28 Effect of deuterium oxide on bovine oocyte cryotolerance

2019 ◽  
Vol 31 (1) ◽  
pp. 140
Author(s):  
F. Salerno ◽  
M. Rubessa ◽  
B. Gasparrini ◽  
M. Wheeler

It is known that cryopreservation triggers spindle disassembly, increased aneuploidy risk, decreased post-thaw survival, fertilization, and embryo development. We hypothesised that a treatment with D2O before vitrification would slow down oocyte metabolism and reduce ice crystal formation by replacing water inside the cells. The aim of the study was to evaluate the effect of a 4-h treatment with different D2O concentrations (0, 3, 15, and 30%) on cryotolerance of bovine in vitro-matured oocytes. Abattoir-derived bovine oocytes were matured in vitro for 20h in TCM-199 medium with 15% of bovine serum (BS), 0.5µg mL−1 of FSH, 5µg mL−1 of LH, 0.8mM l-glutamine, and 50µg mL−1 of gentamicin at 39°C with 5% of CO2 and randomly divided into 5 experimental groups. A group of non-vitrified oocytes was used as the fresh oocyte control group, whereas the remaining oocytes were incubated for 4h in in vitro maturation medium with 0% (vitrified control; n=205), 3% (n=205), 15% (n=205), and 30% D2O (n=205) before vitrification. The experiment was repeated 4 times. Oocytes were denuded in HEPES-buffered TCM-199 (H199)+5% BS and vitrified using a cryotop freezing straw. The oocytes were incubated in 200μL of H199+20% BS with 7.5% ethylene glycol and 7.5% dimethyl sulfoxide for 3min. After that, oocytes were collected in 50μL of H199+20% fetal bovine serum with 15% ethylene glycol+15% dimethyl sulfoxide and 0.5M sucrose for 20s and plunged into LN2. One month later, oocytes were warmed in thawing media with decreasing concentrations of sucrose (1.35M to 0.31M) and then placed into in vitro maturation medium for 2h before IVF. Matured oocytes were IVF and cultured according to standard procedures (Rubessa et al. 2011 Theriogenology 76, 1347-1355). Cleavage and blastocyst rates were evaluated after 7 days of culture. Data were analysed using the GLM procedure of SPSS (SPSS Inc., Chicago, IL, USA). The least statistical difference post-hoc test was used to perform statistical multiple comparison. The α-level was set at 0.05. As expected, both cleavage [60.5±4.6 (fresh control); 36.9±2.6 (0% D2O); 46.3±3.7 (3% D2O); 31.6±2.4 (15% D2O); and 24.4±2.6 (30% D2O)] and blastocyst rates [25.7±0.8 (fresh control); 9.0±0.8 (0% D2O); 9.0±0.7 (3% D2O); 3.6±0.2 (15% D2O); and 4.3±0.8 (30% D2O)] decreased in all vitrified groups compared with the fresh control group. Within vitrified oocytes, cleavage rate increased (P<0.05) with 3% D2O treatment compared with the other groups. However, pretreatment with higher (15-30%) D2O concentrations decreased (P<0.05) blastocyst rates of vitrified-warmed oocytes. In conclusion, a pretreatment with low concentrations (3%) of D2O improved the cleavage rate of bovine vitrified-warmed oocytes, suggesting a potential beneficial effect, whereas deleterious effects were observed using the higher concentrations. Therefore, further studies are required to assess a potential use of D2O to improve oocyte cryotolerance, likely testing different incubation times.

2016 ◽  
Vol 28 (2) ◽  
pp. 151
Author(s):  
H. S. Canesin ◽  
I. Ortiz ◽  
J. G. Brom-de-Luna ◽  
Y. H. Choi ◽  
K. Hinrichs

Oocyte cryopreservation has the potential to preserve female genetics. In addition, equine oocytes are not readily available in some areas, and vitrification could be used to accumulate oocytes at remote locations to provide material for research. To preserve large numbers of oocytes, a method for rapid vitrification of multiple oocytes is needed. First, we determined whether immature equine oocytes could be held overnight before vitrification, and we tested the use of a mesh+capillary-action media-removal vitrification platform. Oocytes were collected via ultrasound-guided transvaginal follicle aspiration and randomly allotted to either immediate vitrification or overnight holding (24 to 27 h in 40% M199-Earle’s salts, 40% M199-Hanks’ salts, 20% fetal bovine serum, and 0.3 mM pyruvate) then vitrification. Oocytes were vitrified using different times (1 or 4 min) in vitrification solution and first warming solution: 1v1w, 1v4w, 4v1w, and 4v4w. The base solution was MH (80% M199-Hanks’ salts and 20% fetal bovine serum). Cryoprotectant concentration (vol/vol) was increased in 3 steps until reaching 7.5% dimethyl sulfoxide and 7.5% ethylene glycol. The oocytes were then held in vitrification solution (MH with 15% dimethyl sulfoxide, 15% ethylene glycol, and 0.5 M sucrose) for either 1 or 4 min, according to treatment, and 3 to 10 oocytes were transferred to a 75-μm sterile stainless steel mesh. The mesh was placed on sterile paper to absorb excess medium, then plunged in LN. The oocytes were warmed in MH solution with 1.25 M sucrose for either 1 or 4 min, then placed in 0.62 M and 0.31 M sucrose solutions for 5 min each and undetermined time in MH. After warming, oocytes were cultured for maturation (in vitro maturation) in M199-Earle’s salts, 5 mU mL–1 FSH, and 10% fetal bovine serum. After 30 to 36 h, the oocytes were denuded and stained with Hoechst 33258. Data were analysed by Fisher’s exact test. There were no significant differences (P > 0.05) in rates of meiotic resumption among timing treatments (35, 24, 26, and 39% for 1v1w, 1v4w, 4v1w, and 4v4w, respectively), nor between immediately vitrified (17/55, 31%) and overnight held-vitrified groups (18/56, 32%). In the second experiment, all oocytes were held overnight. They were vitrified and warmed using only the 1v1w and 4v4w schedules, then subjected to in vitro maturation, intracytoplasmic sperm injection, and embryo culture. The MII rate of the control group (27/37, 73%) was higher (P < 0.05) than that for 1v1w (12/33, 36%) or 4v4w treatments (10/35, 29%). The cleavage rate for control (25/27, 93%) was higher than that for 1v1w (5/9, 56%) but not than that for 4v4w (6/9, 67%). Blastocyst rates were 19% (5/27), 11% (1/9), and 0% (0/9) for control, 1v1w, and 4v4w, respectively (P > 0.05). These results indicate that blastocysts may be produced from equine immature oocytes vitrified en masse; however, both the maturation and blastocyst production rates were relatively low. Additional studies are required to improve the efficiency of this technique. This work was supported by the Clinical Equine ICSI Program, Texas A&M University.


2010 ◽  
Vol 22 (1) ◽  
pp. 214
Author(s):  
G. L. Rios ◽  
G. G. Kaiser ◽  
N. C. Mucci ◽  
R. H. Alberio

In this study the effect of increasing ethylene glycol (EG) concentrations in the vitrification media (VM) and its relation with oocyte activation and in vitro embryo production were evaluated. Cumulus-oocytes complexes (COC) were matured in vitro for 22 h and then partially denuded by gently pipetting with hyaluronidase, and randomly assigned to 4 treatments: T1 = control group; T2 = COC exposed to 10% EG + 10% DMSO (VM1), 20% EG + 20% DMSO (VM2); T3 = 15% EG + 5% DMSO (VM1), 30% EG + 10% DMSO (VM2); T4 = 20% EG + 0% DMSO (VM1), 40% EG + 0% DMSO (VM2). Exposition to VM1 and VM2 lasted 3 min and 30 s, respectively. After treatment COC were incubated in maturation medium up to 24 h. In Experiment 1 COC were cultured for 24 h in fertilization TALP supplemented with 50 μg mL-1 of heparin, then completely denuded and cultured 24 h in CR1-aa. After this, oocytes were stained with bisbenzimide (Hoechst 33342) and the number of nuclei and cells were recorded. Structures presenting 2 cells or 2 nuclei were considered as activated oocytes. In Experiment 2 matured COC exposed to cryoprotectants as in Experiment 1 were fertilized and cultured for 6 days as previously described (Mucci et al. 2006). Variables analyzed included oocyte activation, cleavage rate at 48 h, and percentage of viable embryos at Day 7. Data were analyzed by PROC GENMOD (SAS Institute Inc., Cary, NC, USA). Activated oocytes percentage did not differ between EG concentrations in VM and were higher (T2, 24.7%, n = 101; T3, 25.0%, n = 96; T4, 30.2%, n = 119) compared with controls (T1, 9.8%, n = 61). In Experiment 2 no differences were found in cleavage rates (T1, 81.9%, n = 68; T2, 87%, n = 67; T3, 85.9%, n = 61; T4, 84.2%, n = 64) and Day 7 percentage of viable embryos (T1, 34.9%, n = 29; T2, 28.6%, n = 22; T3, 26.8%, n = 19; T4, 27.6%, n = 21) in treated COC. The exposition of COC to cryoprotectants per se could trigger oocyte activation in the range of 10 to 40%. Thanks toAdriana Cano (Instituto Nacional de Tecnología Agropecuaria) for contributions in statistical analysis.


2004 ◽  
Vol 9 (1) ◽  
Author(s):  
M.G.L. PINTO ◽  
M.I.B. RUBIN ◽  
C.A.M. SILVA ◽  
T.F. HILGERT ◽  
M.F. SÁ FILHO ◽  
...  

O desenvolvimento embrionário de oócitos bovinos maturados in vitro (MIV) foi avaliado em meio suplementado com líquido folicular eqüino (Lfe). Foram distribuídos 1045 oócitos em 11 repetições formando três grupos tratamentos (T1, T2, T3) e um controle (C). O meio de maturação utilizado foi o TCM-199 acrescido de piruvato de sódio, hormônio folículo estimulante recombinante (rFSHh) e hormônio luteinizante equino (LHe). Suplementou-se esse meio com 10% de soro de égua em estro para o grupo controle e para T1, T2 e T3, o meio foi suplementado com 5, 10, e 20% de LFe, respectivamente. Os oócitos foram maturados in vitro (MIV) por 24h. A fecundação in vitro (FIV) foi realizada em meio Talp-Fert. A MIV e a FIV foram realizadas em estufa a 39ºC com 5% de CO2 em ar e umidade saturada. Os zigotos foram cultivados em meio SOFaaci, sob óleo mineral no interior de bolsas plásticas gaseificadas. As taxas de clivagem e de blastocistos foram observadas diariamente (D), e em D7, foram superiores (P0,05) às do grupo controle. Em D9, a taxa de blastocistos do T2 foi superior (P0,05). O LFe, na concentração de 10% pode ser utilizado, em substituição ao soro de égua em estro para suplementar o meio de MIV de oócitos bovinos. Equine follicular fluid on in vitro maturation of bovine oocytes Abstract Embryo development of bovine oocytes was evaluated using maturation medium supplemented with equine follicular fluid (eFF). One thousand and forty five (1045) oocytes were distributed in 11 replications forming three treatment groups (T1, T2 e T3) and one Control (C). TCM-199 added with sodium pyruvate, rFSHh and LHe was used as maturation medium. This medium was supplemented with 10% estrous mare serum for Control group, and 5, 10, and 20% eFF, respectively, for T1, T2 e T3 groups. In vitro maturation (IVM) of all groups was performed during 24h. In vitro fertilization (IVF) was performed in TALP-FERT medium. IVM and IVF were carried out in an incubator at 39ºC with 5% CO2 in air and saturated humidity. Zygotes were cultured in SOFaaci medium, under mineral oil in gasified bags. Cleavage and blastocyst rates were daily observed (D), and at D7, were higher (P0.05) for those from control group. At D9, blastocyst rate of T2 was higher (P0.05). The eFF, at a 10% concentration, can replace the use of estrous mare serum to supplement the IVM medium of bovine oocytes.


2012 ◽  
Vol 24 (5) ◽  
pp. 656 ◽  
Author(s):  
Islam M. Saadeldin ◽  
Ok Jae Koo ◽  
Jung Taek Kang ◽  
Dae Kee Kwon ◽  
Sol Ji Park ◽  
...  

Kisspeptin (Kp) is best known as a multifunctional peptide with roles in reproduction, the cardiovascular system and cancer. In the present study the expression of kisspeptin hierarchy elements (KISS1, GNRH1 and LHB) and their receptors (KISS1R, GNRHR and LHCGR, respectively) in porcine ovary and in cumulus–oocyte complexes (COCs) were investigated, as were its effects on the in vitro maturation (IVM) of oocytes and their subsequent ability to sustain preimplantation embryo competence after parthenogenetic electrical activation. Kp system elements were expressed and affected IVM of oocytes when maturation medium was supplemented with 10–6 M Kp. Oocyte maturation, maternal gene expression (MOS, GDF9 and BMP15), blastocyst formation rate, blastocyst hatching and blastocyst total cell count were all significantly increased when oocytes were matured in medium containing Kp compared with the control group (without Kp). A Kp antagonist (p234) at 4 × 10–6 M interfered with this hierarchy but did not influence the threshold effect of gonadotrophins on oocyte maturation. FSH was critical and permissive to Kp action on COCs by increasing the relative expression of KISS1R. In contrast, Kp significantly increased apoptosis, the expression of pro-apoptotic gene, BAK1, and suppressed trophoblast outgrowths from hatched blastocysts cultured on feeder cells. The present study provides the first functional evidence of the Kp hierarchy in porcine COCs and its role in enhancing oocyte maturation and subsequent developmental competence in an autocrine–paracrine manner. However, Kp supplementation may have a harmful impact on cultured hatched blastocysts reflecting systemic or local regulation during the critical early period of embryonic development.


Author(s):  
Alan da Silva LIRA ◽  
Ricardo de Macedo CHAVES ◽  
Felipe de Jesus MORAES JUNIOR ◽  
Sergio Henrique COSTA JUNIOR ◽  
Brenda Karine Lima do AMARAL ◽  
...  

ABSTRACT We aimed to assess the effects of melatonin in the in vitro production of bovine embryos. Our experiment was conducted at the Laboratório de Reprodução Animal of the Universidade Estadual do Maranhão. The cumulus-oocyte complexes (COCs) were distributed among treatments at concentrations of 0, 10-1, 10-3 and 10-5 µMol/L melatonin. Our experiment was further divided into two: the first was to assess the effect of different concentrations of melatonin (treatments) on the maturation rate of COCs, and the second was to assess the effects of melatonin treatments on the in vitro production of bovine embryos. The results from the first experiment demonstrated no significant difference between the in vitro maturation rate of the cultivated COCs in treatments with melatonin. In the second experiment, however, melatonin treatments yielded statistically higher cleavage, morula and blastocyst rates in the 10-5 µM group (52.9%, 52.9%, and 35.3%, respectively), and lower rates in the 10-1 µM group (19.5%, 19.5% and 7.8%, respectively), compared to the others. The control group (no melatonin) and the 10-3 µM group showed similar results. We concluded that supplementation of melatonin in the in vitro maturation medium resulted in no improvement in the oocyte maturation rate, but in the in vitro production of embryos at different concentrations, the 10-5 µM group displayed better results, but with no improvement in the variables (P < 0.05).


2017 ◽  
Vol 24 (2) ◽  
pp. 56
Author(s):  
Zakiyatul Faizah ◽  
Haryanto Aswin ◽  
Hamdani Lunardhi

Objectives: to compare the expression of Bcl-2, Bax and Bcl-2/Bax ratio in cumulus cell and oocyte between vitrified oocyte pre and post in vitro maturation.Materials and Methods: Maturation was operated in medium TC 100 µl for 24 hours. Vitrification begins with washing oocyte in PBS basic medium supplemented of 20% serum for 1-2 minutes, followed by equilibration medium PBS + 20% serum + 10% ethylene glycol for 10-14 minutes, then transferred to 20% serum + PBS + 0.5 M sucrose + 15% ethylene glycol + PROH 15% for 25-30 seconds. Thawing is processed by submerging the oocytes in the media: 1). PBS + 20% serum + 0.5 M sucrose, 2). PBS + 20% serum + 0.25 M sucrose, and 3). PBS + 20% serum + 0.1 M sucrose. Imunocytochemistry observed the expression of Bcl-2, bax and Bcl-2/bax ratio.Results: Bcl-2 expression on oocyte in control group differed significantly with treatment group, Bcl-2 expression on cumulus in control group differed significantly with treatment 1 group. Bax expression on oocyte in control group differed significantly with treatment group. Bax expression on cumulus in control group differed significantly with treatment group. Bcl-2/Bax expression ratio on oocyte and cumulus did not differ significantly in all groupConclusion: No difference Bcl-2/Bax expression ratio on oocyte and cumulus between vitrified oocyte pre and post in vitro maturation.


2006 ◽  
Vol 18 (2) ◽  
pp. 167
Author(s):  
C. Yamada ◽  
M. D. Goissis ◽  
H. V. A. Caetano ◽  
A. R. S. Coutinho ◽  
M. E. O. A. Assumpção ◽  
...  

The cryopreservation of bovine oocytes remains a challenge despite significant reported progress. Immature bovine oocytes have a complex structure and the conventional cryoprotectants (penetrating cryoprotectants, sugars, and macromolecules) appear to be not sufficient to preserve them efficiently during freezing. Studies on semen and fibroblast cryopreservation indicate that amino acids, particularly l-glutamine, protect enzymes during freezing and increase the post-thaw viability. Therefore, the amino acids may optimize oocyte cryopreservation when associated with conventional cryoprotectants. This work evaluated the effect of l-glutamine on cryopreservation of immature bovine oocytes after in vitro maturation. Oocytes with homogeneous cytoplasm and several cumulus cell layers from slaughterhouse ovaries were distributed randomly in three groups: non-vitrified control, vitrified control, and vitrified with l-glutamine. Oocytes from vitrified groups were exposed for 10 min to PBS + 10% FCS + 10% ethylene glycol (EG) + 0.25 m trehalose (T), and for 30 s to PBS + 10% FCS + 25% EG + 25% dimethylsulfoxide + 0.5 m T at room temperature, adding 80 mm l-glutamine for the third group. Oocytes were loaded into OPS and plunged in liquid nitrogen. For thawing, OPS were immersed in PBS + 10% FCS + 10% EG + 1 m T for three min. Oocytes werethen placed in PBS + 10% FCS + 0.5 m T and in PBS + 10% FCS, remaining three min in each solution. For in vitro maturation, oocytes were washed three times on holding medium (TCM-HEPES + FCS + pyruvate + gentamycin), washed three times in maturation medium (TCM-bicarbonate + FCS + pyruvate + gentamycin + hCG + FSH + estradiol), and cultured in microdrops (90 μL) of maturation medium covered with mineral oil at 38.5°C under 5% CO2 in air and high humidity for 24 h. Oocytes were denuded, fixed in paraformaldehyde and triton, stained with Hoechst 33342, and evaluated under epifluorescence microscopy. Oocytes at metaphase II were considered matured. The group vitrified with l-glutamine had a significantly higher maturation rate than the group vitrified without l-glutamine; however, both had significantly lower maturation rates than the non-vitrified control group. In conclusion, l-glutamine improved the viability of vitrified oocytes. Table 1. Oocyte maturation rates of non-vitrified control, vitrified control, and vitrified with glutamine groups This work was supported by FAPESP 03/08543-1.


2010 ◽  
Vol 22 (1) ◽  
pp. 328
Author(s):  
I. La Rosa ◽  
R. Fernandez y Martín ◽  
D. A. Paz ◽  
D. F. Salamone

BMP4 regulates different events during development in all vertebrates and Noggin is one of its powerful inhibitors that blocks BMP4 interaction with its receptors (Groppe et al. 2002). In this work, the effect of these factors on bovine oocyte maturation and subsequent embryo development has been investigated. COCs were aspirated from abattoir ovaries and in vitro-matured for 22 h or 24 h in a 5% CO2 humidified atmosphere at 39°C in TCM containing 0.6% BSA, 2 mM FSH, 10 mM cysteamine, 1% antibiotic and 1% pyruvate, control group (C), plus 100 ng mL-1 of BMP4 (B), or 100 ngmL-1 of Noggin (NOG). Oocytes were stained with Hoechst 33342 and classified by their nuclear stage. Effects on embryo development were investigated for embryos produced by parthenogenic activation (PA) and IVF For PA, denuded oocytes were chemically activated in 5 μM ionomycine for 4 min, and immediately incubated in 1.9 mM of 6-dimethilaminopurine for 3 h. For IVF, frozen-thawed semen was centrifuged and resuspended in Bracket and Oliphant (BO) solution and incubated with 22 h matured COCs for 5 h. Embryos were cultured in CR2 medium free of serum and co-culture. Cleavage and blastocyst formation were registered at Day 2 and 9 respectively. Fischer’s exact test was used and P ≤ 0.05 was considered significant. Nuclear progression was not affected by maturation treatments [% of MII: 79.4(C, n = 102), 72.4 (B, n = 98), 80.9 (NOG, n = 89)]. For PA, both factors significantly increased cleavage rates [%: 51.7 (C, n = 284), 65 (B, n = 186), 62.1 (NOG, n = 198)] while blastocyst rates were not affected [%: 8.8 (C), 7.5 (B), and 8.6 (NOG)]. On the other hand, for IVF, cleavage rate was statistically lower for Noggin group [%: 70.7 (C, n = 140), 71.3 (B, n = 157), 64 (NOG, n = 159)] while blastocyst rates were similar between groups [%: 15.7 (C), 13.4 (B), 14.5 (NOG)]. Any of the added factors affected cell number of the embryos at Day 2. Blastocysts did not differ in the number of cells at Day 9 (Student’s t-test was used) neither for PA [mean ± SD: 100 ± 33 (C, n = 9), 88 ± 14 (B, n = 3) and 68 ± 8,(NOG, n = 3)] nor for IVF [mean ± SD: 90 ± 24 (C, n = 9), 132 ± 18 (B, n =4) and 99 ± 8 (NOG, n = 3)]. It is noticeable that addition of these factors during in vitro maturation showed different effects on subsequent embryo development depending on whether the embryos were PA or IVF. Probably, these responses represent differences in the BMP signaling system between these embryos which could be associated with different imprinting pattern. Further experiments are needed to elucidate clearly the mechanisms implicated. To our knowledge, this is the first work to study BMP4 inhibition during bovine in vitro maturation. To “Merlo” and “Nueva Escocia” Slaughterhouses


2007 ◽  
Vol 19 (1) ◽  
pp. 258
Author(s):  
B. Agung ◽  
T. Otoi ◽  
D. Fuchimoto ◽  
S. Senbon ◽  
A. Onishi ◽  
...  

When used as a solo maturation medium for oocytes, porcine follicular fluid (pFF) promoted male pronucleus formation (MPF) of oocytes after in vitro maturation (IVM), using a static system, and in vitro fertilization (IVF) in pigs (Naito et al. 1988 Gamete Res. 21, 289–295). However, the developmental competence of oocytes matured in pFF after IVM/IVF has not been reported. This study was conducted to assess the ability of pFF as a maturation medium to support IVM/IVF of porcine oocytes and their subsequent in vitro development. pFF, including cumulus–oocyte complexes (COCs), was aspirated from follicles (2–5 mm in diameter) of prepubertal crossbred gilt ovaries, and large clusters of follicular cells (FC) were removed from pFF by filtration through 212 �m of mesh. All of the COCs in filtered pFF were collected, and COCs with compact cumulus cells were selected for IVM. Also, small clusters of FC were collected by centrifugation of the filtered pFF, and pFF without any cells was prepared by centrifugation and used as a maturation medium (MpFF) after supplementation with FSH and antibiotics. COCs were transferred to 3.5 mL (in a 15-mL test tube) of MpFF with FC (5.2 � 106 cells mL-1) and cultured for 44–48 h at 38.5�C in 5% O2 and 5% CO2 using the rotating culture system. As a control group, COCs were cultured in 2 mL of MpFF without FC in a 35-mm Petri dish by the standard static culture system. After maturation, culture oocytes were co-incubated (IVF) for 5 h with frozen–thawed sperm in vitro, as reported previously (Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041), and then some of them were fixed 10 h after IVF to assess the fertilization status; the rest of them were cultured in PZM (Yoshioka et al. 2002 Biol. Reprod. 60, 112–119) for 7 days to assess their early embryonic development. All of the data were analyzed by ANOVA. Oocytes cultured with FC in the rotating system (R group) showed significantly higher sperm penetration (71.0%), MPF formation (70.5%), and normal fertilization (monospermic fertilization with female and male pronuclei; 31.5%) rates than those in the control group (56.0%, 56.9%, and 17.6%, respectively; P &lt; 0.05). Also, the R group showed significantly higher rates of 8-cell embryos at 2 days after IVF and blastocyst formation at 7 days after IVF than those of the control group (17.2% vs. 8.3% and 10.9% vs. 4.5%, respectively; P &lt; 0.05). These results indicate that porcine oocytes matured in pFF supplemented with FC using the rotating system have the ability to be penetrated by sperm and form MPF, and to develop to the blastocyst stage at higher rates, than oocytes cultured in the standard static maturation culture system. In conclusion, the pFF can be a sole and simple maturation culture medium useful for the in vitro production of blastocysts in pigs.


2019 ◽  
Vol 31 (1) ◽  
pp. 213
Author(s):  
J. Keim ◽  
Y. Liu ◽  
I. Polejaeva

In vitro maturation (IVM) is an important process in the in vitro production of embryos. It has been recently shown that 3 cytokines: fibroblast growth factor 2 (FGF2), leukemia inhibitory factor (LIF), and insulin-like growth factor 1 (IGF1) have increased the efficiency of IVM, blastocyst production, and in vivo development in pig (Yuan et al. 2017 Proc. Natl. Acad. Sci. USA 114, E5796-E5804). In vitro maturation in medium supplemented with cytokines doubled the blastocyst rate and quadrupled the litter size when transferred. It was observed that the addition of cytokines to IVM medium had an effect on the regulation of pMAPK1/3, cumulus cell expansion, and transzonal projections in cumulus-oocyte complexes (COC). This study was designed to assess the effect of these 3 cytokines on IVM in bovine oocytes and their consecutive development to blastocyst. Intracellular glutathione level (GSH), frequently used as an indicator of metaphase II (MII) oocyte quality, was also evaluated. The COC were retrieved from abattoir-derived ovaries and matured for 21h in either our standard maturation medium [TCM-199 (Gibco/Life Technologies, Grand Island, NY, USA), containing 10% fetal bovine serum, 0.5µg mL−1 FSH, 5µg mL−1 LH, and 100U mL−1 penicillin/streptomycin] or maturation medium supplemented with 20ng mL−1 human LIF, 20ng mL−1 human IGF1, and 40ng mL−1 human FGF2. After IVM, COC were placed in fertilization medium and incubated with frozen-thawed sperm for 20h. Cumulus cells were removed from fertilized COC and cultured in SOF culture medium at 38.5°C in 5% CO2/humidified air. Cleavage and blastocyst rates were assessed at 48h and Day 8 post-IVF, respectively. To assess GSH level, MII oocytes were incubated in 20 µM CellTracker Blue CMF2HC (Thermo Fisher Scientific, Waltham, MA, USA) and observed under blue fluorescent light. All statistical analysis was performed using one-way ANOVA and data are presented as mean±s.e.m. The MII rate, assessed by the presence of the first polar body, was significantly higher in the maturation medium supplemented with cytokines compared with the control medium (167/202; 82.4±2.02% v. 136/198; 68.8±1.1%; P&lt;0.05, 4 replicates). For IVF, no statistical difference was found in the cleavage rate between oocytes matured in the medium supplemented with cytokines compared with control medium (351/473; 74.3±4.86% v. 358/573; 63.9±4.03%; P&gt;0.05, 5 replicates), respectively. However, a significant increase in blastocyst rate was observed in the cytokine-containing medium (64/351; 17.7±2.06%) compared with the control group (42/358; 11.0±1.96%; P&lt;0.05, 5 replicates). Furthermore, our preliminary data indicate an increase in GSH in MII oocytes matured in the cytokine-containing medium. In conclusion, the addition of FGF2, LIF, and IGF1 to maturation media improves bovine IVM efficiency and quality of the MII oocytes, leading to a greater blastocyst development rate. Supported by RFBR (18-29-07089) and UAES (1343).


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