115 ADDITION OF ETHANOL AT SUB-STRESS CONCENTRATIONS DURING IN VITRO MATURATION OF BOVINE OOCYTES IMPROVES BLASTOCYST CRYOTOLERANCE

2010 ◽  
Vol 22 (1) ◽  
pp. 216 ◽  
Author(s):  
M. A. M. M. Shehab-El-Deen ◽  
J. L. M. R. Leroy ◽  
D. Maes ◽  
A. Van Soom
Keyword(s):  
In Vitro Maturation ◽  
Embryo Quality ◽  
Calf Serum ◽  
Ethanol Stress ◽  
Stress Concentrations ◽  
Low Concentrations ◽  
Carry Over ◽  
Bovine Oocytes

In in vitro experiments, the percentage of bovine oocytes that develops to the blastocyst stage is much lower compared with the in vivo counterparts. The quality of the oocyte is the main factor affecting blastocyst yield. Moreover, in vitro-produced bovine embryos are more sensitive to cryo-injuries than those produced in vivo. Exposure of oocytes to sub-lethal concentrations of stressors may enhance their quality through upregulation of intracellular shock proteins. We aimed to evaluate whether addition of ethanol at low concentrations (0.27 or 0.53%) during oocyte maturation could have a carry-over effect on embryo quality and could subsequently affect embryo cryotolerance. Cumulus-oocyte complexes (n = 934) were matured in serum-free TCM199 plus 20 ng mL-1 of epidermal growth factor (control), supplemented with ethanol 0.27% (treatment 1) or 0.54% (treatment 2), in 3 replicates. After fertilization, the presumptive zygotes were cultured for 6 days in modified SOF medium supplemented with 5% fetal calf serum (FCS); the number of blastocysts was recorded and classified. Then, expanded blastocysts were cryopreserved by open pulled straw vitrification using the 2-step approach described by Vajta G et al. (1998 Mol. Reprod. Dev. 51, 53-58). After 24 h, vitrified embryos were warmed and cultured in groups of <25 per 50 μL droplet of modified SOF medium with 5% FCS under mineral oil for 48 h and examined for re-expansion and hatching. Differences between the groups in blastocyst yield were analyzed by ANOVA; differences in survival rates between the groups were analyzed using logistic regression analysis. For all statistical models, group was included as fixed effect, and also the effect of replicate was included. Differences were considered to be statistically significant when P < 0.05. Addition of ethanol to in vitro maturation media had no significant effects on blastocyst yield on 7 dpi. Also, addition of ethanol at 0.27% did not affect blastocyst cryotolerance. However, addition of ethanol 0.54% to in vitro maturation media significantly increased the survival of bovine blastocysts after vitrification (P < 0.01; Table 1). The results of the present study indicate that maturation of oocytes under ethanol stress at low concentrations has carry-over effects on embryo quality, leading to improved cryotolerance. Table 1.Survival percentage (mean ± SE) of vitrified expanded bovine blastocysts matured in the presence of sub-stress concentrations of ethanol The authors thank I. Lemahieu and P. Vandamme for their excellent technical support. This research was supported by the special research fund, Ghent University (Grant, BOF/DOS No. 01W05706).

71 VITRIFICATION OF BOVINE OOCYTES IN MEDIA WITH GLYCEROL + ETHYLENE GLYCOL BEFORE AND AFTER IN VITRO MATURATION

2008 ◽  
Vol 20 (1) ◽  
pp. 116
Author(s):  
L. G. Devito ◽  
C. B. Fernandes ◽  
H. N. Ferreira ◽  
F. C. Landim-Alvarenga
Keyword(s):  
Ethylene Glycol ◽  
Liquid Nitrogen ◽  
In Vitro Maturation ◽  
Calf Serum ◽  
Quiescent State ◽  
Developmental Potential ◽  
Immature Oocytes ◽  
Nitrogen Vapor ◽  
Bovine Oocytes

The cryopreservation process aims to keep the cellular metabolism in a quiescent state for an indeterminate length of time. In mammals, oocyte cryopreservation success is important for the establishment of genetic banks. The objective of the present experiment was to evaluate the effect of vitrification on oocyte meiotic ability and the integrity of the metaphase plate in immature and in vitro-matured bovine oocytes. Bovine cumulus–oocytes complexes (COCs) were harvested from slaughterhouse ovaries and randomly divided into 3 groups: (G1) non-vitrified oocytes subjected to in vitro maturation, (G2) immature oocytes vitrified and then subjected to in vitro maturation after warming, and (G3) in vitro-matured oocytes subjected to vitrification. For in vitro maturation, oocytes were incubated for 22 h in 5% CO2 in air in TCM-199 with fetal calf serum, estradiol, LH, FSH, pyruvate, and gentamicin. For vitrification, the oocytes were exposed to the cryoprotectors in three steps: solution 1 containing 1.4 m glycerol in PBS for five min, and then solution 2 containing 1.4 m glycerol and 3.6 m ethylene glycol in PBS for another five min. After exposure to the second solution, the oocytes were transferred to 30-µL drops of solution 3 containing 3.4 m glycerol and 4.6 m ethylene glycol, loaded (5 oocytes per straw) in less than 1 min into 0.25-mL straws between two columns of 0.5 m galactose in PBS separated by two air bubbles, and immediately set in liquid nitrogen vapor. After 1 min of equilibration in liquid nitrogen vapor, the straws were immersed in liquid nitrogen. Warming was performed by holding the straws for 10 s in air, followed by 10 more s in a water bath at 20–22�C. The straws were then shaken 5 to 8 times to mix the bubbles (movement similar to that for a thermometer) and left horizontally for 6 to 8 min at room temperature. The rates of metaphase II and degeneration were analyzed by ANOVA followed by the Student t-test. The oocytes were stained with 100 µg mL–1 Hoechst 33342 and examined in an inverted microscope equipped with fluorescent light (UV filters 535 and 617 mm). Three different routines were realized with a total of 90 oocytes per group. The metaphase II rates in G1 (48/90, 53.3%) and G3 (42/90, 46.6%) were statistically the same (P e 0.05), but were higher (P d 0.05) than in G2 (0/90, 0%). The degeneration rates were: G1 (18/90, 20%), G2 (77/90, 85.6%), and G3 (7/90, 7.8%). The vitrification procedure damaged mainly the immature oocytes, since in the G2 the degeneration rate was higher and the oocytes were not able to resume meiosis. Meanwhile, when oocytes were vitrified after in vitro maturation, the metaphase II rate was similar to the one observed in IVM oocytes not subjected to vitrification. This indicates that the vitrification procedure performed in this experiment did not damage the structure of the metaphase II plate. However, more studies are necessary to predict the developmental potential of these in vitro-matured oocytes.

scholarly journals Differential gene expression between in vivo and in vitro maturation: a comparative study with bovine oocytes derived from the same donor pool

2019 ◽  
Author(s):  
Luiz Sergio Almeida Camargo ◽  
Michele Munk ◽  
Jose Nelio Sales ◽  
Sabine Wohlres-Viana ◽  
Carolina Capobiango Romano Quintão ◽  
...  
Keyword(s):  
Gene Expression ◽  
Comparative Study ◽  
Differential Gene Expression ◽  
In Vitro Maturation ◽  
Donor Pool ◽  
Differential Gene ◽  
Bovine Oocytes

171 IN VIVO AND IN VITRO MATURATION OF WOOD BISON (BISON BISON ATHABASCAE) CUMULUS–OOCYTE COMPLEXES DURING THE OVULATORY SEASON

2014 ◽  
Vol 26 (1) ◽  
pp. 199
Author(s):  
M. P. Cervantes ◽  
M. Anzar ◽  
R. J. Mapletoft ◽  
J. M. Palomino ◽  
G. P. Adams
Keyword(s):  
In Vitro Maturation ◽  
Calf Serum ◽  
Germinal Vesicle ◽  
Bison Bison ◽  
Germinal Vesicle Breakdown ◽  
Cumulus Expansion ◽  
Nuclear Maturation ◽  
Wood Bison

Technologies are being developed to conserve the genetic diversity of wood bison. Knowledge of the characteristics of in vivo and in vitro maturation of the cumulus–oocyte complex (COC) are needed in wood bison to design efficient in vitro embryo production protocols. The objectives were to (1) determine the optimal interval after hCG treatment for in vivo maturation of COC in superstimulated wood bison, and (2) compare the characteristics of COC after in vitro and in vivo maturation. Ovarian synchronization was induced in 25 bison during October and November by giving a luteolytic dose of prostaglandin followed 8 days later by follicular ablation (Day –1). Ovarian superstimulation was induced with FSH (Folltropin-V) given i.m. on Day 0 (300 mg) and Day 2 (100 mg). A second luteolytic dose of prostaglandin was given on Day 3. Bison were assigned randomly to 5 groups (n = 5/group). The COC were collected by transvaginal follicle aspiration on Day 4 and were either assessed immediately (0 h, control), or matured in vitro for 24 or 30 h (in vitro maturation), or collected on Day 5 (in vivo maturation), 24 or 30 h after bison were given 2000 IU of hCG i.m. on Day 4. In vitro maturation was done in TCM-199 with 5% calf serum, 5 μg mL–1 LH, 0.5 μg mL–1 FSH, and 0.05 μg mL–1 gentamicin, at 38.5°C and in a 5% CO2 humidified atmosphere. Nuclear maturation was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), or metaphase II (MII) with anti-lamin AC/DAPI staining. Groups were compared by analysis of variance and Fisher's exact test (Table 1). A mean (±s.e.m.) of 7.3 ± 1.7 COC were collected per bison, with no difference among groups. The COC in the control (0 h) group were at the nonexpanded GV stage. Cumulus cells were more expanded after in vivo than in vitro maturation, and the percentage of fully expanded COC was the highest in the 30-h in vivo maturation group (87%; P < 0.05). The greatest number of oocytes reached MII stage after 24 h of in vitro maturation, and 30 h of in vivo maturation. In conclusion, nuclear maturation occurred more quickly in vitro compared with in vivo, but the degree and incidence of cumulus expansion was greater after in vivo maturation. The competence of oocytes to undergo fertilization and develop into embryos remains to be investigated. Table 1.Cumulus expansion and nuclear maturation of wood bison oocytes

Zona pellucida birefringence correlates with developmental capacity of bovine oocytes classified by maturational environment, COC morphology and G6PDH activity

2012 ◽  
Vol 24 (4) ◽  
pp. 568 ◽  
Author(s):  
Eva Held ◽  
Eva-Maria Mertens ◽  
Abdollah Mohammadi-Sangcheshmeh ◽  
Dessie Salilew-Wondim ◽  
Urban Besenfelder ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Zona Pellucida ◽  
In Vitro Maturation ◽  
Immature Oocytes ◽  
Developmental Capacity ◽  
Bovine Oocytes ◽  
Scanning Electron

In the present study we aimed to analyse structural changes during in vitro maturation of the bovine zona pellucida (ZP) by scanning electron microscopy (SEM) ands zona pellucida birefringence (ZPB). Here we show that alterations during in vitro maturation invasively analysed by SEM are reflected in ZPB. In vivo-matured oocytes displayed significantly lower birefringence parameters and significantly higher blastocyst rates compared with in vitro-derived oocytes (39.1% vs 21.6%). The same was observed for in vitro-matured oocytes with cumulus–oocyte complex (COC) Quality 1 (Q1) compared with Q3-COCs with respect to zona birefringence and developmental capacity. Immature oocytes with Q1-COCs displayed higher ZPB values and a higher developmental capacity to the blastocyst stage (27.7% vs 16.9%) compared with immature Q3-COCs. Considering in vitro-matured oocytes, only those with Q1-COC showed a trend for ZPB similar to in vivo-matured oocytes. Therefore, a decreasing trend for ZPB during in vitro maturation seems to be typical for high-quality oocytes and successful cytoplasmic maturation. In accordance, fully-grown immature oocytes reached significantly higher blastocyst rates (32.0% vs 11.5%) and lower ZPB values compared with still-growing ones. In conclusion, we successfully evaluated the applicability of zona imaging to bovine oocytes: alterations during in vitro maturation invasively analysed by scanning electron microscopy were reflected in the birefringence of the zona pellucida of bovine oocytes affecting developmental capacity at the same value. Therefore ZPB measurement by live zona imaging has potential to become a new tool to assess correctness of in vitro maturation and to predict developmental competence.

scholarly journals Histone deacetylase inhibitor during in vitro maturation decreases developmental capacity of bovine oocytes

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247518
Author(s):  
Thais Preisser Pontelo ◽  
Mauricio Machaim Franco ◽  
Taynan Stonoga Kawamoto ◽  
Felippe Manoel Costa Caixeta ◽  
Ligiane de Oliveira Leme ◽  
...  
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Embryo Quality ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Nuclear Maturation ◽  
Deacetylase Inhibitor ◽  
Developmental Capacity ◽  
Bovine Oocytes

This study aimed to evaluate the effect of scriptaid during pre-maturation (PIVM) and/or maturation (IVM) on developmental competence of bovine oocytes. Cumulus-oocyte complexes (COCs) were submitted to PIVM for 6 h in the presence or absence of scriptaid. COCs were distributed into five groups: T1-IVM for 22 h, T2-PIVM for 6 h and IVM for 22 h, T3-PIVM with scriptaid for 6 h and IVM for 22 h, T4-PIVM for 6 h and IVM with scriptaid for 22 h, and T5-PIVM with scriptaid for 6 h and IVM with scriptaid for 22 h. Nuclear maturation, gene expression, cumulus cells (CCs) expansion, and embryo development and quality were evaluated. At the end of maturation, all groups presented the majority of oocytes in MII (P>0.05). Only HAT1 gene was differentially expressed (P<0.01) in oocytes with different treatments. Regarding embryo development at D7, T4 (23%) and T5 (18%) had lower blastocyst rate (P<0.05) than the other treatments (T1 = 35%, T2 = 37% and T3 = 32%). No effect was observed when scriptaid in PIVM was used in less competent oocytes (P>0.05). In conclusion, presence of scriptaid in PIVM and/or IVM did not improve developmental competence or embryo quality.

252 VITRIFICATION OF BOVINE BLASTOCYSTS PRODUCED AFTER OOCYTE MATURATION IN MEDIA CONTAINING FATTY ACIDS

2008 ◽  
Vol 20 (1) ◽  
pp. 205
Author(s):  
M. A. Shehab-El-Deen ◽  
J. L. M. R. Leroy ◽  
D. Maes ◽  
A. Van Soom
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Dairy Cows ◽  
In Vitro Maturation ◽  
Embryo Quality ◽  
Positive Control ◽  
High Concentrations ◽  
Carry Over

High concentrations of non-esterified fatty acids (NEFA) during negative energy balance (NEB) in high yielding dairy cows have been proven to be partially responsible for reduced fertility. This hypothesis has been tested by the addition of NEFAs to in vitro maturation medium at concentrations present in follicular fluid during NEB. We aimed to evaluate whether high concentrations of palmitic acid (C16:0) (PA), stearic acid (C18:0) (SA), or oleic acid (C18:1) (OA) during oocyte maturation could have a carry-over effect on embryo quality and could subsequently affect embryo cryotolerance. Cumulus–oocyte complexes (n = 4600) were matured in serum-free TCM199 plus epidermal growth factor (EGF, 20 ng mL–1; negative control), supplemented with ethanol alone (positive control) or with 0.133 mmol L–1 PA, 0.067 mmol L–1 SA, or 0.200 mmol L–1 OA (NEFAs dissolved in ethanol). The three NEFAs were tested separately in 4 replicates for PA and 5 replicates for OA or SA. Each fatty acid tested per replicate including a negative and a positive control group. After the embryos were cultured for 7 days in SOF medium, the number of blastocysts was recorded and classified as expanded, hatching, or hatched. Then, blastocysts were cryopreserved by open pulled straw vitrification using the two-step approach described by Vajta et al. (1998 Mol. Reprod. Dev. 51, 53–58). Vitrified warmed embryos were cultured in groups of <25 per 50-μL droplet of modified SOF medium with 5% fetal calf serum (FCS) under mineral oil for 48 h and examined for re-expansion and hatching. The percentages of survival in the different treatment groups were analyzed using logistic regression analyses, including the effect of replicates. Survival or not was included as the dependent variable and group was the independent variable. For every fatty acid a separate model was used. For all analyses, differences were considered to be statistically significant at the P < 0.05 level. Addition of OA to in vitro maturation media had no significant effects on cryotolerance of embryos. However, addition of PA or SA to in vitro maturation media (Table 1) significantly (P < 0.05) decreased the survival of bovine blastocysts from 79% in the positive control to 57% in PA and from 61% to 53% in SA. The results of the present study indicate that maturation of oocytes in the presence of NEB-associated concentrations of PA and SA can have carry-over effects on embryo quality, leading to reduced cryotolerance. We suggest that elevated NEFA concentrations in the follicular fluid may be one of the factors through which NEB exerts its negative effects on fertility in high yielding dairy cows. Table 1. Survival percentage (mean ± SD) of vitrified expanded bovine blastocysts matured in palmitic acid (C16:0) or stearic acid (C18:0) The authors thank J. Mestach and G. Spaepen for their excellent technical support. This research was supported by the Ministry of the Flemish Community, Belgium, in cooperation with the Ministry of Higher Education, Egypt.

253 DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES MATURED IN SERUM-FREE MEDIUM UNDER LOW OXYGEN TENSION

2009 ◽  
Vol 21 (1) ◽  
pp. 224
Author(s):  
M. M. Pereira ◽  
F. Q. Costa ◽  
P. H. A. Campos ◽  
R. V. Serapiao ◽  
J. Polisseni ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Embryo Quality ◽  
Cell Number ◽  
Total Cell ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
Total Cell Number ◽  
Blastocyst Rate ◽  
Bovine Oocytes

In vitro maturation (IVM) is a critical step in in vitro bovine embryo production. A number of factors can influence the IVM environment, such as media composition and protein supplementation. Serum and higher O2 tension have been shown to reduce embryo quality; however, little is known about the effects of serum and O2 tension during IVM on embryo quality and development. This study aimed to evaluate the effect of serum and O2 tension on IVM of bovine oocytes. Immature oocytes obtained from slaughterhouse ovaries were randomly distributed in 4 groups of IVM: G1 (n = 253), 0.1% polyvinyl alcohol (PVA) in air; G2 (n = 248), 10% inactivated estrous cow serum (ECS) in air; G3 (n = 270), 0.1% PVA under 5% O2; and G4 (n = 236), 10% ECS under 5% O2. In vitro maturation was performed with TCM-199 culture medium supplemented with 20 μg mL–1 FSH, under 5% CO2 at 38.5°C for 24 h. After maturation, oocytes were in vitro fertilized with 2.0 × 106 sperm mL–1 in Fert TALP medium, supplemented with heparin, for 20 h. Presumptive zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% fetal calf serum under 5% CO2 and 5% O2 at 38.5°C. Cleavage rate was evaluated 72 h postfertilization, and blastocyst rate and total cell number were evaluated 8 days postfertilization. Morphological classification of embryos was performed at Day 8 according to the International Embryo Transfer Society manual (1998). Cleavage, blastocyst, and grade 1 embryo rates were analyzed by chi-square, and total cell number was analyzed by ANOVA, with means compared by LSD. Results are presented as mean ± SEM. There was no difference (P > 0.05) in cleavage rates among G1, G2, and G4 (61.6, 65.3, and 57.6%, respectively), but cleavage rate was lower (P < 0.05) in G3 (52.5%). Blastocyst rates among G1, G3, and G4 (15.8, 17.7, and 20.3%, respectively) were similar (P > 0.05). However, blastocyst rate in G2 (25.0%) was higher (P < 0.05) than in G1 and G3, but was similar to G4 (P > 0.05). Total cell number was similar (P > 0.05) among G2 (194.1 ± 13.1), G3 (173.3 ± 9.0), and G4 (163.8 ± 8.7), but was lower (P < 0.05) in G1 (124.5 ± 11.4). The grade 1 embryo rate was lower (P < 0.05) in G1 (70.3%) than in G2 (89.5%), but was similar (P > 0.05) to G3 (77.0%) and G4 (83.9%). The results suggest that IVM with PVA in TCM-199 medium under 5% O2 can be performed without reducing embryo development and quality, when compared with ECS. On the other hand, oocyte developmental competence seems to be affected when IVM is performed with PVA under air conditions. Financial support: CNPq, FAPEMIG.

114 Effect of in vivo heat stress on DNA methylation and DNA hydroxymethylation of bovine oocytes

2019 ◽  
Vol 31 (1) ◽  
pp. 183
Author(s):  
F. A. Diaz ◽  
E. J. Gutierrez ◽  
B. A. Foster ◽  
P. T. Hardin ◽  
K. R. Bondioli
Keyword(s):  
Dna Methylation ◽  
Heat Stress ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Dna Hydroxymethylation ◽  
Oocyte Collection ◽  
Grade 3 ◽  
Bovine Oocytes

Cattle under the effect of heat stress have reduced fertility, with negative effects on the oocyte observed at the morphological, biochemical, transcriptional and developmental levels. There are no studies evaluating the effect of heat stress on the epigenetic profile of bovine oocytes, which plays a fundamental role in the regulation of gamete development. The objective of this study was to evaluate the effect of in vivo heat stress during the spring to summer transition on DNA methylation and DNA hydroxymethylation of bovine oocytes at the germinal vesicle (GV) and metaphase II (MII) stages. Ten Bos taurus crossbred nonlactating beef cows located at Saint Gabriel, Louisiana, USA (30°16′11.1″ N, 91°06′12.1″ W), were used for oocyte collection once monthly from April to August. Dominant follicle removal was performed 5-7 days before oocyte collection. Cumulus-oocyte complexes were collected through ovum pick-up from follicles &gt;2mm. Germinal vesicle (GV)-stage oocytes (50% of total obtained per cow) were subjected to a standard bovine in vitro maturation protocol to obtain metaphase II (MII) stage oocytes. The DNA methylation and DNA hydroxymethylation of GV and MII oocytes was assessed by fluorescence immunohistochemistry utilising primary antibodies against 5′-methylcytosine and 5′-hydromethylcytosine. Secondary antibodies utilised were Alexa Fluor 488 goat anti-mouse IgG and Alexa Fluor 546 donkey anti-rabbit IgG. Oocytes were visualised utilising a fluorescence deconvolution microscope and immunofluorescence data were expressed as corrected relative fluorescence per nucleus. The polar body was not included for fluorescence quantification when evaluating MII stage oocytes. Results (least squares means±standard error) were evaluated as cold months (April and May) and hot months (June, July, and August). Results were analysed by the type III test of fixed effects and Tukey media separation utilising Proc Glimmix of SAS 9.4 (P&lt;0.05; SAS Institute Inc., Cary, NC, USA). Maturation rates and percent of grade 1, grade 2, and grade 3 oocytes were square root arcsine transformed for statistical analysis. The number of total oocytes obtained per cow was higher in cold compared to hot months (21.88±2.34 and 14.23±2.17, respectively). Percent of grade-1 oocytes was higher in cold compared to hot months (38.25±3.69 and 27.59±3.09, respectively). There was no difference in percent of grade-2 oocytes between cold and hot months (21.80±2.44 and 22.60±2.20, respectively). There was a lower percent of grade-3 oocytes in cold compared to hot months (39.82±4.54 and 55.87±3.98, respectively). Maturation rate (in vitro maturation) was not different between cold and hot months (81.92±4.04 and 91.11±3.36, respectively). There was no difference between cold and hot months in DNA methylation (417,218.90±71,793.86 and 313,819.88±55,528.01, respectively) and DNA hydroxymethylation (444,931.10±67,920.78 and 352,254.68±56,425.96, respectively) of GV-stage oocytes. There was no difference between cold and hot months in DNA methylation (87,122.36±14,449.47 and 89,807.26±11,303.72 AU, respectively) and DNA hydroxymethylation (102,933.83±15,517.70 and 137,622.45±11,826.86 AU, respectively) of MII-stage oocytes.

Effects of hypoxanthine at low concentrations on in vitro maturation and fertilization of bovine oocytes

2017 ◽  
Vol 44 (5) ◽  
pp. 477-480 ◽  
Author(s):  
I. G. Smetanina ◽  
L. V. Tatarinova ◽  
A. S. Krivokharchenko
Keyword(s):  
In Vitro Maturation ◽  
Low Concentrations ◽  
Bovine Oocytes
Sign in / Sign up

Export Citation Format

Share Document