41 EFFICIENT STRATEGY FOR INTERSPECIFIC CLONING IN FELIDS

2014 ◽  
Vol 26 (1) ◽  
pp. 134
Author(s):  
L. N. Moro ◽  
M. I. Hiriart ◽  
J. Jarazo ◽  
C. Buemo ◽  
A. Sestelo ◽  
...  

Most of the 36 species of wild felids are at a level of threat, and interspecific SCNT (iSCNT) comes as a strategy to contribute to these species conservation. The aim of this study was to evaluate the effect of embryo aggregation in cheetah (Ch, Acinonyx jubatus), bengal (Ben, a hybrid between Felis silvestris and Prionailurus bengalensis), and domestic cat (DC, Felis silvestris) embryos generated by cloning. DC oocytes were in vitro matured and zona-free SCNT (with DC fibroblasts) or iSCNT (with Ch or Ben fibroblasts) was performed. The reconstructed embryos were activated with 5 μM ionomycin and 1.9 mM 6-DMAP, and cultured in SOF using microwells. Cloned embryos were cultured individually or as 2-embryo aggregates. The experimental groups were Ch1X, Ch2X, Ben1X, Ben2X, and the control groups were DC1X and DC2X. Embryo development was compared by Fisher's exact test (P ≤ 0.05). Embryo aggregation improved cleavage (Day 2) and blastocyst (Day 7) rates per well in all the groups (87.2% v. 96.7%, 83.8% v. 93.3% and 87.6% v. 98.2% for cleavage; and 13.7% v. 28.6%, 33.3% v. 43.8% and 27.4% v. 47.7% for blastocyst, for Ch1X (n = 102), Ch2X (n = 91), Ben1X (n = 154), Ben2X (n = 105), DC1X (n = 113), and DC2X (n = 109), respectively. Moreover, the Ch2X blastocyst rate was statistically similar as the control group DC1X. The mean total cell numbers of the blastocysts obtained were 264 ± 211 and 400.8 ± 97 for Ch1X and Ch2X, 278 ± 62 and 517 ± 104 for Ben1X and Ben2X, 385 ± 127 and 625 ± 183 for DC1X and DC2X, respectively. Although no statistical differences were obtained between the 1X and 2X groups, the 2X groups nearly doubled the average number of cells compared with the 1X groups. Blastocysts were also classified as grade 1 (expanded blastocysts with a well-defined ICM), grade 2 (expanded blastocysts without a well-defined ICM), and grade 3 (not expanded blastocysts). This classification showed an increase in grade 1 DC2X blastocyst compared with DC1X blastocysts (36.7% v. 16.1%), but no differences were observed in the other species. Expression of OCT-4 was assessed by inmunocytochemistry. The cheetah blastocysts markedly over-expressed this protein: the percentage of cells that expressed OCT-4 in Ch1X, Ch2X, Ben1X, Ben2X, DC1X, and DC2X was 88.2, 80.2, 46.3, 45.4, 51, and 47.4%, respectively, with statistical differences among all the groups except Ben1X and Ben2X. The proportion of OCT-4 expressing cells over total cell numbers was analysed by the difference of proportions test (P ≤ 0.05). In conclusion, iSCNT resulted in high rates of blastocyst formation, especially when embryo aggregation was applied. This strategy has not been previously evaluated in felids or iSCNT procedures, and has been demonstrated to improve blastocyst formation, the number of cells in the 3 groups, and the blastocyst quality in the DC. Other pluripotent genes besides OCT-4 should be studied to determine whether the overexpression of this gene in cheetah embryos is the consequence of an inefficient nuclear reprogramming that prevents a correct regulation. Finally, the iSCNT and embryo aggregation could contribute to species conservation in felids.

2014 ◽  
Vol 26 (1) ◽  
pp. 180 ◽  
Author(s):  
K. Syoji ◽  
K. Imai ◽  
H. Koyama ◽  
O. Dochi

The objective of this study was to investigate whether progesterone (P4) supplementation to in vitro maturation (IVM) medium could affect the competence of bovine oocyte to develop into blastocysts in vitro. Cumulus–oocyte complexes (COC) were collected by aspiration of ovarian follicles (2 to 6 mm in diameter) obtained from a local abattoir. The COC were matured for 20 h in TCM-199 supplemented with 5% calf serum and 0.02 AU mL–1 FSH at 38.5° in an atmosphere of 5% CO2 in air. After 18 h of gamete co-culture (5 × 106 sperms mL–1), presumptive zygotes were cultured in CRlaa containing 5% calf serum at 38.5°C in an atmosphere of 5% CO2, 5% O2, and 90% N2 for 9 days (fertilization = Day 0). Progesterone was added to the IVM medium 10 h after the start of the culture (1 μg group = 1 μg mL–1 of P4; 5 μg group = 5 μg mL–1 of P4; control group = no P4). The maturation (MII) rates were investigated after 20 h of starting the IVM culture. After maturation, the COC were denuded mechanically, and a part of the oocytes were mounted on slides, fixed with aceto-alcohol (1 : 3) solution for 48 h, stained with aceto-orcein, and observed under a phase-contrast microscope to determine their nuclear status (1 μg group: n = 32; 5 μg group: n = 28; control group: n = 31). The remaining COC were used for IVF. The cleavage rates were investigated on day 2, and the blastocyst formation rates were investigated on Days 7 to 9, respectively (1 μg group: n = 264; 5 μg group: n = 274; control group: n = 277). The blastocysts from Day 7 were used for differential staining of the inner cell mass (ICM) and trophectoderm cells (TE). The total cell numbers, ICM, and TE in the blastocysts were counted (1 μg group: n = 28; 5 μg group: n = 24; control group: n = 24). The rates of MII, cleavage, and blastocyst formation were expressed and analysed by the chi-squared test. Each set of cell numbers (mean ± standard error) was analysed by the unpaired t-test. The MII rate in the control group (76.7%) was significantly lower (P < 0.05) than that in the 1 μg group (93.8%). The cleavage rate in the 1 μg group (85.6%) was significantly higher (P < 0.05) than those in the control group (74.7%) and 5 μg group (77.4%). Further, the blastocyst formation rate in the 1 μg group (47.7%) and 5 μg group (43.4%) were significantly higher (P < 0.05) than that in the control group (35.0%). The ICM numbers (mean ± s.e.) were 39.5 ± 13.8 to 36.2 ± 8.9, the TE numbers were 74.4 ± 22.4 to 66.2 ± 12.9, the total cell numbers of blastocysts were 110.6 ± 28.2 to 103.0 ± 13.8. There was no significant difference in cell numbers among the groups. These results indicate that the cleavage and blastocyst formation rates can be improved by the addition of 1 μg mL–1 of P4 to the maturation medium.


Zygote ◽  
2013 ◽  
Vol 22 (2) ◽  
pp. 286-289 ◽  
Author(s):  
Su Jin Kim ◽  
Ok Jae Koo ◽  
Dae Kee Kwon ◽  
Jung Taek Kang ◽  
Sol Ji Park ◽  
...  

SummaryThe presence of glutamine (Gln) in in vitro maturation (IVM) and in vitro culture (IVC) medium is a more potent factor for improving porcine oocyte and embryo development than other amino acids. However Gln is inherently unstable and spontaneously breaks down into ammonia, and therefore interferes with proper development. To avoid this adverse effect, Gln was replaced in the present study with its stable dipeptide derivative alanyl-glutamine (Ala-Gln) and the effects of this replacement on porcine IVM and IVC were evaluated. Replacement of Gln with Ala-Gln during IVM did not improve nuclear maturation, however numbers of early cleaved embryos were significantly increased after activation. Blastocyst formation rates were also significantly improved by using Ala-Gln during IVM. Replacement of Gln with Ala-Gln during IVC significantly increased total cell numbers in blastocysts. Blastocyst formation rate was also significantly higher when Ala-Gln was used in both IVM and IVC. In conclusion, the use of Ala-Gln rather than Gln gives better results for development in both porcine IVM and IVC.


2012 ◽  
Vol 24 (1) ◽  
pp. 160
Author(s):  
K. Lee ◽  
J. Teson ◽  
L. Spate ◽  
C. N. Murphy ◽  
R. S. Prather

There have been significant improvements in the culture of porcine embryos in vitro; however, it is still suboptimal. Improvements in porcine embryo culture would benefit utilisation of porcine embryos for a variety of purposes. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to be expressed in the female reproductive tract and the level of its expression is high between conception and implantation. Previous studies show supplementing GM-CSF in embryo culture promotes embryonic development in human and bovine embryos. The aim of this study was to investigate the effect of GM-CSF on the culture of porcine embryos derived from somatic cell nuclear transfer (SCNT) and IVF. Different concentrations of recombinant porcine GM-CSF (0, 2, 10 ng mL–1) were introduced into Porcine Zygote Medium 3 from Day 1 to 6. Frequencies of cleaved embryos and blastocyst formation were recorded and analysed by using ANOVA following arcsin transformation. Total cell number in blastocysts from each group were counted and compared by using the Student's t-test. Differences at P < 0.05 were considered significant. A total of 563 SCNT embryos from 6 different donor cell lines on 11 different days were produced for the study. Incubation of SCNT embryos with GM-CSF did not affect the frequency of cleaved embryos. Frequencies of cleaved embryos in control (0 ng mL–1), 2 ng mL–1 GM-CSF and 10 ng mL–1 GM-CSF were 64.2%, 68.1% and 65.0%, respectively. Interestingly, both concentrations of GM-CSF significantly increased the frequency of blastocyst formation as compared with the control. In 2 ng mL–1 and 10 ng mL–1 of GM-CSF groups, 30.8% and 32.3% of embryos reached blastocyst respectively, whereas only 22.4% of embryos reached blastocyst in the control group. A significant increase in total cell number in blastocysts was observed when GM-CSF was introduced into embryo culture. An average of 28.8 ± 0.9 cells was recorded in the control group, whereas 31.9 ± 1.1 and 31.8 ± 1.1 were observed in 2 ng mL–1 and 10 ng mL–1 of GM-CSF groups, respectively. Similar effects were observed when GM-CSF was introduced to the culture of IVF embryos. For IVF study, 525 embryos were generated on 10 different days and embryos cultured in the presence of GM-CSF tended to show higher blastocyst formation (P = 0.1). Frequencies of blastocyst per cleaved in the 3 groups were 55.7% (control), 65.7% (2 ng mL–1 GM-CSF) and 66.7% (10 ng mL–1 GM-CSF). In addition, culture of IVF embryos with GM-CSF significantly increased total cell number in Day 6 blastocysts. Total cell number in blastocysts in 2 ng mL–1 GM-CSF (34.2 ± 0.8) and 10 ng mL–1 GM-CSF (34.4 ± 1.2) were significantly higher compared with control (27.3 ± 1.2). Our results indicate that introducing GM-CSF into embryo culture media can increase the quality of blastocyst stage embryos. An increase in the frequency of blastocyst formation and total cell number in blastocysts suggests that GM-CSF can be used to produce better-quality embryos in vitro. Currently, effects of GM-CSF on implantation of SCNT embryos are under investigation. Further studies would elucidate the specific mechanism of GM-CSF on porcine embryos.


2009 ◽  
Vol 21 (1) ◽  
pp. 166
Author(s):  
Y. H. Zhang ◽  
H. T. Xi ◽  
Y. Liu ◽  
J. Li ◽  
A. Pederson ◽  
...  

The present study was designed to examine if frozen storage of porcine zygote medium (PZM3) plus 3 mg mL–1 BSA (Yoshioka et al. 2002 Bio. Reprod. 66, 112–119) is feasible to culture pig embryos produced by parthenogenetic activation and somatic nuclear transfer. Slaughterhouse-derived sow cumulus–oocyte complexes (COCs) were matured in TCM199 supplemented with 10% porcine follicle fluid, 5% cattle serum, 10 IU mL–1 eCG, 5 IU mL–1 hCG, 0.8 mm L-glutamine and 0.05 mg mL–1 gentamicin at 38.5°C, 100% humidity and 5% CO2 in air. For activation, cumulus cells were removed after 42 to 44 h of maturation, and the denuded oocytes with 1st polar body were activated with a double 160 V mm–1, 100 μs direct pulse followed by culture in PZM3. Each experiment was replicated at least three times. Data were expressed as mean ± SEM and analyzed by using chi-square module in SPSS 11.0, with P < 0.05 denoting significant difference. In Experiment 1, after preparation, liquid PZM3 was aliquoted to 50 mL falcon centrifuge tubes. Randomly, half of the tubes with PZM3 were put into –80°C freezers, and the rest were placed into 4°C refrigerator. Within one week after storage, a tube of frozen PZM3, while that stored at 4°C served as control, was warmed at 38.5°C in CO2 incubator, and more than three 4-well culture dishes were then made with 400 μL PZM3 in each well and balanced for at least 4 h in the incubator before experiment. The results showed that both cleavage (78/93, 83.9 ± 1.2% v. 87/103, 84.5 ± 1.8%, P > 0.05) and blastocyst (60/93, 65.2 ± 2.1% v. 65/103, 63.1 ± 3.8%, P > 0.05) rates were similar between frozen-warmed PZM3 and control, as was total cell numbers per blastocyst (50 ± 7 v. 47 ± 5, P > 0.05) between groups. In Experiment 2, we used somatic cloned embryos to investigate the effect of frozen-warmed PZM3 on pre-implantation development of such embryos. Our results indicated that no significant difference in rates of cleavage (68/95, 71.5 ± 5.1% v. 78/100, 78.1 ± 1.9%, P > 0.05), blastocyst formation (33/95, 34.6 ± 7.6% v. 78/100, 38.2 ± 3.5%, P > 0.05) and total cell numbers per blastocyst (40 ± 11 v. 48 ± 9, P > 0.05) was found between the test and control groups, designed the same as in Experiment 1. In Experiment 3, we tested whether PZM3 in frozen storage for 5 months was able to support in vitro development of parthenotes comparable to freshly-made ones. PZM3 after frozen storage for 5 months was warmed using the same method as Experiment 1, and the newly made PZM3 within 1 week of storage at 4°C acted as control. The results showed that although the cleavage (135/138, 97.8 ± 2.7% v. 117/129, 90.7 ± 3.1%, P > 0.05) and blastocyst (104/138, 75.4 ± 1.6% v. 84/129, 65.1 ± 2.3, P > 0.05) rates in control group were both slightly higher than that in the test group, no statistical differences was observed. We also found no significant difference in total cell numbers per blastocyst (48 ± 7 v. 46 ± 6, P > 0.05) between groups. Taken together, our results imply that frozen storage of PZM3 is feasible, and of practical value for culture pig embryos.


2005 ◽  
Vol 17 (2) ◽  
pp. 170
Author(s):  
J.-G. Kim ◽  
Y.-S. Lee ◽  
S.-L. Lee ◽  
S.-A. Ock ◽  
C.-S. Park ◽  
...  

The purpose of this study was to improve the efficiency of somatic cell nuclear transfer (SCNT) in pigs by assessing the development, cell numbers and apoptosis when using different cell types as nuclear donors and different numbers of passages. Primary cultures of the donor cells, porcine fetal fibroblasts (pFFF) from a female fetus at ∼30 days of gestation and adult female ear skin cells (pAESC), were established in DMEM + 15% FCS. For nuclear donor, cells at different passages were cultured for 5 days until confluent. Cumulus-oocyte complexes were matured and fertilized in vitro as controls by the following methods (2000 Theriogenology 54, 787–797). Following enucleation, oocytes were reconstructed by transfer of donor cells and fusion with two DC pulses (1.4 kV/cm, 50 μs) in 0.28 M mannitol containing 0.01 mM CaCl2 and MgCl2. Eggs were then cultured in NCSU23 + 1.9 mM 6-dimethylaminopurine for 3 h. SCNT and IVF embryos were cultured in NCSU23 for 54 h and subsequently in the same medium with 5.55 mM glucose for 90 h at 38.5°C in 5% CO2 in air. In Experiment 1, when the rates of development between IVF and SCNT embryos constituted with cells at 5–7 passages were compared, no significant (P < 0.05) differences were observed in the cleavage rates. The rates of blastocyst formation were significantly (P < 0.05) higher in IVF than in SCNT embryos with pFFF and pAESC (21% vs. 15% and 10%), but it did not differ between SCNT embryos. Total cell numbers in IVF blastocysts (35.4 ± 12) were significantly (P < 0.05) higher than in SCNT blastocysts with pFFF and pAESC (28.4 ± 8 and 26.2 ± 10, respectively). The apoptosis signal by TUNEL was initiated at Day 3 in IVF and SCNT embryos. Apoptosis rates in SCNT blastocysts with pFFF and pAESC (13.1 ± 2.5 and 16.6 ± 4.3, respectively) were significantly (P < 0.05) higher than in IVF embryos (3.6 ± 1.4). As the embryos developed, the rates of apoptosis were increased. On Day 6, the rates of apoptosis in IVF (4.8%) were significantly (P < 0.05) lower than those in SCNT embryos with pFFF (13.1%) and pAESC (16.6%). However, both total cell number and apoptosis in SCNT embryos with pFFF and pAESC revealed no significant differences. In Experiment 2, SCNT embryos with pFFF in different cell passages were compared for the development and apoptosis. No significant (P < 0.05) differences were observed in the cleavage rates of SCNT embryos among different cell passages. The rates of blastocyst formation were significantly (P < 0.05) higher in SCNT embryos with 5–7 passages than those with other numbers of passages (14% vs. 6–8%, respectively). Although total cell numbers of SCNT blastocysts did not differ among different cell passages, apoptosis rates were significantly (P < 0.05) higher when the number of cell passages was increased. These results suggest that fetal fibroblasts at 5–7 passages are ideal nuclear donor cells for obtaining high-quality porcine SCNT embryos. This work was supported by grant No. 1000520040020000 from Biogreen 21, Republic of Korea.


2013 ◽  
Vol 25 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Castillo-Martín ◽  
M. Yeste ◽  
R. Morató ◽  
T. Mogas ◽  
S. Bonet

The benefits of adding l-ascorbic acid during the cryopreservation procedure have been reported before in mouse and bovine. In this study, the effects of l-ascorbic acid (AC) supplementation during culture, cryopreservation, or both procedures on the developmental ability and embryo quality of in vitro produced porcine blastocysts were examined. Embryo quality criteria consisted of total cell number, percentage of apoptosis, and cryotolerance. After in vitro fertilisation, presumptive zygotes were randomly assigned to 2 culture treatments in which the culture medium NCSU23 was supplemented with 100 µM AC (n = 1162) or nonsupplemented (n = 1163) for a 144-h period. On Day 6, blastocyst formation was assessed by stereomicroscopy, and a representative fraction of Grade I- and II-blastocysts of each culture treatment was evaluated using 4′,6-diamidino-2-phenylindole-TUNEL co-staining and considered as fresh-control. The remaining fraction of Grade I- and II-blastocysts was vitrified/warmed following the Cryotop® method. To determine the effect of AC supplementation during cryopreservation procedures, each culture treatment was divided into 2 groups: (1) embryos exposed to 100 µM AC, and (2) nonexposed embryos (vitrified-control). Survival was determined according to reexpansion rates after 24 h of recovery in NCSU23 medium. After 24 h, reexpanded blastocysts were co-stained using the 4′,6-diamidino-2-phenylindole-TUNEL technique, and total number of cells and apoptosis indexes were determined. Experiment was replicated 9 times for each group. Data were analyzed by t-test for independent variables and a 2-way ANOVA. Results are expressed as means ± SE, and the significant level was set at 5% (Table 1). After culture, supplementing NCSU23 medium with AC showed no significant differences in blastocyst formation (fresh-control 11.6 ± 7.8 v. AC 11.6 ± 7.7), in number of cells (fresh-control 36.7 ± 15.8 v. AC 36.1 ± 15.9), or in apoptosis index (fresh-control 2.9 ± 5.7 v. AC 3.5 ± 4.7). On the other hand, only when both culture and vitrified media were supplemented with AC was there a significant increase of blastocyst survival. In contrast, no significant differences in embryo survival were observed when only 1 of these 2 media (culture or vitrification) was supplemented. Supplementing culture media or cryopreservation solutions with AC did not affect the total cell number or apoptosis index in vitrified blastocysts. In conclusion, the addition of 100 µM l-ascorbic acid to the culture and cryopreservation solutions improves the cryotolerance of in vitro-produced porcine blastocysts. Table 1.Survival of blastocysts (24 h), total cell number, and percentage of apoptosis after vitrification/warming


2009 ◽  
Vol 21 (1) ◽  
pp. 158
Author(s):  
K. Lee ◽  
C. Wang ◽  
D. Miller ◽  
Z. Machaty

Resveratrol (3,4′,5-trihydroxystilbene) is a phytoalexin present in a variety of dietary sources including grapes, plums and peanuts. It was shown to exert a wide variety of pharmacological activities ranging from anti-inflammatory effects to immunomodulation and chemoprevention. The aim of this study was to investigate the effect of resveratrol on porcine embryo development. In vitro-matured pig oocytes were activated by two direct current electric pulses (60 μ seconds each) followed by an incubation with 10 μg mL–1 cycloheximide and 7.5 μg mL–1 cytochalasin B, for 5 h. Activated oocytes (in groups of 10) were then placed in 20 μL drops of Porcine Zygote Medium 3 (PZM-3) supplemented with various concentrations of resveratrol (0 μm, 0.5 μm, 25 μm) and cultured for 7 days. The frequency of blastocyst formation in each group was recorded and compared by Chi-square test; the total cell numbers of the blastocysts from the two best groups (control and 0.5 μm) were counted and compared by Student’s t-test. In addition, expression levels of three genes related to apoptosis (Bax, Bcl-2, and Caspase-3) were quantified in the blastocysts by quantitative real-time RT-PCR. The analysis was repeated three times, and differences in gene expression were compared by ANOVA. Differences at P < 0.05 were considered significant. Incubation of parthenotes with 25 μm resveratrol decreased blastocyst formation from 28.1% (n = 89; control group) to 4.5% (n = 66; P < 0.05). However, when parthenogenetic embryos were cultured in the presence of 0.5 μm resveratrol, blastocyst formation increased significantly: whereas only 33.0% of control embryos (n = 312) reached the blastocyst stage, this percentage in the resveratrol-treated group was 43.5% (n = 301; P < 0.05). The average total cell numbers in control and 0.5 μm resveratrol-treated blastocysts were 42.4 ± 2.1 and 44.0 ± 1.9, respectively; the difference was not statistically significant. Finally, lower expression of the Bcl-2 and Caspase-3 genes was observed in the embryos cultured with 0.5 μm resveratrol. Evidences indicated that resveratrol has a dose-dependent effect on cells. At high concentrations resveratrol exerted an antiproliferation effect, whereas at low concentration it promoted cell division. In this study a similar dose-dependent effect of resveratrol was found. The presence of 25 μm resveratrol had a negative effect on embryonic development. However, 0.5 μm resveratrol in the culture medium induced higher blastocyst formation compared with the control group. The presence of resveratrol also affected expression levels of genes related to apoptosis. Decreased levels of Bcl-2 suggest that resveratrol may suppress the mitochondria-related anti-apoptotic activity; whereas down-regulated Caspase-3 indicates a decreased apoptotic activity in the embryos treated with resveratrol. Our results suggest that the treatment of pig embryos with 0.5 μm of resveratrol has a beneficial effect on preimplantation development leading to improved blastocyst formation. The impact of resveratrol on apoptosis needs further investigation.


Zygote ◽  
2007 ◽  
Vol 15 (2) ◽  
pp. 93-102 ◽  
Author(s):  
M. Kobayashi ◽  
S. Asakuma ◽  
Y. Fukui

SummaryThe present study was carried out to establish porcine defined IVP. In Experiments 1 and 2, we investigated the efficacy of additional 0.6 mM cystine and/or 100 µM cysteamine (Cys) to a defined TCM199 maturation medium with regard to the intracellular glutathione (GSH) concentration and the developmental competence of in vitro matured porcine oocytes following intracytoplasmic sperm injection (ICSI). The control medium was a modified TCM199 containing 0.05% (w/v) polyvinyl alcohol (PVA). Cys and/or cystine were added to the control medium. The control group and immature oocytes (presumptive germinal vesicle oocytes; GV) were prepared for GSH assay. In Experiment 3, the efficacy of epidermal growth factor (EGF) addition to a modified porcine zygote medium (mPZM) for in vitro culture (IVC) medium was investigated on embryonic development and the mean cell number of blastocysts following ICSI. As a positive or negative control, 0.3% BSA (mPZM-3) or 0.3% PVA (mPZM-4), respectively, was added to the base medium. The defined IVC medium was supplemented with 5 or 10 ng/ml EGF. In Experiment 1, no significant difference was found in the rates of cleavage (31.4–64.3%) and blastocyst formation (6.5–22.9%) among the treatment and control groups. The mean cell numbers per blastocyst ranged from 30 to 48 among the groups without significant differences. However, in Experiment 2, the intracellular GSH concentrations in the oocytes cultured in the medium supplemented with 100 µM Cys (9.6 pmol/oocyte) or Cys + cystine (9.9 pmol/oocyte) were significantly (p < 0.05) higher than the control (2.5 pmol/oocyte) and 0.6 mM cystine (6.5 pmol/oocyte) groups, but not different from the GV group (9.0 pmol/oocyte). The GSH concentration in the cystine group was also significantly (p < 0.05) higher than that in the control group, but not different from the GV group. In Experiment 3, the rates of cleavage and blastocyst formation and the mean cell numbers of blastocysts were not significantly different among the groups. However, the addition of 5 ng/ml EGF into the mPZM-4 resulted in a significantly (p < 0.05) higher blastocyst rate per cleaved embryo than the other two defined groups (mPZM-4 + 5 ng/ml: 48.6%, mPZM-4 and mPZM-4 +10 ng/ml: 23.4% and 23.1%, respectively).The present results indicate that the addition of Cys to a defined medium for in vitro maturation (IVM) of porcine oocytes increases intracellular GSH concentration. Further addition of cystine into the IVM medium containing 100 µM Cys is not necessary and TCM199 plus Cys (100 µM) could be used as a defined IVM medium for porcine oocytes. The addition of 5 ng/ml EGF to a defined IVC medium has enhanced subsequent development after ICSI. This study shows that porcine blastocysts can be produced by defined media throughout the steps of IVP (IVM, ICSI and IVC).


2010 ◽  
Vol 22 (1) ◽  
pp. 183
Author(s):  
T. H. C. De Bem ◽  
P. R. Adona ◽  
R. Rochetti ◽  
F. F. Bressan ◽  
M. S. Miranda ◽  
...  

In vitro embryo production by somatic cell nuclear transfer (SCNT) still presents low efficiency and blastocyst production rates are around 20%. Pre-maturation with cell cycle inhibitors is one alternative that has been studied to improve oocyte competence for use in in vitro production systems. The neurotrophin brain-derived neurotrophic factor (BDNF) has been reported to improve oocyte maturation. The aim of this work was to optimize the in vitro pre-maturation culture of bovine oocytes and its use in SCNT. Oocytes that were submitted to meiosis block before IVM (BL group) were cultured in TCM-199 medium supplemented with 10 ng mL-1 BDNF and 10 μM butyrolactone I for 24 h and then matured in IVM medium (TCM-199, 10% FCS, 0.5 μg mL-1 FSH, 5.0 μg mL-1 LH, 2.0 mM pyruvate, and 50 μg mL-1 gentamicin). Control oocytes (control group) were matured in IVM medium. After 19 h of IVM, oocytes from both groups were denuded with 0.2% hyarulonidase, enucleated, and reconstructed. Reconstructed embryos were chemically activated with ionomycin (5 min) and 6-DMAP (3h) and cultured in vitro in SOF medium for 7 or 8 days. Statistical analyses were performed by using BIOSTATS v.4.0 software. In vitro development variables [1st polar body (PB), fusion, cleavage, and blastocyst rates on Days 7 and 8] and in vivo development rates on Days 35, 60, 90, and 120 of pregnancy were analyzed by chi-square test. Total cell numbers and cells with fragmented DNA were analyzed by ANOVA. A level of 5% significance was considered. Extrusion of 1st PB (BL: n = 693; 69.3% and control: n = 639; 63.5%) and fusion rates (BL: n = 397; 79.2% and control: n = 345; 72.9%) were higher (P < 0.05) in the BL group. There were no differences between treatments for cleavage rates (BL: n = 268; 67.5% and control: n = 228; 66.1%) or blastocyst rates on Day 7 (BL: n = 77; 19.4% and control: n = 69; 20.0%) and Day 8 (BL: n = 81; 20.4% and control: n = 73; 21.2%). Cloned blastocysts from both groups were submitted to TUNEL reaction (Day 8 blastocysts, n = 15 for BL and control groups) for DNA fragmentation analysis or were transferred to synchronized recipients (Day 7 blastocysts, n = 26 and n = 28 for BL and control groups, respectively) for in vivo development analysis. No differences were observed (P > 0.05) between BL and control groups for total cell numbers (n = 127 and n = 138, respectively) and cells with fragmented DNA (0.0209 and 0.0188, respectively). Pregnancy rates at 35 (BL: n = 5; 19.2% and control: n = 9; 32.1%), 60 (BL: n = 3; 11.5 and control: n = 3; 10.7), 90 (BL: n = 3; 11.5 and control; n = 3; 10.7), and 120 days (BL: n = 3; 11.5 and control: n = 3; 10.7) also did not differ (P > 0.05) between treatments. In conclusion, pre-maturation enhanced 1st PB extrusion and fusion rates of oocytes submitted to SCNT, and moreover, it was able to establish pregnancies until 120 days, similarly to the control group. Financial support: FAPESP and CNPQ, Brazil.


Zygote ◽  
2016 ◽  
Vol 24 (6) ◽  
pp. 890-899 ◽  
Author(s):  
A.L.S. Guimarães ◽  
S.A. Pereira ◽  
M. N. Diógenes ◽  
M.A.N. Dode

SummaryThe aim of this study was to evaluate the effect of adding a combination of insulin, transferrin and selenium (ITS) and l-ascorbic acid (AA) during in vitro maturation (IVM) and in vitro culture (IVC) on in vitro embryo production. To verify the effect of the supplements, cleavage and blastocyst rates, embryo size and total cell number were performed. Embryonic development data, embryo size categorization and kinetics of maturation were analyzed by chi-squared test, while the total cell number was analyzed by a Kruskal–Wallis test (P < 0.05). When ITS was present during IVM, IVC or the entire culture, all treatments had a cleavage and blastocyst rates and embryo quality, similar to those of the control group (P < 0.05). Supplementation of IVM medium with ITS and AA for 12 h or 24 h showed that the last 12 h increased embryo production (51.6%; n = 220) on D7 compared with the control (39.5%; n = 213). However, no improvement was observed in blastocyst rate when less competent oocytes, obtained from 1–3 mm follicles, were exposed to ITS + AA for the last 12 h of IVM, with a blastocyst rate of 14.9% (n = 47) compared with 61.0% (n = 141) in the control group. The results suggest that the addition of ITS alone did not affect embryo production; however, when combined with AA in the last 12 h of maturation, there was improvement in the quantity and quality of embryos produced. Furthermore, the use of ITS and AA during IVM did not improve the competence of oocytes obtained from small follicles.


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