124 TAXOL™ COULD PROMOTE EMBRYO DEVELOPMENT OF BOVINE OOCYTES VITRIFIED BY OPS

2007 ◽  
Vol 19 (1) ◽  
pp. 179
Author(s):  
R. Morató ◽  
D. Izquierdo ◽  
M. J. Palomo ◽  
B. Anguita ◽  
A. R. Jiménez-Macedo ◽  
...  
Keyword(s):  
Embryo Development ◽  
Calf Serum ◽  
Subsequent Development ◽  
Control Group ◽  
Control Groups ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Microtubule Stabilizer ◽  
Calf Oocytes

Stabilizing the cytoskeleton system during vitrification could be beneficial for improving post-thawed survival and subsequent development of vitrified oocytes. Taxol™, paclitaxel, is a microtubule stabilizer that has been found to improve development competence of vitrified mouse and human oocytes. The objective of this work was to study the effect of a Taxol pretreatment before OPS vitrification on the post-thaw cow and calf oocyte development. Oocytes were aspirated from slaughterhouse-derived ovaries and matured in TCM-199. Oocytes were randomly assigned to one of 3 experimental groups: (1) control oocytes matured in vitro for 24 h, (2) oocytes matured for 22 h and vitrified by the OPS method (Vajta et al. 1998 Mol. Reprod. Dev. 51, 53–58), and (3) oocytes matured for 22 h and vitrified by OPS method with 1 µM Taxol. OPS and Taxol–OPS oocytes were transferred back into the maturation dishes and matured for 2 additional h before being subjected to fertilization. Fertilization was performed using frozen–thawed Percoll-selected sperm. At 22 h after insemination, presumptive zygotes were pipetted and then cultured in drops of 25 µL SOF medium and 5% fetal calf serum under paraffin oil at 38.5°C in 5% CO2, 5% O2, 90% N2, and maximum humidity. The Taxol–OPS group provided a significantly higher cleavage rate than the OPS group in cows (41.9% and 34.0%, respectively) or in calves (33.7% and 23.5%, respectively). However, cleavage rate in the experimental groups was significantly lower than in the control group (78.3% and 69.7% for cow and calf control groups, respectively). Blastocyst yield was also higher for the Taxol–OPS group (3.2%) than the OPS group (0%) in cow oocytes. There was no blastocyst development when calf oocytes were vitrified with or without Taxol pretreatment. As expected, cow and calf vitrification groups triggered a significantly lower blastocyst yield when compared with their control (26.7% and 14.9% for cow and calf control groups, respectively). In conclusion, this study showed that supplementation of 1 µM Taxol could promote embryo development after thawing. Further research is indicated to clarify the function of Taxol and its optimal concentration in order to improve the rate of embryo development. Table 1. Effect of Taxol pretreatment on development of cow and calf oocytes vitrified by OPS

scholarly journals Effect of storage tube material and resveratrol during liquid storage of matured bovine oocytes on subsequent development

2017 ◽  
Vol 65 (4) ◽  
pp. 546-555
Author(s):  
Tayita Suttirojpattana ◽  
Tamás Somfai ◽  
Satoko Matoba ◽  
Takashi Nagai ◽  
Rangsun Parnpai ◽  
...  
Keyword(s):  
Embryo Development ◽  
Subsequent Development ◽  
Control Group ◽  
Tube Material ◽  
Blastocyst Development ◽  
Liquid Storage ◽  
Glass Tubes ◽  
Bovine Oocytes

This study determined the optimum storage vessel and the effects of resveratrol for the storage of in vitro matured (IVM) bovine oocytes. After IVM, the oocytes were kept in a Hepes-buffered medium at 25 °C for 20 h in different containers including Eppendorf tubes (ET) made of polypropylene (PP) and polystyrene (PS), and tissue culture tubes (TCT) made of PP, PS, and glass. Then oocytes were subjected to IVF and subsequent in vitro embryo development was compared among the groups and to that of a control group without storage. The percentage of blastocyst development in the control group was significantly higher than in the stored groups (P < 0.05). Among oocytes stored in TCT, the percentage of blastocyst development of oocytes stored in glass TCT was significantly higher than that of oocytes stored in PP and PS TCT (P < 0.05); however, it did not differ from that of oocytes stored in ET. The quality of blastocysts did not differ among the control and stored groups. Embryo development was not affected when 0.1, 1 or 10 μM resveratrol was added to the medium during oocyte storage. In conclusion, glass tubes were optimal for oocyte storage and resveratrol did not improve the development of stored oocytes.

scholarly journals 296 LEUKEMIA INHIBITORY FACTOR INFLUENCES SHEEP OOCYTE PARTHENOGENETIC DEVELOPMENT DURING THE TRANSITION FROM GERMINAL VESICLE TO EARLY PRONUCLEAR STAGE

2005 ◽  
Vol 17 (2) ◽  
pp. 298
Author(s):  
G. Ptak ◽  
F. Lopes ◽  
P. Loi
Keyword(s):  
Embryo Development ◽  
Leukemia Inhibitory Factor ◽  
Calf Serum ◽  
Blastocyst Stage ◽  
Inhibitory Factor ◽  
Control Group ◽  
Blastocyst Development ◽  
Human Follicular Fluid ◽  
Oocyte Competence

Leukemia inhibitory factor (LIF) is an indispensable cytokine for female fertility. The influence of LIF on embryo development and particularly implantation has been recently confirmed; however, the effect of this cytokine on the oocyte has not been studied. The presence of LIF in human follicular fluid implies its possible role in the acquisition of oocyte competence. Furthermore, the up-regulation of LIF by steroid hormones in sheep makes entirely feasible the hypothesis that ovulatory estradiol peak plays a role in the preparation of female gamete for fertilization. With this in mind, we studied the effect of LIF during in vitro development of sheep oocytes mimicking the physiological expression of LIF induced by the ovulatory peak of estradiol in mice. GV stage oocytes matured and chemically activated in the presence of LIF and anti-LIF antibody were cultured to the blastocyst stage in our standard media. To eliminate the effect of the putative presence of LIF in heat inactivated fetal calf serum used for oocyte maturation, aliquots of LIF were treated at 56°C for 30 min and added to the maturation medium. The proportion of embryos that reached the blastocyst stage in vitro was significantly higher (P < 0.001) for oocytes matured and activated with LIF (36/93; 39%) than for the group incubated with antibody against LIF (6/68; 9%). The significant effect of anti-LIF antibody (P < 0.001) was also observed when compared with blastocysts developed from the control group of oocytes matured without LIF addition (31/106; 29%). Although the beneficial influence of LIF treatment on embryo development demonstrated with those preliminary data was not confirmed statistically, due to low number of oocytes involved, the proportion of embryos reaching the blastocyst stage in vitro was about 10% higher for those incubated with LIF than for either those cultured without the cytokine or those, matured in the presence of heat-treated LIF (15/55; 27%); however, the rate of blastocyst development appeared very similar to that of the control group. This study revealed for the first time a role of LIF in determining oocyte competence. Further investigation to determine how LIF achieves its effects on the oocyte are ongoing in our laboratory. This work was supported by FIRB RBNE01HPMX, COFIN 2002074357, COFIN 2003073943 002, and British Council 2004.

Reduced competence of immature and mature oocytes vitrified by Cryotop method: assessment by in vitro fertilization and parthenogenetic activation in a bovine model

Zygote ◽  
2017 ◽  
Vol 25 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Daiane L. Bulgarelli ◽  
Alessandra A. Vireque ◽  
Caroline P. Pitangui-Molina ◽  
Marcos F. Silva-de-Sá ◽  
Ana Carolina J. de Sá Rosa-e-Silva
Keyword(s):  
Embryo Development ◽  
Germinal Vesicle ◽  
Control Group ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Oocyte Vitrification ◽  
Vitro Fertilization ◽  
Parthenogenetic Activation ◽  
Nuclear Maturation

SummaryThis study aimed to evaluate the embryo development competence, the nuclear maturation and the viability of germinal vesicle (GV) and metaphase II (MII) oocytes vitrified by the Cryotop method. Cumulus–oocyte complexes were derived from bovine ovaries and three experiments were conducted. In Experiment 1, GV oocytes were vitrified and underwent in vitro maturation (IVM) or not and their nuclear maturation was assessed by orcein staining. In Experiment 2, GV oocytes and MII oocytes were vitrified or not and the viability was assessed by calcein/ethidium homodimer-1 staining. In Experiment 3, MII oocytes matured before or after vitrification were submitted to in vitro fertilization (IVF) and parthenogenetic activation (PA) in order to evaluate embryo development. No difference was found for the nuclear maturation rate in the GV group (50%) and the GV control group (67%; P = 0.23) and for viability rate (56%; 77%; P = 0.055, respectively). However, in the MII group (27%) viability was significantly lower than that of the MII control group (84%; P < 0.0001). The cleavage rate by IVF and PA was similar in the GV group and the MII group. In contrast, vitrified MII oocytes showed no capacity for blastocyst development after IVF or PA and vitrified GV oocytes were able to develop to blastocysts only after PA, but not after IVF. In conclusion, oocyte vitrification by the Cryotop method reduced the capacity for embryo development. Vitrification of GV oocytes, however, did not influence the capacity of meiotic nuclear maturation and they exhibited higher viability following vitrification at the MII stage.

scholarly journals Improvement of quality of oocytes collected in the autumn by enhanced removal of impaired follicles from previously heat-stressed cows

Reproduction ◽  
2001 ◽  
pp. 737-744 ◽  
Author(s):  
Z Roth ◽  
A Arav ◽  
A Bor ◽  
Y Zeron ◽  
R Braw-Tal ◽  
...  
Keyword(s):  
Heat Stress ◽  
Embryo Development ◽  
Treated Group ◽  
Oocyte Quality ◽  
Control Group ◽  
Delayed Effect ◽  
Cleavage Rate ◽  
Lactating Cows ◽  
Summer Heat

The fertility of dairy cows decreases during the summer and remains low during the cooler autumn although the animals are no longer under heat stress. The aim of this study was to characterize a delayed effect of summer heat stress on oocyte quality in the autumn and to improve oocyte quality by enhanced removal of follicles damaged during the previous summer. Lactating cows (n = 16) were subjected to heat stress during the summer. In autumn, ovarian follicles (3-7 mm in diameter) were aspirated by an ultrasound-guided procedure during four consecutive oestrous cycles. Follicles were aspirated from control cows on day 4 and from treated cows on days 4, 7, 11 and 15 of each oestrous cycle. All cows received PGF(2alpha) and GnRH injections on days 19 and 21, respectively, and maintained cyclicity, as indicated by plasma progesterone concentrations. On day 4 of each cycle, the oocytes recovered were examined morphologically, matured and activated in vitro, and cultured for 8 days. In cycle 1 (early October) both groups showed low percentages of grade 1 oocytes, cleavage, four- and eight-cell embryos, morulae and parthenogenetic blastocysts. Subsequently, the number of grade 1 oocytes increased earlier (cycle 2) in treated than in control cows (cycle 3; P < 0.05). The cleavage rate in the control group remained relatively low throughout (32-58%), whereas in the treated group it increased from 40% (cycle 1) to 75% (cycles 3 and 4; P < 0.05). The number at each stage of embryo development increased slightly but remained low throughout in the control group, whereas in the treated group significant (P < 0.05) increases of all stages were observed in cycles 3 and 4. The results show a delayed effect of summer heat stress on oocyte quality and embryo development in the autumn. Enhanced removal of the impaired cohort of follicles led to earlier emergence of healthy follicles and high quality oocytes in the autumn.

354 IN VITRO DEVELOPMENT OF BOVINE EMBRYOS AFTER NITRIC OXIDE INHIBITION

2007 ◽  
Vol 19 (1) ◽  
pp. 292
Author(s):  
K. R. L. Schwarz ◽  
T. H. C. de Bem ◽  
T. T. Zampieri ◽  
P. R. Adona ◽  
C. L. V. Leal
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Control Group ◽  
Sperm Cells ◽  
Blastocyst Development ◽  
Nuclear Maturation ◽  
Cytoplasmic Maturation

Nitric oxide (NO) is a chemical messenger detected in several cell types such as endothelial cells, neurons, and macrophages, exerting varied functions including vasodilatation, neurotransmission, and cell death induction. NO is generated by the activity of the enzyme nitric oxide synthase (NOS), which has been detected in several organs and tissues including the reproductive system. The aim of the present study was to assess the dose-response effect of N-omega-nitro-l-arginine-methyl ester (l-NAME), an NOS inhibitor, on in vitro nuclear and cytoplasmic maturation of bovine oocytes. Slaughterhouse ovaries were collected and their follicles (2–6 mm) were aspirated to obtain cumulus–oocyte complexes (COCs). Increasing l-NAME concentrations (0, 10-7, 10-5, 10-4, and 10-3 M) were added to IVM medium (TCM-199, supplemented with 10% fetal calf serum, 0.5 �g mL-1 FSH, 5.0 �g mL-1 LH, 0.2 mM pyruvate, and 10 mg mL-1 gentamicin); oocytes were cultured for 22 h. Nuclear maturation was assessed by propidium iodide staining (10 �g mL-1). For IVF, frozen–thawed semen prepared by Percoll gradient was used. Sperm cells were co-cultured with the oocytes at a final concentration of 2 � 106 sperm cells mL-1 in TALP-IVF medium supplemented with 2 �M penicillamine, 1 �M hypotaurine, 250 �M epinephrine, and 20 �g mL-1 heparin. After 20 h, presumptive zygotes were partially denuded and transferred to IVC medium (TCM-199 supplemented with 10% fetal calf serum, 2.0 mM pyruvate, and 10 mg mL-1 gentamicin). All cultures were at 38.5�C under 5% CO2 in air and maximum humidity. Cytoplasmic maturation was assessed by blastocyst development rates on Day 7. DNA fragmentation was assessed on Day 8 embryos by TUNEL (In Situ–Cell Death Detection kit, fluorescein; Roche Diagnostica Brasil, Sao Paulo, Brazil). Data were analyzed by ANOVA using the GLM procedure (SAS Institute, Inc., Cary, NC, USA), and means were compared by Duncan test at a 5% level. After IVM, the control group (0 M l-NAME) showed a greater number of oocytes in metaphase II (MII: 95.8 � 3.7%; P &lt; 0.05), whereas the groups cultured with l-NAME had lower MII rates (78–82%; P &lt; 0.05), irrespective of concentration (P &gt; 0.05). Many oocytes remained in metaphase I (MI: 18–22%). Cleavage rates at 48 h IVC was not affected (77–88%; P &gt; 0.05). Blastocyst rates (34.0 � 7.2% to 41.5 � 4.8%; P &gt; 0.05) and total cell numbers (151 to 174) were also unaffected by NO inhibition by l-NAME. However, the number of TUNEL-positive cells was lower in the control group (1.4 � 4.7; P &lt; 0.05) than in the treated groups (2.7 � 4.8 to 4.4 � 6.4; P &gt; 0.05). In conclusion, NO synthesis inhibition in oocytes during IVM reduces nuclear maturation, particularly during MI–MII transition, and increases apoptosis in blastocysts, suggesting that NO may be involved in oocyte maturation and apoptosis protection.

Production of in vitro bovine embryos supplemented with l-carnitine in different oxygen tensions and the relation to nitric oxide

Zygote ◽  
2020 ◽  
Vol 28 (5) ◽  
pp. 403-408
Author(s):  
Daniela Moraes Pereira ◽  
Christopher Junior Tavares Cardoso ◽  
Wilian Aparecido Leite da Silva ◽  
Mirela Brochado Souza-Cáceres ◽  
Mariana Santos ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Embryo Development ◽  
Calf Serum ◽  
Hatching Rate ◽  
Bovine Embryos ◽  
Low Oxygen ◽  
Cleavage Rate ◽  
Treatment Groups ◽  
Oxygen Tensions

SummaryThe aim of this study was to evaluate the production of bovine embryos in vitro when supplemented with l-carnitine for 24 h beginning on day 5 (d 5) under two different oxygen tensions (20% or 5%) and the relationship of nitric oxide (NO) in in vitro culture (IVC) medium to embryo development. Cumulus–oocyte complexes (COC; n = 837) were matured in vitro for 24 h and fertilization was performed for 18 h. Zygotes were cultured in vitro for 9 days after in vitro fertilization in synthetic oviductal fluid (SOF) medium with 5% fetal calf serum. At d 5 the plates were assigned to one of four treatment groups: high (20%) or low (5%) O2 tension either with or without the addition of 3.03 mM l-carnitine (High-Cont, High-Lcar, Low-Cont, Low-Lcar). The concentration of NO in the culture medium was evaluated on d 5, d 6 and d 9. On d 7, parts of the embryos were submitted for evaluation of intracellular lipid droplets. The cleavage rate was similar (P > 0.05) between high and low O2 tension and the blastocyst rate was similar in all conditions evaluated. The hatching rate was higher (P < 0.05) for Low-Cont. The NO concentration was higher at d 9 under low O2 tension (P < 0.1). The addition of 3.03 mM l-carnitine between d 5 and d 6 of IVC was not efficient in reducing cytoplasmic lipid content of bovine embryos. Additionally, IVC at a low oxygen tension without l-carnitine promoted better conditions for embryo development. A higher concentration of NO in medium was observed under low O2 tension.

scholarly journals Antioxidant Nobiletin Enhances Oocyte Maturation and Subsequent Embryo Development and Quality

2020 ◽  
Vol 21 (15) ◽  
pp. 5340
Author(s):  
Yulia N. Cajas ◽  
Karina Cañón-Beltrán ◽  
Magdalena Ladrón de Guevara ◽  
María G. Millán de la Blanca ◽  
Priscila Ramos-Ibeas ◽  
...  
Keyword(s):  
Embryo Development ◽  
Biological Effects ◽  
Calf Serum ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Mitochondrial Activity ◽  
Cortical Granules ◽  
Cleavage Rate ◽  
Cytoplasmic Maturation

Nobiletin is a polymethoxylated flavonoid isolated from citrus fruits with wide biological effects, including inhibition of reactive oxygen species (ROS) production and cell cycle regulation, important factors for oocyte in vitro maturation (IVM). Therefore, the objective of the present study was to evaluate the antioxidant activity of nobiletin during IVM on matured bovine oocyte quality (nuclear and cytoplasmic maturation; oocyte mitochondrial activity; intracellular ROS and glutathione (GSH) levels) and their developmental competence, steroidogenesis of granulosa cells after maturation, as well as quantitative changes of gene expression in matured oocytes, their cumulus cells, and resulting blastocysts. Bovine cumulus-oocyte complexes were in vitro matured in TCM-199 +10% fetal calf serum (FCS) and 10 ng/mL epidermal growth factor (EGF) (Control) supplemented with 10, 25, 50, or 100 μM of nobiletin (Nob10, Nob25, Nob50, and Nob100, respectively) or 0.1% dimethyl sulfoxide (CDMSO: vehicle for nobiletin dilution). A significantly higher percentage of matured oocytes in metaphase II was observed in Nob25 and Nob50 compared to other groups. Similarly, cleavage rate and cumulative blastocyst yield on Days 7 and 8 were significantly higher for Nob25 and Nob50 groups. Oocytes matured with 25 and 50 μM nobiletin showed a higher rate of migration of cortical granules and mitochondrial activity and a reduction in the ROS and GSH content in comparison with all other groups. This was linked to a modulation in the expression of genes related to metabolism (CYP51A1), communication (GJA1), apoptosis (BCL2), maturation (BMP15 and MAPK1), and oxidative stress (SOD2 and CLIC1). In conclusion, nobiletin offers a novel alternative for counteracting the effects of the increase in the production of ROS during IVM, improves oocyte nuclear and cytoplasmic maturation, and subsequent embryo development and quality in cattle.

329 SUPPRESSION OF BOVINE OOCYTE IVM BY SERUM AND FSH DEPRIVATION OR BY α-AMANITIN: EFFECT ON FERTILIZATION AND EMBRYO DEVELOPMENT

2006 ◽  
Vol 18 (2) ◽  
pp. 272
Author(s):  
K. Kananen-Anttila ◽  
M. Eronen ◽  
J. Matilainen ◽  
M. Kallio ◽  
J. Peippo ◽  
...  
Keyword(s):  
Embryo Development ◽  
Cumulus Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Blastocyst Development ◽  
Nuclear Maturation ◽  
Embryo Cleavage ◽  
Bovine Oocytes ◽  
Sperm Aster

We have studied the effect of suppressed IVM on the developmental competence of bovine oocytes, aiming at elucidating the importance of cytoplasmic maturation in fertilization and embryo development. Six replicates of abattoir-derived oocytes were randomly divided into three IVM groups. Control (n = 950): TCM-199 with glutamax-I (Gibco, Grand Island, NY, USA), 0.25 mM Na-pyruvate, 100 IU mL−1 penicillin and 100 μg mL−1 streptomycin, 50 ng mL−1 FSH, and 10% fetal bovine serum (FBS) (Gibco); Serum+FSH-free (n = 944): same as control but without FSH and FBS; α-amanitin (n = 977): same as control but with 10 μg mL−1 α-amanitin. Nuclear maturation of oocytes was studied 24 h after the onset of IVM, the formation of sperm aster structure 10 hours post-insemination (hpi) and the formation of pronuclei 20 hpi. Sperm aster was visualized with β-tubulin antibody (modified from Navara et al. 1999 Dev. Biol. 162, 29–40). Presumptive zygotes were cultured until Day 7 in modified SOFaaci + 4 mg mL−1 fatty acid-free BSA in 5% O2. Cumulus cell expansion was seen only in the control group. The results of nuclear maturation, fertilization, and embryo development are summarized in Table 1. Serum and FSH deprivation did not have a statistically significant effect on the parameters studied (vs. control). α-amanitin exposure during IVM reduced nuclear maturation, fertilization, and Day 3 embryo cleavage vs. control, and resulted in total blockage of Day 7 blastocyst development. The treatment groups had significantly smaller mean diameters of male pronuclei (control: 14 ± 0.6 μ­m; serum+FSH-free: 12 ± 0.5 μ­m, P < 0.05; α-amanitin: 10 ± 0.6 μ­m, P < 0.001) and sperm asters (control: 86 ± 4 μ­m; serum+FSH-free: 82 ± 4 μ­m, P < 0.01; α-amanitin: 49 ± 7 μm, P < 0.001) (nonparametric Kruskall Wallis and Mann-Whitney U tests) vs. control group. Despite reduction in pronucleus and sperm aster diameter, serum and FSH deprivation during IVM did not affect in vitro developmental competence of bovine oocytes, suggesting a need for re-evaluation of the components of IVM. α-Amanitin exposure in IVM disturbed nuclear maturation, fertilization, and embryo development, indicating the essence of early transcription. Table 1. Average percentages ± (n) for nuclear maturation, fertilization (min two pronuclei), embryo cleavage, and blastocyst development

179 EFFECT OF SERUM DURING CULTURE ON DAY 14 ELONGATED BOVINE EMBRYOS

2011 ◽  
Vol 23 (1) ◽  
pp. 191 ◽  
Author(s):  
J. Angulo ◽  
G. T. Gentry ◽  
R. A. Godke ◽  
K. R. Bondioli
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Culture Media ◽  
Calf Serum ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Expression Levels ◽  
The Mean

It has been reported that the addition of serum to embryo culture media alters gene expression and triggers the development of large offspring syndrome. The objectives of this study were to determine gene expression levels in embryos cultured in the absence or presence of 5% calf serum and in vivo-derived (IVD) embryos and to determine the effects of serum on the length of elongated embryos. Abattoir-derived oocytes were obtained from a commercial provider and fertilized at 24 h of maturation with semen from a bull previously used for IVF. At 18 h post-insemination (hpi), embryos were denuded and groups of 15 presumptive zygotes were cultured in 30-μL drops of modified SOF medium with amino acids and 6 mg mL–1 of BSA (mSOFaa). At 72 hpi, cleavage rate was assessed and embryos were randomly allocated into 2 treatments: mSOFaa without and with 5% calf serum. Embryos were then cultured to 168 hpi and blastocyst rates were assessed and recorded. Blastocysts (n = 5 to 10) from each treatment were transferred into synchronized recipients, and Day 14 embryos were recovered 7 days post-transfer. Embryos were photographed, measured, and immediately stored at –80°C in a minimal volume of PBS + 0.1% polyvinyl alcohol. Messenger RNA was isolated using a Dynabeads mRNA Direct Kit™ (Invitrogen, Carlsbad, CA), and reverse transcription was performed using an iScript™ cDNA Synthesis Kit (Bio-Rad Laboratories, Inc., CA). Quantitative PCR was performed to determine the transcript abundance for COX6A, IFNT1a, PLAC8, IGF2R, and GAPDH for each sample. The GAPDH was used as a reference gene, and gene expression was calculated as a ratio of expression levels between each gene of interest and GAPDH. Expression levels for each gene were determined from standard curves generated by serial dilutions of PCR amplicons starting with 0.4 pg/reaction. Blastocyst development rates were higher in embryos cultured with serum compared with the nonserum treatment (14.9 and 7.4% respectively; chi-square, P < 0.001). Lengths of elongated embryos from the serum (3395.3 ± 414.7 μm) and nonserum (2784 ± 741.8 μm) culture treatments differed from the IVD (6297.7 ± 677.2 μm) treatment (mean ± SE; ANOVA, P < 0.0052). There were no differences in the mean expression levels for COX6A, IFNT1a, PLAC8, and IGF2R across treatment groups, but in the serum treatment, 3 out 11 overexpressed IFNT1a, 4 out of 11 overexpressed IGF2R, and 2 out of 11 overexpressed PLAC8, defined as being 2 standard deviations above the mean of the IVD treatment for each respective gene. In the in vitro-produced nonserum and IVD treatments, overexpression by this definition was not observed. Although mean expression levels were not affected by culture with serum under these conditions, very high expression of IFNT1a, IGF2R, and PLAC8 was observed in some embryos cultured with serum, but not in embryos cultured without serum or IVD embryos.

68 EFFECT OF CO-CULTURE DURING FERTILIZATION OF BUFFALO (BUBALUS BUBALIS) IN VITRO-MATURED DENUDED OOCYTES VITRIFIED BY CRYOTOP

2008 ◽  
Vol 20 (1) ◽  
pp. 115
Author(s):  
L. Attanasio ◽  
A. De Rosa ◽  
L. Boccia ◽  
R. Di Palo ◽  
G. Campanile ◽  
...  
Keyword(s):  
Survival Rate ◽  
In Vitro Fertilization ◽  
Survival Rates ◽  
Calf Serum ◽  
Cumulus Cells ◽  
Control Group ◽  
Cleavage Rate ◽  
Vitro Fertilization ◽  
Group B

Although removal of cumulus cells improves the efficiency of vitrification of buffalo (Bubalus bubalus) in vitro-matured (IVM) oocytes (Gasparrini et al. 2007 Anim. Reprod. Sci. 98, 335–342), the lack of cells impairs the fertilization process. Therefore, the aim of the present work was to evaluate the influence of a somatic support during in vitro fertilization (IVF) of buffalo vitrified denuded matured oocytes. Since IVF on a cumulus cells monolayer was inefficient, we verified the effects of co-culture with cumulus-enclosed oocytes (COCs). IVM buffalo oocytes (n = 316) were vitrified by the Cryotop� method (Kuwayama and Kato 2000, J. Assist. Reprod. Genet. 17, 477 abst) that was recently proven suitable for buffalo oocyte cryopreservation (Attanasio et al. 2006 Reprod. Domest. Anim. 41, 302–310). Denuded buffalo oocytes were equilibrated in 10% ethylene glycol (EG) and 10% dimethyl sulfoxide (DMSO) for 3 min, transferred into 20% EG and 20% of DMSO in TCM199 with 20% fetal calf serum (FCS) + 0.5 m sucrose, loaded on Cryotops, and plunged into liquid nitrogen within 25 s. For warming, oocytes were exposed for 1 min to 1.2 m sucrose and then to decreasing concentrations of the sugar (0.6, 0.4, 0.3 m for 30 s) in TCM199 + 20% FCS. Oocytes were rinsed and allocated to IVM drops for 1.5 h. Survival rate was evaluated at this point and the oocytes that had survived (292/316 = 92.4%) were split into 2 fertilization groups: (A) approximately 5 buffalo oocytes per 50-µL drop of IVF medium, and (B) approximately 3 buffalo oocytes + 3 bovine fresh COCs per 50-µL drop of IVF medium. Since buffalo COCs easily lose their cells following IVF, for better identification we used bovine COCs that have a brighter and more compact cumulus mass. In vitro fertilization and culture were carried out as previously described (Gasparrini et al. 2007). As control, buffalo oocytes (n = 104) were in vitro-matured, fertilized, and cultured up to the blastocyst stage. On Day 1, survival rate was evaluated in the two vitrification groups; cleavage and blastocyst rates were recorded on Days 5 and 7, respectively, in all groups. The experiment was repeated 4 times. Differences in the percentages of survival, cleavage, and blastocyst formation among treatments were analyzed by chi-square test. Within vitrification groups, despite similar survival rates on Day 1 (90.6% v. 93.3%, respectively, in Groups A and B), cleavage rate was significantly improved in Group B compared to Group A (59.2% v. 45.4%, respectively; P < 0.01). Interestingly, the cleavage rate in Group B was not significantly different from that recorded in the control group (71.0%). Although blastocysts were produced in both vitrification groups (3.6% v. 4.1%, respectively, in Groups A and B), the yield was significantly lower than that of the control group (29.0%, P < 0.01). In conclusion, co-culture with bovine COC during fertilization improves the capability of buffalo denuded vitrified oocytes to cleave.

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