95 DEVELOPMENT OF PORCINE TWO-CELL EMBRYOS WITH OR WITHOUT ZONA PELLUCIDA AND SINGLE BLASTOMERES

2009 ◽  
Vol 21 (1) ◽  
pp. 148
Author(s):  
D. N. Q. Thanh ◽  
K. Matsukawa ◽  
M. Kaneda ◽  
S. Akagi ◽  
Y. Kanai ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Monozygotic Twins ◽  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Total Cell Number ◽  
First Polar Body ◽  
Blastocyst Quality ◽  
Single Blastomeres

In the mouse, single blastomeres of the 2-cell embryos can develop into adult mice and occasionally both separated blastomeres can give rise to twin animals (reviewed by Tarkowski AK et al. 2001 Int. J. Dev. Biol. 45, 591–596). As a preliminary study for production of monozygotic twins from porcine 2-cell embryos, we investigated the effects of removal of zona pellucida and blastomere isolation at the 2-cell stage on subsequent development of parthenogenetic embryos. Oocytes with the first polar body were parthenogenetically activated after 44 h of in vitro maturation. Stimulated oocytes were then incubated in IVC-PyrLac (IVC medium with pyruvate and lactose) according to the method reported by Kikuchi K et al. (2002 Biol. Reprod. 66, 1033–1041). After 24 to 30 h of parthenogenetic activation, equally cleaved 2-cell embryos were selected and used for the experiments. Some 2-cell embryos were then treated with pronase to remove the zona pellucida and cultured individually as zona-free 2-cell embryos having 2 blastomeres in pair (ZF group), and single blastomeres were split from ZF group and cultured separately (SB group) in V-shaped microwells. In addition, intact 2-cell embryos were cultured individually without pronase treatment as a control group. After 24 h of in vitro culture, IVC-PyrLac was replaced by IVC-Glu (IVC with glucose). The blastocyst rates on Day 6 (Day 0 was defined as the day of electrical stimulation) in control, ZF, and SB groups did not differ (47.6, 50.0, and 42.1%, respectively). Nevertheless, blastocysts derived from the ZF (28.6 ± 3.0) and SB groups (25.9 ± 1.3) had a significantly lower total cell number than that of the control group (41.7 ± 3.2; P < 0.01 by ANOVA). Although the total cell number of blastocysts originating from single blastomeres was significantly lower than that in the intact embryos, the blastocyst formation rates were not different between them. This indicated the possibility of production of monozygotic twins from porcine 2-cell embryos divided into 2 single blastomeres. However, further research is needed to improve blastocyst quality descended from single blastomeres. In conclusion, the removal of the zona pellucida had a negative influence on blastocyst quality but did not affect the development of porcine embryos to the blastocyst stage.

scholarly journals Effect of insulin–transferrin–selenium (ITS) and l-ascorbic acid (AA) during in vitro maturation on in vitro bovine embryo development

Zygote ◽  
2016 ◽  
Vol 24 (6) ◽  
pp. 890-899 ◽  
Author(s):  
A.L.S. Guimarães ◽  
S.A. Pereira ◽  
M. N. Diógenes ◽  
M.A.N. Dode
Keyword(s):  
Ascorbic Acid ◽  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Bovine Embryo ◽  
Total Cell Number ◽  
Embryo Production ◽  
Embryo Size ◽  
Blastocyst Rate

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.

Effect of vitrification technique and assisted hatching on rabbit embryo developmental rate

Zygote ◽  
2009 ◽  
Vol 17 (1) ◽  
pp. 57-61 ◽  
Author(s):  
M. Popelková ◽  
Z. Turanová ◽  
L. Koprdová ◽  
A. Ostró ◽  
S. Toporcerová ◽  
...  
Keyword(s):  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Assisted Hatching ◽  
Hatching Rate ◽  
Total Cell Number ◽  
Developmental Potential ◽  
Significant Difference ◽  
Rabbit Embryos

SummaryThe aim of the study was to determine the efficiency of two vitrification techniques followed by two assisted hatching (AH) techniques based on post-thaw developmental capacity of precompacted rabbit embryos and their ability to leave the zona pellucida (hatching) during in vitro culture. The total cell number and embryo diameter as additional markers of embryo quality after warming were evaluated. In vivo fertilized, in vitro cultured 8–12-cell rabbit embryos obtained from superovulated rabbit does were cryopreserved by two-step vitrification method using ethylene glycol (EG) as cryoprotectant or by one-step vitrification method with EG and Ficoll (EG+Ficoll). Thawed embryos were subjected to enzymatic or mechanical AH. Vitrified EG group showed significantly lower (P < 0.05) blastocyst rate (22.5%) and hatching rate (15%) than those vitrified with EG + Ficoll (63 and 63% resp.) and that of control (97 and 97% respectively). Significantly lower values of total cell number (P < 0.05) as well as embryo diameter (P < 0.01) in EG group compared with EG + Ficoll and control group were recorded. No significant difference was found in developmental potential of warmed embryos treated by either mechanical or enzymatic AH. The present study demonstrates that the EG + Ficoll vitrification protocol provides superior embryo survival rates over the EG vitrification protocol for 8–12-cell stage precompacted rabbit embryos. No positive effect of either mechanical or enzymatic AH on the post-thaw viability and quality of rabbit embryos in vitro was observed.

PSX-B-11 Comparing effects of FGF2 and IGF1 on the development competence of parthenogenetic activated bovine oocytes maturing in vitro

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 327-328
Author(s):  
Galina Singina
Keyword(s):  
Growth Factor ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Control Group ◽  
Total Cell Number ◽  
Developmental Potential ◽  
Maturation Medium ◽  
Bovine Oocytes

Abstract The oocyte quality acquired during in vitro maturation (IVM) are the main limitative factors affecting the embryo production. The aim of the present research was to study effects of fibroblast growth factor 2 (FGF2) and insulin-like growth factor 1 (IGF1) during IVM of bovine oocytes on their developmental potential after parthenogenetic activation. Bovine cumulus-oocyte complexes (COC; n = 1176) were cultured for 22h in either standard maturation medium (TCM-199 supplemented with 10% fetal calf serum (FCS), 0.2 mM sodium pyruvate, 10 μg/ml FSH and 10 μg/ml LH; Control) or maturation medium supplemented with different concentrations (5–160 ng/ml) of FGF2 and IGF1. After IVM, matured oocytes activated by sequential treatment with ionomycin followed by DMAP and cyclohexamide and then cultured up to the blastocyst stage. The obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using DAPI and TUNEL staining. The data from 4 replicates (77–91 oocytes per treatment) were analyzed by ANOVA. Cleavage rates of activated oocytes did not differ between groups and ranged from 63.7 to 68.1%. The addition of 10, 20 and 40 ng/ml of FGF2 to the IVM medium led to an increase in the yield of blastocysts [from 19.6±1.8% (Control) to 35.2±3.4, 29.8±1.9 and 31.1±2.1%, respectively (P&lt;0.05)] and in the total cell number in embryos that developed to the blastocyst stage (P&lt;0.05). Meanwhile, the blastocyst yield and the total cell number in blastocysts in the IGF1-treated groups were similar to that in the control group. No effects of both growth factors on the proportion of apoptotic nuclei in blastocysts (5.3–7.1%) were observed. Thus, FGF2 (but not IGF1) are able to maintain competence for parthenogenetic development of bovine COC during their maturation invitro. Supported by RFBR (18-29-07089) and the Ministry of Science and Higher Education of Russia.

Effect of nucleocytoplasmic ratio on the in vitro porcine embryo development after in vitro fertilization or parthenogenetic activation

Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
Nguyen Thi Men ◽  
Thanh Quang Dang-Nguyen ◽  
Tamas Somfai ◽  
Hiep Thi Nguyen ◽  
Junko Noguchi ◽  
...  
Keyword(s):  
Formation Rate ◽  
Cell Number ◽  
Control Group ◽  
Total Cell Number ◽  
Vitro Fertilization ◽  
Blastocyst Quality ◽  
Porcine Embryo ◽  
Oocyte Cytoplasm

Summary This study was conducted to examine whether the nuclear to cytoplasmic (N/C) ratio had any influence on the timing of embryo compaction and blastocoel formation, as well as formation rate and quality of blastocyst. First, we produced embryos with increased N/C ratio by removal of approximately one-third of the cytoplasm and with decreased N/C ratio by doubling the oocyte cytoplasm with an enucleated oocyte. The initiation of compaction and cavitation in reduced cytoplasm group was significantly earlier (P < 0.05) compared with the control and doubled cytoplasm groups. The rate of blastocysts in the reduced cytoplasm and doubled cytoplasm groups was significantly lower (P < 0.05) compared with the control group. Blastocyst quality in terms of total cell number in the reduced cytoplasm group was significantly lower (P < 0.05) compared with the doubled cytoplasm group, but not different from the control group. Next, we produced embryos with various N/C ratios by oocyte fusion combined with cytochalasin D treatment. The onset of compaction and cavitation in the 2N/2C group (decreased N/C ratio) was significantly delayed (P < 0.05) or had the tendency to be delayed (P = 0.064), respectively, compared with the control group (2N/1C). A significantly higher rate of blastocyst was observed in the 4N/2C group compared with the 1N/1C group (P < 0.05) but not different from the remaining groups. These results demonstrated that an increase in N/C ratio caused an earlier occurrence of morula compaction and blastocyst formation in both in vitro fertilization (IVF) and parthenogenetically activated pig embryos.

190 EFFECT OF TRANS-ε-VINIFERIN ON IN VITRO PORCINE OOCYTE MATURATION AND SUBSEQUENT DEVELOPMENTAL COMPETENCE IN PRE-IMPLANTATION EMBRYOS

2012 ◽  
Vol 24 (1) ◽  
pp. 207
Author(s):  
Y. Jeon ◽  
S.-S. Kwak ◽  
S.-A. Jeong ◽  
R. Salehi ◽  
Y. H. Seong ◽  
...  
Keyword(s):  
Cell Number ◽  
Total Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Vitis Amurensis ◽  
Total Cell Number ◽  
Treatment Groups ◽  
Nuclear Maturation ◽  
Porcine Oocyte

Trans-ε-viniferin is a naturally occurring polyphenol belonging to the stilbenoids family. Trans-ε-viniferin is isolated from Vitis amurensis, 1 of the most common wild grapes in Korea, Japan and China. We investigated the effects of trans-ε-viniferin on in vitro maturation (IVM) and developmental competence after IVF or parthenogenesis (PA). At the laboratory of Veterinary Pharmacology, College of Veterinary Medicine, Chungbuk National University, trans-ε-viniferin was purified from the leaves and stems of Vitis amurensis. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. First, in total, 594 cumulus–oocyte complexes (COC) were used for the evaluation of nuclear maturation. The COC were matured in TCM-199 medium supplemented with various concentrations of trans-ε-viniferin (0, 0.1, 0.5, 1.0 and 5.0 μM) with 10% porcine follicular fluid, 10 IU mL–1 of eCG and 10 IU mL–1 of hCG. After 22 h in maturation culture, the COC were cultured in hormone-free medium supplemented with various concentrations of trans-ε-viniferin for an additional 22 h and then nuclear maturation was evaluated. Second, in total, 300 matured oocytes were used to examine the effects of different trans-ε-viniferin concentrations (0, 0.5 and 5.0 μM) on porcine oocyte intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. Lastly, the developmental competence of oocytes matured with different concentrations of trans-ε-viniferin (0, 0.5 and 5.0 μM) was evaluated after IVF or PA. In total, 711 embryos were evaluated. As results, we observed that trans-ε-viniferin treatment during IVM did not improve the nuclear maturation of oocytes in any group (84.2, 86.6, 85.5, 83.3 and 79.2%, respectively), but significantly increased (P < 0.05) intracellular GSH levels in the 0.5 μM group (0 μM vs 0.5 μM; 14.6 vs 16.8 pmol oocyte–1) and reduced ROS levels (0 μM vs 0.5 μM and 50 μM; 174.6 vs 25.7 and 23.8 pixel oocyte–1). Oocytes treated with trans-ε-viniferin during IVM did not have significantly different cleavage rates or blastocyst formation rates after IVF, but total cell numbers were significantly higher (P < 0.05) in the 0.5 and 5.0 μM treatment groups (53.6 ± 4.0 and 47.9 ± 3.1) compared to the control group (36.4 ± 2.2). The PA embryos showed similar results; there were no significant differences in cleavage rates and blastocyst formation rates, but the total cell number significantly increased in the 0.5 and 5.0 μM treatment groups (59.6 ± 4.2 and 60.8 ± 4.6) compared to the control group (43.1 ± 2.1). In conclusion, these results indicate that trans-ε-viniferin treatment during porcine IVM increased total cell number of blastocysts, possibly through increasing intracellular GSH synthesis and reducing ROS levels. This work was supported by a grant from the Korea institute of Planning & Evaluation for Technology in Food, Agriculture, Forestry & Fisheries, Republic of Korea.

96 GRANULOCYTE–MACROPHAGE COLONY-STIMULATING FACTOR INCREASES DEVELOPMENTAL POTENTIAL OF PORCINE EMBRYOS IN VITRO

2012 ◽  
Vol 24 (1) ◽  
pp. 160
Author(s):  
K. Lee ◽  
J. Teson ◽  
L. Spate ◽  
C. N. Murphy ◽  
R. S. Prather
Keyword(s):  
Embryo Culture ◽  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Blastocyst Formation ◽  
Total Cell Number ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony

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.

Aggregation of Leopardus geoffroyi hybrid embryos with domestic cat tetraploid blastomeres

Reproduction ◽  
2021 ◽  
Vol 161 (5) ◽  
pp. 539-548
Author(s):  
Matteo Duque Rodriguez ◽  
Andrés Gambini ◽  
Laura D Ratner ◽  
Adrian J Sestelo ◽  
Olinda Briski ◽  
...  
Keyword(s):  
Endangered Species ◽  
Cell Number ◽  
Domestic Cat ◽  
Control Group ◽  
Embryonic Cells ◽  
Total Cell Number ◽  
Blastocyst Quality ◽  
Developmental Rates ◽  
Cat Model

Heterospecific embryo transfer of an endangered species has been carried out using recipients from related domestic females. Aggregation of an embryo from an endangered species with a tetraploid embryo from the species to be transferred could improve the development of pregnancy to term. The main objective of the present study was to analyze embryo aggregation in domestic cat model using hybrid embryos. For this purpose, we compared in vitro development of synchronic (Sync) or asynchronic (Async) and asynchronic with a tetraploid (Async4n) aggregation of domestic cat IVF embryos. Furthermore, aggregated blastocyst quality was analyzed by evaluation of the total cell number, cell allocation by mitotrackers staining of embryonic cells, expression of Oct4, Nanog, Sox2, Cdx2 genes, number of OCT4+ nuclei, and presence of DNA fragmentation. Additionally, the developmental rates of Async4n aggregation of domestic cat with Leopardus geoffroyi hybrid (hLg) embryos were evaluated. Async aggregation increased blastocyst cell number and the number of OCT4+ nuclei as compared to non-aggregated diploid (2n) and tetraploid (4n) embryos. Moreover, blastocysts produced by Async4n aggregation showed reduced rates of fragmented DNA. No differences were found in the expression of the pluripotent genes, with exception of the Cdx2 expression, which was higher in 4n and aggregated embryos as compared to the control group. Interestingly, hybrids embryos derived by Async4n aggregation with domestic cat embryos had similar rates of blastocysts development as the control. Altogether, the findings support the use of two-cell-fused embryos to generate tetraploid blastomeres and demonstrate that Async4n aggregation generates good quality embryos.

88 IS STEREOMICROSCOPY AN EFFICIENT METHOD FOR EVALUATING THE VITRIFIED PORCINE EMBRYO QUALITY?

2006 ◽  
Vol 18 (2) ◽  
pp. 152
Author(s):  
C. Cuello ◽  
F. Berthelot ◽  
B. Delaleu ◽  
C. Almiñana ◽  
J. M. Vázquez ◽  
...  
Keyword(s):  
Cell Death ◽  
Embryo Quality ◽  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Hatching Rate ◽  
Total Cell Number ◽  
Large White ◽  
Porcine Embryo

The development of the open pulled straw vitrification has provided excellent results of in vitro porcine embryo development. Embryo quality evaluation after vitrification has been traditionally focused on morphological assessment performed by stereomicroscopy. The objective of this experiment was to evaluate the efficiency of the stereomicroscopic evaluation of vitrified-warmed (V) porcine blastocysts. Unhatched blastocysts were obtained after slaughter from Large-White gilts (n = 9). Blastocysts (n = 75) were vitrified and warmed using the protocol described by Cuello et al. (2004 Theriogenology 61, 353-361). After warming, vitrified blastocysts were cultured for 24 h. Then blastocysts were morphologically assessed for their progression and morphology by stereomicroscopy. Blastocysts that reformed their blastocoelic cavities showing an excellent appearance were considered viable. Some of the viable blastocysts kept their zonae pellucidae (V viable expanded blastocysts) and others hatched during the in vitro culture (V viable hatched blastocysts). The remaining blastocysts were classified as degenerated embryos. A group of fresh blastocysts was not vitrified and cultured in vitro for 24 h (control group). All of the control blastocysts were considered viable by stereomicroscopy. Some fresh, V viable expanded, V viable hatched, and V degenerated blastocysts (n = 13, n = 19, n = 9, and n = 9, respectively) were processed for ultrastructural study by light and transmission electron microscopy or stained with Hoechst-33342 and TUNEL for cell death evaluation (n = 16, n = 21, n = 11, and n = 6, respectively). All V hatched blastocysts showed ultrastructure similar to that of control hatched blastocysts. However, 26.3% of the V viable expanded blastocysts revealed important ultrastructural alterations in comparison with control expanded blastocysts. These observations suggest that stereomicroscopic evaluation was not efficient enough for V expanded blastocysts. As expected, degenerated blastocysts showed ultrastructural disintegration and disorganization. Hatched V blastocysts did not differ (P < 0.05) from control hatched blastocysts with regard to the total cell number and ratio of death cells (173 � 4.8 vs. 202.1 � 10.9 and 2.8 � 0.5% vs. 1.9 � 0.3%, respectively). However, V expanded blastocysts a had higher (P < 0.01) cell death level (4.3 � 3.4%) than that observed in the control expanded blastocysts (1.1 � 0.3%). Degenerated embryos showed the lowest (P < 0.01) total cell number (45.7 � 4.0). The 66.7% of the degenerated blastocysts exhibited wide TUNEL-labeled areas, and the remaining 33.3% showed TUNEL label over 19.4 � 6.3% of the cells. In conclusion, the hatching rate assessed by stereomicroscopy is a more efficient parameter than assessing the in vitro viability (ratio of blastocysts that reformed their blastocoelic cavities after warming) for estimating the quality of V blastocysts. This work was supported by CICYT (AGL2004-07546) and S�neca (01287/PD/04).

27 EFFECT OF A SPECIFIC INHIBITOR OF DOT1L ON PREIMPLANTATION DEVELOPMENT OF PORCINE SOMATIC CLONED EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 106
Author(s):  
J. Tao ◽  
Y. Zhang ◽  
D. Song ◽  
Y. Li ◽  
Y. Zhang
Keyword(s):  
Treatment Group ◽  
Specific Inhibitor ◽  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Cleavage Rate ◽  
Total Cell Number ◽  
In Vitro Development ◽  
Vitro Development

EPZ004777 (EPZ), a specific inhibitor of DOT1L (a methyltransferase of H3K79), can significantly improve the generation and quality of mouse induced pluripotent stem cells [Onder et al. 2012 Nature 483(7391), 598–602), suggesting that H3K79 dimethylation (H3K79me2) is involved in controlling cell pluripotency. To date, however, it is unclear whether H3K79me2 regulates development competency of animal cloned embryos. Thus, we aimed to examine the dynamic changes of H3K79me2 in pre-implantation cloned embryos of pigs, and to explore effect of EPZ treatment of embryos on in vitro development fate in order to lay the foundation for revealing the role of H3K79me2 and mechanisms in controlling cell pluripotency. Porcine cloned embryos were treated immediately when fusion and activation stimuli were conducted, in vitro with porcine zygote medium (PZM)-3, including 0.5, 5, or 50 nM EPZ (S7353, Selleck Chemicals, Houston, TX, USA) and 1‰ DMSO (vol/vol, control group) for 24 h, respectively. Then, they were transferred into fresh PZM-3 without EPZ. We found that there was no significant difference in cleavage rate among groups, whereas the blastocyst rate of 0.5 nM EPZ group was higher than that of control group [28.97 ± 2.65% (28/96) v. 17.13 ± 2.69% (17/96)]. No obvious difference was observed for the total cell number of blastocyst among groups. We further treated the SCNT embryos with 0.5 nM EPZ for 0 (control group), 12, 24, and 36 h, respectively. No significant differences were found for cleavage rate among groups, whereas the blastocyst rates of the 12- and 24-h groups were significantly higher than that of control and 36-h groups [28.56 ± 3.51% (27/97), 28.34 ± 3.00% (25/88) v. 16.32 ± 1.93% (16/97), 17.93 ± 0.64% (18/100)]. Except for the remarkable decrease in the 36-h treatment group, no obvious difference was observed for the total cell number of blastocyst among the other 3 groups. All the above experiments were repeated at least 3 times. These results suggested that treatment of porcine SCNT embryos with 0.5 nM EPZ for 12 to 24 h could improve their development during the early stage. Then, we tested whether the EPZ favoured the in vitro development of porcine SCNT embryos by regulating H3K79me2 reprogramming. Porcine SCNT embryos were treated with 0.5 nM EPZ from the onset of electric activation and fusion stimuli was performed, and then the H3K79me2 signal (by immune-fluorescent staining) and expression of DOT1L (by RT-qPCR) at different development stages was analysed. We found that the H3K79me2 signal in control group (without EPZ treatment) decreased slowly from the time of electric stimulation to 4 hpa, and it disappeared in 8 hpa stage. In the EPZ treatment group, H3K79me2 signal started decreasing from 2 hpa, and disappeared in 8 hpa stage. The mRNA level of DOT1L in EPZ treatment group was lower than that in control group, although the difference was not significant. Taken together, treatment with EPZ at the appropriate concentration and for an appropriate time can improve the early in vitro development of pig SCNT embryos, probably by inhibiting expression of DOT1L and facilitating reprogramming of H3K79me2.Research was supported by NSFC No. 31272442.

253 EFFECTS OF ADDITION OF ALPHA-LINOLENIC ACID INTO MATURATION MEDIUM ON IN VITRO DEVELOPMENT AND EXPRESSION OF APOPTOSIS-RELATED GENES OF GOAT EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 216 ◽  
Author(s):  
A. Veshkini ◽  
M. Khajenabi ◽  
A. Mohammadi-Sangcheshmeh
Keyword(s):  
Cell Number ◽  
Total Cell ◽  
Control Group ◽  
Apoptotic Cells ◽  
Total Cell Number ◽  
Beneficial Effects ◽  
Maturation Medium ◽  
And Control ◽  
P53 Genes

Fatty acids are important sources of energy for oocytes and embryos. In bovine, an increased level of rumen-inert fatty acids in the diet improved the developmental competence of oocytes to the blastocyst stage and also embryo quality. As described in our previous report, providing appropriate levels of α-linolenic acid (ALA) in maturation medium had beneficial effects on nuclear maturation and embryonic development in the goat. Considering these beneficial effects, here we have conducted experiments to evaluate whether addition of ALA to goat oocyte maturation medium can affect the quality of blastocyst and the transcription of apoptosis-related Bax, Bcl-2, and p53 genes. Ovaries were collected from goats, and cumulus-oocyte complexes (COC) were recovered by the slicing method. The COC were placed in maturation medium supplemented with 50 µM ALA. Oocytes in the control group were incubated in the same maturation medium without ALA. In vitro maturation (IVM) was performed in a humidified atmosphere containing 5% CO2, 5% O2, and 90% N2 at 38.5°C for 24 h. After IVM, oocytes from both the treatment (n = 113) and control (n = 104) groups were subjected to IVF followed by culture in CR1aa medium for 8 days under the conditions stated above. The cleavage and blastocyst rates were recorded at Days 3 and 8 of culture, respectively. To examine the effect of ALA on total cell number and apoptosis of the blastocyst cells, the blastocysts from 50 μM ALA-treated and control oocytes were stained with 4′,6-diamidino-2-phenylindole to count total cell number, and apoptotic cells in these blastocysts were detected with TUNEL assay. Blastocysts derived either from 50 μM ALA-treated oocytes or control oocytes were also evaluated for the expression of Bax, Bcl-2, and p53 genes. The cleavage and blastocyst rates were compared by chi-square analysis. Differentially expressed genes were analysed by 1-way ANOVA. A P-value of less than 0.05 was considered significant. Although cleavage rates after IVF were similar (P > 0.05) between 50 μM ALA-treated (68.1%) and control (55.8%) groups, 50 μM ALA-treated oocytes produced more (25.7%) blastocysts than the control group (13.5%; P < 0.05). Blastocysts derived from oocytes supplemented with 50 μM ALA not only had a greater (P < 0.05) total cell number (115.2), but also a lower (P < 0.05) number of apoptotic cells (3.1) compared with the control blastocysts (110.8 and 4.2, respectively). The relative transcript abundance of Bax and p53 was decreased (P < 0.05) in blastocysts that originated from the 50 μM ALA group compared with control blastocysts. Furthermore, there was an increased (P < 0.05) expression of Bcl-2 transcripts in blastocysts derived from the 50 μM ALA-treated oocytes compared with the control. In conclusion, our findings revealed that ALA-treated medium led to an improvement in blastocyst rate and quality as determined by greater total cell number, lower number of apoptotic cells, and altered expression of apoptosis-related genes.

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