANSFER EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 110
Author(s):  
N. I. Alexopoulos ◽  
K. Schauser ◽  
M. K. Holland ◽  
T. T. Peura ◽  
K. M. Hartwich ◽  
...  

The present study aimed to characterize development of in vivo and somatic cell nuclear transfer (SCNT) Merino ovine embryos on Days 17 and 19 using the mesoderm marker vimentin, the neuroectoderm marker β-tubulin III, and the pluripotency marker OCT4 for primordial germ cells. In vivo embryos were obtained by transferring 10 to 20 zygotes to each of 20 intermediate recipient ewes. On Day 6, 4 final recipients were used to obtain embryos for recovery at Day 17 (n = 2) and at Day 19 (n = 2). SCNT embryos were constructed from in vitro-matured oocytes and adult granulosa cells. On Day 6, 9 embryos (with intact inner cell masses) were transferred to each recipient for collection at Day 17 (n = 2) and Day 19 (n = 2). Ewes were euthanazed with phenobarbitone and excised reproductive tracts flushed with saline. A total of 24 embryos at Day 17 (14 in vivo and 10 SCNT) and 23 embryos at Day 19 (11 in vivo and 12 SCNT) were collected and processed for immunohistochemistry. On Day 17, length of embryo proper for in vivo and SCNT embryos was 6.2 and 5.6 mm, width of allantois was 9.3 and 3.8 mm, and number of somites was 19 and 13, respectively. On Day 19, length of embryo proper for in vivo and SCNT embryos was 11.5 and 7.3 mm, width of allantois was 70.6 and 13.7 mm, and number of somites was 28 and 22, respectively. On both Day 17 and Day 19, in vivo embryos had a much larger allantois, more somites, and were longer in length. Vimentin staining was observed in all in vivo embryos at Day 17 and Day 19; however, in 75% of Day 17 SCNT embryos, differentiation of the somites into dermatome with underlying sclerotome was either delayed or absent. Similarly, at both Day 17 and Day 19, a larger proportion of embryos did not stain for β-tubulin III, and of those that did, only a small amount was found in the neural tube. The intensity of both stains was much weaker in the SCNT embryos compared to in vivo embryos. Oct-4 was initially found in the splanchnic mesoderm lining the endoderm in the wall of the yolk sac and later in the dorsal mesentery and medial aspect of the mesonephros with in vivo embryos having double the number of positively stained cells than SCNT embryos. The delay in mesoderm compartments of SCNT embryos could imply future problems in the musculoskeletal system. However, lack of any neuroectoderm staining in more than half SCNT embryos could point to neurological problems being more of an issue in terms of survival and well-being. Equally, the smaller allantois could induce later placental abnormalities. The current project was funded by the Co-operative Research Centre for Innovative Dairy Products (CRC-IDP), Australia.

2006 ◽  
Vol 18 (2) ◽  
pp. 131
Author(s):  
K. Kaneyama ◽  
S. Kobayashi ◽  
S. Matoba ◽  
Y. Hashiyada ◽  
K. Imai ◽  
...  

Although many studies have been conducted on somatic cell nuclear transfer, there are only a few reports on cryopreservation of reconstructed embryos after nuclear transplantation. The objective of this study was to examine in vitro or in vivo development of vitrified blastocysts obtained by nuclear transfer. Nuclear transfer was carried out according to the procedure of Goto et al. (1999 Anim. Sci. J. 70, 243–245), and conducted using abattoir-derived oocytes and cumulus cells derived by ovum pickup from Holstein and Japanese Black cows. Embryos were vitrified as described by Saito et al. (1998 Cryobiol. Cryotech. 43, 34–39). The vitrification solution (GESX solution) was based on Dulbecco's PBS containing 20% glycerol (GL), 20% ethylene glycol (EG), 0.3 M sucrose (Suc), 0.3 M xylose (Xyl), and 3% polyethylene glycol (PEG). The blastocysts were equilibrated in three steps, with 10% GL, 0.1 M Suc, 0.1 M Xyl, and 1% PEG for 5 min (1); with 10% GL, 10% EG, 0.2 M Suc, 0.2 M Xyl, and 2% PEG for 5 min (2) and GESX solution (3). After transfer to GESX, equilibrated embryos were loaded to 0.25-mL straws and plunged into liquid nitrogen for 1 min. The vitrified blastocysts were warmed in water (20°C) and diluted in 0.5 M and 0.25 M sucrose for 5 min each. Equilibration and dilution procedures were conducted at room temperature (25–26°C). After dilution, the vitrified blastocysts were cultured in TCM-199 supplemented with 20% fetal calf serum and 0.1 mM β-mercaptoethanol at 38.5°C under gas phase of 5% CO2 in air. In Experiment 1, survival rates after vitrification were compared between the nuclear transfer and the IVF blastocysts. Survival rates of vitrified nuclear transfer blastocysts (n = 60, Day 8) at 24 and 48 h were 70.0% and 56.7%, respectively, and those of vitrified IVF blastocysts (n = 41) were 82.9% and 82.9%, respectively. There were no significant differences in survival rates at 24 and 48 h between the two groups. In Experiment 2, one (VIT-single) or two (VIT-double) vitrified and one (nonVIT-single) or two (nonVIT-double) nonvitrified reconstructed blastocysts per animal were transferred into Holstein dry cows. The result of Experiment 2 is shown in Table 1. This experiment demonstrated that the vitrification method in this study can be used for cloned embryo cryopreservation but the production rate should be improved. Table 1. Comparison of survival rates of vitrified or nonvitrified cloned embryos after transfer


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.


Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 681-694 ◽  
Author(s):  
P Tveden-Nyborg ◽  
T T Peura ◽  
K M Hartwich ◽  
S K Walker ◽  
P Maddox-Hyttel

The processes of cellular differentiation were studied in somatic cell nuclear transfer (SCNT), in vitro cultured (IVC) and in vivo developed (in vivo) ovine embryos on days 7, 9, 11, 13, 17 and 19. SCNT embryos were constructed from in vitro matured oocytes and granulosa cells, and IVC embryos were produced by in vitro culture of in vivo fertilized zygotes. Most SCNT and IVC embryos were transferred to recipients on day 6 while some remained in culture for day 7 processing. In vivo embryos were collected as zygotes, transferred to intermediate recipients and retransferred to final recipients on day 6. All embryos were processed for examination by light and transmission electron microscopy or immunohistochemical labelling for alpha-1-fetoprotein and vimentin. Overall, morphological development of in vivo embryos was superior to IVC and SCNT embryos. Day 7 and particularly day 9 IVC and SCNT embryos had impaired hypoblast development, some lacking identifiable inner cell masses. On day 11, only in vivo and IVC embryos had developed an embryonic disc, and gastrulation was evident in half of in vivo embryos and one IVC embryo. By day 13, all in vivo embryos had completed gastrulation whereas IVC and SCNT embryos remained retarded. On days 17 and 19, in vivo embryos had significantly more somites and a more developed allantois than IVC and SCNT embryos. We conclude that IVC and particularly SCNT procedures cause a retardation of embryo development and cell differentiation at days 7–19 of gestation.


Zygote ◽  
2008 ◽  
Vol 16 (3) ◽  
pp. 211-222 ◽  
Author(s):  
Wakayama Sayaka ◽  
Kishigami Satoshi ◽  
Nguyen Van Thuan ◽  
Ohta Hiroshi ◽  
Hikichi Takafusa ◽  
...  

SummaryAnimal cloning methods are now well described and are becoming routine. Yet, the frequency at which live cloned offspring are produced remains below 5%, irrespective of the nuclear donor species or cell type. One possible explanation is that the reprogramming factor(s) of each oocyte is insufficient or not properly adapted for the receipt of a somatic cell nucleus, because it is naturally prepared only for the receipt of a gamete. Here, we have increased the oocyte volume by oocyte fusion and examined its subsequent development. We constructed oocytes with volumes two to nine times greater than the normal volume by the electrofusion or mechanical fusion of intact and enucleated oocytes. We examined their in vitro and in vivo developmental potential after parthenogenetic activation, intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT). When the fused oocytes were activated parthenogenetically, most developed to morulae or blastocysts, regardless of their original size. Diploid fused oocytes were fertilized by ICSI and developed normally and after embryo transfer, we obtained 12 (4–15%) healthy and fertile offspring. However, enucleated fused oocytes could not support the development of mice cloned by SCNT. These results suggest that double fused oocytes have normal potential for development after fertilization, but oocytes with extra cytoplasm do not have enhanced reprogramming potential.


2014 ◽  
Vol 26 (1) ◽  
pp. 128
Author(s):  
C. P. Buemo ◽  
A. Gambini ◽  
I. Hiriart ◽  
D. Salamone

Somatic cell nuclear transfer (SCNT) derived blastocysts have lower cell number than IVF-derived blastocysts and their in vivo counterparts. The aim of this study was to improve the blastocyst rates and quality of SCNT blastocysts by the aggregation of genetically identical free zona pellucida (ZP) porcine clones. Cumulus–oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the ZP using a protease and then enucleated by micromanipulation; staining was performed with Hoechst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos (RE) were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% PVA) by a DC pulse of 1.2 kV cm–1 for 80 μs. Then, the oocytes were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of free ZP embryos was achieved in a system of well of wells in 100 μL of medium, placing 3 activated oocytes per microwell (aggregation embryo), whereas the control group was cultivated with equal drops without microwells. Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. The RE were placed in microwells. Two experimental groups were used, control group (not added 1X) and 3 RE per microwell (3X). At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality and evaluate if the embryo aggregation improves it. Results demonstrated that aggregation improves in vitro embryo development rates until blastocyst stage and indicated that blastocysts rates calculated over total number of oocytes do not differ between groups (Table 1). Embryo aggregation improves cleavage per oocyte and cleavage per microwell rates, presenting statistical significant differences and increasing the probabilities of higher embryo development generation until the blastocyst stage with better quality and higher diameter. Table 1.Somatic cell nuclear transfer cloning and embryo aggregation


2011 ◽  
Vol 411 (2) ◽  
pp. 397-401 ◽  
Author(s):  
Yongye Huang ◽  
Xiaochun Tang ◽  
Wanhua Xie ◽  
Yan Zhou ◽  
Dong Li ◽  
...  

2016 ◽  
Vol 28 (11) ◽  
pp. 1762 ◽  
Author(s):  
Daehwan Kim ◽  
Sangkyu Park ◽  
Yeon-Gil Jung ◽  
Sangho Roh

We established and maintained somatic cell nuclear transfer embryo-derived stem-like cells (SCNT-eSLCs) from the traditional Korean beef cattle species, HanWoo (Bos taurus coreanae). Each SCNT blastocyst was placed individually on a feeder layer with culture medium containing three inhibitors of differentiation (3i). Primary colonies formed after 2–3 days of culture and the intact colonies were passaged every 5–6 days. The cells in each colony showed embryonic stem cell-like morphologies with a distinct boundary and were positive to alkaline phosphatase staining. Immunofluorescence and reverse transcription–polymerase chain reaction analyses also confirmed that these colonies expressed pluripotent markers. The colonies were maintained over 50 passages for more than 270 days. The cells showed normal karyotypes consisting of 60 chromosomes at Passage 50. Embryoid bodies were formed by suspension culture to analyse in vitro differentiation capability. Marker genes representing the differentiation into three germ layers were expressed. Typical embryonal carcinoma was generated after injecting cells under the testis capsule of nude mice, suggesting that the cultured cells may also have the potential of in vivo differentiation. In conclusion, we generated eSLCs from SCNT bovine embryos, using a 3i system that sustained stemness, normal karyotype and pluripotency, which was confirmed by in vitro and in vivo differentiation.


2005 ◽  
Vol 17 (2) ◽  
pp. 185
Author(s):  
P. Tveden-Nyborg ◽  
T. Peura ◽  
K. Hartwich ◽  
P. Maddox-Hyttel

Despite advances in the production of somatic cell nuclear transfer (SCNT) embryos, significant embryo losses are persistent, particularly around implantation. Malformations of the placenta and in a variety of organs are seen, and have been linked to deviant epigenetic reprogramming. The aim of the present study was to examine the formation of germ layers, which are prerequisites for formation of the embryo proper and placenta, in invivo-derived (in vivo), partly in vitro-cultured (IVC), and SCNT ovine embryos. Embryos were derived as follows: In vivo embryos (n = 27) were flushed from the uterus on Days 7, 9, 11, and 13. For IVC embryos (n = 22) in vivo zygotes were flushed, followed by culture in the presence of 20% human serum, transfer to the uterus on Day 6, and flushing as in vivo embryos. SCNT embryos (n = 41) were produced by fusion of serum starved granulosa cells with enucleated oocytes, followed by activation, culture in SOF, transfer to the uterus on Day 6, and flushing as described for in vivo embryos. Recovered embryos were processed for light microscopy (LM) and transmission electron microscopy (TEM), and paraffin sections were immunohistochemically labelled for the germ layers: alpha-1-fetoprotein for potential endoderm, cytokeratin-8 for potential ectoderm, and vimentin for potential mesoderm. A consistent delay of the IVC and particularly the SCNT embryos was noted throughout all time points: On Days 7 and 9, differentiation of the inner cell mass into hypoblast and epiblast was evident in 7 out of 12 in vivo embryos, whereas this phenomenon was less prominent or absent in 9 out of 13 IVC and 13 out of 15 SCNT embryos. Furthermore, 6 of the IVC and 12 of the SCNT embryos lacked an identifiable embryonic disc. On Day 11, half of the in vivo embryos had initiated gastrulation, evidenced by localization of endoderm and mesoderm precursor cells between the hypoblast and the epiblast. This feature was noted in only a single IVC and in none of the SCNT embryos. On Day 13, all in vivo embryos had completed gastrulation including the formation of somatic and visceral mesoderm. This feature was noted in only 1 out of 3 IVC and in none of the SCNT embryos. Likewise, amniotic folds were seen in one third of the in vivo embryos at this stage, but not observed in any IVC or SCNT embryos. The immunohistochemical markers displayed the same cell lineage localization in all three groups of embryos, but a developmental delay in the IVC and in particular the SCNT embryos was evident. In conclusion, ovine IVC and SCNT embryos develop at a slower rate than in vivo embryos at least up until Day 13 of gestation.


2011 ◽  
Vol 23 (1) ◽  
pp. 125
Author(s):  
R. S. Deshmukh ◽  
O. Oestrup ◽  
E. Oestrup ◽  
M. Vejlsted ◽  
H. Niemann ◽  
...  

DNA de- and re-methylation are crucial for reprogramming of the differentiated parental/somatic genome in the ooplasm. The presented research was aimed at analysis of the DNA methylation dynamics in porcine preimplantation embryos developed in vivo (IV) and produced in vitro by IVF, somatic cell nuclear transfer (SCNT), and parthenogenetic activation (PA). Embryos of early and late 1-cell, 2-, 4-, and 8-cell, and early and late blastocysts stages obtained by the mentioned methods were fixed in 4% paraformaldehyde and subjected to immunocytochemistry using anti-5MetC (Mouse monoclonal, Abcam, Cambridge, MA, USA) antibody. DNA was labelled using Hoechst 33258 (Sigma, Copenhagen, Denmark). Epifluorescence microscopy (Leica Microsystems, Wetzlar, Germany) images were subjected to NIH imageJ software to measure the DNA methylation/DNA content signal by manually outlining the nuclei (n = 2003) of the embryos. The data were analysed using PROC-GLM statistical procedure in SAS 9.1 (SAS Institute Inc., Cary, NC, USA), least square means were compared and P-values were used to decide the significant differences within and between different groups of embryos. The 1-cell stages lacked active demethylation of paternal genome in IV and IVF embryos. Embryos produced under in vitro conditions presented higher levels of DNA methylation than IV. A lineage specific DNA methylation (hypermethylation of inner cell mass and hypomethylation of trophectoderm) observed in porcine IV late blastocysts was absent in PA and SCNT blastocysts despite the occurrence of de novo methylation in early blastocysts. SCNT early (50%) and late (14%) blastocysts presented DNA methylation pattern similar to IV early and late blastocysts, respectively. Concluding, DNA methylation patterns are strongly impaired under in vitro conditions in porcine preimplantation embryos.


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