236 CREATION OF PARTHENOGENETIC SHEEP EMBRYOS: EFFECTS OF SERUM AND BREEDING SEASON

2009 ◽  
Vol 21 (1) ◽  
pp. 216
Author(s):  
A. T. Grazul-Bilska ◽  
P. P. Borowicz ◽  
D. A. Redmer ◽  
J. J. Bilski ◽  
L. P. Reynolds
Keyword(s):  
Breeding Season ◽  
Kinase Inhibitor ◽  
Calcium Ionophore ◽  
Culture Conditions ◽  
Imprinted Genes ◽  
Blastocyst Formation ◽  
Placental Development ◽  
Developmentally Regulated ◽  
Paternal Genome

The monoparental embryo (with only the maternal genome, termed a parthenogenote, or with only the paternal genome, termed an androgenote) is a powerful model to study the epigenetic status of developmentally regulated genes, including imprinted genes (those expressed only when inherited from one parent). Therefore, to use monoparental embryos for future study of placental development in normal and compromised pregnancies, the objective of this study was to test, validate and optimize the methodologies necessary to create parthenogenetic sheep embryos. In Exp. 1, cumulus–oocyte complexes (COC) were collected during the breeding season from nonpregnant and early pregnant ewes (n = 18) and matured overnight in vitro. The oocytes were then activated using ionomycin (a calcium ionophore) and 6-dimethylaminopurine (DMAP; a protein kinase inhibitor) in medium with (n = 47 COC) or without (n = 112 COC) 2% serum. In Exp. 2, COC were collected from nonpregnant, seasonally anestrous (n = 7; 79 COC) and late pregnant (n = 4; 44 COC) ewes, matured in vitro and activated as in Exp. 1 in the presence of serum. In Exp. 1, the rates of activation and blastocyst formation were not affected by reproductive status (nonpregnant v. pregnant). Activation of oocytes in serum-containing v. serum-free medium resulted in 76.3% v. 4.35% (P < 0.0001) cleavage rates and 21.9% v. 8.3% (P < 0.006) blastocyst formation rates, respectively. In Exp. 2, cleavage rates were similar for nonpregnant and pregnant ewes (31.9 v. 37.5%), but blastocyst formation was 13% in nonpregnant and 0% in pregnant ewes. These data demonstrate that (1) during the breeding season, the presence of serum in activation medium enhances cleavage and blastocyst formation rates; (2) in out-of-season ewes blastocyst formation but not cleavage rates are greater for nonpregnant than pregnant ewes, and (3) cleavage and blastocyst formation rates are greater (P < 0.0001 and P < 0.04, respectively) during the breeding season than out-of-season. Thus, oocytes obtained from ewes during the breeding season and activation medium containing serum should be used for creating parthenogenetic embryos in sheep. This study also demonstrated that creation of parthenogenotes in sheep, which can be used in the future to study parentally imprinted genes, is feasible but requires specific season and culture conditions. Supported by USDA-NRI grant 2007-01215 to LPR and ATGB, and NIH grant P20 RR016741 (INBRE program of the NCRR, NIH).

89 METHYLATION STATUS OF IGF2/H19 DMR3 REGION AFFECTS IN VITRO BLASTOCYST PRODUCTION IN GOAT (CAPRA HIRCUS)

2017 ◽  
Vol 29 (1) ◽  
pp. 152
Author(s):  
M. Tiwari ◽  
N. Rawat ◽  
P. Vats ◽  
D. Nagoorvali ◽  
M. Mahajan ◽  
...  
Keyword(s):  
Methylation Status ◽  
Calcium Ionophore ◽  
Methylation Pattern ◽  
Capra Hircus ◽  
Paternal Allele ◽  
Placental Development ◽  
Embryo Production ◽  
Cpg Sites ◽  
H19 Gene

Parthenogenesis has been observed in lower animals but no known instance has been reported in mammals because both maternal and paternal genomes are a fundamental prerequisite for embryogenesis. A major reason for developmental failure of uniparental zygotes is expression of certain genes in a parent-of-origin-specific manner, i.e. genomic imprinting of genes. Out of many imprinted genes identified so far, IGF2/H19 have been extensively studied and known to play an important role in fetal and placental development. Gene IGF2 is expressed by the paternal allele, H19 is transcribed from the maternal allele, and the reciprocal expression of both genes is regulated by the DMR3 region placed upstream of the H19 gene. In the present study we compared the methylation status of IGF2/H19 DMR in parthenogenetic activated (PA) and IVF goat (Capra hircus) blastocyst through bisulphite sequencing. For this, immature oocytes of usable quality were subjected to in vitro maturation and subsequently used for embryo production through parthenogenesis (n = 993) (by calcium ionophore and 6-DMAP activation) and IVF (n = 1096). It was found that embryo production rate at all the embryonic stages (2-cell, 4-cell, 8–16-cell, morula, and blastocyst) was significantly higher (P < 0.05) in parthenogenesis (74.66 ± 3.35%, 61.90 ± 2.73%, 47.83 ± 2.95%, 38.13 ± 5.28%, and 21.11 ± 2.51%, respectively) as compared with IVF (55.21 ± 2.02%, 38.12 ± 2.48%, 28.53 ± 1.67%, 21.57 ± 1.59%, and 8.23 ± 1.02%, respectively). When blastocysts (n = 6 each) were subjected to TUNEL, it was found that PA blastocyst showed significantly higher (P < 0.05) total cell number (217.83 ± 18.80 v. 159.67 ± 13.94) and significantly low (P < 0.05) apoptotic index (2.04 ± 0.25 v. 4.03 ± 0.29) as compared with IVF blastocysts. For the methylation pattern study, we analysed 17 CpG sites on the DMR3 region of the IGF2/H19 gene. Variable methylation pattern was observed within these CpG sites in different clones (n = 15) of PA and IVF blastocyst. The DMR3 region of the IGF2/H19 gene was significantly hypermethylated (P < 0.05) in PA blastocysts as compared with IVF blastocysts (80.39 ± 2.96, 32.55 ± 4.37, respectively), which suggests higher expression of IGF2 in parthenotes. The result suggests IGF2 might play different roles in different species; the same expression pattern of IGF2 is observed in ovine, but a contrary result is found in porcine species. Our results signify the hypermethylation of IGF2/H19 DMR3, which leads to higher expression of IGF2 to support embryonic development at the blastocyst stage. This work was supported by the NFBSFARA Project on Parthenogenetic Goat (CA-4002), New Delhi, India.

scholarly journals Effects of cycloheximide or 6-dimethyl aminopurine on the parthenogenetic activation of pig oocytes using pulsatile treatment with nitric oxide donor

2009 ◽  
Vol 54 (No. 7) ◽  
pp. 293-306 ◽  
Author(s):  
T. Krejčová ◽  
J. Petr ◽  
M. Krejčová ◽  
K. Kheilová
Keyword(s):  
Nitric Oxide ◽  
Kinase Inhibitor ◽  
Calcium Ionophore ◽  
Continuous Treatment ◽  
Nitric Oxide Donor ◽  
Activation Rate ◽  
Morula Stage ◽  
Inhibitor Of Protein Synthesis ◽  
Parthenogenetic Embryos

Pig oocytes matured <I>in vitro</I> were parthenogenetically activated using nitric oxide donor SNAP (2mM). Continuous treatment successfully activated the oocytes only after more than 12 hours of exposure. Pulsatile treatments during which oocytes were repeatedly exposed to 2mM SNAP for a short time (10, 20 or 30 minutes) were more efficient with regard to the activation rate, even when the total exposure time did not exceed 4 hours. Parthenogenetic development was very limited after continuous treatment with 2mM SNAP. A significantly higher proportion of developing parthenogenetic embryos was observed after the pulsatile treatment (development to the morula stage 0 vs. 18%; development to the blastocyst 0 vs. 7%; <I>P</I> < 0.05). However, this developmental rate was significantly lower (<I>P</I> < 0.05) than the development induced by conventional activation treatment with calcium ionophore (development to the morula stage, 23%; development to the blastocyst stage, 18%). When we combined pulsatile SNAP-treatment with the effect of protein kinase inhibitor 6-dimethyl aminopurine (6-DMAP) (2mM 6-DMAP for 2 hours) or with the inhibitor of protein synthesis cycloheximide (CHX) (10 µM CHX for 2 hours), we observed a significant increase (<I>P</I> < 0.05) in the activation rate when compared to the respective pulsatile SNAP-treatment without 6-DMAP or CHX (63 vs. 78% of activated oocytes for 6-DMAP; 63 vs. 83% of activated oocytes for CHX). However, the development of parthenogenetic embryos was not enhanced when the pulsatile SNAP-treatment was combined with 6-DMAP or with CHX.

scholarly journals Embryotoxic impact of Zika virus in a rhesus macaque in vitro implantation model†

2020 ◽  
Vol 102 (4) ◽  
pp. 806-816 ◽  
Author(s):  
Lindsey N Block ◽  
Matthew T Aliota ◽  
Thomas C Friedrich ◽  
Michele L Schotzko ◽  
Katherine D Mean ◽  
...  
Keyword(s):  
Rhesus Macaque ◽  
Pregnancy Outcomes ◽  
Zika Virus ◽  
Negative Impact ◽  
Culture Media ◽  
Blastocyst Formation ◽  
Placental Development ◽  
Zikv Infection ◽  
The Impact

Abstract Zika virus (ZIKV) infection is associated with adverse pregnancy outcomes in humans, and infection in the first trimester can lead to miscarriage and stillbirth. Vertical and sexual transmissions of ZIKV have been demonstrated, yet the impact of infection during the initial stages of pregnancy remains unexplored. Here we defined the impact of ZIKV on early embryonic and placental development with a rhesus macaque model. During in vitro fertilization (IVF), macaque gametes were inoculated with a physiologically relevant dose of 5.48log10 plaque-forming units (PFU) of Zika virus/H.sapiens-tc/PUR/2015/PRVABC59_v3c2. Exposure at fertilization did not alter blastocyst formation rates compared to controls. To determine the impact of ZIKV exposure at implantation, hatched blastocysts were incubated with 3.26log10, 4.26log10, or 5.26log10 PFU, or not exposed to ZIKV, followed by extended embryo culture for 10 days. ZIKV exposure negatively impacted attachment, growth, and survival in comparison to controls, with exposure to 5.26log10 PFU ZIKV resulting in embryonic degeneration by day 2. Embryonic secretion of pregnancy hormones was lower in ZIKV-exposed embryos. Increasing levels of infectious virus were detected in the culture media post-exposure, suggesting that the trophectoderm is susceptible to productive ZIKV infection. These results demonstrate that ZIKV exposure severely impacts the zona-free blastocyst, whereas exposure at the time of fertilization does not hinder blastocyst formation. Overall, early stages of pregnancy may be profoundly sensitive to infection and pregnancy loss, and the negative impact of ZIKV infection on pregnancy outcomes may be underestimated.

Sphingosine-1-phosphate receptor expression in cardiac fibroblasts is modulated by in vitro culture conditions

2007 ◽  
Vol 292 (6) ◽  
pp. H2698-H2711 ◽  
Author(s):  
Lee K. Landeen ◽  
Nakon Aroonsakool ◽  
Jason H. Haga ◽  
Betty S. Hu ◽  
Wayne R. Giles
Keyword(s):  
Transforming Growth Factor ◽  
Kinase Inhibitor ◽  
Cardiac Fibroblasts ◽  
Culture Conditions ◽  
Receptor Expression ◽  
Receptor Subtypes ◽  
Essential Components ◽  
Sphingosine 1 Phosphate ◽  
S1p Receptor

The bioactive molecule sphingosine-1-phosphate (S1P) binds with high affinity to five recognized receptors (S1P1–5) to affect various tissues, including cellular responses of cardiac fibroblasts (CFbs) and myocytes. CFbs are essential components of myocardium, and detailed study of their cell signaling and physiology is required for a number of emerging disciplines. Meaningful studies on CFbs, however, necessitate methods for selective, reproducible cell isolations. Macrophages reside within normal cardiac tissues and often are isolated with CFbs. A protocol was therefore developed that significantly reduces macrophage levels and utilizes more CFb-specific markers (discoidin domain receptor-2) instead of, or in addition to, more commonly used cytoskeletal markers. Our results demonstrate that primary isolated, purified CFbs express predominantly S1P1–3; however, the relative levels of these receptor subtypes are modulated with time and by culture conditions. In coculture experiments, macrophages altered CFb S1P receptor levels relative to controls. Further investigations using known macrophage-secreted factors showed that S1P and H2O2 had minimal effects on CFb S1P1–3 expression, whereas transforming growth factor-β1, TNF-α, and PDGF-BB significantly altered all S1P receptor subtypes. Lowering FBS concentrations from 10% to 0.1% increased S1P2, whereas supplementation with either PDGF-BB or Rho-associated protein kinase inhibitor Y-27632 significantly elevated S1P3 levels. S1P2 and S1P3 receptor levels are known to regulate cell migration. Using cells isolated from either normal or S1P3-null mice, we demonstrate that S1P3 is important and necessary for CFb migration. These results highlight the importance of demonstrating CFb culture purity in functional studies of S1P and also identify conditions that modulate S1P receptor expression in CFbs.

scholarly journals 245RELATIVE ABUNDANCE OF HSP 70 MRNA IN BOVINE EMBRYOS PRODUCED IN VITRO USING DIFFERENT EMBRYO/VOLUME RATIOS IN CULTURE

2004 ◽  
Vol 16 (2) ◽  
pp. 243
Author(s):  
A.T.D. Oliveira ◽  
C. Gebert ◽  
R.F.F. Lopes ◽  
H. Niemann ◽  
J.L. Rodrigues
Keyword(s):  
Relative Abundance ◽  
Blastocyst Stage ◽  
Culture Conditions ◽  
Hatching Rate ◽  
Bovine Embryos ◽  
Blastocyst Formation ◽  
Cleavage Rate ◽  
Gene Transcripts

In spite of in vitro embryo production systems having been greatly improved over recent years, employing a variety of culture conditions (media, protein sources, gas atmosphere, etc.), we still do not know much about the real necessity of embryos to develop under the same conditions as occur in vivo. These differences between in vivo and in vitro culture at preimplantation embryonic stages can produce deviations in gene expression and in normal fetal development (large offspring syndrome). Heat shock proteins (Hsp) are engaged in cell response to regulatory signals or perturbations in the microenviroment and can be used as a sensitive indicator of stress caused by suboptimal culture conditions (Wrenzycki et al., 2001Hum. Reprod. 16, 893–901). Hsp act as chaperones in facilitating protein folding and assembly and stabilize damaged proteins to prevent aggregation of fragments, thereby allowing repair or degradation. The aim of the present study was to investigate the effects of different embryo/volume ratios on bovine embryo development and the relative abundance of Hsp 70.1 gene transcripts. In this experiment, oocytes were isolated from slaugterhouse ovaries and matured, fertilized and cultured in groups of 5, 10, 20 or 30 per each drop of 100μL. The oocytes were matured in TCM 199 supplemented with 0.4% BSA. After maturation, oocytes were fertilized in TALP medium, using frozen/thawed sperm, selected using a percoll density gradient. The zygotes were cultured to the morula or Day 7 blastocyst stage employing SOF supplemented with 0.4 % BSA. Developmental check points were cleavage rate (Day 3pi), blastocyst formation (Day 8pi) and hatching (Day 11pi). A semi-quantitative RT-PCR assay was used to determine the relative levels of gene transcripts in single embryos at morula (Day 6) and blastocyst (Day 7) stages (Wrenzycki et al., 2001 Biol. Reprod. 65, 309–317). Data of cleavage, blastocyst formation and hatching rates were analyzed using chi-square test. Relative abundance (RA) of Hsp 70.1mRNA were compared in tested groups using ANOVA followed a Tukey test. Differences at P&lt;0.05 were considered significant. Results show that no significative difference in hatching rate per blastocyst produced was detected among the four groups. Cleavage rate and blastocyst formation were significantly higher in groups with 5, 10 and 20 embryos compared with drops containing 30 embryos. Hsp transcripts were detected in morula and blastocyst stages in all groups. In morula stage, no differences were observed in the RA of Hsp 70.1mRNA among groups with 5, 10, 20 and 30 embryos cultured per drop. However, in blastocyst stage, the RA was significantly increased in the group with 20 embryos per drop as compared to the group with 5 embryos. The results show that different embryo/volume ratios in culture influence not only cleavage rate, blastocyst formation and hatching rate, but also expression of Hsp 70.1 gene. Further studies changing other culture conditions and using in vivo-derived bovine embryos will aid in elucidating which culture systems are ideal to produce bovine embryos in vitro. This research was supported by CAPES/DAAD program and CNPq.

291 EFFECTS OF ANTIOXIDANT AND CULTURE MEDIUM ON THE DEVELOPMENT OF PORCINE IN VITRO-MATURED - IN VITRO-FERTILIZED EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 261
Author(s):  
C. Choe ◽  
D.-S. Son ◽  
S.-H. Choi ◽  
S.-R. Cho ◽  
H.-J. Kim ◽  
...  
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Culture Conditions ◽  
Free Oxygen Radicals ◽  
Blastocyst Formation ◽  
Free Oxygen ◽  
Statistical Analysis System ◽  
Developmental Rates ◽  
Analysis System

Most cells cultured in vitro are exposed to the risk of injury by free oxygen radicals (FOR). However, some of FOR-induced injury could be reduced by the antioxidants and culture medium used for in vitro embryos. This study was undertaken to examine the effects of the antioxidant and culture medium on the development of porcine in vitro-matured–in vitro-fertilized embryos. In Experiment 1, we treated the porcine oocytes in NCSU23 medium with various concentrations of β-mercaptoethanol (β-ME) to determine the effective concentration of antioxidants during IVM of porcine oocytes. In Experiment 2, we tested different culture media to find the proper culture conditions for in vitro porcine embryos. The porcine oocytes that were matured in NCSU23 medium and then fertilized in mTBM medium were cultured in NCSU23 or porcine zygote medium-5. All steps (maturation, fertilization, and development) were carried out in vitro. Differences were analyzed among treatments using the general linear model (GLM) procedure in the Statistical Analysis System (SAS Institute, Inc., Cary, NC, USA). The results were summarized as follows. Various concentrations of β-ME showed different developmental rates in porcine embryos. The rates of blastocyst formation at Day 7 after IVF were 9.2 � 1.8 (n = 65), 10.0 � 4.2 (n = 80), 17.5 � 1.1 (n = 63), 20.7 � 1.7 (n = 82), and 14.6 � 1.4 (n = 82) in oocytes treated with β-ME at 0, 10, 25, 50, and 100 �M during IVM, respectively. Of the concentrations of β-ME tested, 50 �M β-ME markedly increased the rates of blastocyst formation at Day 7 (P &lt; 0.05). The rates of blastocyst formation at Day 7 in the NCSU23 and PZM-5 culture media of porcine IVF-derived embryos were 18.8 � 2.6 (n = 96) and 15.6 � 7.1 (n = 77), respectively. The developmental rates were slightly increased in NCSU23, compared with those in PZM-5, but there were no significant differences (P &lt; 0.05) between the NCSU23 and PZM-5 media. In conclusion, these results suggest that the addition of 50 �M β-ME in the IVM medium can improve developmental the rates of porcine embryos in vitro.

scholarly journals Modeling human trophoblast, the placental epithelium at the maternal fetal interface

Reproduction ◽  
2020 ◽  
Vol 160 (1) ◽  
pp. R1-R11 ◽  
Author(s):  
Mariko Horii ◽  
Ojeni Touma ◽  
Tony Bui ◽  
Mana M Parast
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Culture Conditions ◽  
Model Systems ◽  
Placental Development ◽  
Human Organ ◽  
Human Trophoblast

Appropriate human trophoblast lineage specification and differentiation is crucial for the establishment of normal placentation and maintenance of pregnancy. However, due to the lack of proper modeling systems, the molecular mechanisms of these processes are still largely unknown. Much of the early studies in this area have been based on animal models and tumor-derived trophoblast cell lines, both of which are suboptimal for modeling this unique human organ. Recent advances in regenerative and stem cell biology methods have led to development of novel in vitro model systems for studying human trophoblast. These include derivation of human embryonic and induced pluripotent stem cells and establishment of methods for the differentiation of these cells into trophoblast, as well as the more recent derivation of human trophoblast stem cells. In addition, advances in culture conditions, from traditional two-dimensional monolayer culture to 3D culturing systems, have led to development of trophoblast organoid and placenta-on-a-chip model, enabling us to study human trophoblast function in context of more physiologically accurate environment. In this review, we will discuss these various model systems, with a focus on human trophoblast, and their ability to help elucidate the key mechanisms underlying placental development and function. This review focuses on model systems of human trophoblast differentiation, including advantages and limitations of stem cell-based culture, trophoblast organoid, and organ-on-a-chip methods and their applications in understanding placental development and disease.

scholarly journals 229 EFFECT OF CULTURE CONDITIONS ON AQUAPORIN mRNA ABUNDANCE IN MOUSE BLASTOCYSTS

2005 ◽  
Vol 17 (2) ◽  
pp. 265
Author(s):  
H. Offenberg ◽  
P.D. Thomsen
Keyword(s):  
Blastocyst Stage ◽  
Culture Conditions ◽  
Mrna Abundance ◽  
Control Group ◽  
Mrna Levels ◽  
Blastocyst Formation ◽  
Gapdh Mrna ◽  
The Media

It is known that culture conditions can alter gene expression of the pre-implantation embryo. We have previously shown that aquaporins (AQPs) are expressed in the mouse embryo and that they are involved in the passage of water across the trophoblast cells during blastocyst formation. This study was conducted to investigate whether AQP mRNA abundance is altered by culturing embryos in vitro compared to in vivo developed embryos. Furthermore we wanted to investigate if AQP mRNA abundance was influenced by the osmolality of the media. It is possible to compare the effect of hyperosmolality that the embryo may be able to compensate for by adding glycerol which can cross some AQPs, compared to the addition of sucrose which can not cross the membranes. Mouse embryos were obtained by superovulating B6D2F1 mice followed by culture of the flushed presumptive zygotes in KSOM to the blastocyst stage (in vitro) or by flushing blastocysts from the uterus (in vivo). For the study of the influence of osmolality on AQP mRNA abundance, zygotes were flushed and cultured to the compacted 8-cell stage and then placed in media of increasing osmolality, using either glycerol or sucrose. The osmolalities of the media were 243 (control), 300, 350, and 400 mOsm. Embryos were cultured to the blastocyst stage and frozen in liquid nitrogen. Embryonic RNA was extracted using a Dynabeads mRNA Capture kit (Dynal, Oslo, Norway). Real time PCR was performed on embryonic cDNA on a Lightcycler (Roche Diagnostics, 2650 Hvidovre, Denmark) using aquaporin-specific primers and primers for β-actin and GAPDH. The results of the quantitative RT-PCR analysis showed that in vitro-cultured embryos had a lower mRNA abundance for AQP 8, 9, and 11 compared to the in vivo-developed embryos but that the AQP 3 mRNA abundance was unaltered. Analysis of the housekeeping genes showed that GAPDH mRNA levels were unchanged in vitro, whereas β-actin was up-regulated in vitro. The osmotically challenged embryos showed the following blastocyst rates compared to the controls: glycerol 300: 100%; glycerol 350: 100%; glycerol 400: 100%; sucrose 300: 100%; sucrose 350: 78%; and sucrose 400: 0%. Thus, glycerol up to 400 mOsm had no effect on blastocyst rates, whereas addition of sucrose reduced blastocyst formation, with a total inhibition at 400 mOsm. Analysis of the mRNA abundance showed a reduction of AQP 8 in the glycerol solutions. The level was reduced to 30% of the control group at 300 mOsm, to 27% at 350 mOsm and to 8% at 400 mOsm. There was no corresponding reduction of AQP 8 mRNA abundance in sucrose solutions. Further, AQP 3, 7, 9, and 11 mRNA levels as well as β-actin and GAPDH mRNA levels were unaltered in the osmotically challenged embryos. In conclusion, this study shows that embryonic culture affects the abundance of several AQPs and that compensation of a glycerol-induced osmotical challenge induces down-regulation of AQP 8 expression. Embryos tolerate high glycerol concentrations better than high sucrose concentrations but the possible role of AQP 8 in this process is unclear at present.

scholarly journals Activation of cumulus-free equine oocytes: effect of maturation medium, calcium ionophore concentration and duration of cycloheximide exposure

Reproduction ◽  
2001 ◽  
pp. 177-183 ◽  
Author(s):  
YH Choi ◽  
CC Love ◽  
DD Varner ◽  
JA Thompson ◽  
K Hinrichs
Keyword(s):  
Follicular Fluid ◽  
Culture Media ◽  
Calcium Ionophore ◽  
Culture Conditions ◽  
Activation Rate ◽  
Maturation Medium ◽  
Fetal Bovine ◽  
Decondensed Chromatin ◽  
Rate Of Activation

Two different culture media (TCM-199 and follicular fluid), two activation treatments (10 and 50 micromol calcium ionophore l(-1)) and three culture periods with cycloheximide were evaluated to find effective culture conditions for activation of cumulus-free equine oocytes. Oocytes were collected by scraping the follicle walls of ovaries obtained from an abattoir. Oocytes with expanded cumuli were matured at 38.2 degrees C in a humidified atmosphere of 5% CO(2) in air, in either TCM-199 with 10% fetal bovine serum (FBS) and 5 microU FSH ml(-1), or in 100% follicular fluid derived from a preovulatory follicle 24 h after injection of hCG. After 40--42 h of in vitro maturation, oocytes were denuded by gentle pipetting in TCM-199 plus 10% FBS with hyaluronidase. Oocytes with intact cytoplasmic membranes (n = 398; 94% presumed metaphase II) were treated in protein-free PBS with 10 or 50 micromol calcium ionophore l(-1) for 5 min. After washing, the oocytes were cultured in TCM-199 containing 10% FBS and 10 microg cycloheximide ml(-1) for 6 h, in cycloheximide for 6 h and then in cycloheximide-free medium for 18 h, or in cycloheximide for 24 h. The oocytes were fixed and evaluated by fluorescence microscopy. Oocytes with pronucleus I--II (dense to decondensing chromatin), pronucleus III--IV (decondensed chromatin) or progressing towards the first cleavage division were considered activated. The activation rate for oocytes matured in TCM-199 was significantly (P < 0.05) higher than for oocytes matured in follicular fluid (49% (99/204) versus 35% (60/171), respectively; P < 0.05). Culture with cycloheximide for 24 h resulted in a significantly higher rate of activation (67%, 74/111) than did the 6 h (33%, 44/136) or 6 h plus 18 h (32%, 41/128) treatments. The highest rate of activation (82%) was observed in oocytes matured in TCM-199, treated with 50 micromol calcium ionophore l(-1) and cultured with cycloheximide for 24 h.

156 PRETREATMENT WITH THE ANTIOXIDANT EPIGALLOCATECHIN GALLATE (EGCG) COUNTERACTS THE NEGATIVE EFFECTS OF MATERNAL HYPERTHERMIA ON EMBRYONIC DEVELOPMENT IN MICE

2006 ◽  
Vol 18 (2) ◽  
pp. 185 ◽  
Author(s):  
A. Aroyo ◽  
S. Yavin ◽  
Z. Roth ◽  
A. Arav
Keyword(s):  
Embryonic Development ◽  
Ex Vivo ◽  
Formation Rate ◽  
Epigallocatechin Gallate ◽  
Saline Group ◽  
Culture Conditions ◽  
Developmental Competence ◽  
Blastocyst Formation ◽  
Negative Effects

Hyperthermia-induced oxidative stress is one of the suggested mechanisms underlying the loss of developmental competence in heat-stressed embryos. The objective of the present study was to determine whether pretreatment with the antioxidant epigallocatechin gallate (EGCG) would counteract the negative effects of maternal hyperthermia on oocyte competence and improve subsequent embryonic development. Exp. 1 examined the effect of pretreatment with EGCG on ex vivo embryonic development under normal culture conditions (KSOM, 37°C, 5% CO2, 95% RH in air). Female mice (CB6F1) were synchronized (PMSG + hCG) and injected with 0.4 mL EGCG (100 mg/kg body weight) or with saline. Both EGCG- and saline-treated females were paired with stud males overnight. Mated mice were sacrificed and putative zygotes recovered and cultured in vitro. Cleavage and blastocyst formation rates were recorded on Days 1 and 5 post-fertilization, respectively. The percentage of putative zygotes that cleaved into the two-cell stage did not differ between the groups; however, blastocyst formation rate was higher (P < 0.05) in the EGCG group (85 ± 2%) than in the saline group (75 ± 2%). In Exp. 2 (a 2 × 2 factorial study), both EGCG- and saline-treated mice were exposed to normo-thermal conditions (NT; 22°C, 45% RH) or heat stress (HS; 40°C, 70% RH) for 1.5 to 2 h, the latter to induce a rise of 2°C in body temperature. Synchronized mice were paired with stud males overnight and mated mice were then sacrificed. Putative zygotes were recovered and cultured in vitro as described above. The number of putative zygotes recovered, cleavage and blastocyst formation rates and percentage of hatched blastocysts are presented in Table 1. Blastocyst formation rate was higher (P < 0.05) in the HS-EGCG group than in the HS-saline group. In addition, HS-EGCG embryos exhibited developmental competence similar to that of embryos from both NT groups. In summary, pretreatment with EGCG improved developmental competence under the described culture conditions. Furthermore, pretreatment with the antioxidant EGCG counteracted the negative effects of maternal hyperthermia. Further studies are warranted to evaluate the effect of pretreatment with EGCG on embryo quality. Table 1. Effect of pretreatment with EGCG on developmental competence of heat stressed oocytes

Sign in / Sign up

Export Citation Format

Share Document