Oocyte and follicular morphology as determining characteristics for developmental competence in bovine oocytes

Blondin, Patrick; Sirard, Marc‐André

doi:10.1002/mrd.1080410109

Cited by 419 publications

(293 citation statements)

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“…The present culture conditions may be suboptimal, since we divided embryos into several groups according to their developmental stages at 72 hpi. This procedure reduces the embryo density in culture and decreases the embryonic developmental rate [2,6,13]. Therefore, we might have failed to detect differences in the developmental rate of the two categories.…”

Section: Discussionmentioning

confidence: 99%

“…The number of oocytes with heterogeneous ooplasm having dark clusters collected from the ovary is more than double (approximately 25%) that of the oocytes with homogeneous ooplasm [8]. Recent studies have suggested that the oocytes with heterogeneous ooplasm with dark clusters have a similar or higher capacity for in vitro maturation [4,5], fertilization [8,12] and development [2,7,8] than the oocytes with homogeneous ooplasm. However, the previous results were inconsistent and fragmental, since in vitro maturation, fertilization, or subsequent development were separately examined by different groups under the different culture conditions.…”

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confidence: 99%

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In Vitro Fertilization and Cortical Granule Distribution of Bovine Oocytes Having Heterogeneous Ooplasm with Dark Clusters.

Nagano

Takahashi

Katagiri

1999

The Journal of Veterinary Medical Science

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ABSTRACT. In vitro maturation, fertilization and subsequent development of oocytes with homogeneous (category 1), or heterogeneous ooplasm (category 2) were investigated. No significant differences were observed in the nuclear maturation and total fertilization rates between the two categories. However, category 2 oocytes showed a higher normal fertilization rate due to their lower incidence of polyspermy as compared to category 1 oocytes. Electron microscopic study revealed that all category 2 oocytes had cortical granules lined up next to the plasma membrane, and that some category 1 oocytes still had small clusters of cortical granules after maturation. Although the proportion of cleaved zygotes was higher in category 2, the percentages of cleaved zygotes that developed to the blastocyst stage did not differ between the two categories. These results demonstrate that oocytes with heterogeneous ooplasm have a higher capacity for normal fertilization due to the reduction in polyspermy. This can be attributed to the normal distribution of cortical granules in category 2 oocytes after maturation. -KEY WORDS: bovine, cortical granule, fertilization, morphology.J. Vet. Med. Sci. 61(5): 531-535, 1999 Sigma Chemical Co., St. Louis, U.S.A.), 0.2 mM sodium pyruvate (Sigma) and 50 µg/ml gentamicin sulfate (Sigma). During the washing procedure, oocytes were examined, selected and classified under a stereomicroscope by the following criteria. Category 1 represented oocytes with homogeneous ooplasm and multilayered cumulus investment. Category 2 represented oocytes having heterogeneous ooplasm with dark clusters, and multilayered cumulus investment.In vitro maturation, fertilization and culture: In vitro maturation, fertilization and culture were carried out using the procedure described previously [15]. Briefly, the COCs were washed once in the maturation medium; 25 mM Hepesbuffered TCM 199 supplemented with 10% fetal calf serum (Gibco Laboratories, Grand Island, NY, U.S.A.), 0.02 units/ ml follicle-stimulating hormone (Sigma), 1 µg/ml estradiol-17β (Sigma) and 0.2 mM sodium pyruvate and 50 µg/ml gentamicin sulfate. The oocytes in each category were cultured separately for 22 hr in a 50 µl droplet of maturation medium (10 or 11 oocytes per droplet) covered with paraffin oil at 39°C in a humidified atmosphere of 5% CO 2 in air. Frozen bovine semen collected from a Holstein bull was used for in vitro fertilization. After thawing the semen in a 37°C water bath for 30 sec, the motile sperm were separated using a discontinuous gradient with 45 and 90% Percoll (Pharmacia BioProcess, Uppsala, Sweden) by centrifugation at 700 × g for 20 min. The sperm were subsequently washed with a modified Brackett and Oliphant (mBO) medium [3] by centrifugation at 500 × g for 5 min. The mature oocytes were co-incubated with the sperm at the concentration of 5 × 10 6 sperm/ml in a 100 µl droplet of mBO medium containing 3 mg/ml fatty-acid-free BSA (Sigma) and 2.5 mM theophylline (Sigma) covered with paraffin oil for 20 hr at 39°C in a humidif...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

In Vitro Fertilization and Cortical Granule Distribution of Bovine Oocytes Having Heterogeneous Ooplasm with Dark Clusters.

Nagano

Takahashi

Katagiri

1999

The Journal of Veterinary Medical Science

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“…Moreover, the meiotic competence in bovine species is closely related to the follicular dimension; oocytes derived from small follicles showed a lower capacity to resume meiosis and to develop up to early embryonic stages [4]. Previous works [8,19,23] [9,26,27].…”

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confidence: 95%

Follicular size affects the meiotic competence of in vitro matured prepubertal and adult oocytes in sheep

Ledda¹,

Bogliolo²,

Leoni³

et al. 1999

Reprod. Nutr. Dev.

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“…This led to the search for a reliable indicator of oocyte quality. Thus, one of the important puzzles for reproductive biologists today is the search for a reliable noninvasive marker of the quality of oocytes for both human and animal assisted reproduction.Initial attempts at evaluating the quality of oocytes meant for in vitro fertilization (IVF) focused on the physical/morphological characteristics of the Cumulus-oocyte-complexes (COCs) [1,2]. These criteria are both noninvasive and rapid and are still generally in use today.…”

mentioning

confidence: 99%

“…Initial attempts at evaluating the quality of oocytes meant for in vitro fertilization (IVF) focused on the physical/morphological characteristics of the Cumulus-oocyte-complexes (COCs) [1,2]. These criteria are both noninvasive and rapid and are still generally in use today.…”

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confidence: 99%

Factors Influencing the Biochemical Markers for Predicting Mammalian Oocyte Quality

Ola

Sun

2012

Journal of Reproduction and Development

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Abstract. The need for accurate selection of the best oocytes for in vitro fertilization protocols and thus, production of embryos has driven the search for oocyte quality markers from morphological criteria to biochemical parameters. Current studies are focused on the biochemical constituents of the follicular fluid and gene expression profiling of the cumulus cells. These parameters are, however, affected by factors that must be considered before making a judgment of the oocyte's quality. These includes factors such as the type of hormonal stimulation protocol, age of oocyte donor and heat stress on the donor, all of which have been reported to influence the concentrations of many hormones, apolipoproteins, metabolites, fatty acids and growth factors in the follicular fluid and the expression of several genes in the cumulus cells. Another important point to note is species variation in the response to these extraneous influences, which thus calls for species targeted investigations. As reports are still scanty and investigations assumed to be very keen, we employed this review paper to bring attention of researchers and clinicians to those factors that may come to bear on the outcome of their investigations on oocyte and embryo quality. Key words: Cumulus cells, Follicular fluid, Mammalian oocytes, Quality prediction (J. Reprod. Dev. 58: [385][386][387][388][389][390][391][392] 2012) I t is well known that only part of the in vivo ovulated oocytes and in vitro matured oocytes are capable of developing to viable embryos after fertilization. This led to the search for a reliable indicator of oocyte quality. Thus, one of the important puzzles for reproductive biologists today is the search for a reliable noninvasive marker of the quality of oocytes for both human and animal assisted reproduction.Initial attempts at evaluating the quality of oocytes meant for in vitro fertilization (IVF) focused on the physical/morphological characteristics of the Cumulus-oocyte-complexes (COCs) [1,2]. These criteria are both noninvasive and rapid and are still generally in use today. However, recent reports on the inadequacies of a simple morphological appearance as a measure of quality suggest that morphological markers cannot be completely relied upon [3,4]. This has led to intensification of the search for alternative or complementary criteria with focus on the follicular fluid (FF) and the cumulus cells (CCs) around the oocyte.The preovulatory oocyte communicates intimately and directly with the surrounding cumulus granulosa cells through specialized transzonal cytoplasmic projections [5] and with the more distant mural granulosa cells through the follicular fluid [6]. Many biochemical substances found in these close associates of the oocyte have been studied and correlated with the developmental competence of the oocyte. Very recent attempts are even looking beyond a single substance to the totality of the biochemical constituents of the follicular fluid. This area of research is referred to as metabolomics [7]. Revelli e...

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Oocyte and follicular morphology as determining characteristics for developmental competence in bovine oocytes

Cited by 419 publications

References 32 publications

In Vitro Fertilization and Cortical Granule Distribution of Bovine Oocytes Having Heterogeneous Ooplasm with Dark Clusters.

In Vitro Fertilization and Cortical Granule Distribution of Bovine Oocytes Having Heterogeneous Ooplasm with Dark Clusters.

Follicular size affects the meiotic competence of in vitro matured prepubertal and adult oocytes in sheep

Factors Influencing the Biochemical Markers for Predicting Mammalian Oocyte Quality

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