scholarly journals Phyto-oestrogens affect fertilisation and embryo development in vitro in sheep

2018 ◽  
Vol 30 (8) ◽  
pp. 1109 ◽  
Author(s):  
Anna Aryani Amir ◽  
Jennifer M. Kelly ◽  
David O. Kleemann ◽  
Zoey Durmic ◽  
Dominique Blache ◽  
...  

Phyto-oestrogens such as isoflavones are natural compounds that can profoundly affect reproductive function. In the present study, we tested whether including isoflavone compounds (genistein, biochanin A, formononetin) in the maturation medium would affect the outcomes for ovine oocytes in vitro. Each isoflavone compound was evaluated at five concentrations (0, 2.5, 5, 10, 25 µg mL−1) and the entire protocol was repeated four times. Cumulus–oocyte complexes were randomly allocated to the treatments, then fertilised and cultured in vitro. Compared with control (0 µg mL−1), the lower concentrations of isoflavone (2.5, 5 and 10 µg mL−1) had no detectable effect on the rates of cleavage or embryo development, or on embryo total cell counts (TCC). However, the highest concentration (25 µg mL−1) of all three isoflavones exerted a variety of effects (P < 0.05): genistein decreased cleavage rate, blastocyst rate and blastocyst efficiency (blastocysts produced per 100 oocytes); biochanin A decreased cleavage rate and blastocyst efficiency; and formononetin decreased blastocyst rate and blastocyst efficiency. Biochanin A (25 µg mL−1) reduced embryo TCC specifically at the hatched blastocyst stage (P < 0.05). We conclude that the presence of isoflavones at 25 µg mL−1 during IVM decreases the cleavage rate and inhibits blastocyst hatching.

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 748
Author(s):  
Joanna Kochan ◽  
Agnieszka Nowak ◽  
Barbara Kij ◽  
Sylwia Prochowska ◽  
Wojciech Niżański

The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision®, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest proportion of embryos (46%) cleaving between 21 and 24 hpi. The timing of the first cleavage significantly affected further embryo development, with the highest development occurring in embryos that cleaved at 21–22 hpi. Embryos that cleaved very early (17–18 hpi) developed poorly to the blastocyst stage (2%) and none of the embryos that cleaved later than 27 hpi were able to reach the blastocyst stage. Morphological defects were observed in 48% of the embryos. There were no statistically significant differences between the timing intervals of the first cleavage division and the frequency of morphological defects in embryos. Multiple (MUL) morphological defects were detected in more than half (56%) of the abnormal embryos. The most frequent single morphological defects were cytoplasmic fragmentation (FR) (8%) and blastomere asymmetry (AS) (6%). Direct cleavage (DC) from 1–3 or 3–5 blastomeres, reverse cleavage (RC) and vacuoles were rarely observed (2–3%). The timing of blastocyst cavity formation is a very good indicator of embryo quality. In our study, blastocyst cavity formation occurred between 127–167 hpi, with the highest frequency of hatching observed in blastocysts that cavitated between 142–150 hpi. Blastocysts in which cavitation began after 161 h did not hatch. In conclusion, the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 310-310
Author(s):  
Saulo Menegatti Zoca ◽  
Julie Walker ◽  
Taylor Andrews ◽  
Adalaide C Kline ◽  
Jerica J Rich ◽  
...  

Abstract Sire conception rate (SCR) is a field measure of fertility among bulls, but it can be influenced by several factors (Sperm transport, sperm-egg binding, early embryo development, etc). The objective of this study was to evaluate the relationship between SCR, sperm motility, SERPINA5 concentrations, and in vitro embryo development. Measurements were performed in 19 bulls with SCR values ranging from -7.7 to 4.45. For each bull, an aliquot of frozen-thawed semen was used for analyses of total (TMOT) and progressive (PROG) motility. Remaining semen was fixed with 2% formaldehyde, and concentration of SERPINA5 was determined by immunolocalization (antibody SERPINA5/Dylight405; PA5-79976-Invitrogen / ab201798-Abcam). Mean fluorescence intensity was determined in ~200 sperm heads/bull. Approximately 149 oocytes/bull were fertilized in vitro for embryo development analysis (cleavage and blastocyst rates). Statistical procedures were performed in SAS (9.4) using the procedures CORR for correlations (SCR, TMOT, PROG, SERPINA5, cleavage and blastocyst) and GLIMMIX for comparison of “field-fertility” (SCR divided in HIGH or LOW) and “field-embryo-fertility” (LOW-SCR sires were divided based on blastocyst rate (HIGH or LOW) resulting in two classifications; LOW-HIGH≥31% and LOW-LOW≤26%, respectively). There were positive correlations (P &lt; 0.05) between cleavage-blastocyst (r=0.50), SERPINA5-cleavage (r=0.48), and TMOT-PROG (r=0.76). Sire SCR was not associated with SERPINA5, TMOT, PROG, cleavage and blastocyst rate (P &gt; 0.52). Among LOW-SCR sires, LOW-LOW sires (-4.83±0.60) tended to have a better SCR score than LOW-HIGH (-6.18±0.42) sires (P = 0.08), but there were no differences (P &gt; 0.43) between LOW-HIGH, LOW-LOW, and HIGH sires for SERPINA5, TMOT, PROG, and cleavage. In conclusion, some LOW SCR sires have good embryo development indicating a different mechanism for their low SCR; however, these differences in SCR could not be explained by TMOT, PROG, SERPINA5, cleavage and blastocyst. There were, however, positive correlations between cleavage-blastocyst rate, and SERPINA5-cleavage rate.


2008 ◽  
Vol 20 (1) ◽  
pp. 177
Author(s):  
P. Bermejo-Álvarez ◽  
A. Gutiérrez-Adán ◽  
P. Lonergan ◽  
D. Rizos

The faster-developing blastocysts in IVC systems are generally considered more viable and better able to survive following cryopreservation or embryo transfer than those that develop more slowly. However, evidence from several species indicates that embryos that reach the blastocyst stage earliest are more likely to be males than females. The aim of this study was to determine whether the duration of maturation could affect early embryo development and, furthermore, the sex ratio of early- or late-cleaved embryos and blastocysts. Cumulus–oocyte complexes were matured in vitro for 16 h (n = 2198) or 24 h (n = 2204). Following IVF, presumptive zygotes from each group were examined every 4 h between 24 and 48 h postinsemination (hpi) for cleavage, and all embryos were cultured to Day 8 in synthetic oviduct fluid to assess blastocyst development. Two-cell embryos at each time point and blastocysts on Days 6, 7, and 8 from both groups were snap-frozen individually for sexing. Sexing was performed with a single PCR using a specific primer BRY. There was a significantly lower number of cleaved embryos from the 16-h compared with the 24-h maturation group at 28 (10.0 � 1.51 v. 28.8 � 3.57%), 32 (35.3 � 1.48 v. 57.6 � 3.33%), 36 (54.8 � 1.76 v. 67.4 � 2.81%), 40 (63.3 � 1.82 v. 72.0 � 2.54%), and 48 (70.6 � 1.78 v. 77.1 � 2.18%) hpi, respectively (mean � SEM; P d 0.05). However, the blastocyst yields on Day 6 (17.1 � 3.11 v. 16.4 � 2.11%), 7 (30.6 � 4.10 v. 34.6 � 3.51%), or 8 (34.1 � 3.90 v. 39.4 � 4.26%) were similar for both groups (mean � SEM; 16 v. 24 h, respectively). Significantly more 2-cell early cleaved embryos (up to 32 hpi) were male compared with the expected 1:1 ratio from both groups (16 h: 1.24:0.76 v. 24 h: 1.17:0.83, P ≤ 0.05); however, the overall sex ratio among 2-cell embryos was significantly different from the expected 1:1 in favor of males only for the 16-h group (1.18:0.82, P ≤ 0.05). The sex ratio of blastocysts on Day 6, 7, or 8 from both groups was not different from the expected 1:1. However, the total number of male blastocysts obtained after 8 days of culture from the 24-h group was significantly different from the expected 1:1 (1.19:0.81, P ≤ 0.05) and approached significance in the 16-h group. These results show that the maturational stage of the oocyte at the time of fertilization has an effect on the kinetics of early cleavage divisions but not on blastocyst yield. Furthermore, irrespective of the duration of maturation, the sex ratio of early-cleaving 2-cell embryos was weighted in favor of males, and this observation was maintained at the blastocyst stage.


2016 ◽  
Vol 28 (2) ◽  
pp. 147
Author(s):  
J. Block ◽  
A. M. Zolini ◽  
E. Carrascal-Triana ◽  
A. Ruiz ◽  
P. J. Hansen ◽  
...  

The objective of the present study was to determine the effect of supplementation of maturation media with L-carnitine and trans-10,cis-12 conjugated linoleic acid (CLA) on embryo development and survival following cryopreservation. Immature bovine cumulus-oocyte complexes (n = 1796) were harvested from abattoir-derived ovaries and randomly assigned in a 2 × 2 factorial design to be matured in maturation medium [TCM-199 with Earle salts supplemented with 10% (vol/vol) bovine steer serum, 2 μg mL–1 oestradiol 17-β, 20 μg mL–1 bovine FSH, 22 μg mL–1 sodium pyruvate, 50 μg mL–1 gentamicin sulfate, and 1 mM glutamax®] supplemented with or without 100 mM CLA and with or without 3.03 mM L-carnitine for 22 to 24 h at 38.5°C in a humidified atmosphere of 5% CO2. The proportion of oocytes that cleaved was determined on Day 3 after insemination, and the proportion of oocytes developing to the blastocyst and advanced blastocysts stages (expanded, hatching, and hatched) was assessed on Day 7. Blastocyst and expanded blastocyst stage embryos (n = 270) were harvested on Day 7 and subjected to controlled-rate freezing following equilibration in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h in SOF-BE1 (Fields et al. 2011) supplemented with 10% (vol/vol) fetal bovine serum and 50 μM dithiothreitol. Post-thaw re-expansion and hatching rates were determined at 24, 48, and 72 h. The experiment was replicated 5 times. There was no effect of supplementation of maturation medium with either CLA or L-carnitine on the proportion of oocytes that cleaved at Day 3 or that developed to the blastocyst and advanced blastocyst stages at Day 7 after insemination. There was no interaction between CLA and L-carnitine affecting cleavage rate or embryo development. Supplementation of maturation medium with L-carnitine did not affect post-thaw re-expansion or hatching rates. In contrast, treatment with CLA during maturation reduced (P < 0.05) post-thaw re-expansion (24 h: 75.2 ± 3.8% v. 60.3 ± 4.1%; 48 h: 82.0 ± 3.4% v. 64.9 ± 4.0%; 72 h: 78.9 ± 3.6% v. 65.9 ± 4.0%, respectively) and hatching (24 h: 33.7 ± 4.2% v. 23.5 ± 3.6%; 48 h: 61.1 ± 4.3% v. 44.0 ± 4.2%; 72 h: 62.6 ± 4.3% v. 50.2 ± 4.2%, respectively) rates at all time points. There was no interaction between CLA and L-carnitine affecting post-thaw viability. In conclusion, supplementation of maturation medium with L-carnitine did not affect embryo development or post-thaw viability. Although addition of CLA during maturation did not affect embryo development, post-thaw cryotolerance was reduced following CLA supplementation. There was no beneficial effect of supplementing maturation medium with both CLA and L-carnitine on embryo development or post-thaw cryosurvival.


2006 ◽  
Vol 18 (2) ◽  
pp. 119
Author(s):  
S. Arat ◽  
H. Bagis ◽  
A. Tas ◽  
T. Akkoc

The activation of oocytes is one of the most important steps for a successful cloning and has great importance on embryo development in vitro. The objective of this study was to examine the different parameters affecting parthenogenetic embryo development in vitro. In the first experiment, two activation protocols were compared to examine the effect of electrical pulse on activation. Bovine oocytes isolated from slaughterhouse ovaries were matured in TCM-199 supplemented with fetal bovine serum (FBS), sodium pyruvate, penicillin/streptomycin, rat insulin-like growth factor (rIGF-1), bovine follicle-stimulating hormone (bFSH), and bovine luteinizing hormone (bLH). A group of oocytes was exposed to a DC pulse of 133 V/500 �m for 25 �s, and then activated by calcium ionophore (5 �M) for 10 min, cytochalasin D (CD) (2.5 �g/mL) + cycloheximide (CHX, 10 �g/mL) for 1 h, and CHX alone for 5 h (Group 1). Another group of oocytes was activated only by chemicals without electrical pulse. Activated oocytes were cultured for 72 h in G1-3 and then 4-6 days in G2-3 medium. In the second experiment, oocytes activated by electrical pulse and chemicals were cultured in Barc medium for 7-9 days or 72 h in G1-3 and then 4-6 days in G2-3 medium. In the third experiment, oocytes activated by electrical pulse and chemicals were cultured for 48 h or 72 h in G1-3 and then 5-7 days or 4-6 days in G2-3 medium. The differences among groups were analyzed by one-way ANOVA after arcsin square transformation. In the first experiment, cleavage rate (75.6%), development rate (37.3%), and blastocyst cell number (78.4 � 3.2) of oocytes activated by electrical pulse was higher than for the group without electrical pulse (28.7%, 8.0%, 59.5 � 4.3, respectively; P < 0.05). This result showed that activation was started more effectively by electrical pulse than by chemicals. In the second experiment, there was no significant difference on cleavage rate between the two groups (66.6%, 65.0%, respectively), and the blastocyst development rate of parthenogenetic embryos cultured in G1-3/G2-3 (36.6%) was higher than in the Barc medium group (16.6%; P < 0.05). This result showed that G1-3/G2-3 medium was more effective for parthenogenetic embryo development than Barc medium. In the third experiment, although significant differences could not be found between the two groups in the development rate of parthenogenetic embryos cultured for a total of 7-9 days (30.8%, 39.2%, respectively), the development rate of embryos cultured for 72 h in G1-3 was higher (26.4%) than for the 48-h group (15%; P < 0.05) on Day 7. This result showed that embryos developed more slowly when cultured for a shorter time in G1-3 medium before transfer to G2-3 medium. This study was supported by a grant from TUBITAK, Turkey (VHAG-1022).


2015 ◽  
Vol 27 (1) ◽  
pp. 243
Author(s):  
M. E. Dell'Aquila ◽  
F. Ariu ◽  
N. A. Martino ◽  
F. Minervini ◽  
A. Cardinali ◽  
...  

Verbascoside (VB), a bioactive polyphenol from olive mill wastewater with known antioxidant activity, was shown to act as a pro-oxidant molecule, by impairing energy/redox status and embryo developmental competence of prepubertal ovine oocytes when added at micromolar concentrations in a continuative 24-h in vitro maturation (IVM) exposure protocol (1). The aim of the present study was to determine whether a lower (nanomolar) VB concentration and a shorter exposure time (2 v. 24 h) during IVM may improve the maturation rates of prepubertal ovine oocytes and their subsequent embryonic development in vitro. Cumulus-oocyte complexes derived from the ovaries of slaughtered 1-mo-old prepubertal sheep oocytes underwent IVM in TCM 199 with 10% oestrus sheep serum, 0.1 IU mL–1 of FSH/LH, and 100 µM cysteamine, in 5% CO2 in air at 38.5°C for 24 h. Based on our previous results (Dell'Aquila et al. 2014 Biomed. Res. Int. 2014, 878062), VB was added in the IVM medium at 1.03 nM, and 2 incubation times (24 and 2 h) were tested. In the 2-h exposure group, after 2 h of exposure to VB, oocytes were washed and cultured up to 24 h without VB. A group of oocytes were cultured in absence of VB, as controls. Matured oocytes were fertilized with frozen-thawed ram semen in SOF medium for 22 h and zygotes were cultured in vitro for 8 days. Metaphase II (MII) cleavage and blastocyst rates were analysed by Chi-squared test. Embryo quality was evaluated by staining and total cell count of the blastocyst and analysis of variance (ANOVA) was applied. Differences were considered to be significant when P < 0.05. Compared to controls, VB treatment at the concentration of 1.03 nM and 24 h of exposure had no effect on MII rates (196/268, 73% v. 226/323, 70% MII/cultured oocytes; P > 0.05). However, this treatment allowed to obtain significantly higher rates of cleaved embryos/MII oocytes (156/196, 80% v. 165/226, 73%; respectively; P < 0.05), blastocyst yield/cleaved embryos (59/156, 38% v. 45/165, 27%, respectively; P < 0.05), and total blastocyst cell numbers (108.62 ± 19.87 v. 89.61 ± 26.32, respectively; P < 0.05) compared to control oocytes. The VB treatment at the same concentration but for 2 h induced only significantly higher cleavage rate (196/210, 93% v. 165/226, 73%; P < 0.05). In conclusion, our results showed that VB treatment at 1.03 nM during 24 h of IVM exerted a positive effect on in vitro embryo development of prepubertal ovine oocytes by increasing the blastocyst yield and their quality. The hypothesis that VB at nanomolar concentrations may improve cumulus-oocyte energy/redox status is under investigation.The authors acknowledge support by the Regione Autonoma della Sardegna (LR 7, Agosto 2007, no. 7, CRP-17602). The authors thank Dr D. Bebbere and L. Falchi, Dept. Veterinary Medicine, Sassari, for statistical analysis.


2017 ◽  
Vol 29 (1) ◽  
pp. 183 ◽  
Author(s):  
T. A. Patrocínio ◽  
C. A. C. Fernandes ◽  
L. S. Amorim ◽  
J. R. Ribeiro ◽  
G. C. Macedo ◽  
...  

Oxidative stress is one of the main effects of in vitro culture. Generation of reactive oxygen species (ROS) by embryos can be enhanced by the sub-optimal in vitro culture conditions and are associated with a delay in embryonic development. However, supplementation of culture medium with antioxidant agents can minimize the effects of ROS (Guérin et al. 2001 Hum. Reprod. Update 7, 175–189). Resveratrol is an example of a potent antioxidant, and modifications in its structure can improve its biological activity. This study evaluated the effect of AR33 (formula with patent pending), an analogue of resveratrol with high antioxidant activity, on embryo development. Bovine cumulus-oocyte complexes recovered from ovaries collected at the slaughterhouse were in vitro matured for 24 h and oocytes were in vitro fertilized for 20 h, both at 38.8°C under 5% CO2 in air and high humidity. Partially denuded presumptive zygotes were randomly distributed in 4 treatments (with 6 replicates): 0 µM (control, n = 347), 0.1 µM (n = 337), 0.5 µM (n = 277), and 2.5 µM (n = 343) of AR33. The base medium was SOFaa supplemented with 2.5% FCS and incubation conditions were 38.8°C under 5% CO2 in air and high humidity. Half of culture medium was renewed (feeding) at Day 3 and 5 post-fertilization. Cleavage was evaluated at Day 3 and blastocyst rates at Day 7 and 8 post-fertilization. Data were analysed by logistic regression considering the significance level of P < 0.05. Values are shown as mean ± SEM. Cleavage rate was higher (P < 0.05) for 2.5 µM (69.0 ± 4.4%) than for 0, 0.1, and 0.5 µM AR33 (62.1 ± 2.0%, 60.7 ± 5.9%, and 56.7 ± 5.8%, respectively). At Day 7, the blastocyst rate was similar (P > 0.05) among 0.1, 0.5, and 2.5 µM (18.1 ± 5.4%, 17.5 ± 2.9%, and 19.4 ± 3.3%, respectively) and all of them were higher (P < 0.05) than 0 µM AR33 (12.4 ± 2.5%). At Day 8, there was again no difference (P > 0.05) among 0.1, 0.5, and 2.5 µM AR33 (21.0 ± 5.0%, 18.4 ± 2.1%, and 24.6 ± 3.3%, respectively) but only 0.1 and 2.5 µM showed higher (P < 0.05) blastocyst rate than 0 µM AR33 (15.2 ± 2.5%). In conclusion, the synthetic analogue of resveratrol tested in this study can improve bovine embryo development in culture medium supplemented with 2.5% FCS under 5% CO2 in air. A concentration of 2.5 µM AR33 can be a choice for further studies. This study was supported by Fapemig, CAPES, and CNPq.


2009 ◽  
Vol 21 (1) ◽  
pp. 206
Author(s):  
M. B. Raito ◽  
M. L. Mphaphathi ◽  
L. M. Schwalbach ◽  
J. P. C. Greyling ◽  
T. L. Nedambale

In an attempt to optimize germplasm and reproduction biotechnology IVF laboratory conditions in South Africa, we compared the effects of 2 triple-gas incubation systems, a tri-gas thermo incubator and a modular chamber with premixed gas, on the development of bovine embryos in vitro. After aspirating ovaries collected from a local abattoir, 778 oocytes were matured for 24 h in M-199 supplemented with 10% FBS, and 1 μg mL–1 of FSH and LH at 39°C in 5% CO2. Oocytes were then fertilized in vitro in Brackett and Oliphant (BO) medium at 39°C in 5% CO2. Presumptive zygotes were randomly allocated to the tri-gas thermo incubator or the modular chamber with premixed gas and cultured in synthetic oviductal fluid (SOF) medium at 39°C in 5% CO2, O2, and 90% N2. Total cleavage (Day 2), 8-cell (Day 2), morula (Day 6), and blastocyst (Day 7) rates were recorded postfertilization. Data were analyzed by ANOVA. There was no statistical difference in total cleavage rate between the 2 incubation systems. However, the 8-cell, morula, and blastocyst rates were significantly higher for the modular chamber group compared with the tri-gas incubator group (Table 1). In summary, this study suggests that the modular chamber with premixed gas was a better system for culturing zygotes of South African domestic animals to the blastocyst stage. Table 1.Effect of modular chamber and tri-gas incubator on embryo development in vitro This work was funded by the South African National Department of Agriculture, DST-PDP, and the National Research Foundation (NRF, Grant Nos. RT21 and 24000).


2012 ◽  
Vol 24 (1) ◽  
pp. 141
Author(s):  
C. M. O'Meara ◽  
T. Fair ◽  
P. Lonergan

Progesterone plays a key role in the reproductive events associated with pregnancy establishment and maintenance. High concentrations of circulating progesterone in the immediate post-conception period are associated with an advancement of conceptus elongation, an associated increase in interferon-tau production and higher pregnancy rates in cattle. Progesterone-induced changes in the uterine environment are thought to be responsible for the reported advancement in conceptus elongation; however, the function of the progesterone receptor in embryos is not known. Therefore, the aim of the current study was to examine the effect of adding a progesterone receptor antagonist (mifepristone, RU486) at various stages of early embryonic development and at varying concentrations to examine the effects on subsequent embryo development in vitro. Bovine zygotes (n = 2902), 2-cell (n = 1991) and 8-cell (n = 1244) embryos, derived by in vitro maturation and fertilization, were cultured in synthetic oviduct fluid medium in the absence or presence of RU486 at concentrations ranging from 0.0004 to 20 μg mL–1. Cleavage rate (of zygotes), 8-cell development rate (of 2-cell embryos) and development to the blastocyst stage (for all cell stages) were recorded at Day 2, 3 and 8 post-insemination (day of IVF = Day 0), respectively. Cultures of zygotes in the presence of RU486 at concentrations of 0.004 and 0.04 μg mL–1 resulted in a decline in cleavage rate (62.5 ± 2.55% and 48.8 ± 5.07% for respective treatments vs controls without RU486 81.9 ± 5.97%; P ≤ 0.05). These same concentrations resulted in a significant decline in blastocyst development on Day 8 (18.8 ± 1.82% and 17.4 ± 4.85% for respective treatments compared to controls 35.1 ± 4.89%; P ≤ 0.05). Cultures at concentrations of 0.4 μg mL–1 resulted in a 10-fold decrease in blastocyst development (3.3 ± 1.3%; P ≤ 0.05) and concentrations in excess of 10 μg mL–1 completely ablated blastocyst development (P ≤ 0.05). Cultures of 2-cell embryos with RU486 at concentrations below 8 μg mL–1 had no effect on 8-cell rate or blastocyst development. However, cultures with RU486 at 10 μg mL–1 resulted in a significant decline in the proportion reaching the 8-cell stage (59.1 ± 4.59% vs 38.1 ± 2.13% for control and treated, respectively) and developing to the blastocyst stage (32.8 ± 4.68% vs 17.8 ± 3.77% for control and treated, respectively; P ≤ 0.05). Cultures with RU486 at a concentration of 20 μg mL–1 resulted in a dramatic effect in 8-cell rate (16.3 ± 2.55%; P ≤ 0.05) and prevented blastocyst development. Similarly, cultures of 8-cell embryos with RU486 at concentrations at or below 10 μg mL–1 had no effect on blastocyst development. However, cultures at concentrations of 15 or 20 μg mL–1 resulted in no blastocyst development. In conclusion, addition of the progesterone and glucocorticoid receptor antagonist RU486 to culture media has a clear stage-specific and concentration-dependent effect on bovine embryo development, which is more pronounced at earlier developmental stages. Supported by Science Foundation Ireland (07/SRC/B1156).


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 361-362
Author(s):  
McKenzie L Haimon ◽  
Eliab Estrada-Cortés ◽  
Thiago F Amaral ◽  
Surawich Jeensuk ◽  
Froylan Sosa ◽  
...  

Abstract Choline is a nutrient that plays a role as a precursor for the neurotransmitter acetylcholine, the membrane phospholipid phosphatidylcholine, and the methyl donor betaine. Embryos produced in vitro are usually cultured without an exogenous choline source. We hypothesized that exposure to 1.8 mM choline chloride would increase percent of embryos becoming blastocysts in culture and pregnancy rate after transfer of embryos into recipients. A total of 39 Brahman and Senepol donors were used to produce embryos for transfer into recipient crossbred females. Donors were assigned to have their embryos cultured in either 1.8 mM choline chloride or, as a control, 1.8 mM extra NaCl. The percent of oocytes cleaved were measured 3 days after insemination and percent blastocyst at day 7.5. Embryos were transferred into recipient cows and pregnancy was diagnosed at 28–31 days of gestation and then confirmed at 50–56 days. Data were analyzed using PROC GLIMMIX in SAS. Treatment did not affect cleavage rate (67.3 + 1.6 vs 68.6 + 1.6% for choline vs control; P = .0.5632) or percent of cleaved embryos becoming blastocysts (17.6 + 1.3 vs 18.1 + 1.3%; P = 0.5355). Similarly, there was no effect of treatment on pregnancy days 28–31 [42.5% (48/113 cows) vs 47.3% (54/114 cows) for choline vs control; P = 0.4339] or at days 50–56 [39.1% (36/92) vs 38.5% (32/83); P = 0.5348]. In summary, 1.8 mM choline chloride does not impact embryo development to the blastocyst stage or pregnancy establishment. Further investigation is needed to evaluate the phenotype of the subsequent calves to determine whether early exposure to choline has consequences for postnatal function. Support: USDA-NIFA 2020-67015-30821.


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