Development of reconstituted pig embryos by nuclear transfer of cultured cumulus cells

2000 ◽  
Vol 12 (2) ◽  
pp. 15 ◽  
Author(s):  
H. T. Cheong ◽  
K. Ikeda ◽  
M. A. Martinez Diaz ◽  
S. Katagiri ◽  
Y. Takahashi

This study tested the effects of oocyte collection method, activation protocol and maturational age of recipient oocytes on the in vitro development of nuclear transfer embryos reconstructed with cultured cumulus cells. Cumulus cells synchronized in G0/G1 phase by serum-starvation culture were transferred into enucleated oocytes that were collected by aspiration or dissection method and cultured for 33 or 44 h. Reconstituted embryos were activated with a combination of calcium ionophore A23187 or electric pulse and cycloheximide (CHXM), and cultured for 6 days. Oocyte collection methods, activation treatment in the presence of cytochalasin B and activation protocols did not affect the developmental rate of embryos reconstituted with 44-h-matured recipients. However, the development of embryos reconstituted with 33-h-matured recipients was significantly improved (P<0.05) by activation with the combination of electric pulse and CHXM. The present study shows that reconstituted porcine embryos derived from cultured cumulus cells can develop to the blastocyst stage, and that their development can be improved by reconstruction with young oocyte cytoplasts following activation with a combination of electric pulse and CHXM.

2004 ◽  
Vol 16 (3) ◽  
pp. 315 ◽  
Author(s):  
P. M. Kragh ◽  
G. Vajta ◽  
T. J. Corydon ◽  
S. Purup ◽  
L. Bolund ◽  
...  

Recently, a zona-free technique for bovine somatic cell nuclear transfer (NT) with no requirement for micromanipulation (i.e. hand-made cloning (HMC)) has been described. The present study demonstrates the application of the HMC technique in the production of transgenic porcine blastocysts. In vitro-matured zona-free porcine oocytes were bisected manually using a microblade and halves containing no chromatin (i.e. the cytoplasts) were selected. Two cytoplasts were electrofused with one transgenic fibroblast expressing enhanced green fluorescent protein and reconstructed embryos were activated in calcium ionophore (A23187) followed by 6-dimethylaminopurine. Subsequently, embryos were cultured in NCSU-23 medium supplemented with 4 mg mL–1 bovine serum albumin for 7 days. In five replicates, 93.0 ± 7.0% (mean ± s.e.m.) of attempted reconstructed embryos fused and survived activation (31/31, 15/23, 28/28, 37/37 and 28/28). On Day 7 after activation, the respective blastocyst rates (per successfully reconstructed embryos) were 6% (2/31), 7% (1/15), 7% (2/28), 3% (1/37) and 7% (2/28), resulting in an average of 6.0 ± 0.8%. Enhanced green fluorescent protein was expressed in all cells of all eight developing blastocysts. Efforts are now directed towards the production of offspring from such transgenic NT blastocysts.


2005 ◽  
Vol 48 (1) ◽  
pp. 60-67 ◽  
Author(s):  
S. Yin ◽  
M. Hishinuma ◽  
K. Hamana ◽  
J. Sekine

Abstract. This study was designated to clarify the influence of activation of porcine matured oocytes by calcium ionophore on in vitro development of the parthenotes. The follicular oocytes were matured, activated and cultured in North Carolina State University-23 (NCSU-23) medium supplemented with 10% porcine follicular fluid (pFF). The in vitro-matured oocytes were exposed to calcium ionophore at concentrations of 12.5, 25 or 50 μM for 3, 5, 7 or 9 min. The activation rate of the oocytes increased as concentration of ionophore decreased, being at 27–33 and 68–77 % for the oocytes treated with 50 and 12.5 μM ionophore, respectively. Almost all activated oocytes were haploid. The highest cleavage rate (76%) and developmental rate to morula (41%) were observed in the oocytes treated with 12.5 μM ionophore for 5 min. However, development to blastocyst was observed only in the oocytes treated with 25 μM ionophore for 3 and 5 min (3 and 4% of treated oocytes, respectively). We concluded that the activation treatment of the porcine oocytes with 12.5 μM ionophore for 5 min provided the highest develop-mental rate to morula, but this treatment is not sufficient to overcome a developmental block at the morula stage.


Zygote ◽  
2000 ◽  
Vol 8 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Tao Tao ◽  
Zoltán Macháty ◽  
Lalantha R. Abeydeera ◽  
Billy N. Day ◽  
Randall S. Prather

Experiments were conducted to examine the effects of (a) different activation methods, (b) incubation time in calcium-free medium and (c) bisbenzimide staining on the activation and subsequent development of pig oocytes. Oocytes were matured in vitro and activated by one of the following methods: combined thimerosal/dithiothreitol (DTT) treatment, calcium ionophore A23187 treatment followed by incubation in the presence of 6-dimethylaminopurine (6-DMAP), electroporation, and electroporation followed by incubation with cytochalasin B. There were no significant differences in the activation rate (ranging from 70.0% to 88.3%) and the percentage of cleaved embryos after activation (ranging between 48.8% and 58.8%) among the four treatment groups (p < 0.05). The rate of development to the blastocyst stage in oocytes activated by thimerosal/DTT (10.0%) or electroporation followed by cytochalasin B treatment (12.3%) was significantly higher (p < 0.05) than in the group activated with A23187/6-DMAP (2.5%). Both the activation rate and the rate of blastocyst formation in oocytes that were incubated in Ca2+-free medium for 8 h before thimerosal/DTT activation were significantly lower (p < 0.05) than in those incubated for 0, 1 or 4 h. Intracellular Ca2+ measurements revealed that the Ca2+ homeostasis in these oocytes were severely altered. Staining of oocytes with 5 μg/ml bisbenzimide for 2 h decreased the quality of blastocysts and increased the rate of degenerated embryos at day 6. Two activation protocols (thimerosal/DTT and electroproation) were used for activation after nuclear transfer; the rate of nuclear formation did not differ in the oocytes activated by the two different methods.


2008 ◽  
Vol 20 (1) ◽  
pp. 181
Author(s):  
M. R. Hudson ◽  
G. E. Seidel Jr ◽  
E. L. Squires ◽  
B. E. Spizzirri ◽  
D. J. Walker ◽  
...  

In vitro fertilization in the horse does not work reliably. Several methods of capacitating sperm in other species fail in the horse. The goal of this experiment was to develop a method to capacitate equine spermatozoa using calcium ionophore A23187 or phosphatidylcholine 12 (PC12). We also studied effects of maturing bovine oocytes for 24 or 28 h on fertilizability by capacitated equine sperm, hypothesizing that longer maturation would yield oocytes more easily fertilized by equine spermatozoa. Two sets of bovine oocytes were aspirated from 3 to 8 mm follicles of abattoir ovaries 4 h apart, but fertilized at the same time. On the day of fertilization, semen from 1 of 3 stallions was collected, evaluated, and centrifuged through 33% Percoll to remove seminal plasma. The resultant pellet was extended to 5 × 107 cells mL–1 in M199 containing 0.6% BSA, 2 mm caffeine, and 5 mm CaCl2. Sperm were treated with A23187 (1 or 3 μm) or PC12 (40 or 70 μm) or both A23187 and PC12 (1 μm/40 μm) in 500- μL aliquots. Sperm were incubated at 39°C for 10 min (for A23187 and combination treatments) or 15 min (for PC12 treatments), and then diluted 1:20 for fertilization. Oocytes from each maturation time were fertilized using the same semen preparation for each treatment. Oocytes and sperm were incubated together for 18 h in FCDM in 5% CO2 at 39°C (De La Torre-Sanchez et al. 2006 Reprod. Fertil. Devel. 18, 585–596). Presumptive zygotes were cultured for 30 h in CDM-1, vortexed to remove cumulus cells, and evaluated for cleavage. Oocytes were also co-incubated with killed sperm to determine the level of parthenogenesis. Cleaved embryos were stained with orcein to ensure that each cell had a nucleus. Number of cell divisions were recorded as 0 for a 1-cell, 1 for a 2-cell, 1.5 for a 3-cell, etc. More oocytes cleaved after 28 h (18%) than 24 h (14%) maturation (P < 0.01). Sperm of Stallion 1 resulted in higher overall cleavage (24%) than Stallions 2 or 3 (11 and 12%; P < 0.01). Highest cleavage was seen with 28 h maturation and 70 μm PC12 and 3 μm A23187 (27 and 24%, respectively). The most cell divisions were seen with 28 h maturation and 70 μm PC12 (0.48); 28 of the 49 cleaved in this treatment reached ≥4-cell stage. In conclusion, both A23187 and PC12 were able to capacitate equine sperm in a dose-dependent manner as determined from cleavage of bovine oocytes matured for 28 h; maturation for the conventional 24 h was an inferior model for this purpose. Table 1. Mean responses of bovine oocytes fertilized by equine sperm


2004 ◽  
Vol 16 (2) ◽  
pp. 125 ◽  
Author(s):  
J-H. Lee ◽  
K.H.S. Campbell

In nuclear transfer (NT) embryos, exposure of the donor chromatin to the MII cytoplasm results in premature chromatin condensation (PCC) which may be beneficial for nuclear reprogramming (Campbell KHS and Alberio R 2003 Reprod. Suppl. 61, 477–494). Following enucleation, maturation promoting factor (MPF) activity in murine oocytes is primarily associated with the meiotic spindle. This reduced MPF activity in the cytoplast may result in decreased PCC and reprogramming. Conversely, increasing cytoplast MPF activity may increase reprogramming. The aims of this study were to perform quantitative analysis of MPF and MAPK activities in ovine oocytes: 1. at anaphase/telophase I (A/TI) or MII; 2. following enucleation; 3. following treatment with caffeine (an inhibitor of Myt1/Wee1 activity). The development of ovine NT embryos reconstructed using caffeine-treated oocytes as cytoplast recipients was then determined. Oocytes were matured in TCM 199, 10% FBS, 5μgmL−1 FSH, 5μgmL−1 LH,1μgmL−1 estradiol, 0.3mM sodium pyruvate and 100μM cysteamine. 15h post-onset of maturation (hpm) oocytes were stripped of cumulus cells and enucleated in HSOF containing 5μgmL−1 Hoechst 33342 and 7.5μgmL−1 cytochalasin B (CB). Control oocytes were sham-enucleated by removing an equal volume of cytoplasm. Oocytes were cultured in SOF±10mM caffeine. Groups of 10 oocytes were sampled and analyzed for MPF and MAPK activities as previously described (Ye JP et al., 2003 Reproduction 125, 645–656). For NT, primary foetal fibroblasts were quiesced in DMEM containing 0.1% FBS for 2–3 days. Cell fusion was induced with two DC pulses of 25VcM-1 for 80μs. 3 methods of NT were compared: A. fusion 20hpm, activation 21hpm; B. fusion 24hpm, activation 25hpm; C. 10mM caffeine 18–24hpm, fusion 24hpm, activation 25hpm. All oocytes were activated in HSOF containing 5μgmL−1 calcium ionophore (A23187), cultured in SOF with 10μgmL−1 of cycloheximide and 7.5μgmL−1 CB for 5h, and then transferred to mSOFaaBSA medium, all at 5% CO2, 5% O2 and 90% N2 at 39°C. On Day 2 cleavage was assessed and 10% FBS added to the medium. Development to blastocyst was assessed on Day 7. All data were analyzed by chi-square test. Both MPF and MAP kinase activities were increased at MII compared to A/TI (P&lt;0.05). There were no differences in activities of both kinases between intact and enucleated oocytes. Following enucleation, both kinase activities were identical in all groups, reaching maximum activities 24hpm followed by a slow decline. Caffeine increased the activity of both kinases (MPF in particular) in all groups. Following 5 replicates (total oocytes 145, 143, 144 for NT methods A,B,C, respectively), no significant differences were observed between fusion (82.1%, 67.8%, 67.4%), cleavage (90.8%, 88.7%, 89.7%) or development to blastocyst (20.2%, 18.6%, 25.8%). Analysis of total cell numbers on limited numbers of blastocysts (7, 6, 7) were NS(70.9±38.5, 69.3±25.4, 93.3±17.8).


1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.


2004 ◽  
Vol 16 (2) ◽  
pp. 154
Author(s):  
H.S. Park ◽  
M.Y. Lee ◽  
S.P. Hong ◽  
J.I. Jin ◽  
J.K. Park ◽  
...  

Recent techniques in somatic cell nuclear transfer (SCNT) have been widely used for animal research. In addition, SCNT techniques may allow for the rescue of endangered species. Despite efforts for wildlife preservation, however, some threatened or endangered wild animal species will likely become extinct. As a preliminary experiment of a series in wildlife research, we tried to identify an improved method for the production of more transferable NT embryos in goats. Mature donor animals of Korean native goats (20–25kg) were synchronized with a CIDR (type G; InterAg, New Zealand) vaginal implant for 10 days followed by a total of 8 twice daily injections of 70mg of FSH (Folltropine, London, Ontario, Canada) and 400IU of hCG (Chorulon, Intervet, Moxmeer, The Netherlands). Oocytes were then collected surgically by retograde oviduct flush or direct aspiration from ovarian follicles in vivo at 29–34h after hCG. Oocytes collected from follicles were matured in TCM-199 containing 10% FBS and hormones. Prepared ear skin cells from the goat were cultured in TCM-199 containing 10% FBS at 39°C, 5% CO2 in air, and confluent monolayers were obtained. Oocytes were enucleated and donor cells from serum starvation (0.5%) culture were fused through a single electric pulse (DC 2.36kvcm−1, 17μs), and then activated by a single electric pulse (AC 5vmm−1, 5s+DC 1.56kvcm−1, 30μs) or chemical treatment (5μgmL−1 ionomycin 5min−1, 1.9mM 6-DMAP/4h). Reconstructed oocytes were cultured in M16 medium with 10% goat serum (GS) for 6–7 days. Data were analyzed by chi-square test. In in vitro development, significantly (P&lt;0.05) more oocytes were cleaved (24/30, 80.0%) and developed (7/24, 29.2%) to morula or blastocyst stage, respectively, in NT oocytes activated by Iono + DMAP compared to electric stimulated oocytes (2/21, 40.0%; 0/2, 0%). There was a significant difference in in vitro development of NT embryos by the method of oocyte collection. Cleavage rate was higher (P&lt;0.05) in NT embryos from in vivo oocytes (23/28, 82.1%) than in in vitro matured oocytes (19/35, 54.3%), and further development to morula or blastocyst was also significantly (P&lt;0.05%) higher in NT embryos from in vivo oocytes (7/23, 30.4%) than in NT embryos from in vitro matured oocytes (0/19, 0%). When we compared NT embryos to parthenotes, developmental rate was not significantly different between NT embryos and parthenotes. These results strongly suggest that the in vivo oocytes will have superior developmental potential to oocytes matured in vitro. Table 1 Effect of different oocyte source on in vitro development following caprine SCNT


2007 ◽  
Vol 97 (03) ◽  
pp. 425-434 ◽  
Author(s):  
Dmitry Kireev ◽  
Nadezhda Popenko ◽  
Aleksei Pichugin ◽  
Mikhail Panteleev ◽  
Olga Krymskaya ◽  
...  

SummaryPlatelet microparticles (PMPs) are small vesicles released from blood platelets upon activation. The procoagulant activity of PMPs has been previously mainly characterized by theirability to bind coagulation factors VIII and Va in reconstructed systems. It can be supposed that PMPs can contribute to the development of thrombotic complications in the pathologic states associated with the increase of their blood concentration. In this study we compared procoagulant properties of calcium ionophore A23187-activated platelets and PMPs using several in-vitro models of hemostasis. Surface densities of phosphatidylserine, CD61, CD62P and factor X bound per surface area unit were determined by flow cytometry. They were 2.7-, 8.4-, 4.3-, and 13-fold higher for PMPs than for activated platelets, respectively. Spatial clot growth rate (Vclot) in the reaction-diffus ion experimental model and endogenous thrombin potential (ETP) were determined in plasma, which was depleted of phospholipid cell surfaces by ultra-centrifugation and supplemented with activated platelets or PMPs at different concentrations. Both Vcllot and ETP rapidly increased with the increase of PMP or platelet concentration until saturation was reached. The plateau values of Vclot and ETP for activated platelets and PMPs were similar. In both assays, the procoagulant activity of one PMP was almost equal to that of one activated platelet despite at least two-orders-of-magnitude difference in their surface areas. This suggests that the PMP surface is approximately 50- to 100-fold more procoagulant than the surface of activated platelets.


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