Effects of Oxygen Tension on Survival and Growth In Vitro of Bovine Oocytes from Early Antral Follicles

Oocyte maturation is the key factor affecting the fertilization and embryonic development. Factors such as oocyte density and oxygen tension can directly influence the IMV. Thus, the objective of this study was to evaluate the effect of the association of oxygen tensions (5% or 20%) with different oocyte densities (1:10?l or 1:20?l) in the in vitro maturation (IVM) of bovine oocytes on maturation and fertilization rates, ROS production and antioxidant activity. Three experiments were performed with bovine oocytes that were obtained from slaughterhouse ovaries. After selection, the oocytes were randomly distributed in four treatments: 1:10/5%; 1:10/20%; 1:20/5%and 1:20/20% for each experiment. In experiment I, nuclear maturation status and cytoplasmic maturation were evaluated through detection of the first polar body by immunofluorescence and the mitochondrial reorganization assay. In experiment II, ROS production and antioxidant activity were analyzed in oocytes and IVM medium after 24 h of maturation through detection of ROS, reduced glutathione (GSH) and Superoxide dismutase activity by spectrofluorimetric methods. In experiment III, fertilization was evaluated through pronucleus formation, sperm penetration with or without decondensation and polyspermy rates by immunofluorescence. In experiment I, the nuclear maturation and cytoplasmic maturation were similar among treatments (P>0.05). In experiment II, reactive oxygen species in oocytes were elevated in treatments with low oxygen tension which was independent of oocyte density (P<0.05). Additionally, ROS levels in IVM medium were higher in treatments with high oocyte density by volume of medium, which was independent of oxygen tension (P<0.05). In Experiment III, the fertilization and penetration rates were higher in the treatment with 20% oxygen tension and high oocyte density (P<0.05). Furthermore, a high incidence of polyspermy was observed in groups with high oxygen tension and low oocyte density (P<0.05). In conclusion, the results of this study indicate an interaction between oxygen tension and oocyte density, which increases ROS production in certain associations and subsequently influences the rates of in vitro fertilization of bovine oocytes. The improved rates of IVF were obtained when IVM was conducted using 20% oxygen tension and high oocyte density (1:20 ul).

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Effect of oxygen tension and serum during IVM on developmental competence of bovine oocytes

Reproduction Fertility and Development ◽

10.1071/rd10007 ◽

2010 ◽

Vol 22 (7) ◽

pp. 1074 ◽

Cited By ~ 14

Author(s):

Michele M. Pereira ◽

Marco A. Machado ◽

Fernanda Q. Costa ◽

Raquel V. Serapiao ◽

Joao H. M. Viana ◽

...

Keyword(s):

Oxygen Tension ◽

Cell Number ◽

Total Cell ◽

Developmental Competence ◽

In Vitro Production ◽

Total Cell Number ◽

Effect Of Oxygen ◽

Vitro Production ◽

Bovine Oocytes

With an aim to improve the in vitro production of bovine embryos, the present study investigated the effect of serum and oxygen tension during IVM on oocyte developmental competence. Four experimental groups were evaluated: G1, 10% oestrus cow serum (OCS) with 20% O2; G2, 0.1% polyvinyl alcohol (PVA) with 20% O2; G3, 10% OCS with 5% O2; and G4, 0.1% PVA with 5% O2. The proportion of MII oocytes, blastocyst rates and total cell number were not affected (P > 0.05) when the OCS was replaced with PVA under 5% O2, whereas a higher (P < 0.05) blastocyst rate and total cell number were found with OCS compared with PVA under 20% O2. The apoptosis index was lower in blastocysts from oocytes matured with PVA under 5% O2 (G4) compared with other groups (G1, G2 and G3), but no differences (P > 0.05) were found in maturation and blastocyst rates. Significant differences were found in the amount of specific transcripts in oocytes matured under different conditions. In conclusion maturation with PVA and 5% O2 provides an efficient in vitro culture condition for the maturation of bovine oocytes.

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Interactions between oxygen tension and glucose concentration that modulate actions of heat shock on bovine oocytes during in vitro maturation

Theriogenology ◽

10.1016/j.theriogenology.2007.06.005 ◽

2007 ◽

Vol 68 (5) ◽

pp. 763-770 ◽

Cited By ~ 34

Author(s):

L.A. de Castro e Paula ◽

P.J. Hansen

Keyword(s):

Heat Shock ◽

Oxygen Tension ◽

Glucose Concentration ◽

In Vitro Maturation ◽

Bovine Oocytes

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Partenogenetic development of Bos taurus embryos from oocytes matured in different culture systems

Agrarian Bulletin of the ◽

10.32417/1997-4868-2020-197-6-66-72 ◽

2020 ◽

Vol 197 (6) ◽

pp. 66-72

Author(s):

T. I. KUZMINA

Keyword(s):

Oocyte Maturation ◽

Granulosa Cells ◽

Cold Shock ◽

Bos Taurus ◽

Embryonic Stem ◽

Structural Components ◽

Antral Follicles ◽

Culture Systems ◽

Bovine Oocytes

Abstract. Identification of the factors determining of donor’s oocyte competence to parthenogenetic development will allow developing an effective method for obtaining parthenotes to solve fundamental problems of regulating gene activity in ontogenesis, creating homozygous embryonic stem cell lines, improving the stages of cloning technology, and modeling of in vitro oocyte maturation media. The purpose of study is to evaluate the potencies of Bos taurus oocytes matured in different culture systems to cold shock-induced parthenogenesis. Methods. For oocyte maturation, culture systems of the following composition were used: 1 – TC-199 with 10 % fetal bovine serum (FBS), 50 μg/ml estradiol, 10 μg/ml luteinizing hormone, 10 μg/ml follicle-stimulating hormone; 2 – TC-199 with 10 % estrous serum of cows; 3 – TC-199 with 50 % fluid from follicles (Ø 3–8 mm); 4 – TC-199 with 50 % protein of follicular fluid (molecular weight of 65 kDa); 5 – TC-199 with 10 % FBS, 1×106 granulosa cells/ml medium; 6 – TC-199 with 10 % FBS and walls of follicles (Ø 6–8 mm); 7 – TC-199 with 10 % FBS, 1×106 granulosa cells/ml medium and walls of follicles (Ø 6–8 mm). After 24 hours of cultivation, the oocytes were activated by cold shock (exposure time 20 minutes, temperature 0…–4 °C. Results. The proportion of embryos at the stages of late morula and blastocysts from oocytes matured in system 7 was 45 % (58/129), which was significantly higher than in other systems: 1 – 28 % (39/141), P < 0.05; 2 – 31 % (42/137), P < 0.05; 3 – 25 % (33/133), P < 0.01; 4 – 18 % (25/139), P < 0.001; 5 – 31 % (41/132), P < 0.05; 6 – 33 % (43/129). The introduction of estradiol or structural components of antral follicles into the oocytes maturation medium contributed to an increase in the proportion of parthenotes at the preimplantation stages of development, including blastocysts, and a decrease in the level of degenerated embryos. Scientific novelty. A comparative morphological analysis of the potentials for parthenogenesis of bovine oocytes matured in various culture systems and activated by cold shock was carried out for the first time. Optimal systems for in vitro maturation of female gametes were proposed. Based on the analysis of the results, we recommend before induction to parthenogenesis bovine oocytes culture in media supplemented with 50 ng/ml estradiol or structural components of antral follicles producing estradiol.

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Oxygen tension and oocyte density during in vitro maturation affect the in vitro fertilization of bovine oocytes

Semina Ciências Agrárias ◽

10.5433/1679-0359.2015v36n6sup2p4277 ◽

2015 ◽

Vol 36 (6Supl2) ◽

pp. 4277

Author(s):

Angelo Bertani Giotto ◽

Daniela Dos Santos Brum ◽

Francielli Weber Santos ◽

Antonio Carlos Galarça Guimarães ◽

Cibele Garcia Moreira Gonçalves ◽

...

Keyword(s):

Antioxidant Activity ◽

In Vitro Fertilization ◽

Oxygen Tension ◽

In Vitro Maturation ◽

Ros Production ◽

Vitro Fertilization ◽

Nuclear Maturation ◽

Cytoplasmic Maturation ◽

Bovine Oocytes

Oocyte maturation is the key factor affecting the fertilization and embryonic development. Factors such as oocyte density and oxygen tension can directly influence the IMV. Thus, the objective of this study was to evaluate the effect of the association of oxygen tensions (5% or 20%) with different oocyte densities (1:10?l or 1:20?l) in the in vitro maturation (IVM) of bovine oocytes on maturation and fertilization rates, ROS production and antioxidant activity. Three experiments were performed with bovine oocytes that were obtained from slaughterhouse ovaries. After selection, the oocytes were randomly distributed in four treatments: 1:10/5%; 1:10/20%; 1:20/5%and 1:20/20% for each experiment. In experiment I, nuclear maturation status and cytoplasmic maturation were evaluated through detection of the first polar body by immunofluorescence and the mitochondrial reorganization assay. In experiment II, ROS production and antioxidant activity were analyzed in oocytes and IVM medium after 24 h of maturation through detection of ROS, reduced glutathione (GSH) and Superoxide dismutase activity by spectrofluorimetric methods. In experiment III, fertilization was evaluated through pronucleus formation, sperm penetration with or without decondensation and polyspermy rates by immunofluorescence. In experiment I, the nuclear maturation and cytoplasmic maturation were similar among treatments (P>0.05). In experiment II, reactive oxygen species in oocytes were elevated in treatments with low oxygen tension which was independent of oocyte density (P<0.05). Additionally, ROS levels in IVM medium were higher in treatments with high oocyte density by volume of medium, which was independent of oxygen tension (P<0.05). In Experiment III, the fertilization and penetration rates were higher in the treatment with 20% oxygen tension and high oocyte density (P<0.05). Furthermore, a high incidence of polyspermy was observed in groups with high oxygen tension and low oocyte density (P<0.05). In conclusion, the results of this study indicate an interaction between oxygen tension and oocyte density, which increases ROS production in certain associations and subsequently influences the rates of in vitro fertilization of bovine oocytes. The improved rates of IVF were obtained when IVM was conducted using 20% oxygen tension and high oocyte density (1:20 ul).

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