scholarly journals A novel embryo culture media supplement that improves pregnancy rates in mice

Reproduction ◽  
2017 ◽  
Vol 153 (3) ◽  
pp. 327-340 ◽  
Author(s):  
A R Highet ◽  
T Bianco-Miotto ◽  
K G Pringle ◽  
A Peura ◽  
S Bent ◽  
...  

The preimplantation embryoinvivois exposed to numerous growth factors in the female reproductive tract, which are not recapitulated in embryo culture mediain vitro. The IGF2 and plasminogen activator systems facilitate blastocyst development. We hypothesized that the addition of IGF2 in combination with urokinase plasminogen activator (uPA) and plasminogen could improve rates of blastocyst hatching and implantation in mice. B6BcF1 and CBAB6F2 mouse embryos were divided into one of four supplemented culture media treatment groups: (1) control (media only); (2) 12.5 nM IGF2; (3) 10 µg/mL uPA and 5 µg/mL plasminogen; or (4) a combination of IGF2, uPA and plasminogen treatments. Embryo development to blastocyst stage and hatching were assessed before transfer to pseudopregnant recipient females and implantation, pregnancy rates and postnatal growth were assessed. After 90.5 h of culture, IGF2 + U + P treatment increased the percentage of B6BcF1 embryos that were hatching/hatched and percentage developing to blastocyst stage compared with controls (P < 0.02). Following B6BcF1 embryo transfer, IGF2 + U + P treatment increased implantation sites at day 8 of pregnancy compared with controls (P < 0.05). Replication in the CBAB6F2 mouse strain showed significant improvements in pregnancy rates at days 8 and 18 but not in blastocyst development. No adverse effects were seen on gestational age, litter size or birthweight, or the reproductive capacity of offspring of IGF2 + U + P treated embryos. For embryos susceptible to detrimental effects ofin vitroculture, IGF2, uPA and plasminogen supplementation of culture media can improve pregnancy success, but the effect of treatment is dependent on the mouse strain.

2016 ◽  
Vol 28 (2) ◽  
pp. 180

The nonhuman primate (NHP) is a valuable translational model for human health studies and is widely used to investigate pre-implantation embryo development. Central to these investigations is the dependency on in vitro embryo culture (IVC). Since 2001, the single-step hamster embryo culture medium (HECM) has been the accepted standard for NHP IVC. With recent advances in formula optimization for IVC in human clinics, a re-examination of optimal NHP IVC media is warranted. Thus, two types of commercially available IVC media routinely used in human applications were compared with HECM-9: Global (single-step; LifeGlobal Group, Guilford, CT, USA), and Quinns Advantage (sequential; SAGE, Trumbull, CT, USA). Normally cycling, adult rhesus monkeys (n = 3) underwent controlled ovarian stimulations, and follicles were aspirated via laparoscope. Recovered ova were fertilized in vitro and the resultant zygotes (n = 138) were cultured for 9 days in HECM-9, Global, or Quinns with 10% protein supplement at 37.5°C in humidified tri-gas (6% CO2, 5% O2, and 89% N). Single-step media (HECM-9 and Global) were refreshed every two days while embryos were cultured for Days 1–3 in Quinns Advantage Cleavage medium without being replaced and in Quinns Advantage Blastocyst medium for Days 4–9 with medium changes every 2 days. Embryos were observed for cleavage, compaction, and blastocyst development. Proportional data with equal variance and normal distribution were analysed by one-way ANOVA, and significance was determined post-hoc by the Holm-Sidak method with P < 0.05. Developmental stage data ± s.e.M are presented in Table 1; a change in superscript indicates a significant difference within the column. There was no difference in embryonic cleavage or morula compaction between the three culture media evaluated, indicating no obvious differences in their effects on embryonic development 1 to 3 days after fertilization. However, a greater proportion of blastocysts developed in Global medium compared with HECM-9, and though it was not statistically different, embryos cultured in Global tended to reach the blastocyst stage more frequently than those in Quinns. Although not significant due to large variances in each group, blastocyst expansion also tended to occur more frequently in Global medium than in HECM-9 or Quinns. Taken together, these data indicate that single-step Global is as supportive of early embryonic development as HECM-9 but is better formulated to facilitate later stage differentiation and would be better suited for use in updated standard NHP IVC protocols. Table 1.Cleavage, compaction, blastocysts, and expansion of embryos in HECM-9, Global, and Quinns media


2004 ◽  
Vol 16 (2) ◽  
pp. 202 ◽  
Author(s):  
W.F. Swanson ◽  
A.L. Manharth ◽  
J.B. Bond ◽  
H.L. Bateman ◽  
R.L. Krisher ◽  
...  

Domestic cat embryos typically are cultured in media formulated for somatic cells or embryos from rodents or livestock species. Under these conditions, blastocyst development has been inconsistent and delayed relative to embryos grown in vivo, and embryo viability following transfer has been low. Our goal is to systematically define the culture requirements of the feline embryo to improve embryo development and viability. The objective of this study was to determine the ionic (NaCl, KCl, KH2PO4, and CaCl2:MgSO4) preferences of domestic cat IVF embryos. Anestral female cats were injected (i.m.) with 150IU eCG followed 84h later by 100IUhCG. Oocytes were recovered via laparoscopic follicular aspiration approximately 24h post-hCG injection (Day 0). Semen was collected from one of two males by means of an artificial vagina and washed once in HEPES-buffered IVF medium. Mature cumulus-oocyte complexes were co-incubated with 2.5–5×105 motile sperm mL−1 in IVF medium (100mM NaCl, 4.0mM KCl, 1.0mM KH2 PO4, 2.0mM CaCl2, 1.0mM MgSO4-7H2O, 25.0mM NaHCO3, 3.0mM glucose, 0.1mM pyruvate, 6.0mM L-lactate, 1.0mM glutamine, 0.1mM taurine, 1×MEM nonessential amino acids, 50μgmL−1 gentamicin, and 4.0mgmL−1 BSA) for 19 to 22h in 6% CO2 in air (38.7°C). Cumulus cells were removed and embryos cultured (8–11 embryos/50μL drop; 6% CO2, 5% O2, 89% N2, 38.7°C) in media containing 100.0 or 120.0mM NaCl, 4.0 or 8.0mM KCl, 0.25 or 1.0mM KH2PO4, and 1.0mM:2.0mM or 2.0mM:1.0mM CaCl2:MgSO4 (2×2×2×2 factorial design). The remaining components of the culture medium were identical to the IVF medium (but w/o gentamicin). Development to the blastocyst stage by Day 6, metabolism (glycolysis and pyruvate) of each blastocyst, and final cell number (Hoechst 33342 staining) of all embryos were evaluated. Final cell number of cleaved embryos and development to the blastocyst stage were analyzed using analysis of variance in the GLIMMIX macro of SAS. A total of 236 oocytes were inseminated, yielding 128 cleaved embryos (54%), including 6 blastocysts (4.7% of cleaved embryos). Cell number was not (P&gt;0.05) affected by NaCl, KCl, or KH2PO4 concentrations, but tended (P=0.057) to be higher after culture in 2.0mM:1.0mM CaCl2:MgSO4. Treatments did not significantly affect (P&gt;0.05) development to the blastocyst stage, but numerically more blastocysts were produced in 100.0mM NaCl (4/6), 8.0mM KCl (5/6), or 1.0mM KH2PO4 (5/6). Both CaCl2:MgSO4 ratios resulted in 3 blastocysts. Blastocysts contained 61.08±5.1 (mean±SEM, n=6) cells and actively metabolized glucose (glycolysis, 3.7±0.8pmol/embryo/3h or 0.06±0.01pmol/cell/3h) and pyruvate (0.75±0.27pmol/embryo/3h or 0.013±0.005pmol/cell/3h). These results suggest that the ionic composition of culture media influences the in vitro development of cat IVF embryos. (Supported by NIH grant RR15388.)


2014 ◽  
Vol 26 (1) ◽  
pp. 154 ◽  
Author(s):  
D. Moreno ◽  
A. Neira ◽  
L. Dubreil ◽  
L. Liegeois ◽  
S. Destrumelle ◽  
...  

In the majority of media for embryo culture, 2 of typical components used are FCS or BSA; however, the presence of FCS in the culture medium has been shown to have a negative effect on embryo quality and the use of animal-derived proteins in culture media increases the risks of disease transmission through in vitro embryo production. The aim of this study was to develop an in vitro embryo culture medium free from FCS and BSA, but with the addition of various growth factors and cytokines (GF-CYK: IGF-I, IGF-II, bFGF, LIF, GM-CSF) 50 ng mL–1 and (TGF-β1) 100 ng mL–1 supplemented with hyaluronan (HA) and recombinant albumin (RA). Bovine oocytes (n = 1043, 6 replicates) from abattoir ovaries were matured in TCM-199 medium with 60 μg mL–1 penicillin, 60 μg mL–1 streptomycin, and 10 ng mL–1 EGF for 24 h at 39°C and 5% CO2 in humidified air. Afterward, the oocytes were fertilized in IVF-TALP medium with 6 mg mL–1 fatty acid-free BSA and 1.7 IU mL–1 heparin for 18 h under the same conditions. After fertilization, presumptive zygotes were divided into two groups and cultured in 30 μL droplets of SOF supplemented with (1) 0.4% BSA + 5 μg mL–1 insulin, 5 μg mL–1 transferrin, and 5 ng mL–1 selenium (ITS) as a control; or (2) GF-CYK + 0.5 mg mL–1 HA + 0.15% RA (M1). Droplets were preserved under mineral oil in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 at 39°C. Blastocyst development and blastocyst diameter was observed at 7 and 8 days post-fertilization (dpf). Developmental and diameter data were analysed using the Wilcoxon test by using R software. The blastocyst rates were not significantly different between the control and M1 medium: at 7 dpf (22.9% ± 4.8 and 30.2% ± 3.0), and at 8 dpf (29.6% ± 5.1 and 37.4% ± 2.0 respectively; P > 0.05). The blastocyst diameter obtained with the M1 medium was significantly greater (P < 0.05) than that of the control at 7 dpf (173.3 μm ± 4.9 and 157.2 μm ± 4.1, respectively); however, no significant differences were observed at 8 dpf (190.3 μm ± 5.2 and 179.7 μm ± 5.3, respectively). In conclusion, the FCS- and BSA-free medium with GF-CYK, HA, and RA (M1) showed a comparable development rate to the control medium at 7 and 8 dpf. These growth factors and cytokines in association with hyaluronan and recombinant albumin have a synergistic action by promoting an increase in the blastocyst diameter at 7 dpf. This is fully synthetic method of embryo culture; it presents a valuable tool to reduce the risks of disease transmission via embryo transfer.


2018 ◽  
Vol 36 (03/04) ◽  
pp. 211-220 ◽  
Author(s):  
Sneha Mani ◽  
Monica Mainigi

AbstractAssisted reproductive technologies (ARTs) lead to an increased risk for pregnancy complications, congenital abnormalities, and specific imprinting disorders. Epigenetic dysfunction is thought to be one common mechanism which may be affecting these outcomes. The timing of multiple ART interventions overlaps with developmental time periods that are particularly vulnerable to epigenetic change. In vitro embryo culture is known to impact blastocyst development, in vitro fertilization (IVF) success rates, as well as neonatal outcomes. Embryo culture, in contrast to other procedures involved in ART, is obligatory, and has the highest potential for causing alterations in epigenetic reprograming. In this review, we summarize progress that has been made in exploring the effects of embryo culture, culture media, and oxygen tension on epigenetic regulation in the developing embryo. In humans, it is difficult to isolate the role of embryo culture on epigenetic perturbations. Therefore, additional well-controlled animal studies isolating individual exposures are necessary to minimize the epigenetic effects of modifiable factors utilized during ART. Findings from these studies will likely not only improve IVF success rates but also reduce the risk of adverse perinatal outcomes.


2004 ◽  
Vol 16 (2) ◽  
pp. 195
Author(s):  
Y.H. Choi ◽  
D.D. Varner ◽  
K. Hinrichs

Research on in vitro culture of equine embryos has been scant, due to failure of equine in vitro fertilization to be repeatably successful. We have recently obtained high fertilization rates of equine oocytes via intracytoplasmic sperm injection (ICSI) using a piezo drill (Choi et al., 2002 Reproduction 123, 455–465). Culture of presumptive zygotes in G1.2/2.2 medium resulted in 63% cleavage and an average of 15 cells at 4d, but only 2 to 9% blastocyst development at 7 days (Choi et al., 2003 Theriogenology 59, 1219–1229). In the present study, we evaluated the effect of two different culture media, G1.3/G2.3 v. DMEM/F-12, with or without FBS, on blastocyst development after ICSI. Oocytes were collected from slaughterhouse-derived ovaries by follicular scraping and were matured in vitro for 24h in M199 with 10% FBS and 5μUmL−1 FSH. After culture, oocytes having a polar body (198/305; 65%) were fertilized by ICSI with frozen-thawed equine sperm using a piezo drill. Presumptive zygotes were cultured in 1 of 4 media: G1.3/G2.3 (which includes 0.8% BSA) with or without 10% FBS, or in DMEM/F-12 with 0.5% BSA, with or without 10% FBS. Culture was performed in microdroplets at 5μL/zygote under oil at 38.2°C in an atmosphere of 5% CO2, 5% O2 and 90% N2 for 7.5 days. In G1.3/2.3 treatments, G1.3 media were completely refreshed at 48h, zygotes were transferred to G2.3 (with or without FBS as per the first stage) at 96h, and were completely refreshed with the same media at 144h. In DMEM/F-12 treatments, media were completely refreshed every other day. Three to 5 replicates were performed in each treatment, and data were analyzed by chi-square test. There were no significant differences in cleavage rates (59–64%) among treatments. The rate of development to blastocyst, per oocyte injected, in G1.3/G2.3/BSA (1/49, 2%) was significantly lower (P&lt;0.05) than that for the other three treatments: G1.3/2.3/BSA/FBS (9/49, 18%), DMEM/F-12/BSA (9/50, 18%), or DMEM/F-12/BSA/FBS (10/50, 20%). There was no significant difference in blastocyst development among the latter three treatments. These findings indicate that G1.3/2.3 media with BSA only do not adequately support growth of equine embryos. Development of up to 20% of injected oocytes to the blastocyst stage in G media supplemented with FBS, in DMEM/F-12/BSA or in DMEM/F-12/BSA/FBS represents the highest in vitro equine blastocyst rate in medium alone (i.e. without co-culture) yet reported. The success of DMEM/F-12 as an embryo culture medium may provide a relatively simple basis for equine in vitro culture programs. To determine whether this medium was able to support further developmental competence, we cultured equine embryos resulting from nuclear transfer of in vitro-matured oocytes in DMEM/F-12+10% FBS (without BSA). We transferred 4 resulting blastocysts to recipient mares by transcervical transfer; one pregnancy is ongoing at 230d gestation at the time of this writing. This work was supported by the Link Equine Research Endowment Fund, Texas A&amp;M University.


2007 ◽  
Vol 19 (1) ◽  
pp. 168
Author(s):  
Y.-H. Zhang ◽  
Y.-T. Du ◽  
K. Zhang ◽  
J. Li ◽  
P. M. Kragh ◽  
...  

The present study was designed to examine the effect of trichostatin A (TSA, a histone deacetylase inhibitor) treatment on in vitro developmental ability of pig cloned embryos and to evaluate the feasibility of producing piglets from these embryos. Cell lines were established from 40-day-old fetuses, and adult ear skin was used as nuclear donor. In vitro-matured oocytes from abattoir-derived sow ovaries were used as cytoplast recipients for micromanipulator-assisted somatic cell nuclear transfer (SCNT). Data were analyzed by using SPSS (11.0) with one-way ANOVA, and each experiment was replicated at least 3 times. In Experiment 1, immediately after simultaneous fusion and activation, the reconstructed couplets were randomly cultured in porcine zygote medium 3 (PZM3; Yoshioka et al. 2002 Biol. Reprod. 66, 112–119) with 10 �g mL-1 cytochalasin B (CB), 10 �g mL-1 cycloheximide (CHX), and 0 nM, 5 nM, or 50 nM TSA for the first 4 h. Cloned embryos (fused reconstructed couplets) were moved to the same culture media but without CB and CHX and further cultured at 38.5�C, under 5% CO2, 5% O2, 90% N2 and 100% humidity. After incubation for a total of 8–14 h in 50 nM, 19–24 h in 50 nM or 5 nM, and 31–36 h in 50 nM TSA in PZM3 (0 nM TSA serves as control for each group), the embryos were further cultured in vitro without TSA in PZM3 for up to 168 h. Cleavage and blastocyst development rates, based on embryos cultured, were recorded at 48 and 168 h of IVC, respectively. Results showed that 50 nM TSA treatment for 19-24 h supported a higher blastocyst development rate than the control group [No. blastocysts/No. embryos cultured (mean � SEM): 107/258, 47.4 � 5.9% vs. 65/324, 20.0 � 2.3%, respectively; P &lt; 0.05], whereas similar pre-implantation development was obtained between the other 3 test groups and the control. In Experiment 2, TSA-treated cloned embryos at the one-cell stage or blastocyst stage were transferred to recipients to examine the possibility of producing piglets. Ten cloned piglets (2 are healthy and 8 died shortly after birth) and one ongoing pregnancy were obtained from 3 recipients who received an average of 110 one-cell stage embryos, whereas 4 piglets originating from traditional cloning were produced from one recipient which received 28 traditional cloned blastocysts (produced from the effective group in Experiment 1) and 30 handmade but non-TSA-treated ones. Our data demonstrate that TSA treatment after SCNT in porcine can significantly improve the in vitro blastocyst production, and embryos treated with TSA could support full-term development and result in healthy offspring.


2017 ◽  
Vol 29 (1) ◽  
pp. 150 ◽  
Author(s):  
L. D. Spate ◽  
S. L. Murphy ◽  
J. A. Benne ◽  
A. Giraldo ◽  
D. Hylan ◽  
...  

It has long been thought that oocytes obtained from sows yielded a higher level of developmental competence compared with oocytes obtained from prepubertal gilts. Because gilt-derived oocytes are more readily available to our laboratory and they are less developmentally competent, we hypothesised that by making alterations to our maturation system we could improve the developmental competence of the gilt-derived oocytes to that of their sow-derived counterparts. We performed 2 experiments that evaluated the ability of each source of oocyte to develop to the blastocyst stage, using altered maturation media. The first experiment focused on the developmental ability of each source of oocytes, through IVF and culture. The second experiment again focused on the developmental competence of each oocyte source but through somatic cell NT. For both experiments, the sow-derived oocytes were obtained from Desoto Biosciences and the gilt ovaries were collected from Smithfield Inc. in Milan, Missouri. Both sets of oocytes were in vitro matured in M199 supplemented with 0.57 mM cysteine, 5 μg mL−1 LH and FSH, and 10 ng mL−1 epidermal growth factor; however, the gilt derived media was altered to contain 40 ng mL−1 fibroblast growth factor 2 and 20 ng mL−1 insulin-like growth factor and leukemia inhibitory factor. Additionally, the maturation media for the sow-derived oocytes contained the addition of 5 μg mL−1 insulin and 10% follicular fluid. In the first experiment we performed IVF on oocytes from the 2 sources as per our laboratory standard IVF procedure, co-incubating the oocytes with 0.25 × 106 porcine semen for 4 h, followed by washing and moving the oocytes to MU2 culture media at 38.50°C in 5% CO2, humidified air overnight. After overnight culture the presumptive zygotes were transferred to the same conditions with 5% CO2, 5% O2, and 90% N2. After an additional 5 days, blastocyst development was assessed. The gilt oocytes yielded 39.3a ± 7.2% blastocyst, and the sow oocytes had a blastocyst rate of 24.9b ± 6.9%, with an n of 389 and 313, respectfully. Statistical analysis was performed by using Genmod in SAS 9.4. In the second experiment, using standard laboratory protocol for somatic cell NT, we activated both sets of oocytes with 200 μM thimerosal for 10 min followed by 30-min incubation with 4 mM dithiothreitol. The embryos were co-incubated for 15 h with 500 nM Scriptaid in the MU2 culture media in 5% CO2, humidified air; then these embryos were also moved to 5% CO2, 5% O2, and 90% N2 and cultured to Day 6. The sow oocytes produced a blastocyst percentage of 38.6%, and the gilt oocyte group had a blastocyst percentage of 43.5%, with an n of 290 and 285, respectfully. There was no difference statistically between these treatments. Both gilt and the sow oocyte sources have yielded live piglets at this time. We concluded that the maturation system used for our gilt-derived oocytes resulted in equal or better development in vitro compared with the sow-derived oocytes. Follow-up experiments evaluating in vivo development are needed for a complete comparison. This work was funded by Food for the 21st Century University of MO, and the NIH U42OD011140.


2007 ◽  
Vol 87 (4) ◽  
pp. 539-542 ◽  
Author(s):  
A. Marques ◽  
G. Antunes ◽  
P. Santos ◽  
A. Chaveiro ◽  
F. Moreira da Silva

Bovine oocytes were matured and fertilised under 5% CO2. Presumptive zygotes were co-cultured in synthetic oviductal fluid droplets, supplemented with either 0 (control), 25, 50, 100, or 200 µM of α-tocopherol. Blastocyst development rates were significantly influenced (P < 0.05) by the level of antioxidant in the culture media. Control showed a blastocyst yield of 18.46, 21.11, 27.92, and 31.66%, respectively, at α25; α50 and α100. Blastocyst yield for α200 was severely decreased, to 8.01%. An increase in overall IVF results was also observed as the concentration of α-tocopherol increased (control, 14.21%; α25, 14.35%; α50, 19.52%; α100, 21.11%), decreasing to 5.75% for the concentration of α200. The present study clearly demonstrates that α-tocopherol at a concentration of 100 µM significantly improves the proportion of oocytes that develop to the blastocyst stage. Key words: Antioxidant, α-tocopherol, reactive oxygen species, bovine, embryo


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.


2012 ◽  
Vol 24 (1) ◽  
pp. 156
Author(s):  
C. Vigneault ◽  
S. L. Underwood ◽  
V. Fournier ◽  
D. Bousquet ◽  
J. Belanger ◽  
...  

Despite hundreds of scientific papers published, no system has resulted in in vitro embryos comparable to those produced in vivo. We hypothesised that assembling the most pertinent elements of IVF studies into one system would result in a highly efficient in vitro culture system. Here we report the in vitro production of bovine embryos using a culture system with strict environmental conditions that produces very-good-quality embryos at high rates. This system consists of a sequential culture system with media composition based on recent reports that characterise the bovine female reproductive tract (Hugentobler et al. 2007 Mol. Reprod. Dev. 74, 445–454; Hugentobler et al. 2007 Theriogenology 68, 538–548; Hugentobler et al. 2008 Mol. Reprod. Dev. 75, 496–503). This system uses a 3-step culture media to prevent toxicity resulting from ammonium accumulation and nutrient depletion and also to adjust the component concentrations to support embryo needs at different developmental stages. Fatty acid-free BSA is used as the protein source and the culture is in droplets under high-quality paraffin oil at 38.5°C under 6.8% CO2, 5% O2 and 88.2% N2. Numerous other aspects were investigated to limit embryo stresses (Lane et al. 2008 Reprod. Fertil. Dev. 20, 23–32) during manipulations, including the use of mini-incubators and very-high-purity gas combined with stringent laboratory practices. In the first year using this new embryo production system, 2839 oocytes were fertilized, resulting in a transferable blastocyst rate of 51%. Of the 1448 embryos produced, 779 were transferred fresh at our facility with pregnancy rates of 55 and 49% at 28 and 60 days, respectively. Pregnancy rates were directly related to the quality of the embryos transferred as 61% of grade 1 embryos transferred induced a pregnancy at Day 28, compared with 41% of grade 2 embryos. Pregnancy induction is not the only indication of good embryo quality. As is well-documented, in vitro-produced bovine embryos do not tolerate slow freezing, so vitrification was applied to surmount this intolerance. However, this is difficult to apply to industry because direct transfer of vitrified embryos is challenging. We hypothesised that the improvement of embryo culture would result in embryos that could tolerate slow freezing. Grade 1 blastocysts (n = 229) were frozen in 1.6M ethylene glycol and 0.1 M sucrose using standard slow freezing procedures. A very high proportion (91%) of frozen–thawed in vitro-produced embryos re-expanded after 24 h of culture with a good quality inner cell mass. Subsequently, 45 grade 1 blastocysts were frozen and transferred, giving pregnancy rates of 58% at Day 60. In conclusion, combining good-quality culture media and conditions resulted in the production of in vitro embryos that were very efficient at inducing pregnancies and tolerating slow freezing, which makes it now possible to consider direct transfer of frozen in vitro-produced bovine embryos.


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