130 FLAVANOID INCREASES THE IN VITRO DEVELOPMENTAL ABILITY OF CLONED AND PARTHENOGENETIC PORCINE EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 165 ◽  
Author(s):  
S. J. Uhm ◽  
M. K. Gupta ◽  
Z. C. Das ◽  
K. T. Kim ◽  
J. H. Yang ◽  
...  

Flavonoid has anti-oxidant properties and has been shown to protect cells against oxygen radical damage. This study therefore, evaluated the effect of flavonoid on the in vitro development ability of porcine embryos produced by parthenogenesis (PA) or somatic cell nuclear transfer (SCNT). Porcine embryos were produced from abattoir-derived prepubertal oocytes either by PA or SCNT of fetal fibroblast into enucleated oocytes essentially as we described earlier (Gupta et al. 2008 Mol. Reprod. Dev. 75, 588–597). One-cell embryos were subsequently cultured in NCSU23 + 0.4% polyvinyl alcohol supplemented with or without 10 μm flavanoid for 7 days at 39°C in a humidified atmosphere of 5% CO2 in air. Results showed that the presence of flavonoid in the culture medium increased (v. controls) the rate of blastocyst in both PA (31.7 ± 4.0 v. 20.4 ± 2.0%) and SCNT (20.6 ± 2.5 v. 12.2 ± 2.9%) groups, respectively (P < 0.05). These blastocysts also had higher ability to hatch (PA: 53.7 ± 3.6 v. 34.0 ± 2.4%; SCNT: 70.9 ± 2.5 v. 45.7 ± 2.9%) and contained higher cell number (PA: 38.9 ± 2.0 v. 31.3 ± 2.1; SCNT: 37.5 ± 2.0 v. 29.7 ± 2.5) than those of control groups (P < 0.05). Western blot analysis of parthenogenetic blastocysts showed that, flavonoid also reduced the expression of caspase-3 and p38 mitogen-activated protein kinase (MAPK) proteins by 3.1 ± 0.1 and 7.7 ± 0.2 fold, respectively while expression of ERK1/2 protein was increased by 4.7 ± 2.3 fold. The 2′,7′-dichlorofluorescene fluorescence staining of embryos further revealed that the activity of reactive oxygen species (ROS) was significantly reduced in flavonoid treated embryos by 2 fold(P < 0.05). These data therefore, suggest that flavonoid may improve the in vitro development rate and quality of porcine embryos by reducing ROS activity and change in protein expression.

2007 ◽  
Vol 19 (1) ◽  
pp. 152
Author(s):  
K. Naruse ◽  
Y. M. Shin ◽  
Y. S. Quan ◽  
C. S. Park ◽  
D. I. Jin

Streptolysin O (SLO) is known to bacterial proteins that form very large pores in the plasma membrane of mammalian cells. SLO has been used in the delivery of proteins into living cells following permeabilization. The objective of this study was to investigate the effect of permeabilization of donor cells using SLO on in vitro development of porcine reconstructed embryos. Porcine fetal fibroblast cells were treated with Ca2+-free DMEM medium containing 200 ng mL−1 of SLO for 50 min before or after trypsinization. Those SLO-treated donor cells were injected into enucleated oocytes, fused with 2 DC pulses (1.2 kV cm−1, 30 µs) and cultured in procine zygote medium-3 (PZM-3) for 6 days. In vitro development of the reconstructed embryos was examined. SLO treatment after trypsinzation significantly increased (P &lt; 0.05) the percentage of fusion rates and blastocyst developmental rates compared with that before trypsinization or in the nontreated group. Additionally there were no significant differences in fusion rates, cleavage rates, blastocyst developmental rates, and total cell number of blastocysts between the SLO-treated group before trypsinzation and the nontreated group. Next, after the trypsinzation treatment, fetal fibroblast cells were incubated in Ca2+-free DMEM containing 200 ng mL−1 of SLO for 0, 30, 50, and 70 min and SLO-treated donor cells were also tested for fusion rate and developmental capability following reconstruction. The 50-min group of SLO-treated cells significantly increased (P &lt; 0.05) the percentage of fusion rates (90.6 vs. 77.6, 85.4, and 78.5%) and blastocyst developmental rates (24.7 vs. 13.5, 11.2, and 13.5%) compared with the other groups (Table 1). However, there was no significant difference in the total cell number of blastocysts among SLO-treated groups. Although cleavage rates the in SLO-treated groups were not significantly different from those of the nontreated group, there the cleavage rates were slightly in SLO-treated groups. In conclusion, permeabilization of porcine fetal fibroblast cells with SLO improves the fusion rates and in vitro development of porcine reconstructed embryos. Table 1.Effects of SLO treatment of fetal fibroblasts by different exposure times on in vitro development of porcine reconstructed embryos


2015 ◽  
Vol 27 (1) ◽  
pp. 269
Author(s):  
A. De Stefano ◽  
A. Gambini ◽  
D. Salamone

Embryo aggregation has been shown to improve embryo development in several species. However, the effects seem to be different among species. Thus, the aim of this study was to compare the effect of embryo aggregation over in vitro development and blastocyst quality of bovine and feline parthenogenetic (PA) embryos. To this aim, bovine cumulus-oocyte complexes (COC) were collected from slaughterhouse ovaries, whereas cat ovaries were obtained from ovariectomized animals. The COC were in vitro matured in TCM199 supplemented following standard protocols for each species. After 24 h, cumulus cells and zona pellucidae were removed. Matured oocytes were selected and activated by 5 µM ionomycin treatment for 4 min followed by incubation in 1.9 mM 6-DMAP. Bovine and feline PA embryos were cultured in SOF medium in the well of well system in two different groups: only one PA embryo per microwell (1X); and three PA embryos per microwell (3X, aggregated embryos). Cleavage and blastocyst rates from all groups were assessed at Days 2 and 7, respectively. Size of blastocysts was measured at Day 7 using a millimetre eyepiece, and total cell number was determined by Hoechst 33342 staining. Blastocyst rates and embryo size were analysed by Fisher's test (P < 0.05) and total cell numbers by Kruskal–Wallis test with Dunn's correction (P < 0.05). Statistical differences were found in PA blastocyst rates between experimental groups (1X: 15/104, 24.6% v. 3X: 27/37, 62.2% for feline; and 1X: 21/113, 19.4% v. 3X: 20/32, 62.5% for bovine), but no differences were found between species. In addition, there was no statistical difference in the number of blastocysts obtained per oocyte used in any of the experimental groups. Bovine aggregated PA blastocysts were significantly larger than non-aggregated embryos (>200 microns, 1X: 2/20, 10% v. 3X: 9/19, 47.4%), but no differences were found in cell number. On the other hand, cat aggregated PA blastocysts had significantly higher cell numbers (1X: 122.4 ± 79.66 cells v. 3X: 259.8 ± 137.1 cells), but no differences were found in blastocyst size. This observation can contribute in the understanding of embryo physiology, suggesting that benefits of embryo aggregation in parthenogenic embryos vary among these species.


2009 ◽  
Vol 21 (1) ◽  
pp. 114
Author(s):  
Y. Du ◽  
Z. Yang ◽  
B. Lv ◽  
L. Lin ◽  
P. M. Kragh ◽  
...  

Delayed activation is commonly used in pig somatic cell nuclear transfer (SCNT) where electrical activation is followed by chemical activation. However, chemical incubation of several hours (up to 4 or 6) is logistically not very convenient even though handmade cloning (HMC) could improve the overall efficiency of pig cloning (Du et al. 2007 Theriogenology 68, 1104–1110). It was reported that a brief exposure of cycloheximide (CX) before electrical activation could significantly increase developmental rate and total blastocyst cell number when simultaneous activation was performed in micromanipulator-based pig cloning (Naruse et al. 2007 Theriogenology 68, 709–716). The purpose of our present work is to investigate whether such activation method is also applicable for pig HMC. Data were analyzed by t-test using SPSS (11.0, SPSS Inc., Chicago, IL, USA). After 42 h in vitro maturation, cumulus cells were removed. In vitro-cultured porcine fetal fibroblasts were used as donor cells. Cytoplast-fibroblast pairing, electrical fusion and activation of fused cytoplast-fibroblast pairs were performed as described previously (Kragh et al. 2005 Theriogenology 64, 1536–1545; Du et al. 2005 Cloning Stem Cells 7, 199–205). Three groups were compared due to different activation protocol. In Group 1 (control), reconstructed embryos were cultured in porcine zygote medium 3 (PZM3) supplemented with 4 mg mL–1 BSA, 5 μg mL–1 cytochalasin B (CB), and 10 μg mL–1 CX for 4 h. In Group 2 (CX priming), fused pairs and the other halves of cytoplasts were incubated in HEPES-buffered TCM-199 medium supplemented with 10% calf serum, 10 μg mL–1 CX for 10 min just before the second fusion or electrical activation. In Group 3 (CB + CX priming), treatment similar to Group 2 was performed except that additional 5 μg mL–1 CB was added for the 10-min incubation. Reconstructed embryos were in vitro cultured in the well of the well (WOW) system for 6 days. Blastocyst rates and total cell numbers of Day 6 blastocysts were evaluated. As illustrated in Table 1, embryos pretreated with both CB and CX gave the best results, with better blastocyst formation (53.8 ± 4.8%; mean ± SEM) and higher cell number (77.2 ± 5.4) compared to the other 2 groups. Our data suggested that CX and CB priming could be used as a solution to the long chemical incubation in porcine SCNT by HMC, making the embryos more receptive to electrical activation. Table 1.In vitro development of HMC reconstructed embryos with different activation protocols


2004 ◽  
Vol 16 (2) ◽  
pp. 202 ◽  
Author(s):  
W.F. Swanson ◽  
A.L. Manharth ◽  
J.B. Bond ◽  
H.L. Bateman ◽  
R.L. Krisher ◽  
...  

Domestic cat embryos typically are cultured in media formulated for somatic cells or embryos from rodents or livestock species. Under these conditions, blastocyst development has been inconsistent and delayed relative to embryos grown in vivo, and embryo viability following transfer has been low. Our goal is to systematically define the culture requirements of the feline embryo to improve embryo development and viability. The objective of this study was to determine the ionic (NaCl, KCl, KH2PO4, and CaCl2:MgSO4) preferences of domestic cat IVF embryos. Anestral female cats were injected (i.m.) with 150IU eCG followed 84h later by 100IUhCG. Oocytes were recovered via laparoscopic follicular aspiration approximately 24h post-hCG injection (Day 0). Semen was collected from one of two males by means of an artificial vagina and washed once in HEPES-buffered IVF medium. Mature cumulus-oocyte complexes were co-incubated with 2.5–5×105 motile sperm mL−1 in IVF medium (100mM NaCl, 4.0mM KCl, 1.0mM KH2 PO4, 2.0mM CaCl2, 1.0mM MgSO4-7H2O, 25.0mM NaHCO3, 3.0mM glucose, 0.1mM pyruvate, 6.0mM L-lactate, 1.0mM glutamine, 0.1mM taurine, 1×MEM nonessential amino acids, 50μgmL−1 gentamicin, and 4.0mgmL−1 BSA) for 19 to 22h in 6% CO2 in air (38.7°C). Cumulus cells were removed and embryos cultured (8–11 embryos/50μL drop; 6% CO2, 5% O2, 89% N2, 38.7°C) in media containing 100.0 or 120.0mM NaCl, 4.0 or 8.0mM KCl, 0.25 or 1.0mM KH2PO4, and 1.0mM:2.0mM or 2.0mM:1.0mM CaCl2:MgSO4 (2×2×2×2 factorial design). The remaining components of the culture medium were identical to the IVF medium (but w/o gentamicin). Development to the blastocyst stage by Day 6, metabolism (glycolysis and pyruvate) of each blastocyst, and final cell number (Hoechst 33342 staining) of all embryos were evaluated. Final cell number of cleaved embryos and development to the blastocyst stage were analyzed using analysis of variance in the GLIMMIX macro of SAS. A total of 236 oocytes were inseminated, yielding 128 cleaved embryos (54%), including 6 blastocysts (4.7% of cleaved embryos). Cell number was not (P&gt;0.05) affected by NaCl, KCl, or KH2PO4 concentrations, but tended (P=0.057) to be higher after culture in 2.0mM:1.0mM CaCl2:MgSO4. Treatments did not significantly affect (P&gt;0.05) development to the blastocyst stage, but numerically more blastocysts were produced in 100.0mM NaCl (4/6), 8.0mM KCl (5/6), or 1.0mM KH2PO4 (5/6). Both CaCl2:MgSO4 ratios resulted in 3 blastocysts. Blastocysts contained 61.08±5.1 (mean±SEM, n=6) cells and actively metabolized glucose (glycolysis, 3.7±0.8pmol/embryo/3h or 0.06±0.01pmol/cell/3h) and pyruvate (0.75±0.27pmol/embryo/3h or 0.013±0.005pmol/cell/3h). These results suggest that the ionic composition of culture media influences the in vitro development of cat IVF embryos. (Supported by NIH grant RR15388.)


2006 ◽  
Vol 18 (2) ◽  
pp. 187
Author(s):  
J. De la Fuente ◽  
A. Gutiérrez-Adán ◽  
P. Beltrán Breña ◽  
S. S. Pérez-Garnelo ◽  
A. T. Palasz

It is assumed that, contrary to phosphate buffers, zwitterionic buffers are neutral. However, zwitterionic buffers containing hydroxymethyl or hydroxyethyl residues may interact with OH-groups in the media and produce formaldehyde (Shiraishi et al. 1993 Free Radic. Res. Commun. 19, 315-321). Also, it was shown that three zwitterionic buffers tested in this study interact with DNA (Stellwagen et al. 2000 Anal. Biochem. 287, 167-175). Our objective was to evaluate the effect of the following buffers: TES (T), MOPS (M), HEPES (H) (pKa values at 20�C: 7.2-7.5), and PBS on in vitro development and morphology of bovine embryos. Zwitterionic buffers and PBS were prepared at a concentration of 10 mM in TALP medium and the final pH was adjusted to 7.2. Bovine follicular fluid was aspirated from abattoir-derived ovaries and evenly divided into four tubes. Collected oocytes (five replicates) from each tube were processed separately through the entire IVM, IVF, and IVC procedures using washing medium buffered with: PBS (n = 490), Group 1; H (n = 438), Group 2; M (n = 440), Group 3; and T (n = 394), Group 4. All buffers contained 4 mg/mL BSA. Oocytes were matured in TCM-199 + 10% FCS and 10 ng/mL of epidermal growth factor and fertilized in Fert-TALP containing 25 mM bicarbonate, 22 mM sodium lactate, 1 mM sodium pyruvate, 6 mg/mL BSA-FAF, and 10 �g/mL heparin with 1 � 106 spermatozoa/mL. After 24 h, oocytes-sperm co-incubation presumptive zygotes were cultured in SOFaa medium with 8 mg/mL BSA at 39�C under paraffin oil and 5% CO2 in humidified air. Cumulus-oocyte complexes and zygotes were held in designated buffers ?16 min before oocyte maturation, ~7 min after IVM and before IVF, and ~18 min after IVF and before culture. The total time of oocyte/embryo exposure to each buffer was ?41 min. Embryo development was recorded on Days 4, 7, 8, and 9. A total of ten, Day 8 blastocysts were taken randomly from each treatment and fixed in 4% paraformaldehyde for total and apoptotic cells counts, and five blastocysts from each replicate and treatment were frozen for later mRNA analysis. Apoptosis were determined by TUNEL, using commercial In situ Cell Death Detection Kit (Roche Diagnostic, SL, Barcelono, Spain). Embryo development among groups was compared by chi-square analysis. The cleavage rates were not different among the groups: PBS, 70.8%; H, 76.5%; M, 77.5% and T, 73.6%. The number of embryos that developed to d8 cells at Day 4 was higher in M, 36.2%, and PBS, 37.6%, than in H, 30.6%, and T, 29.7%, but was not significantly different. However, more (P < 0.05) blastocysts developed at Days 7, 8, and 9 in H and M than in PBS and T groups (21.9% and 22.9% vs. 16.9% and 14.9%, respectively). No difference was found between groups in total cell number (98.8 � 7, PBS; 111.8 � 11.9, M; 106.8 � 12.9, H; and 104.3 � 9.7, T) and the number of apoptotic cells (9.2 � 1.0, P; 9.2 � 0.8, M; 12.9 � 1.8, H; and 9.7 � 0.9, T). Based on the results of this study, we conclude that within our protocol choice of buffer may affect embryo developmental rates but not morphology.


2008 ◽  
Vol 20 (1) ◽  
pp. 105
Author(s):  
E. S. Ribeiro ◽  
R. P. C. Gerger ◽  
L. U. Ohlweiler ◽  
I. Ortigari Jr ◽  
F. Forell ◽  
...  

Cloning by somatic cell nuclear transfer has been associated with developmental abnormalities, with the level of heteroplasmy imposed by cell fusion being one of many potential determining factors. As the cytoplast exerts a key role in nuclear reprogramming, embryo aggregation is an alternative to minimize such negative effects during cloning. The aim of this study was to determine the effect of fusion of hemi-cytoplasts or aggregation of hemi-embryos on in vitro development and cell number of clone and parthenote embryos. Bovine cumulus–oocyte complexes (COCs) from slaughterhouse ovaries, after 17 h of IVM, were used for the production of parthenotes by chemical activation, and clone embryos by handmade cloning (HMC) (Vajta et al. 2003 Biol. Reprod. 68, 571–578). Following cumulus and zona removal, oocytes were manually bisected, followed by segregation of nucleated and enucleated hemi-cytoplasts by fluorescence using Hoechst stain. One or two enucleated hemi-cytoplasts were paired with an adult skin somatic cell from primary cultures (>90% confluence) and fused using a 25V AC pre-pulse, followed by a single 1.2 kV cm–1 DC pulse for 10 μs. Reconstructed clone structures and groups of zona-intact oocytes and nucleated hemi-cytoplasts were chemically activated in ionomycin and 6-DMAP. Clone and parthenote structures were in vitro-cultured in the WOW system (Vajta et al. 2000 Mol. Reprod. Dev. 55, 256–264) for 7 days, as follows: (G1) clone embryos reconstructed by aggregation of two hemi-embryos per WOW; or (G2) one embryo (two hemi-cytoplasts + cell) perWOW; and parthenote embryos composed of (G3) zona-intact oocytes cultured in wells; or aggregation of one (G4), two (G5), three (G6), or four (G7) nucleated hemi-cytoplasts per WOW. Fusion, cleavage (Day 2), and blastocyst (Day 7) rates, evaluated on a per WOW basis, were compared by the chi-square test (8 replications). Total cell number estimated by fluorescence (Hoechst stain) in blastocysts was analyzed by the Student t-test. Fusion rates of one hemi-cytoplast + cell (G1; 275/592, 46.5%) were lower than for two hemi-cytoplasts + cell (G2; 264/337, 78.3%). Cleavage rates were lower in G1 and G4 and higher in G6 and G7 than G2 and G3. A significant linear increase in blastocyst rates was observed in G5, G6, and G7. Total cell numbers were lower in parthenotes than in clones, except in G6 and G7. The lower fusion and cleavage rates after the aggregation of two clone hemi-embryos (G1) caused nearly a 50% reduction in the overall cloning efficiency. In addition, the aggregation of parthenogenetic hemi-embryos increased cleavage and blastocyst rates and cell number. However, aggregation of hemi structures did not improve blastocyst yield or cell number on a hemi-cytoplast basis. Table 1. In vitro development of parthenote or clone bovine embryos This work was supported by funding from CAPES/Brazil.


2004 ◽  
Vol 16 (2) ◽  
pp. 144
Author(s):  
G.-S. IM ◽  
L. Lai ◽  
Z. Liu ◽  
Y. Hao ◽  
C.M. Murphy ◽  
...  

Although nuclear transfer (NT) has successfully produced cloned piglets, the development to blastocyst and to term is still low. Activation of the NT embryos is one of the key factors to improve the developmental ability of porcine NT embryos. Electric pulses as well as chemicals have been used to activate porcine NT embryos. This study was conducted to investigate the effect of continued activation following fusion pulses on in vitro development of porcine NT Embryos. Oocytes derived from a local abattoir were matured for 42 to 44h and enucleated. Ear skin cells were obtained from a 4-day-old transgenic pig transduced with eGFP recombinant retrovirus. Enucleated oocytes were reconstructed and cultured in PZM-3 in a gas atmosphere of 5% CO2 in air. Cleavage and blastocyst developmental rates were assessed under a stereomicroscope on Day 3 or 6. Blastocysts were stained with 5μg of Hoechst 33342 and total cell number was determined with an epifluorescent microscope. In Experiment 1, oocytes were activated with two 1.2kV/cm for 30μs (E) in 0.3M mannitol supplemented with either 0.1 or 1.0mM Ca2+. In each treatment, activated oocytes were divided into three groups. The first group was control (E). Other two groups were exposed to either ionomycin and 6-DMAP (E+I+D) or 6-DMAP (E+D) immediately after the electric pulses. In Experiment 2, fusion was conducted by using 1.0mM Ca2+ in the fusion medium. Fused NT embryos were divided into three treatments. NT embryos were fused and activated simultaneously with electric pulse as a control (C); the second group was treated with 6-DMAP immediately after fusion treatment (D0); and the third group was treated with 6-DMAP at 20min (D20) after fusion. In experiment 1, for 0.1mM Ca2+, developmental rates to the blastocyst stage for E, E+I+D or E+D were 12.5, 26.7 and 22.5%, respectively. For 1.0mM Ca2+, developmental rates to the blastocyst stage were 11.4, 28.3 and 35.6%, respectively. The activated oocytes treated with 6-DMAP following the electric pulses by using 1.0mM Ca2+ in fusion medium had higher (P&lt;0.05) developmental rates to the blastocyst stage. In Experiment 2, developmental rates to the blastocyst stage for C, D0 or D20 were 10.0, 12.3, and 19.9%, respectively. Developmental rate to the blastocyst stage was higher (P&lt;0.05) in D20. Fragmentation rates were 19.9, 10.8, and 9.0%, respectively. Regardless of Ca2+ concentration in fusion medium, continued treatments with chemicals following electric pulses supported more development of porcine activated oocytes. Treating NT embryos with 6-DMAP alone after fusion was completed by using 1.0mM Ca2+ in fusion medium improved the developmental rates to the blastocyst stage and prevented fragmentation accompanied by electric fusion. This study was supported by NIH NCRR 13438 and Food for the 21st Century.


2018 ◽  
Vol 46 (1) ◽  
pp. 70-78
Author(s):  
Fatma Ibrahim ◽  
Hassan Mansour ◽  
Faten Labib ◽  
Hussein Amer ◽  
Magdy Badr

2011 ◽  
Vol 23 (1) ◽  
pp. 119
Author(s):  
S. Akagi ◽  
E. Mizutani ◽  
Y. Inaba ◽  
M. Kaneda ◽  
T. Somfai ◽  
...  

The efficiency of somatic cell cloning is very low, probably because of incomplete reprogramming of the somatic cell nucleus. In recent studies, it is suggested that transient exposure of donor somatic cells to mouse embryonic stem cell (ESC) extract enhances pluripotency of the cells in vitro (Bru et al. 2008 Exp. Cell Res. 314, 1634–1642; Xu et al. 2009 Anat. Rec. 292, 1229–1234). In the present study, we examined the effect of treatment of donor cells with mouse ESC extract on the in vitro development of bovine NT embryos. First, in order to examine effect of treatment of donor cells with streptolysin O (SLO), which reversibly permeabilizes the plasma membrane, we compared the in vitro development of NT embryos using donor cells treated with 5 μg mL–1 SLO (SLO group) and untreated donor cells (control group). As donor cells for NT, bovine fibroblast cells of passages 3 to 5 were used. Fibroblasts were treated with 5 μg mL–1 SLO for 45 min, and then incubated for resealing in DMEM including 2 mM CaCl2 for 60 min. NT was performed as previously described (Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). After in vitro culture for 8 days, blastocyst formation and cell number of blastocysts were examined. There were no significant differences between SLO and control groups in the fusion rate (80% and 72%, respectively), cleavage rate (60% and 65%, respectively), developmental rate to the blastocyst stage of NT embryos (31% and 28%, respectively), and blastocyst cell number (127 ± 6 and 112 ± 14, respectively). These results suggest that SLO treatment of donor cells has no negative effect on the in vitro development of NT embryos. Next, we examined the in vitro developmental ability of NT embryos using donor cells treated with mouse ESC extract (ES extract group). After SLO treatment for 45 min, permeabilized fibroblast cells were treated with mouse ESC extract for 45 min, and then incubated in DMEM including 2 mM CaCl2 for 60 min, and used for producing NT embryos. There were no differences between ES extract and control groups in the fusion rate (68% and 69%, respectively), cleavage rate (86.7% and 80.6%, respectively), and developmental rate to the blastocyst stage of NT embryos (39.8% and 43.5%, respectively). The cell number of NT embryos at the blastocyst stage in ES extract group (201 ± 30) was significantly (t-test; P < 0.05) higher than that in control group (140 ± 14). In conclusion, treatment of bovine donor cell with mouse ESC extract did not affect the in vitro developmental ability of NT embryos, but improved the quality of blastocysts.


2016 ◽  
Vol 28 (2) ◽  
pp. 171
Author(s):  
J. A. Benne ◽  
L. D. Spate ◽  
B. M. Elliott ◽  
R. S. Prather

For decades it has been known that reactive oxidative species (ROS) form during in vitro embryo culture. A buildup of ROS can be detrimental to individual cells in the embryo and lead to a decrease in development and quality. To overcome oxidative stress in culture systems, additives, such as taurine and/or hypotaurine, have been used. In the pig, taurine or hypotaurine addition is deemed necessary for normal in vitro development. Another commonly used technique to reduce ROS is to culture embryos in a lowered oxygen environment (e.g. 5%). Porcine zygote medium 3 (PZM3) base culture medium is used in the following experiments and contains 5 mM hypotaurine, which is one of the most costly additives in the medium. The objective of this experiment was to determine if hypotaurine is still necessary if the embryos were cultured in 5% O2 from the zygote to the Day 6 blastocyst stage. In Experiment 1, oocytes were matured for 44 h and fertilized in vitro. After fertilization, presumptive zygotes were then transferred to 500 µL of MU-1 medium (PZM3 with 1.69 mM arginine) that either contained or did not contain hypotaurine for overnight culture at 20% O2. On Day 1, the same embryo culture plates were moved to 5% O2, 5% CO2, and 90% N2 and cultured to Day 6. The percent blastocyst stage was determined, and total cell number was counted in 3 of the 5 replicates in order to give us an indication of the embryo quality. The percent blastocyst in the controls (+hypotaurine) was 34.4% ± 2.8 and not different from the no hypotaurine (32.9% ± 2.2; N = 830; 5 replications; P > 0.10). Furthermore, total cell number was not different between the two groups (30.8 ± 1.5 v. 33.6 ± 1.8, respectively, N = 146; 3 replications; P > 0.10). In Experiment 2, the same experiment was repeated in somatic cell nuclear transfer derived embryos, which may be more sensitive to ROS due to the micromanipulation procedure. Wild type fetal fibroblast cells were used as donor cells. There was no significant difference in development to the blastocyst stage due to the presence or absence of hypotaurine (17.7% ± 2.5 v. 11.8% ± 2.3, respectively; N = 454; 4 replications; P = 0.07). All blastocyst data were analysed using the GENMOD procedure in SAS 9.4 (SAS Institute Inc., Cary, NC, USA), and cell number data were analysed using the PROC GLM also with SAS 9.4. These data show that porcine embryos can be efficiently cultured to the blastocyst stage without adding any oxygen free radical scavengers to the media when culturing in reduced oxygen atmosphere. Further studies include evaluating term development via embryo transfers and measuring ROS production of these embryos. Funding was provided by Food for the 21st Century and the National Institutes of Health (U42 OD011140).


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