In vitro production of bovine embryos: Developmental competence is acquired before maturation

Blondin, Patrick; Coenen, Karine; Guilbault, L.A.; Sirard, Marc‐André

doi:10.1016/s0093-691x(97)00063-0

Cited by 162 publications

(62 citation statements)

References 27 publications

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“…Others have attempted to modify the follicular environment of the oocyte before recovery, in an effort to improve developmental competence. A 'coasting' period between hormonal stimulation and ovary collection (Blondin et al 1997b) as well as the time interval between ovary collection and oocyte aspiration (Blondin et al 1997a) have been shown to significantly affect the developmental competence of the oocyte. In addition, donors were administered six doses of FSH and an injection of LH, before ovum pick up approximately 80% of the recovered oocytes formed blastocysts following in vitro procedures .…”

Section: The Oocytementioning

confidence: 99%

Oocyte and Embryo Quality: Effect of Origin, Culture Conditions and Gene Expression Patterns

Lonergan

Rizos

Gutiérrez‐Adán

et al. 2003

Reprod Domestic Animals

271

164

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In general, the majority of immature bovine oocytes fail to develop to the blastocyst stage following maturation, fertilization and culture in vitro. The evidence suggests that while culture conditions during in vitro embryo production can impact on the developmental potential of the early embryo, the intrinsic quality of the oocyte is the key factor determining the proportion of oocytes developing to the blastocyst stage. In addition, evidence suggests that the period of post-fertilization embryo culture is the most critical in determining blastocyst quality. This paper reviews the current literature, with emphasis on the bovine model, demonstrating evidence for an effect of oocyte origin and/or in vitro maturation conditions on the developmental capacity and gene expression patterns in the oocyte. Furthermore, the well-documented effects of post-fertilization culture environment on embryo gene expression and quality are highlighted.

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Section: The Oocytementioning

confidence: 99%

Oocyte and Embryo Quality: Effect of Origin, Culture Conditions and Gene Expression Patterns

Lonergan

Rizos

Gutiérrez‐Adán

et al. 2003

Reprod Domestic Animals

271

164

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“…Together with the morphological selection of cumulus-oocyte complexes, the diameter of the follicle is one of the most commonly used parameters in the prediction of bovine oocyte competence (Anguita et al 2007). The relationship between the diameter of the follicle and the developmental competence of the oocyte has already been shown (Pavlok et al 1992), whereby some studies indicate a positive relationship between the diameter of the follicle and the in vitro blastocyst developmental competence (Blondin et al 1997;Kauffold et al 2005;Han et al 2006). Oocytes from follicles smaller than 3 mm in diameter are less competent for the in vitro production embryos when compared with those from larger follicles (Lonergan et al 1994;Kauffold et al 2005).…”

Section: Introductionmentioning

confidence: 99%

The Influence of Morphology, Follicle Size and Bcl‐2 and Bax Transcripts on the Developmental Competence of Bovine Oocytes

Adona

Bressan

et al. 2014

Reprod Domestic Animals

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This study analysed two non-invasive oocyte selection methods in relation to in vitro embryo development capacity and expression of apoptosis-related genes. Selection was based on morphological quality of oocytes or follicle diameter. Oocytes were classified as grade I (GI ≥3 layers compact cumulus cells and homogeneous cytoplasm; grade II (GII ≤3 layers compact cells and homogeneous cytoplasm;, and grade III (GIII ≥3 layers, but cells with slight expansion and slightly granulated cytoplasm). Blastocyst development was lower for GII (28.5%) than for GIII (47.7%, p < 0.05), and GI was similar to both (36.9%, p > 0.05). Relative expression of Bcl-2 gene was lower in the GI (1.0, p < 0.05) than in the GII (1.8) and GIII (2.2), which were not different (p > 0.05). There was no difference (p > 0.05) between GI (1.0), GII (0.92) and GIII (0.93) regarding the Bax transcript. However, the Bax and Bcl-2 transcript ratios in GII (Bax; 0.92 and Bcl-2; 1.8) and GIII (Bax; 0.93 and Bcl-2; 2.2) were different (p < 0.05). Regarding oocytes from follicles of different sizes, cleavage and blastocyst rates for 1-3 mm (82.5; 23.7%) were lower (p < 0.05) than for 6-9 mm (95.6; 41.1%), but similar (p > 0.05) to 3-6 mm (93.7; 35.4%), which were not different (p > 0.05). Regarding Bax and Bcl-2 expression, the oocytes were similar (p > 0.05) for 1-3 mm (Bax; 1.0 and Bcl-2; 1.0), 3-6 mm (Bax; 1.0 and Bcl-2; 0.93) and 6-9 mm (Bax; 0.92 and Bcl-2; 0.91). In conclusion, oocyte selection based on morphological appearance does not guarantee the success of embryonic development. Additionally, the absence of apoptosis is not necessarily a benefit for the development of oocytes. Bovine COCs with initial signs of atresia may be used for the in vitro production of embryos, and COCs taken from follicles >3 mm in diameter are better suited to in vitro embryo development.

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“…The initial coasting time was chosen based on previous studies indicating that, following one bolus injection of FSH, the optimal blastocyst rate was obtained when oocytes were recovered 48 h later instead of 24 or 72 h (Blondin et al 1997). Therefore, the initial clinical trial was set for a coasting of 33 vs 48 h following the last FSH injection and both periods resulted in a significant increase in competence compared with slaughterhouse controls.…”

Section: Introductionmentioning

confidence: 99%

FSH withdrawal improves developmental competence of oocytes in the bovine model

Nivet¹,

Bunel²,

Labrecque³

et al. 2012

Reproduction

128

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Combinations of genetic, environmental, and management factors are suspected to explain the loss in fertility observed for over 20 years in dairy cows. In some cases, IVF is used. When compared with in vivo embryo production, IVF resulted in low success rates until the FSH coasting process (FSH starvation after superstimulation) was introduced in 2002. Increased competence associated with FSH withdrawal of aspirated oocyte for in vitro maturation and IVF has not been optimized nor explained yet. The goal here was to determine and characterize the optimal oocyte competence acquisition window during the coasting period by determining blastocyst rates and follicular cohort development. Commercial milking cycling cows (nZ6) were stimulated with 3 days of FSH (6!40 mg NIH Folltropin-V given at 12 h intervals) followed by a coasting period of 20, 44, 68, or 92 h. Each animal was exposed to the four conditions and served as its own control. At the scheduled time, transvaginal aspirations of immature oocytes were performed followed by IVF of half the oocytes. The outcomes were as follows: i) FSH coasting was optimal at a defined period: between 44 and 68 h of coasting; ii) The best estimated coasting duration was w54G7 h; iii) Under these conditions, the best statistical blastocyst rate estimation was w70%; iv) Between 44 and 68 h of coasting, follicle size group proportions were similar; v) Follicle diameter was not linearly associated with competence. In conclusion, coasting duration is critical to harvest the oocytes at the right moment of follicular differentiation.

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In vitro production of bovine embryos: Developmental competence is acquired before maturation

Cited by 162 publications

References 27 publications

Oocyte and Embryo Quality: Effect of Origin, Culture Conditions and Gene Expression Patterns

Oocyte and Embryo Quality: Effect of Origin, Culture Conditions and Gene Expression Patterns

The Influence of Morphology, Follicle Size and Bcl‐2 and Bax Transcripts on the Developmental Competence of Bovine Oocytes

FSH withdrawal improves developmental competence of oocytes in the bovine model

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