Oocyte quality and embryo production in cattle

1998 ◽  
Vol 78 (4) ◽  
pp. 513-516 ◽  
Author(s):  
M.-A. Sirard ◽  
P. Blondin
Keyword(s):  
Growth Phase ◽  
Ovarian Follicle ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Full Potential ◽  
Plateau Phase ◽  
Follicular Growth ◽  
Transvaginal Aspiration ◽  
New Evidence ◽  
Bovine Oocytes

New evidence indicates that bovine oocytes are not always in synchrony with their surrounding follicles. During rapid follicular growth, the oocytes do not acquire a full developmental competence. The plateau phase at the end of the growth phase resulting in dominance or atresia seems important for oocytes to accumulate the information required to become viable embryos. The ovarian follicle has a behavior similar to a fruit where the seed must await the ripening of the envelope to achieve its full potential. This knowledge can now be applied to harvest oocytes of higher quality through transvaginal aspiration in cows. Key words: Oocyte, embryo, cattle

Gene-specific profiling of DNA methylation and mRNA expression in bovine oocytes derived from follicles of different size categories

2017 ◽  
Vol 29 (10) ◽  
pp. 2040 ◽  
Author(s):  
F. Mattern ◽  
J. Heinzmann ◽  
D. Herrmann ◽  
A. Lucas-Hahn ◽  
T. Haaf ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Mrna Expression ◽  
Candidate Genes ◽  
Growth Phase ◽  
Methylation Status ◽  
Developmental Competence ◽  
Follicular Growth ◽  
Antral Follicles ◽  
Follicle Diameter ◽  
Bovine Oocytes

Epigenetic changes, such as DNA methylation, play an essential role in the acquisition of full developmental competence by mammalian oocytes during the late follicular growth phase. Here we used the bovine model to investigate the DNA methylation profiles of seven candidate genes (imprinted: bH19, bSNRPN; non-imprinted: bZAR1, bDNMT3A, bOCT4, bDNMT3 Lo and bDNMT3 Ls) and the mRNA expression of nine candidate genes (imprinted: bSNRPN, bPEG3, bIGF2R; non-imprinted: bPRDX1, bDNMT1B, bDNMT3A, bZAR1, bHSF1 and bNLRP9) in oocytes from antral follicles of three different size classes (≤2 mm, 3–5 mm, ≥6 mm) to unravel the epigenetic contribution to this process. We observed an increased number of aberrantly methylated alleles in bH19, bSNRPN and bDNMT3 Lo of oocytes from small antral follicles (≤2 mm), correlating with lower developmental competence. Furthermore, we detected an increased frequency of CpG sites with an unclear methylation status for DNMT3 Ls, specifically in oocytes from follicles ≥6 mm, predominantly at three CpG positions (CpG2, CpG7 and CpG8), of which CpG7 is a potential regulatory site. No major differences in mRNA expression were observed, indicating that the transcriptional machinery may not yet be active during the follicular growth phase. Our results support the notion that a follicle diameter of ~2 mm is a critical stage for establishing DNA methylation profiles and indicate a link between DNA methylation and the acquisition of oocyte developmental competence.

In vitro Culture of Early Secondary Preantral Follicles to Obtain MII Oocyte Developmental Competence from CD-1 Outbred Mice

2020 ◽  
Author(s):  
Jongwon Kim ◽  
Seungki Lee ◽  
Jung Kyu Choi
Keyword(s):  
In Vitro Culture ◽  
Culture System ◽  
Ovarian Follicle ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Vitro Fertilization ◽  
Preantral Follicles ◽  
Successful Isolation ◽  
In Vitro Culture System

Background: The ovarian follicle is the fundamental functional tissue unit that consists of mammalian ovary. In humans, it has been known that females are born with a maximum number of follicles or oocytes that are not only non-renewable, but also undergoing degeneration with time with a sharply decreased oocyte quality after the age of 35. Methods: Here, we demonstrate that successful isolation of primary, early secondary and late secondary follicles from the ovaries of CD-1 outbred female mice and in vitro culture system to successfully induce the development of MII oocytes. Result: The 9 days of in vitro culture of early secondary follicles showed significant higher rates in growth and maturation displaying higher numbers of antral follicles and MII oocytes developed from early secondary follicles compared to those cultured for 11 days. However, there was no visible difference induced by the size of initial follicles in the rates of growth and maturation. MII oocytes derived from in vitro culture of early secondary follicles following in vitro fertilization developed into two-cell embryos. These observations demonstrate that developmentally competent MII oocytes can be obtained by in vitro culture of preantral follicles derived from the ovaries of CD-1 mice and reveal a crucial role for CD-1 mice as a novel model for research on human ovarian follicles. Furthermore, this study proposes an in vitro culture system using preantral follicle as a therapeutic strategy for fertility preservation of humans for assisted reproductive medicine. 

scholarly journals Evaluation of bovine zona pellucida characteristics in polarized light as a prognostic marker for embryonic developmental potential

Reproduction ◽  
2011 ◽  
Vol 141 (6) ◽  
pp. 779-787 ◽  
Author(s):  
M Koester ◽  
A Mohammadi-Sangcheshmeh ◽  
M Montag ◽  
F Rings ◽  
T Schimming ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Polarized Light ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Blue Staining ◽  
Developmental Potential ◽  
Preimplantation Embryo Development ◽  
Intensity Parameters ◽  
Bovine Oocytes

It has previously been demonstrated that zona pellucida imaging of human oocytes using polarized light microscopy is a clinically applicable method for the noninvasive assessment of oocyte quality. This study was designed to investigate whether zona pellucida characteristics of bovine oocytes and zygotes in polarized light may similarly serve as a useful marker for developmental competence in bovine reproductive biotechnologies. Zona birefringence intensity parameters of 2862 oocytes/zygotes were objectively evaluated with an automatic analysis system and correlated with oocyte/zygote quality. In detail, immature oocytes of good quality assessed with brilliant cresyl blue staining showed significantly lower zona birefringence than poor-quality counterparts (P<0.001). Afterin vitromaturation and classification according to maturational status, the birefringence intensity parameters were significantly different in those oocytes that reached metaphase II compared with arrested stages (P<0.001). Following either parthenogenetic activation or IVF with subsequentin vitroculture in a well-of-the-well system until day 9, superior development as determined by cleavage, blastocyst formation, and hatching ability was associated with lower zona birefringence intensity parameters. When early zygote-stage embryos were selected and assorted in groups based on zona birefringence (high/medium/low), the group of embryos derived from high-birefringence zygotes displayed a significantly compromised developmental potential compared with low-birefringence zygotes. These results clearly show that developmentally competent bovine oocytes/zygotes exhibit lower zona birefringence intensity parameters. Therefore, birefringence imaging of zona pellucida is a suitable technique to predict bovine preimplantation embryo development.

The FSH–HIF-1α–VEGF Pathway Is Critical for Ovulation and Oocyte Health but Not Necessary for Follicular Growth in Mice

Endocrinology ◽  
2020 ◽  
Vol 161 (4) ◽  
Author(s):  
Chengyu Li ◽  
Zhaojun Liu ◽  
Weijian Li ◽  
Liangliang Zhang ◽  
Jilong Zhou ◽  
...  
Keyword(s):  
Ovarian Follicle ◽  
Hypoxia Inducible Factor ◽  
Oocyte Quality ◽  
Ovarian Follicles ◽  
Actin Dynamics ◽  
Independent Effect ◽  
Follicular Growth ◽  
Growth And Survival ◽  
Ovarian Follicle Development ◽  
Antral Follicles

Abstract Follicle-stimulating hormone (FSH)-induced growth of ovarian follicles is independent of follicular vascularization. Recent evidence has indicated that follicular vascularization is critical to ovarian follicle development and survival. FSH, a gonadotropin that induces follicular growth and development, also acts as the major survival factor for antral follicles. FSH has been reported to stimulate angiogenesis in the theca layers mediated in part by the vascular endothelial growth factor A (VEGFA) and the transcription factor hypoxia inducible factor 1α (HIF-1α). However, it remains largely undetermined whether FSH-dependent growth and survival of antral follicles relies on FSH-induced vascularization. Here, we first demonstrated that induction of angiogenesis through the FSH–HIF–1α-VEGFA axis is not required for FSH-stimulated follicular growth in mouse ovary. FSH increased the total number of blood vessels in mouse ovarian follicles, which was correlated with elevated expression of VEGFA and HIF-1α in granulosa cells. In contrast, blocking of follicular angiogenesis using inhibitors against the HIF-1α-VEGFA pathway repressed vasculature formation in follicles despite FSH administration. Interestingly, by measuring follicular size and ovarian weight, we found that the suppression of angiogenesis via HIF-1α–VEGFA pathway did not influence FSH-mediated follicular growth. However, inhibition of FSH-induced follicular vascularization by PX-478, a small-molecule inhibitor that suppresses HIF-1α activity, blocked ovulation and triggered atresia in large follicles. On the other hand, PX-478 injection reduced oocyte quality via impairing the meiotic apparatus, showing a prominently defective spindle assembly and actin dynamics. Collectively, our findings unveiled a vascularization-independent effect of FSH on follicular growth, whereas follicular survival, ovulation, and oocyte development relies on FSH-mediated angiogenesis in the follicles.

Intrafollicular conditions as a major link between maternal metabolism and oocyte quality: a focus on dairy cow fertility

2012 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
J. L. M. R. Leroy ◽  
D. Rizos ◽  
R. Sturmey ◽  
P. Bossaert ◽  
A. Gutierrez-Adan ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Embryo Quality ◽  
Ovarian Follicle ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Metabolic Disturbances ◽  
Oocyte Growth ◽  
Adverse Conditions ◽  
Maternal Metabolism

Reduced oocyte and embryo quality are recognised as major factors in the problem of disappointing fertility in high producing dairy cows. This review aims to shed more light on the importance of the intrafollicular environment in the subfertility problem in dairy cows. Metabolic disturbances associated with negative energy balance (NEB) early postpartum are associated with ovarian dysfunction. Changes in the growth pattern of the ovarian follicle during a period of NEB can indirectly affect oocyte quality. Furthermore, a maternal metabolic disorder (linked with NEB or nutritionally induced) may alter the endocrine and biochemical composition of the follicular fluid, the micro-environment of the growing and maturing female gamete. The maturing oocyte is very sensitive to any perturbation in its direct environment and in vitro maturation models revealed that some of these metabolic changes reduce the oocyte’s developmental competence. Also, embryo quality is significantly reduced due to maturation in adverse conditions. Well balanced and timed oocyte metabolism and gene expression are crucial to safeguard an optimal oocyte development. In that perspective, metabolome and transcriptome parameters of the oocyte may serve to predict reproductive success rates. Finally, there is growing evidence that adverse conditions for oocyte growth and maturation may also jeopardise the health and performance of the offspring.

Effect of stage of follicular growth during superovulation on developmental competence of bovine oocytes

2005 ◽  
Vol 63 (4) ◽  
pp. 1149-1166 ◽  
Author(s):  
P. Humblot ◽  
P. Holm ◽  
P. Lonergan ◽  
C. Wrenzycki ◽  
A.-S. Lequarré ◽  
...  
Keyword(s):  
Developmental Competence ◽  
Follicular Growth ◽  
Bovine Oocytes

scholarly journals Kinetics of tau aggregation reveals patient specific tau characteristics among Alzheimer's cases

2021 ◽  
Author(s):  
Tarun V Kamath ◽  
Naomi Klickstein ◽  
Caitlin Commins ◽  
Analiese R Fernandes ◽  
Derek H Oakley ◽  
...  
Keyword(s):  
Growth Phase ◽  
Tau Proteins ◽  
Patient Specific ◽  
Lag Phase ◽  
Plateau Phase ◽  
Kinetic Assay ◽  
Cellular Processes ◽  
Morphological Differences ◽  
Tau Aggregation ◽  
Kinetics Of

Abstract The accumulation of tau aggregates throughout the human brain is the hallmark of a number of neurodegenerative conditions classified as tauopathies. Increasing evidence shows that tau aggregation occurs in a “prion-like” manner, in which a small amount of misfolded tau protein can induce other, naïve tau proteins to aggregate. Tau aggregates have been found to differ structurally among different tauopathies. Recently, however, we have suggested that tau oligomeric species may differ biochemically among individual patients with sporadic Alzheimer disease, and have also showed that the bioactivity of the tau species, measured using a cell-based bioassay, also varied among individuals. Here, we adopted a live-cell imaging approach to the standard cell-based bioassay to explore further whether the kinetics of aggregation also differentiated these patients. We found that aggregation can be observed to follow a consistent pattern in all cases, with a lag phase, a growth phase, and a plateau phase, which each provide quantitative parameters by which we characterize aggregation kinetics. The length of the lag phase and magnitude of the plateau phase are both dependent upon the concentration of seeding-competent tau, the relative enrichment of which differs among patients. The slope of the growth phase correlates with morphological differences in the tau aggregates, which may be reflective of underlying structural differences. This kinetic assay confirms and refines the concept of heterogeneity in the characteristics of tau proteopathic seeds among individuals with Alzheimer’s disease and is a method by which future studies may characterize longitudinal changes in tau aggregation and the cellular processes which may influence these changes.

scholarly journals N-acetyl-L-cysteine Improves the Developmental Competence of Bovine Oocytes and Embryos Cultured In Vitro by Attenuating Oxidative Damage and Apoptosis

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 860
Author(s):  
Wu-Sheng Sun ◽  
Hoon Jang ◽  
Mi-Ryung Park ◽  
Keon Bong Oh ◽  
Haesun Lee ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Early Stage ◽  
Developmental Competence ◽  
Beneficial Effects ◽  
Developmental Rates ◽  
A Cell ◽  
Bovine Oocytes ◽  
Dose Dependent

Oxidative stress has been suggested to negatively affect oocyte and embryo quality and developmental competence, resulting in failure to reach full term. In this study, we investigated the effect of N-acetyl-L-cysteine (NAC), a cell-permeating antioxidant, on developmental competence and the quality of oocytes and embryos upon supplementation (0.1–10 mM) in maturation and culture medium in vitro using slaughterhouse-derived oocytes and embryos. The results show that treating oocytes with 1.0 mM NAC for 8 h during in vitro maturation attenuated the intracellular reactive oxygen species (ROS) (p < 0.05) and upregulated intracellular glutathione levels (p < 0.01) in oocytes. Interestingly, we found that NAC affects early embryonic development, not only in a dose-dependent, but also in a stage-specific, manner. Significantly (p < 0.05) decreased cleavage rates (90.25% vs. 81.46%) were observed during the early stage (days 0–2), while significantly (p < 0.05) increased developmental rates (38.20% vs. 44.46%) were observed during the later stage (from day 3) of embryonic development. In particular, NAC supplementation decreased the proportion of apoptotic blastomeres significantly (p < 0.05), resulting in enhanced hatching capability and developmental rates during the in vitro culture of embryos. Taken together, our results suggest that NAC supplementation has beneficial effects on bovine oocytes and embryos through the prevention of apoptosis and the elimination of oxygen free radicals during maturation and culture in vitro.

scholarly journals Heat Shock Protein 70 Improves In Vitro Embryo Yield and Quality from Heat Stressed Bovine Oocytes

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1794
Author(s):  
Konstantina Stamperna ◽  
Themistoklis Giannoulis ◽  
Eleni Dovolou ◽  
Maria Kalemkeridou ◽  
Ioannis Nanas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Cumulus Cells ◽  
Intramolecular Interactions ◽  
Developmental Competence ◽  
Embryo Yield ◽  
Bovine Oocytes

Heat shock protein 70 (HSP70) is a chaperon that stabilizes unfolded or partially folded proteins, preventing inappropriate inter- and intramolecular interactions. Here, we examined the developmental competence of in vitro matured oocytes exposed to heat stress with or without HSP70. Bovine oocytes were matured for 24 h at 39 °C without (group C39) or with HSP70 (group H39) and at 41 °C for the first 6 h, followed by 16 h at 39 °C with (group H41) or without HSP70 (group C41). After insemination, zygotes were cultured for 9 days at 39 °C. Cleavage and embryo yield were assessed 48 h post insemination and on days 7, 8, 9, respectively. Gene expression was assessed by RT-PCR in oocytes, cumulus cells and blastocysts. In C41, blastocysts formation rate was lower than in C39 and on day 9 it was lower than in H41. In oocytes, HSP70 enhanced the expression of three HSP genes regardless of incubation temperature. HSP70 at 39 °C led to tight coordination of gene expression in oocytes and blastocysts, but not in cumulus cells. Our results imply that HSP70, by preventing apoptosis, supporting signal transduction, and increasing antioxidant protection of the embryo, protects heat stressed maturing bovine oocyte and restores its developmental competence.

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