332 EFFECT OF DIFFERENT PIG OOCYTE ACTIVATION PROTOCOLS ON EMBRYO DEVELOPMENT IN SOF AND NCSU-23

2007 ◽  
Vol 19 (1) ◽  
pp. 281 ◽  
Author(s):  
I. Lagutina ◽  
G. Lazzari ◽  
C. Galli

Several factors affect nuclear transfer success. These include efficient parthenogenetic activation and embryo culture medium that should efficiently support pre-implantation development of good quality blastocysts. We investigated pig oocyte activation and embryo development in SOFaa in response to ionomycin (Io = 5 µM Io for 4 min; Io° = 15 µM Io for 20 min) and electric impulse (EL; one 30-µs pulse of DC 1.5 kV cm−1 in the presence of 50 µM Ca) in combination with 2 mM 6-DMAP or 10 µg mL−1 cycloheximide (CHX) +5 µg mL−1 cytochalasin B (CB) for 4 h. In addition, we studied the effect of elevated (1 mM) (Cheong et al. 2002 Mol. Reprod. Dev. 61, 488) in comparison with 50 µM Ca during EL activation on embryo development in SOFaa and NCSUaa-23. Porcine oocytes were recovered from slaughtered donors and matured in vitro for 44 h in DMEM-F12 supplemented with 10% FCS, 0.05 IU LH and FSH (Menogon®, Ferring, Milan, Italy), 0.3 mM cystine, 0.5 mM cysteamine, 50 ng mL−1 long-EGF, 100 ng mL−1 long-IGF1, 5 ng mL−1 bFGF (Sigma-Aldrich, Milan, Italy) in 5% CO2 at 38.5°C. The rates of cleavage, blastocyst formation (BL) and BL cell number on Day 7 (BL-D7) were recorded. All experiments were done with 3 replicates. The data were compared by chi-square test. There was no difference in the ability of Io (all groups) and EL + CB activated oocytes to cleave, whereas the additional treatment of EL-activated oocytes with DMAP and CHX + CB significantly increased cleavage. Io activation resulted in poor blastocyst development in comparison with all EL-activated groups (see Table 1). When calcium levels were elevated during EL activation, significantly more embryos developed in SOFaa (35.6%, n = 191 vs. 26%, n = 192; P < 0.05), but no differences were observed with culture in NCSUaa-23 (about 56%). The BL rate was significantly higher in NCSUaa-23 vs. SOFaa (55.9%, n = 68 vs. 34.8%, n = 69, respectively); however, the BL total cell number was significantly higher in SOFaa (58 ± 18, n = 40 vs. 86 ± 35, n = 56, respectively; P < 0.05). In conclusion, we have found that SOFaa and NCSUaa-23 differ in ability to support pig parthenogenetic embryo development. EL activation combined with elevated Ca significantly increased the embryo developmental capacity in SOFaa but not in NCSUaa-23. NCSUaa-23 was more efficient for embryo culture, whereas SOF produced BLs of higher quality. Table 1.Effect of activation protocol on the development of pig parthenogenetic embryos in SOFaa This work was supported by grants ISS-CS11 and Fondazione Cariplo.

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Haixia Wang ◽  
Wenbin Cao ◽  
Huizhong Hu ◽  
Chenglong Zhou ◽  
Ziyi Wang ◽  
...  

Summary Many studies have focused on the optimization of the composition of embryo culture medium; however, there are few studies involving the effect of a culture medium changing procedure on the preimplantation development of embryos. In this study, three groups were designed: a non-renewal group, a renewal group and a half-renewal group. The levels of reactive oxygen species (ROS), apoptotic index, blastocyst ratio and blastocyst total cell number were analyzed in each group. The results showed that the ROS level and the apoptotic index of blastocyst in the non-renewal group were significantly higher than in the renewal group and the half-renewal group (P < 0.05). The blastocyst ratio and blastocyst total cell number were significantly higher in the half-renewal group than that in non-renewal group and the renewal group (P < 0.05). These results demonstrated that the procedure of changing the culture medium influenced ROS level, apoptotic index, blastocyst ratio and total cell number of blastocysts. In addition, the result suggested that changing the culture medium may lead to a loss of important regulatory factors for embryos, while not changing the culture medium may lead to the accumulation of toxic substances. Half-renewal can alleviate the defects of both no renewal and renewal, and benefit embryo development. This study will be of high value as a reference for the optimization of embryo culture in vitro, and is very significant for assisted reproduction.


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

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


2009 ◽  
Vol 21 (1) ◽  
pp. 131 ◽  
Author(s):  
M. De Blasi ◽  
E. Mariotti ◽  
M. Rubessa ◽  
S. Di Francesco ◽  
G. Campanile ◽  
...  

Despite the increasing interest, buffalo oocyte cryopreservation is still inefficient, especially in terms of blastocyst development after IVF. The aim of this work was to evaluate chromatin and spindle organization of buffalo in vitro-matured oocytes after vitrification/warming by cryotop and after their simple exposure to cryoprotectants (CP). An overall amount of 251 COC was selected and matured in vitro. In the vitrification group, COC were first exposed to 10% ethylene glycol (EG) + 10% DMSO for 3 min, and then to 20% EG + 20% of DMSO and 0.5 m sucrose, loaded on cryotops, and plunged into liquid nitrogen within 25 s. Oocytes were warmed into a 1.25 m sucrose solution for 1 min and then to decreasing concentrations of sucrose (0.625 m, 0.42 m, and 0.31 m) for 30s each. In order to test CP toxicity, COC were simply exposed to the vitrification and warming solutions. Two hours after warming, oocytes were fixed and immunostained for microtubules using a method previously described (Messinger SM and Albertini DF 1991 J. Cell Sci. 100, 289–298), stained for nuclei with Hoechst, and examined by fluorescence microscopy. Fresh in vitro-matured oocytes were fixed and stained as controls. Data were analyzed by chi-square test; results are shown in Table 1. The percentages of MII oocytes in the control and vitrification groups were greater than in the toxicity group, in which a greater percentage of telophase II stage oocytes were found compared with both the control and vitrification groups, indicating occurrence of activation. Of the MII oocytes, both exposure to CP and vitrification procedures gave greater percentages of oocytes with abnormal spindle and abnormal chromatin configuration compared with the control. An unexpected datum was the evidence of a significant percentage of spontaneously activated oocytes in the toxicity group. We speculate that the lack of activation in the vitrification group may be related to the slowing down of metabolic activity subsequent to thermal shock, and hence, that activation after vitrification may occur later than 2 h post-warming. In conclusion, the simple exposure to CP causes activation of the COC and damage to the cytoskeleton similar to that induced by the whole vitrification protocol. The damages to the meiotic spindle and DNA fragmentation may lead to aneuploidy incompatible with subsequent embryo development and account for the poor embryo development currently recorded in buffalo. Table 1.Chromatin and spindle organization in oocytes vitrified and exposed to cryoprotectants


2010 ◽  
Vol 22 (1) ◽  
pp. 184
Author(s):  
A. Gambini ◽  
J. Jarazo ◽  
R. Olivera ◽  
D. Salamone

The availability of viable equine oocytes is a limiting factor on in vitro embryo production; therefore, it is necessary to assess some of the variables that affect oocyte viability. The aim of our study was to evaluate one of those variables: the effect of time between the collection of the ovary and oocyte in vitro maturation. Ovaries of slaughtered mares were collected during the breeding season (Argentine, Southern hemisphere). They were separated in bags every half hour and treated separately after arriving at the laboratory. COCs were recovered by a combination of scraping and washing of all visible follicles with a syringe filled with DMEM supplemented with 1 mM sodium pyruvate and 15 IU mL-1 heparin. COCs were matured for 24 to 26 h in 3 groups, according to time interval: 4 to 7 (group I), 7 to 10 (II), and 10 to 12 (III) hours. The medium for maturation was TCM-199 supplemented with 10% fetal bovine serum (FBS), 1 μL mL-1 insulin-transferrin-selenium, 1 mM sodium pyruvate, 100 mM cysteamine, and 0.1 mg mL-1 of FSH at 39°C in a humidified atmosphere of 5% CO2 in air. The cumulus was removed by a trypsin treatment and vortexing in hyaluronidase (1 mg mL-1). Cloning and fusion procedures were performed following the zona-free technique described by Lagutina et al. (2007 Theriogenology 67, 90-98). Two experiments were carried out by using different activation protocols. In experiment 1, the activation process was 22 mM ionomycin in H-TALP for 4 min followed by 3h culture in 1.9 mM 6-DMAP in SOF, whereas in experiment 2, we used 8.7 mM ionomycin in H-TALP for 4 min followed by 4 h culture in 1 mM 6-DMAP and 10 mg mL-1 cycloheximide in SOF. Embryos were cultured in wells of well (WOW) system. Half of the medium was renewed on Day 3 with fresh SOF and on Day 5 with DMEM/F12 with 10% FBS. Cleavage was assessed 48 h after activation; the rate of blastocyst formation was recorded at Days 8 and 9. Results were compared using chi-square test (P < 0.05). In experiment 1, maturation rates were significantly different between group I (n = 135, 54.1%) and III (n = 94, 40.4%), group II did not differ from them (n = 138, 53%). Cleavage rates differed statistically between II (n = 44, 75%) and III (n = 27, 40.7%), but not with group I (n = 53, 98%). No significant differences were found in blastocyst development; however, we observed a certain tendency towards an increase in the blastocyst rate as the time interval was lower (I: 3/53, 5.7%; II: 1/44, 2.3%; III: 0/27, 0%). In experiment 2, there were no significant differences between group I and II in rates of maturation (n = 56, 59% v. n = 111, 44.5%), cleavage (n = 22, 91% v. n = 34, 82%) or blastocyst rates (1/22, 4.5% v. 7/34, 20.6%). We conclude that cloned equine embryo development, using the two activation protocols tested, is not affected when the time interval between ovary collection and oocyte IVM is within 4 to 10 h.


2007 ◽  
Vol 19 (1) ◽  
pp. 256
Author(s):  
W. J. Son ◽  
M. K. B. ◽  
Y. J. Jeong ◽  
S. Balasubramanian ◽  
S. Y. Choe ◽  
...  

Various factors are known to influence the survival and development of in vitro-produced embryos, including co-culture with somatic cells, antioxidants, and O2 tension. Studies in several species report that embryo development and quality were enhanced at low O2 concentrations. This study compared the effects of 2 O2 concentrations on IVP embryo development, embryo quality, and gene expression to those of in vivo counterparts. Cumulus–oocyte complexes were matured in vitro in TCM-199 with hormones and 10% FCS, and inseminated in TALP medium. Presumptive zygotes were cultured in SOF medium under either 5% or 20% O2 in air. In triplicate, sets of 5 embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula, and Day 7 blastocyst stages were used for analyzing the expression patterns of apoptotic (Bax and Bcl2), metabolism (Glut-1 and Glut-5), stress (Sox, Hsp70, and G6PDH), compaction (Cx43), oxidation (PRDX5, NADH, and MnSOD), and implantation (VEGF and IFN-tau) genes using real-time quantitative PCR. The expression of each gene was normalized to that of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Statistical analysis was performed with Bonferroni and Duncan tests by ANOVA (P &lt; 0.05). Cleavage rates did not differ among groups. Blastocyst and hatched blastocyst development in 5% O2 was significantly (P &lt; 0.05) higher than in 20% O2. Total cell number of in vivo blastocysts was significantly (P &lt; 0.05) higher than that of IVP blastocysts. ICM ratio and apoptosis of in vivo blastocysts were significantly (P &lt; 0.05) lower than for IVP blastocysts. The relative abundances (RAs) of Glut-1, Glut-5, MnSOD, NADH, PRDX5, Cx43, Bcl2, and IFN-τ were significantly (P &lt; 0.05) higher in in vivo embryos, whereas the RAs of Sox, G6PDH, Hsp70, Bax, and VEGF were significantly (P &lt; 0.05) lower than for IVP counterparts. In conclusion, culture at 5% O2 concentration resulted in higher rates of development to the blastocyst stage, higher total cell numbers, and decreased apoptosis. Furthermore, differences in expression of genes including Glut-1, Glut-5, Sox, G6PDH, Hsp70, Bax, Bcl2, Cx43, PRDX5, NADH, MnSOD, VEGF, and IFN-τ may prove useful in determining optimal culture conditions. This work was supported by ARPC (204119-03-SB010), Republic of Korea.


2007 ◽  
Vol 19 (1) ◽  
pp. 302
Author(s):  
C. Kani ◽  
M. Takenaka ◽  
T. Muneto ◽  
M. Yamamoto ◽  
T. Horiuchi

In vitro spermatogenesis can be applied to generate spermatids or spermatozoa and produce a genetically modified male germ line. Intracytoplasmic injection of the spermatids or spermatozoa is an important technique for effective production of offspring. The objective of this study is to evaluate oocyte-activation capacity of bovine spermatids or spermatozoa and to determine the effective activation treatment for in vitro development of bovine oocytes injected with round spermatids. Cryopreserved testicular spermatogenic cells and cauda epididymal spermatozoa obtained from a 1-year-old Japanese bull were used. In the first experiment, we injected bovine round (ROS) and elongated (ELS) spermatids, or testicular (TES) and cauda epididymal (CES) spermatozoa into mouse oocytes to examine their oocyte-activating capacity. The presence of pronuclei within whole-mounted oocytes was observed 4 h after injection. In the second experiment, we injected similar spermatids and spermatozoa into bovine oocytes without additional activation, and examined cleavage and blastocyst development. In the third experiment, bovine oocytes injected with ROS were activated with 7% ethanol or 5 �M ionomycin for 5 min (1 � Et or 1 � Iono) immediately after injection; some were further activated repeatedly at 3 h after injection (2 � Et or 2 � Iono), and some of these were subjected to 1.9 mM 6-dimethylaminopurine (DMAP) for 3 h after the second activation (2 � Et + DMAP or 2 � Iono + DMAP). Data were analyzed by the chi-square test in all experiments. The vast majority of bovine ROS failed to activate mouse oocytes (activation rate 10%). Activation rates of mouse oocytes injected with bovine ELS, TES, and CES were 61%, 75%, and 91%, respectively. The results suggest that oocyte-activation capacity is acquired during transformation from ROS to ELS. Cleavage and blastocyst rates of bovine oocytes injected with CES (59% and 19%, respectively) were significantly higher (P &lt; 0.05) than the rates obtained with injections of TES (37% and 9%) and ROS (5% and 0%) without additional activation. However, cleavage and blastocyst rates of bovine oocytes injected with ROS in the groups of 2 � Et + DMAP (80% and 19%) and 2 � Iono + DMAP (76% and 19%) were significantly higher (P &lt; 0.05) than those in the groups of 1 � and 2 � Et (37% and 2%, 59% and 4%), 1 � and 2 � Iono (10% and 7%, 22% and 4%), or those receiving a sham injection and activated with 2 � Iono + DMAP (43% and 4%). These results demonstrate that intracytoplasmic injection of ROS with repeated Et or Iono activation followed by DMAP treatment is more efficient than single or double Et or Iono activation.


2007 ◽  
Vol 19 (1) ◽  
pp. 210
Author(s):  
D. W. Linck ◽  
D. K. Gardner

Recently, there has been much debate involving the time necessary to effectively equilibrate an embryo culture system, i.e. dishes, media, and oil. Glutamine present in the culture medium spontaneously deaminates at 37�C to release embryo-toxic ammonium. Additionally, the source of the oil overlay can impact the culture environment. A sub-optimal oil overlay, combined with free glutamine (Gln), could effectively become embryo-toxic over a short time period (&lt;48 h). Therefore, the aim of this study was to determine how times of media equilibration, using various combinations of oil source and type of Gln, affect embryo development. Zygotes were collected from 4-week-old CF1 outbred female mice following superovulation and mating. Embryos were cultured in groups of 10 in 20-�L drops of medium G1.2. Initially, embryos were cultured in one of 4 treatment media. In this 2 � 2 factorial design, the culture medium was pre-equilibrated 18 h prior to embryo retrieval and contained free Gln or the heat-stable dipeptide alanyl-glutamine (AlaGln), combined with an oil source of either Sigma mineral oil (Sigma-Aldrich Corp., St Louis, MO, USA) or Ovoil paraffin oil (Vitrolife, Inc., Englewood, CO, USA). The initial study was then repeated using only the best and worst case groups to determine the effect of incubation time as a variable (either 2 h or 18 h). Blastocyst development and total cell numbers were analyzed after 72 h of culture, and differences between treatments were assessed using Fisher&apos;s exact test and Student&apos;s t-test. After 18 h of pre-equilibration (n e 300 embryos/treatment), blastocyst development in Ovoil + AlaGln (38.6%) was significantly greater when compared to: Ovoil + Gln: 25.5% (P &lt; 0.01), Sigma + AlaGln: 12.8% (P &lt; 0.01), and Sigma + Gln: 11.9% (P &lt; 0.01). Additionally, the total cell numbers in comparison to Ovoil + AlaGln (44.6 � 10) were significantly decreased: 35.5 � 7 (P &lt; 0.001), 34.9 � 9 (P &lt; 0.001), and 29.9 � 9 (P &lt; 0.001), respectively. In the second experiment, blastocyst development and total cell number between Ovoil + AlaGln (n = 224) and Sigma + Gln (n = 264) after 18 h of pre-equilibration were: 40.4% vs. 9.9% (P &lt; 0.01) and 46.6 � 9 vs. 29.4 � 9 P &lt; 0.001), respectively. However, after 2 h of pre-equilibration, the results between Ovoil + AlaGln (n = 260) and Sigma + Gln (n = 284) were: 42.3% vs. 18.3% (P &lt; 0.01) and 46.9 � 10 vs. 33.6 � 6 (P &lt; 0.001), respectively. Therefore, when comparing blastocyst development and total cell number between pre-equilibration times (2 h vs. 18 h), the Ovoil + AlaGln group, 42.3% vs. 40.4% and 46.9 � 10 vs. 46.6 � 9, showed no significant differences, respectively. In contrast, the Sigma + Gln group produced significant differences for both blastocyst development, 18.3% vs. 9.9% (P &lt; 0.01), and total cell number, 33.6 � 6 vs. 29.4 � 9 (P &lt; 0.05), between pre-equilibration times (2 h vs. 18 h), respectively. Data presented confirm the need for an alternative source of glutamine in embryo culture media. The data also indicate that the source of oil has a profound effect on the experimental outcome. Using the appropriate oil and form of Gln means that media can be safely equilibrated for 18 h.


2019 ◽  
Vol 97 (12) ◽  
pp. 4946-4950 ◽  
Author(s):  
Lydia K Wooldridge ◽  
Madison E Nardi ◽  
Alan D Ealy

Abstract Deficiencies in current embryo culture media likely contribute to the poor blastocyst development rates and pregnancy retention rates for in vitro produced (IVP) bovine embryos. Of special concern is the lack of micronutrients in these media formulations. One micronutrient of interest is zinc, an essential trace element involved with various enzyme and transcription factor activities. The objective of this work was to describe whether zinc sulfate supplementation during in vitro embryo culture affects bovine embryo development and blastomere numbers. Either 0, 2, 20, or 40 µM zinc sulfate was supplemented to presumptive zygotes cultured in synthetic oviductal fluid containing AAs and bovine serum albumin for 8 d. None of the treatments affected cleavage rates. Percentage of blastocysts on days 7 and 8 postfertilization was not affected by supplementing 2 or 20 µM zinc but were reduced (P &lt; 0.05) with 40 µM zinc. In blastocysts harvested on day 8, inner cell mass (ICM) and total cell number were increased (P &lt; 0.05) with 2 µM zinc supplementation but not with the other zinc concentrations. Numbers of trophectoderm cells were not affected by zinc treatment. In conclusion, supplementing zinc during bovine embryo culture did not impact blastocyst development but improved ICM cell numbers. This improvement in ICM cell number may have implications for improved pregnancy retention rates after IVP embryo transfer as smaller ICM sizes are associated with poor pregnancy success in cattle.


2014 ◽  
Vol 26 (1) ◽  
pp. 138 ◽  
Author(s):  
A. Ruiz ◽  
P. J. Hansen ◽  
J. Block

The overall objective was to determine the effects of addition of lipid metabolic regulators during embryo culture on blastocyst development and survival following cryopreservation. For Experiment 1, embryos produced in vitro were cultured in 5% (vol/vol) oxygen in SOF-bovine embryo 1 (SOF-BE1) medium supplemented with or without 100 μM trans-10,cis-12 conjugated linoleic acid (CLA) and 0.3 μM phenazine ethosulfate (PES). Treatment with CLA began at the initiation of culture, whereas treatment with PES began at Day 3 after insemination. At Day 7 after insemination, the proportion of oocytes that developed to the blastocyst and advanced blastocyst (expanded, hatching, or hatched) stages was recorded. Blastocysts and expanded blastocyst-stage embryos were harvested and slow frozen in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h in SOF-BE1 medium containing 10% (vol/vol) fetal bovine serum and 50 μM dithiothreitol. Re-expansion and hatching rates were recorded at 24, 48, and 72 h. Addition of CLA had no effect on embryo development, whereas PES reduced (P < 0.01) development to the blastocyst (26.0 ± 0.8 v. 22.1 ± 0.8%) and advanced blastocyst (19.2 ± 0.9 v. 14.4 ± 0.9%) stages. Blastocysts cultured in the presence of CLA had higher (P < 0.05) re-expansion rates at 24, 48, and 72 h (50.8 ± 3.7 v. 65.7 ± 3.7%, 57.2 ± 4.0 v. 72.0 ± 4.05%, and 57.2 ± 4.0 v. 72.0 ± 4.0%, respectively). Addition of CLA tended (P < 0.07) to increase the hatching rate at 24 h and did increase (P < 0.05) the hatching rate at 48 h (12.4 ± 1.3 v. 16.2 ± 1.3% and 39.0 ± 3.2 v. 50.0 ± 3.2%, respectively). Treatment with PES had no effect on re-expansion rates but reduced (P < 0.05) hatching rates at 24 and 48 h (18.2 ± 1.3 v. 10.3 ± 1.3 and 50.2 ± 3.2 v. 38.8 ± 3.2%, respectively). There was no interaction between CLA and PES affecting embryo development or cryosurvival. For Experiment 2, embryos were produced in vitro as in Experiment 1 and cultured in SOF-BE1 medium with or without 3.03 mM L-carnitine (LC) and 10 μM forskolin (FK). Treatment with LC began at the initiation of culture and treatment with FK began at Day 6. All other methods were as described for Experiment 1. Addition of LC did not affect development to the blastocyst stage but reduced (P < 0.05) development to the advanced blastocyst stage (21.0 ± 1.2 v. 17.1 ± 1.2%). Treatment with FK had no effect on embryo development to the blastocyst or advanced blastocyst stages. Blastocysts cultured in the presence of LC had increased (P < 0.05) re-expansion rates at 24, 48, and 72 h (60.2 ± 2.0 v. 78.0 ± 2.0%, 62.9 ± 1.2 v. 83.3 ± 1.2%, and 63.0 ± 2.4 v. 82.8 ± 2.4%, respectively) and hatching rates at 48 and 72 h (48.6 ± 4.3 v. 64.1 ± 4.3% and 59.6 ± 3.0 v. 78.5 ± 3.0%, respectively). There was no effect of FK on cryosurvival and no interaction between LC and FK affecting embryo development or cryosurvival. In conclusion, blastocyst yield was not improved by any of the lipid metabolic regulators tested. Cryosurvival was enhanced by addition of CLA and LC but FK reduced survival following freezing. There were no additive effects of either CLA and PES or LC and FK for blastocyst yield or cryosurvival.Support was provided by USDA AFRI Grant 2010-85122-20623.


Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 615-621 ◽  
Author(s):  
Junhe Hu ◽  
Chenzhong Jin ◽  
Hui Zheng ◽  
Qinyan Liu ◽  
Wenbing Zhu ◽  
...  

SummaryPrevious studies have reported that the first polar body (PB1) morphology reflects embryo development competence, but the effects of PB1 on porcine embryo development remain unknown. This study aims to determine whether the ability of porcine embryo development is related to oocytes’ PB1 in vitro. The distribution of type II cortical granules (CGs) of porcine matured oocytes in grade B PB1 is significantly greater compared with those in grades A and C PB1 (71.43% versus 52.46% and 50%; P < 0.05). The ratio of porcine parthenogenetic blastocysts and the mean cell number in each blastocyst in the group with grade B PB1 is significantly greater than that with grades A and C PB1 (30.81% vs. 19.02% and 15.15%; P < 0.05) and (36.67 versus 24.67, 28.67; P < 0.05), and no significant differences are found in the embryo cleavage for all groups (79.75%, 84.30%, and 78.18% in grades A, B, and C PB1; P > 0.05). The acetylation level of porcine embryos in the group with grade B PB1 is significantly greater compared with those in the other groups (P < 0.05), and is almost 2.5 times higher than that in grade A. Therefore, porcine oocytes with PB1 in grade B are more competitive in cytoplasmic maturation and further embryo development in vitro.


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