Oocyte age and nuclear donor cell type affect the technical efficiency of somatic cloning in rabbits

Zygote ◽  
2003 ◽  
Vol 11 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Rita P. Cervera ◽  
Fernando García-Ximénez
Keyword(s):  
Technical Efficiency ◽  
Nuclear Transfer ◽  
Donor Cell ◽  
Cumulus Cells ◽  
Cell Types ◽  
Cell Type ◽  
Fetal Fibroblasts ◽  
Somatic Nuclear Transfer ◽  
Metaphase Ii Oocytes

The present study in rabbits compared, in the first experiment, the effect of two commonly used oocyte ages, 13 h and 17 h after ovulation induction treatment, on the technical efficiency of somatic nuclear transfer steps, using fresh cumulus cells as nuclear donors. Recently ovulated metaphase II oocytes (13 h) showed higher fusion (13 h: 83% vs 17 h: 67%, p < 0.05) and in vitro development rates than in vivo slightly aged metaphase II oocytes (morula, 13 h: 74% vs 17 h: 25%, p < 0.05; blastocyst, 13 h: 16% vs 17 h: 8%; p < 0.05). In contrast, activation rate was higher in the 17 h group (13 h: 45% vs 17 h: 67%; p < 0.05). In a second experiment, using recently ovulated oocytes (13 h) as recipients, two donor cell types (from primary cultures of either cumulus cells or fetal fibroblasts) were tested to evaluate their effects on the efficiencies of the different technical steps of somatic nuclear transfer procedure. A better fusion rate was obtained when fetal fibroblasts were used as nuclear donors (cumulus cells: 45% vs fetal fibroblasts: 67%, p < 0.05). No statistically significant differences were detected in cleavage rate regardless of the cell type used (cumulus cells: 44% vs fetal fibroblasts: 60%, p > 0.05). However, in vitro development to morula (cumulus cells: 41% vs fetal fibroblasts: 14%, p < 0.05) and to blastocyst stage (cumulus cells: 27% vs fetal fibroblasts: 3%, p < 0.05) were different between cell types.

scholarly journals 66 IN VITRO DEVELOPMENT OF YAK (POEPHAGUS MUTUS) CLONED EMBRYOS BY INTERSPECIES SOMATIC NUCLEAR TRANSFER

2005 ◽  
Vol 17 (2) ◽  
pp. 183
Author(s):  
L. Su ◽  
F.L. Du ◽  
L.Y. Sung ◽  
S. Yang ◽  
B.S. Jeong ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Bos Taurus ◽  
Donor Cell ◽  
Cumulus Cells ◽  
Fusion Rate ◽  
Cell Number ◽  
Developmental Potential ◽  
Somatic Nuclear Transfer ◽  
Humidified Air

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

Effect of donor cell age on development of ovine nuclear transfer embryos in vitro

Zygote ◽  
2010 ◽  
Vol 18 (4) ◽  
pp. 331-338 ◽  
Author(s):  
B. Heidari ◽  
A. Shirazi ◽  
P. Tajic ◽  
E. Ahmadi ◽  
H. Nazari ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Formation Rate ◽  
Donor Cell ◽  
Fibroblast Cell ◽  
Cumulus Cells ◽  
Blastocyst Formation ◽  
Donor Animal ◽  
Cell Age ◽  
Fetal Fibroblasts

SummaryThe effects of the age of cell donor animal on in vitro development of ovine nuclear transfer (NT) embryos were investigated. Somatic donor cells were obtained from two different sources: (1) adult cells (adult fibroblast cells; AFC and adult cumulus cells; ACC); and (2) fetal fibroblasts (40-day-old; FFC-40 and 65-day-old; FFC-65). The fibroblast cell lines were used for NT procedures within 4–13 subpassages. While the cumulus cells were used as non-cultured (fresh) cells. The in vitro matured abattoir-derived oocytes were considered as recipients. No differences in the rates of fusion (75.7, 77.7, 76.3 and 86.7%) and cleavage (80.1, 84.3, 77.8 and 74%) were detected among couplets reconstructed with FFC-40, FFC-65, AFC and ACC, respectively. Blastocyst formation rate of those oocytes reconstructed with FFC-40 was higher (18%; p < 0.001) than those reconstructed with FFC-65 (13%) and AFC (10.9) and comparable with those reconstructed with ACC (17.5%). When the effect of passage number was analysed within groups (FFC-40, FFC-65 and AFC) there were no significant differences in fusion, cleavage and blastocyst rates between reconstructed oocytes. The present study demonstrates that the fetal and adult fibroblasts as well as fresh cumulus cells are comparable in their ability to attain cell fusion and embryonic cleavage. Moreover, the blastocyst formation rate is influenced by the age of the donor animal and the fresh cumulus cells have similar remodelling potential to that of fetal fibroblasts in term of blastocyst formation rate.

Preimplantation and postimplantation development of rat embryos cloned with cumulus cells and fibroblasts

Zygote ◽  
2001 ◽  
Vol 9 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Philip Iannaccone ◽  
Greg Taborn ◽  
Ray Garton
Keyword(s):  
Nuclear Transfer ◽  
Donor Cell ◽  
Cumulus Cells ◽  
Cell Types ◽  
Blastocyst Stage ◽  
Surrogate Mothers ◽  
Rat Embryos ◽  
Adult Rat ◽  
Rat Fibroblasts

In this report we demonstrate the successful in vitro culture of fertilised embryos from 1-cell to blastocyst stage, albeit in a strain-dependent fashion. We report procedures for the enucleation of rat oocytes; nuclear transfer by injection of nuclei (NT) from adult rat cumulus cells, rat primary embryonic fibroblasts and genetically modified rat fibroblasts; and activation resulting in advanced preimplantation development. Blastocyst stage rat embryos were obtained after in vitro culture of nuclear transfer zygotes at similar frequencies with each of these nuclear donor cell types. Transfer of NT embryos to surrogate mothers leads to implantation of 24% of the zygotes. These results suggest that the nuclei of cultured rat cells, even following genetic modification, can be reprogrammed to support early embryonic development, which is a prerequisite to cloning the rat.

scholarly journals 63 IMPROVED IN VITRO DEVELOPMENT OF PORCINE EMBRYOS PRODUCED BY NUCLEAR TRANSFER, IVF AND PARTHENOGENESIS

2005 ◽  
Vol 17 (2) ◽  
pp. 181 ◽  
Author(s):  
D. Sage ◽  
P. Hassel ◽  
B. Petersen ◽  
W. Mysegades ◽  
P. Westermann ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Culture Media ◽  
Cumulus Cells ◽  
Cell Number ◽  
Foster Mother ◽  
Chi Square ◽  
Fetal Fibroblasts ◽  
Blastocyst Rate ◽  
Parthenogenetic Embryos

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.

scholarly journals Metabolic programming of a Warburg effect-like phenotype in donor fibroblasts prior to somatic cell nuclear transfer

2017 ◽  
Author(s):  
◽  
Bethany Rae Mordhorst
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Donor Cell ◽  
Nuclear Reprogramming ◽  
In Vitro Development ◽  
Fetal Fibroblasts ◽  
Pharmaceutical Agents ◽  
Vitro Development

Gene edited pigs serve as excellent models for biomedicine and agriculture. Currently, the most efficient way to make a reliably-edited transgenic animal is through somatic cell nuclear transfer (SCNT) also known as cloning. This process involves using cells from a donor (which may have been gene edited) that are typically grown in culture and using their nuclear content to reconstruct a new zygote. To do this, the cell may be placed in the perivitelline space of an enucleated oocyte and activated artificially by a calcium-containing media and electrical pulse waves. While it is remarkable that this process works, it is highly inefficient. In pigs the success of transferred embryos becoming live born piglets is only 1-3%. The creation of more cloned pigs enables further study for the benefit of both A) biomedicine in the development of prognosis and treatments and B) agriculture, whether it be for disease resistance, feed efficiency, gas emissions, etc. Two decades of research has not drastically improved the cloning efficiency of most mammals. One of the main impediments to successful cloning is thought to be due to inefficient nuclear reprogramming and remodeling of the donor cell nucleus. In the following chapters we detail our efforts to improve nuclear reprogramming of porcine fetal fibroblasts by altering the metabolism to be more blastomere-like in nature. We used two methods to alter metabolism 1) pharmaceutical agents and 2) hypoxia. After treating donor cells both methods were used in nuclear transfer. Pharmaceutical agents did not improve in vitro development of gestational survival of clones. Hypoxia did improve in vitro development and we are currently awaiting results of gestation.

31 FULL-TERM AND LIVE RABBIT CLONES PRODUCED BY SOMATIC CELL NUCLEAR TRANSFER

2006 ◽  
Vol 18 (2) ◽  
pp. 124 ◽  
Author(s):  
F. Du ◽  
J. Xu ◽  
S. Gao ◽  
L. Y. Sung ◽  
D. Stone ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Fusion ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Donor Cell ◽  
Cumulus Cells ◽  
Full Term ◽  
Fusion Method ◽  
Nuclear Injection

Transgenic/knockout (KO) rabbits can serve as an excellent animal model for human cardiovascular diseases (CVD) and other diseases. However, the production of transgenic/KO rabbits is hindered by low efficiency of traditional DNA microinjection and the unavailability of embryonic stem cell lines. An alternative approach is to produce transgenic/KO rabbits by somatic cell nuclear transfer (SCNT) using genetically modified somatic cells as nuclear donors. Our initial objective of the study was to prove the feasibility of cloning rabbits by SCNT because rabbit is a difficult species to be cloned. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of follicle-stimulating hormone (FSH) and human choriani gonadotropin (hCG). Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in M199 + 10% fetal bovine serum (FBS) and confirmed by fluorescence microscopy. Cumulus cells used for nuclear donors were prepared from fresh cumulus-oocytes complexes. The donor nucleus was transferred into a recipient oocyte by either cell fusion or direct nuclear injection method. In the cell fusion method, a small donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte; subsequently the somatic cell-cytoplast pair was fused by applying three direct current pulses at 3.2 kV/cm for a duration of 20 µs/pulse. In the direct nuclear injection method, a mechanically lysed donor cell was injected into oocyte cytoplasm with the aid of a piezo-drill system. Fused embryos or injected oocytes were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg/mL cycloheximide for 2 h. For the in vitro study, cloned embryos were cultured in B2 medium plus 2.5% FBS for 5 days (initiation of activation = day 0) at 38.5°C in 5% CO2 humidified air. For the in vivo study, cloned embryos were cultured for 20–22 h in vitro before transfer into pseudopregnant rabbit recipients. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post embryo transfer (ET). The results (Table 1) show that the donor nuclei-introducing rate was higher with nuclear direct injection than with the cell fusion method (P < 0.05). There were no significant differences among subsequent cleavage and development to morula and blastocysts between both methods, although the development rates of cloned embryos via electrically mediated fusion were higher than those derived from the injection group. One recipient in the injection group (1/6, 17%) and six recipients in the fusion group (6/16, 38%) were diagnosed as pregnant. From the fusion group, one full-term but stillborn and one live and healthy clone rabbit were delivered on Days 33 and 31 post-ET, respectively. To our knowledge, this is the second report of full term development of cloned rabbit by somatic nuclear transfer cloning. Our further study is to clone live rabbit offspring with modified transgenic/KO somatic cell lines. Table 1. In vitro development of rabbit cloned embryos with cumulus cells as nuclear donors This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261–11.

Development and spindle formation in rat somatic cell nuclear transfer (SCNT) embryos in vitro using porcine recipient oocytes

Zygote ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Atsushi Sugawara ◽  
Satoshi Sugimura ◽  
Yumi Hoshino ◽  
Eimei Sato
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Fluorescent Protein ◽  
Cumulus Cells ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Spindle Formation ◽  
Fetal Fibroblasts

SummaryCloning that uses somatic cell nuclear transfer (SCNT) technology with gene targeting could be a potential alternative approach to obtain valuable rat models. In the present study, we determined the developmental competence of rat SCNT embryos constructed using murine and porcine oocytes at metaphase II (MII). Further, we assessed the effects of certain factors, such as: (i) the donor cell type (fetal fibroblasts or cumulus cells); and (ii) premature chromosome condensation (PCC) with normal spindle formation, on the developmental competence of rat interspecies SCNT (iSCNT) embryos. iSCNT embryos that had been constructed using porcine oocytes developed to the blastocyst stage, while those embryos made using murine MII oocytes did not. Rat iSCNT embryos constructed with green fluorescent protein (GFP)-expressing fetal fibroblasts injected into porcine oocytes showed considerable PCC with a normal bipolar spindle formation. The total cell number of iSCNT blastocyst derived from GFP-expressing fetal fibroblasts was higher than the number derived from cumulus cells. In addition, these embryos expressed GFP at the blastocyst stage. This paper is the first report to show that rat SCNT embryos constructed using porcine MII oocytes have the potential to develop to the blastocyst stage in vitro. Thus the iSCNT technique, when performed using porcine MII oocytes, could provide a new bioassay system for the evaluatation of the developmental competence of rat somatic cells.

scholarly journals 68EFFECT OF ROSCOVITINE ON FIBROBLASTS' ABILITY TO FORM BLASTOCYSTS AND ESTABLISH PREGNANCIES AFTER BOVINE NUCLEAR TRANSFER

2004 ◽  
Vol 16 (2) ◽  
pp. 155
Author(s):  
A.M. Powell ◽  
P. Graininger ◽  
N. Talbot ◽  
R.J. Wall
Keyword(s):  
Nuclear Transfer ◽  
Donor Cell ◽  
Culture Conditions ◽  
Contact Inhibition ◽  
Serum Starvation ◽  
Blastocyst Development ◽  
Variable Effect ◽  
Return Rates ◽  
Fetal Fibroblasts

Cloning efficiency of fibroblast nuclear transfer is dependent on donor cell chromatin status. Chromatin status is commonly regulated by serum starvation or contact inhibition. We have tested 3 methods of synchronizing chromatin activity, roscovitine exposure (in MEM + 10% serum) for 24h, with serum starvation (0.5% serum) for 5 days or growth to confluence in 10% serum prior to nuclear transfer. Roscovitine, a specific cyclin-dependent kinase (CDK)2 inhibitor, provides a means of precisely synchronizing bovine fetal fibroblasts (BFF) at G0/G1 cell cycle stage. Fibroblasts were from 100-day-old Jersey fetuses. Cells, frozen at passage 2, from fetus 10 are known to produce calves. Fetus 13 cells, frozen at passages 1 and 2, were compared for their ability to serve as nuclear donor cells. Oocytes, either purchased from Bomed or harvested from ovaries obtained from a local slaughterhouse and matured in Ham’s F10, were enucleated between 18–21h post-maturation initiation. Couplets were produced and fused by standard techniques. Embryos were activated 2 to 4 hours after fusion by exposure to ionomycin for 4min and DMAP for 4h. Embryos were then held in CR1aa for 12h before being cultured in G1 media for 3 days and then G2 media for another 3 days (38.5°C and 5% O2 + 5% CO2 + 90% N). On Day 7, good quality blastocysts were transferred to synchronized recipient heifers. The remaining embryos were evaluated after another day in culture. Blastocyst development [(100) X (total blastocysts/fused couplets)] was not influenced by fetus (BFF10, 31±3%; BFF13, 26±2%, P=0.126). However, a higher proportion of blastocysts were produced when fibroblasts were cultured in 0.5% serum (38±3%) compared to culture in 10% serum (29±3%) or in roscovitine (23±2%, P=0.001). Time in culture, as measured by passage, had a variable effect on the fibroblast’s ability to product blastocysts from the three fibroblast culture conditions tested. Passage 1 and 2 fibroblasts responded similarly to the 0.5% and 10% serum treatments (P&gt;0.80). When cultured in roscovitine, passage 1 fibroblasts performed better then passage 2 fibroblasts (29±4% v. 16±3% blastocysts, P=0.010). Embryos have been transferred to 51 recipients to date. Ten recipients have given birth or are still pregnant. The 60-day non-return rate for those animals was 29%, 50%, and 31% for serum starvation, 10% serum, and roscovitine treatments, respectively. BFF10 and BFF13 cells have generated the same non-return rates (33%). In this study, of the 3 methods of synchronizing fibroblast chromatin, serum-starvation had an in vitro advantage. Cells cultured for different lengths of time (passages) responded differently to synchronization treatments. This may reflect a heterogeneous population of cells at early passages. Current non-return rates seem to favor synchronization by contact inhibition. Any advantage roscovitine offers may not be revealed until calving.

19 CHANGES IN PLASMA STEROID CONCENTRATIONS DURING GESTATION IN COWS WITH SPONTANEOUS ABORTION OF SOMATIC CELL CLONED FETUSES

2012 ◽  
Vol 24 (1) ◽  
pp. 121
Author(s):  
M. Hirako ◽  
H. Takahashi ◽  
K. Kimura ◽  
N. Adachi ◽  
S. Akagi
Keyword(s):  
Sex Steroids ◽  
Repeated Measures ◽  
Nuclear Transfer ◽  
Plasma Concentrations ◽  
Donor Cell ◽  
Cumulus Cells ◽  
Blastocyst Stage ◽  
Steroid Synthesis ◽  
Estrone Sulfate

Cloning of mammals by nuclear transfer frequently results in gestational failure with a variety of abnormalities that are likely due to inappropriate epigenetic reprogramming. Monitoring the placental function during gestation is important to clarify the cause of abnormalities in cloned animals. Sex steroids are produced in the bovine placenta and their levels in maternal peripheral blood are a useful measure of placentation. The objective of this study was to investigate changes in plasma concentrations of sex steroids during gestation in cows aborting cloned fetuses. Donor cells for nuclear transfer were obtained from subculture of cumulus cells retrieved from ovarian follicles of a Japanese Black cow. Recipient oocytes were derived from ovaries obtained at an abattoir and matured in vitro. Metaphase II oocytes were enucleated and each fused with a donor cell by DC pulses. Nuclear-transferred oocytes were activated and cultured for 7 days. Embryos developed to the blastocyst stage were each transferred into the uterine horn ipsilateral to the ovary bearing the CL of 39 multiparous Japanese Black and Holstein crossbred cows at 7 to 8 days after the day of standing oestrus (day 0). Fourteen recipient cows were diagnosed pregnant on Day 40 by ultrasonography and 7 cows delivered at full term. The other seven miscarried on Day 66, 81, 85, 89, 97, 104 and 211. Blood was collected from these cows at least once a week following the pregnancy diagnosis. Progesterone, estrone, oestradiol-17β and estrone sulfate in the blood plasma were measured by RIA and were compared with those in pregnant AI cows. Statistical differences at stages of gestation were analysed with repeated-measures ANOVA. In all miscarried cows, progesterone concentrations were similar to those in AI cows until several days before abortion and then rapidly decreased to the basal level. Concentrations of all estrogens stayed low until abortion in six cows aborting by day 104, whereas estrone and oestradiol-17β started to increase around Day 80 and estrone sulfate gradually increased from around Day 50 and started to increase drastically around Day 80 in AI cows. In another cow aborting on Day 211, profiles of estrone and oestradiol-17β were similar to those in AI cows until around Day 150. Thereafter, concentrations of these estrogens gradually decreased to the basal levels by Day 160 and stayed low until abortion. In this cow, gradual increase in estrone sulfate during Day 50 to 80 was not observed, but the difference in the concentration was not statistically significant from AI cows. The following profile of estrone sulfate was similar to those in active estrogens. The fetus was still alive on day 160 and fetal death was confirmed on day 180 by ultrasonography. These results suggest the possibility that developmental or functional failure of placenta associated with steroid synthesis may be a cause of mid-term miscarriage of a cloned fetus.

30 IN VITRO EXPRESSION OF BAX AND BCL2 GENES IN NUCLEAR DONOR SKIN FIBROBLAST, CUMULUS, AND GRANULOSA CULTURED CELLS DURING CULTURE AND THEIR SOMATIC CELL NUCLEAR TRANSFER-CLONED EMBRYOS IN INDIAN BUFFALOES (BUBALUS BUBALIS)

2009 ◽  
Vol 21 (1) ◽  
pp. 115
Author(s):  
N. Gupta ◽  
A. Pandey ◽  
S. C. Gupta
Keyword(s):  
Somatic Cell ◽  
Cell Lines ◽  
Granulosa Cells ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Skin Fibroblast ◽  
Cultured Cells ◽  
Donor Cell ◽  
Cumulus Cells

Somatic cell nuclear transfer (SCNT) involves functional changes in the genome which result in low efficiency for the production of viable and cloned embryos. It is primarily due to incomplete reprogramming of genome of donor cell nuclei in the reconstructed embryos (Vassena et al. 2007 Dev. Biol. 304, 75–89). Expression of BCL2 and Bax can be correlated with apoptosis. BCL2 inhibits apoptosis by regulating the release of cytochrome-c and other proteins from mitochondria (Keep et al. 2007 EMBO J. 26, 825–834). Antiapoptotic BCL2 is antiproliferative by facilitating G0. Bax is proapoptotic and accelerates S-phase progression. The dual functions in apoptosis and cell cycle are coordinately regulated by the BCL2 family and suggest that survival is maintained at the expense of proliferation (Zinkel et al. 2006 Cell Death Differ. 13, 1351–1359). The aim of this study was to estimate the relative expression of BCL2 oncogene and Bax gene in regulating apoptosis, in skin fibroblast, cumulus, and granulosa cells in culture, so that ideal-type donor cell lines are developed for higher success rates in SCNT-derived buffalo cloning. The cell lines up to 25th passage were from all the 3 tissue types by previous method (Gupta et al. 2007 Cell Biol. Int. 31, 1257–1264). The cells between passages 5th to 15th were selected as competent donor cells and transferred into enucleated in vitro-matured oocytes from slaughter ovaries. The couplets were activated electrically (1.5 kV cm–2, 15 μs) and chemically (ionomycin, 6-DMAP, CHX, and Cyto-B) and were cultured up to blastocyst. The cDNA were prepared from the growing cells in culture at 5, 10, and 15 passages from all cell lines and SCNT-cloned blastocysts from these cell lines at respective passages for Bax and BCL2 gene expression analysis. Relative expression of these candidate genes was quantified using real-time PCR. The data was analyzed for 1-way ANOVA and post-hoc Duncan multiple range test at P ≤ 0.05 level of significance. The cell proliferation rate in cultured cells at fifth passage was higher in all the 3 cell lines and declined in subsequent passages (range from 1.06 to 0.67). The relative abundance of Bax mRNA in granulosa cell was comparable with skin fibroblasts but significanly higher than cumulus cells at respective passages. BCL2 mRNA expression was significantly upregulated in cumulus cells as compared to granulosa cells but not with skin fibroblasts. The SCNT blastocyst production rates from granulosa were highest (24.28%) as compared to fibroblast (22.6%) and cumulus (21.4%) at passage 10. Level of Bax and BCL2 mRNA in granulosa and fibroblast SCNT blastocysts was not significantly different from IVF (control), whereas cumulus-derived blastocyst showed abnormal patterns with downregulated expression of Bax mRNA and upregulated expression of BCl2 mRNA. Identification of expressed genes in cells and cloned embryos will help to investigate the causes of developmental abnormality due to deregulation of expression of important gene associated with ART.

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