scholarly journals In Vitro Developmental Potential of Bovine Nuclear Transfer Embryos Derived from Primary Cultured Cumulus Cells.

2000 ◽  
Vol 62 (3) ◽  
pp. 339-342 ◽  
Author(s):  
Mohamed Sayed MOHAMED NOUR ◽  
Yoshiyuki TAKAHASHI
2003 ◽  
Vol 5 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Satoshi Akagi ◽  
Seiya Takahashi ◽  
Noritaka Adachi ◽  
Kiyotoshi Hasegawa ◽  
Toru Sugawara ◽  
...  

2005 ◽  
Vol 17 (2) ◽  
pp. 183
Author(s):  
L. Su ◽  
F.L. Du ◽  
L.Y. Sung ◽  
S. Yang ◽  
B.S. Jeong ◽  
...  

Interspecies nuclear transfer (NT) is an important tool for preservation of endangered animal species. This study was carried out to clone Yak (Poephagus mutus) embryos by using Yak skin fibroblasts and bovine (Bos taurus) recipient cytoplasts, and to compare the efficiency of YAK interspecies NT (bovine cytoplast-Yak donor cell) and bovine somatic NT (bovine cytoplast-bovine donor cell). Recipient oocytes were extracted from antral follicles of bovine ovaries, and subsequently cultured in maturation medium for 18–20 h in 5% CO2 and 95% humidified air at 39°C. Cumulus cells were removed from the oocytes by vortexing also facilitated further enucleation. Yak skin fibroblast cells were prepared from cultured ear explants of an adult 5-year-old female. Fibroblasts were cultured at passage 6–9 in 10% FBS DMEM at 37°C in 5% CO2 humidified air. The donor cell at a diameter of 19–20 μm was inserted into the perivitelline space of an enucleated oocyte. A bovine female cell line at similar passage number was used for bovine somatic NT as control. Somatic cell-cytoplast pairs were then fused by applying two direct current pulses at 2.0 kV/cm for a duration of 6–10 μs/pulse. Fused embryos were activated in 10 μg/mL cycloheximide and 2.5 μg/mL cytochalasin D in M199 plus 7.5% FBS for 5 h. Reconstructed Yak embryos were cultured in CR1aa plus 6 mg/mL BSA for 2 days (initiation of activation = Day 0) at 39°C, 5% CO2, 5% O2, and 90% N2, and then in 7.5% FBS CR1aa medium for 5 successive days on bovine cumulus monolayers. Expanding and hatching blastocysts on Day 7 were recorded and cryopreserved for further embryo transfer trials. The percentage of cleavage and the development to morulae and blastocysts were statistically analyzed using a General Linear Model (GLM, Univariate, SPSS 9.0, SPSS Inc, Chicago, IL, USA). As indicated in Table 1, the results demonstrated that the efficiencies of fusion rate as well as developmental potential in vitro were significantly higher in the bovine somatic NT group compared to those of the Yak interspecies NT group. However, the morphology and cell number per embryo of interspecies Yak cloned embryos were indistinguishable from those of bovine NT embryos. Our data suggest that bovine oocytes possess the capability of reprogramming/reactivation of the genome from differentiated somatic Yak nuclei. Table 1. Comparison of yak interspecies and bovine somatic nuclear transfer


Zygote ◽  
2001 ◽  
Vol 9 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Jeong Tae Do ◽  
Kwon Ho Hong ◽  
Bo Yon Lee ◽  
Seung Bo Kim ◽  
Nam-Hyung Kim ◽  
...  

In this study we examined the developmental potential of reconstructed embryos and the fate of donor mitochondria during preimplantation development after nuclear transfer in cattle. Isolated cumulus cells were used as donor cells in nuclear transfer. Cumulus cells labelled with MitoTracker Green FM fluorochrome were injected into enucleated bovine MII oocytes and cultured in vitro. MitoTracker labelling on donor cells did not have a detrimental effect on blastocyst formation following nuclear transfer. Cleavage rate was about 69% (56/81) and blastocyst formation rate was 6.2% (5/81) at 7 days after nuclear transfer. The labelled mitochondria dispersed to the cytoplasm and became distributed between blastomeres and could be identified up to the 8- to 15-cell stage. Small patches of mitochondria were detected in some 8- to 15-cell stage embryos (5/20). However, donor mitochondria were not detected in embryos at the 16-cell stage and subsequent developmental stages. In the control group, mitochondria could be identified in arrested 1-cell embryos up to 7 days after nuclear transfer. These results suggest that disappearance of the labelled donor mitochondria in nuclear transfer bovine embryos is not due to fading of the fluorochrome marker, but is rather an as yet undefined cytoplasmic event.


2007 ◽  
Vol 19 (1) ◽  
pp. 138 ◽  
Author(s):  
K. Hasegawa ◽  
S. Takahashi ◽  
S. Akagi ◽  
K. Takeda ◽  
K. Imai ◽  
...  

We previously produced a cloned calf by nuclear transfer (NT) using cumulus cells removed from cumulus–oocyte complexes (COCs) after IVM. If both cumulus cells and oocytes are obtained identically and individually, and can be used simultaneously for NT, the production of cloned cows will be more expedient. And the cloned offspring produced from them will not exhibit the heteroplasmic mixed mtDNAs of donor cells and recipient oocytes. In this study, we examined the developmental potential of NT embryos using cumulus–oocyte complexes (COCs) collected from cows individually by ovum pickup (OPU). The cumulus cells were removed from COCs after IVM. The cumulus cells and cumulus-free MII oocytes derived from the same cow were used as donor nuclei and recipient oocytes, respectively. NT was performed as previously described (Akagi et al. 2003 Clon Stem Cells 5, 101–108). In Experiment 1, we examined the in vitro development of NT embryos using COCs collected by OPU. The aspiration of the follicles was performed once a week consecutively for 6 weeks in 6 cows (Cows A, B, C, D, E, and F) without hormone stimulation. In Experiment 2, we examined fetal development after the transfer of NT embryos. A Japanese black cow (Cow G) was used for OPU. On Day 7, 13 NT blastocysts were transferred to 7 recipient cows. The mtDNA genotypes of the donor cow and the cloned calf were analyzed by PCR-mediated single-strand conformation polymorphism analysis as previously described (Takeda et al. 2003 Mol. Reprod. Dev. 64, 429–437). The results of Experiment 1 are summarized in Table 1. Fusion rates did not differ among individual cows. However, the developmental rates of NT embryos at the blastocyst stage varied widely among individual cows, with a range of 19 to 64%. In Experiment 2, 2 of 7 recipient cows became pregnant on Day 30. One pregnant cow aborted on Day 60, and another cow calved a healthy calf. The mtDNA genotype of the cloned calf was confirmed to be identical with that of the donor cow. These results indicate that COCs from an identical individual can be used as donor nuclei and recipient oocytes for NT in order to produce female clones with the same mtDNA as that of the donor cow. Table 1.In vitro development of NT embryos using COCs collected by OPU


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p > 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable


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<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<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<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


2005 ◽  
Vol 17 (2) ◽  
pp. 181 ◽  
Author(s):  
D. Sage ◽  
P. Hassel ◽  
B. Petersen ◽  
W. Mysegades ◽  
P. Westermann ◽  
...  

Porcine nuclear transfer (NT) is an inefficient process and it is necessary to use as many as 120 NT embryos for each foster mother to obtain small litters of live piglets. In these experiments, we evaluated the effects of culture atmosphere and medium on the development of NT embryos by monitoring blastocyst rate and cell number of Day 6 blastocysts. Age matched IVF and parthenogenetic embryos were also evaluated for comparison. For all experiments a pool of oocytes was aspirated from ovaries collected in a local abattoir. Following aspiration, oocytes were allowed to mature for 40 h in North Carolina State University (NCSU)-37 medium (supplemented with cAMP and hCG/eCG for the first 22 h). After removal of the cumulus cells, denuded oocytes with polar bodies were selected for NT, enucleated, fused with fetal fibroblasts, and sequentially activated electrically and chemically by 3 h of treatment with 6-dimethylaminopurine (6-DMAP). A second group of oocytes from the same denuded pool were maintained in TL-HEPES medium and activated in parallel with the NT group to produce parthenogenetic embryos. A third group was fertilized with frozen-thawed epididymal semen and co-cultured for ∼12 h to give IVF embryos. All three treatment groups were subdivided into a control subgroup and an experimental subgroup. In the first experiment, we compared the effects of atmosphere (20% vs. 5% oxygen) on in vitro embryonic development in NCSU-23 medium. In the second experiment, we used only the 5% oxygen concentration and compared different culture media. One subgroup was maintained in standard NCSU-23 medium and the second subgroup was cultured in a two-step system for the first 58 h in modified NCSU-23 (without glucose but supplemented with 2.0 mM lactate and 0.2 mM pyruvate), followed by addition of glucose to give a final concentration of 5.55 mM. Data were statistically analyzed by analysis of variance and chi square test. Blastocyst rate and mean cell number in all three embryo groups were improved under 5% oxygen. The most dramatic effect was observed in the NT group, in which the blastocyst rate increased significantly (P < 0.001) from 6.7% ± 5.9 (n = 279) to 19.6% ± 8.9 (n = 250) and mean cell number increased from 17.7 ± 12.1 to 25.8 ± 10.3 cells per blastocyst. With 5% oxygen there was also an increase of blastocyst rates and mean cell numbers in both IVF and parthenogenetic groups. In the second experiment, blastocyst rate for NT embryos increased significantly (P < 0.05) from 21.8% ± 7.6 (n = 242) in conventional NCSU-23 to 31.5% ± 11.0 (n = 271) in the modified system whereas there was almost no difference in the mean cell number of both groups (29.2 ± 4.3 vs. 31.5 ± 5.3). In the groups of IVF and parthenogenetic embryos no difference was found. These results indicate that both the reduced oxygen and the modified culture medium are important for pre-implantation development of porcine nuclear transfer embryos.


2002 ◽  
Vol 14 (4) ◽  
pp. 191 ◽  
Author(s):  
M. A. Martinez-Diaz ◽  
K. Ikeda ◽  
Y. Takahashi

The effects of cycloheximide (CHX) treatment and the interval between fusion and activation on the development of pig nuclear transfer (NT) embryos constructed with enucleated oocytes and serum-starved granulosa/cumulus cells were examined. One group of couplets was fused and activated simultaneously (FAS) by a single electrical pulse (activation pulse). Another three groups of couplets were fused electricaly 1.5, 2.5 or 4.5 h before being subjected to the activation pulse (FBA). Each group was divided into two subgroups and incubated with or without CHX. The NT embryos treated with CHX showed a high and stable cleavage rate, regardless of the interval between fusion and activation; however, development to blastocysts was improved only when the NT embryos were subjected to FAS with CHX. These results indicate that CHX-sensitive events occurring shortly after FAS may be responsible for the development to blastocysts. Fusion pulse rarely activated M II oocytes, but rapidly dropped the p34cdc2 kinase activity in NT embryos. A pronucleus-like structure was observed 2-2.5 h after the activation pulse with CHX in NT embryos of both the FAS and FBA groups. Therefore, successive inactivation of M-phase promoting factor and cytostatic factor at a certain short interval may also play an important role in the development of NT embryos.


2014 ◽  
Vol 26 (2) ◽  
pp. 337 ◽  
Author(s):  
Satoko Matoba ◽  
Katrin Bender ◽  
Alan G. Fahey ◽  
Solomon Mamo ◽  
Lorraine Brennan ◽  
...  

The follicle is a unique micro-environment within which the oocyte can develop and mature to a fertilisable gamete. The aim of this study was to investigate the ability of a panel of follicular parameters, including intrafollicular steroid and metabolomic profiles and theca, granulosa and cumulus cell candidate gene mRNA abundance, to predict the potential of bovine oocytes to develop to the blastocyst stage in vitro. Individual follicles were dissected from abattoir ovaries, carefully ruptured under a stereomicroscope and the oocyte was recovered and individually processed through in vitro maturation, fertilisation and culture. The mean (± s.e.m.) follicular concentrations of testosterone (62.8 ± 4.8 ng mL–1), progesterone (616.8 ± 31.9 ng mL–1) and oestradiol (14.4 ± 2.4 ng mL–1) were not different (P > 0.05) between oocytes that formed (competent) or failed to form (incompetent) blastocysts. Principal-component analysis of the quantified aqueous metabolites in follicular fluid showed differences between oocytes that formed blastocysts and oocytes that degenerated; l-alanine, glycine and l-glutamate were positively correlated and urea was negatively correlated with blastocyst formation. Follicular fluid associated with competent oocytes was significantly lower in palmitic acid (P = 0.023) and total fatty acids (P = 0.031) and significantly higher in linolenic acid (P = 0.036) than follicular fluid from incompetent oocytes. Significantly higher (P < 0.05) transcript abundance of LHCGR in granulosa cells, ESR1 and VCAN in thecal cells and TNFAIP6 in cumulus cells was associated with competent compared with incompetent oocytes.


Sign in / Sign up

Export Citation Format

Share Document