Transduction mechanisms for gonadotrophin-induced oocyte maturation in mammals

Zygote ◽  
1994 ◽  
Vol 2 (4) ◽  
pp. 347-349 ◽  
Author(s):  
Mauro Mattioli
Keyword(s):  
Oocyte Maturation ◽  
Normal Development ◽  
Somatic Cells ◽  
Transduction Mechanisms

Although many validated techniques for oocyte maturation in vitro have been developed and eggs with normal development competence can be produced by these methods, the mechnism triggering oocyte maturation in vivo is still poorly understood. Little doubt exists that meiosis is reinitiated in pre-ovlulatory follicles by peak levels of gonadotrophins and that follicle somatic cells are directly involved since no receptors for gonadotrophins have been found on the oolemma.

scholarly journals Investigating the Intrafollicular Factors Affecting Oocyte Developmental Competency

2021 ◽  
Author(s):  
◽  
Zaramasina Clark
Keyword(s):  
Gene Expression ◽  
Oocyte Maturation ◽  
Granulosa Cells ◽  
Embryo Quality ◽  
Cumulus Cells ◽  
Significant Finding ◽  
High Quality ◽  
Final Maturation

<p>The number of cycles of assisted reproductive technologies (ART) performed increased by ~9.5 % globally between 2008 and 2010. In spite of this, the success rate in terms of delivery was only ~19.0 % (Dyer et al., 2016). This discrepancy between the demand for, and success of, these technologies necessitates the development of tools to improve ART efficiency. To facilitate this, a better understanding of how the microenvironment changes within the developing follicle to culminate in a mature, developmentally-competent oocyte is required. This study employed an in vivo and in vitro ovine model to investigate the relationship between the surrounding microenvironment and oocyte maturation, and in particular, the attainment of oocyte developmental competency and high-quality embryos.  The first objective of this PhD study was to comprehensively investigate the changing microenvironment of in vivo matured, presumptive preovulatory (PPOV) follicles from wild-type (++) and high ovulation rate (OR; I+B+) ewes. The high OR ewes were heterozygous carriers of mutations in BMP15 (I+) and BMPRIB (B+). Functional differences in follicular somatic (granulosa and cumulus) cells between these genotypes, including differential gonadotropin responsiveness of granulosa cells, composition of follicular fluid and gene expression profiles in cumulus cells were evident. These differences emerged as part of a compensatory mechanism by which oocytes from smaller follicles, containing fewer granulosa cells, achieved developmental competency in I+B+ ewes.  The second objective of this PhD study was to develop new approaches for improving current in vitro maturation (IVM) strategies. The first approach utilised in this study focused on developing biomarkers that could be used to improve prediction of developmental competency in oocytes and in vitro produced embryos. This involved interrogating the hypothesis that a combination of molecular and morphokinetic biomarkers would better predict the developmental competency of oocytes and embryos compared to using these biomarkers alone. The second approach utilised in this PhD study tested the effects of modulating IVM conditions to better mimic the follicular microenvironment of a high, compared to a low, OR species on oocyte developmental competency and embryo quality. This involved supplementing IVM media with different ratios of two oocyte-secreted growth factors, i.e. GDF9:BMP15, that were representative of low or high OR species. These approaches demonstrated significant potential and warrant further investigation.  The most significant finding of this study was that despite variances in the surrounding microenvironment during in vivo and in vitro oocyte maturation that culminated in differential gene expression patterns in cumulus cells, and divergent gonadotropin-responsiveness of granulosa cells, the gene expression signatures of developmentally-competent oocytes and the morphokinetics of high-quality embryos were unaltered. This confirms the value of developing such biomarkers for oocyte development competency and embryo quality that remain unaltered despite a changing surrounding environment. Interestingly, simulating the ratio of GDF9:BMP15 that oocytes from high OR species are exposed to during maturation improved developmental competency in oocytes as demonstrated by increased blastocyst rates. Furthermore, this study has demonstrated that combinations of molecular (cumulus cell gene expression) and morphokinetic biomarkers improved the ability to predict developmental competency in oocytes and embryos. Overall, this study revealed novel information regarding the follicular microenvironment during final maturation and identified several novel approaches to improving the efficiency of ART.</p>

P–199 A case report to suggest that there must be other mutations than PATL2 or TUBB8 to cause oocyte maturation arrest

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
E Molinari ◽  
M Yang ◽  
J Hu ◽  
L Zhang ◽  
D F Albertini ◽  
...  
Keyword(s):  
Case Report ◽  
Oocyte Maturation ◽  
Fertilization Rate ◽  
Functional Study ◽  
Embryo Morphology ◽  
Loss Of Function ◽  
Maturation Arrest ◽  
Polar Bodies

Abstract Study question What causes our patient’s repeated almost complete oocyte maturation arrest (OMA)? Summary answer Since we did not detect PATL2 and TUBB8 mutations, both known to cause OMA, this case was likely caused by mutations in HUS1 and ITGB3 What is known already OMA has been associated with loss-of-function in key genes, such as PATL2 and TUBB8. Such patients have, however, uniformly have been unable to conceive with IVF Study design, size, duration We here report the case of repeatedly presenting patient between 2009 until 2020 (age 30 at 1st and 41 at last visit). Participants/materials, setting, methods The couple underwent 7 IVF treatments under several ovarian stimulation protocols at different gonadotropin dosages and in different preparations to try to recruit mature eggs. She conceived in her 2nd IVF cycle in 2009 and delivered uneventfully in 2010. She then conceived spontaneously and delivered a healthy boy in 2014. The couple since then has been attempting another pregnancy. Remarkably, in all IVF cycles all eggs but one arrested at prophase. Main results and the role of chance The female demonstrates abnormally high ovarian reserve for age (AMH=5.9 ng/mL in 2019) (mean, 10.6 oocytes). In all cycles, all but one retrieved were immature. In vitro maturation rate for the GV oocytes was 28%. Resultant M2s, however, demonstrated morphological abnormalities, such as giant polar bodies. In vivo M2s, in contrast, were always morphologically unremarkable, and their fertilization rate was 85%. Embryo morphology deteriorated appreciatively with advancing age. Sanger sequencing for TUBB8 and PATL2 genes were unremarkable. Whole genome sequencing of her and her sister (who had no fertility problems) revealed mutations of genes belonging to the integrin family (ITGB3) and DNA repair checkpoint (HUS1), both of which could be determinants in the observed maturation arrest. Limitations, reasons for caution A functional study, coupled with imaging of the discarded material, will likely offer further information regarding the mechanisms leading to OMA in this female. Wider implications of the findings: This case report represents a new phenotype of female infertility, characterized by almost complete maturation arrest which, however, still offers opportunity for pregnancy. Further isolation of underlying mutation(s) may offer additional insights about checkpoints required for the transition of prophase to metaphase in human oocytes. Trial registration number NA

P–442 Cancer does not adversely affect oocyte maturation in vitro with the exception of breast cancer

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
I Viran. . Klun ◽  
J Bedenk ◽  
N Jancar
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Hormonal Stimulation ◽  
Infertile Women ◽  
Maturation In Vitro ◽  
Infertile Patients

Abstract Study question Do different types of cancer affect the success of oocyte maturation in vitro compared to infertile women included in the in vitro fertilization (IVF) program? Summary answer Cancer does not adversely affect oocyte maturation in vitro, with the exception of breast cancer, compared to infertile women in the in vitro fertilization program. What is known already Vitrification and storage of oocytes in liquid nitrogen is one of the real options for maintaining reproductive function in cancer patients. Despite careful hormonal stimulation of the ovaries, however, the proportion of oocytes is immature and lost to the patient. In vitro maturation of oocytes can play an important role in resolving immature oocytes and increasing the chances of conception in cancer patients. Moreover, it can mean a safe way to store oocytes when ovarian hormonal stimulation could worsen the disease. Therefore, the aim of this study was to determine whether different types of cancer affect oocyte in vitro maturation. Study design, size, duration After ovarian stimulation in 18 cancer patients, the number and maturity of oocytes were compared to 21 infertile patients in the IVF program over a three-year period. In both groups, 119 germinal vesicle-GV oocytes were matured in vitro to compare the maturation rate. After IVF in a subset of 17 infertile patients, the fertilization of in vitro and in vivo matured oocytes was compared in the same cycles. The procedure was considered in cancer patients. Participants/materials, setting, methods In this prospective study, forty-five GV oocytes in cancer patients and 74 GV oocytes in infertile patients underwent in vitro maturation procedure. Each oocyte was matured in vitro in the MediCult IVM System by conditioning in LAG medium and maturation for up to 28 hours in IVM medium with added hormones FSH and hCG, in coculture with cumulus cells from mature oocytes in the same patients. Oocytes were fertilized by intracytoplasmic sperm injection (ICSI). Main results and the role of chance After controlled ovarian hormonal stimulation, 198 oocytes were retrieved in cancer patients and 259 oocytes in infertile women and there were no significant differences in the number of retrieved oocytes, proportion of degenerated oocytes and proportion of GV oocytes. In cancer patients, the proportion of oocytes that matured in vitro was lower than in infertile patients (66.0 vs. 80.0%), but the difference was not significant. Among cancer patients, the oocyte maturation rate tended to be lower in patients with breast cancer than in patients with other cancers (54.5% vs. 81.2%; difference not significant). However, in patients with breast cancer, significantly fewer oocytes matured in vitro than in infertile patients (54.5% vs. 80.0%; P &lt; 0.05, Chi-Square test) even though they tended to be younger (29.3 ± 7.4 vs. 33.4 ± 5.0 years; non-significant difference). After in vitro maturation, there was a 13% increase in mature oocyte yield in cancer patients and a 20.1% increase in infertile women with no significant difference observed. After ICSI in a subset of infertile women, there was approximately the same fertilization rate between oocytes matured in vitro and in vivo (55.1% vs. 57.0%) in the same cycles. Limitations, reasons for caution For ICSI in oocytes matured in vitro, we had to use semen collected the day before, while oocytes matured in vivo were fertilized with fresh semen in the same cycle. Therefore, we could not compare the development of embryos in both groups. Wider implications of the findings: In vitro maturation of oocytes in connection with their vitrification or vitrification of embryos after their fertilization appears to be a valuable way to maintain the fertility of young cancer patients, but a worse outcome is expected in breast cancer patients. Trial registration number National Medical Ethical Committee Approval, No. 0120–222/2016–2; KME 115/04/16.

scholarly journals The Usefulness of Retinoic Acid Supplementation during in Vitro Oocyte Maturation for the in Vitro Embryo Production of Livestock: A Review

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 561 ◽  
Author(s):  
Abdelnour ◽  
El-Hack ◽  
Swelum ◽  
Saadeldin ◽  
Noreldin ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Mammalian Species ◽  
Antioxidant Properties ◽  
Reproductive Function ◽  
Embryonic Growth ◽  
Oxidative Damages

Retinoic acid (RA) is an indigenous metabolite and descriptive physiologically functioning constituent of vitamin A. Retinoids were documented as vital regulators for cell development and distinction, embryonic growth, and reproductive function in both male and female livestock. Previously, RA has been shown to have several positive impacts in vivo and in vitro and critically control many reproductive events, such as oocyte development, follicular growth, and early embryonic growth. In addition, RA manages apoptotic signaling and oxidative damages in cells. Recently, RA has been used widely in assisted reproductive technology fields, especially during in vitro embryo development in various mammalian species, including buffaloes, bovine, goats, sheep, pigs, and rabbits. However, the optimum concentration of RA greatly differs based on the condition of maturation media and species. Based on the obtained findings, it was generally accepted that RA enhances nuclear oocyte maturation, cleavage and maturation rates, blastocyst formation, and embryo development. As such, it possesses antioxidant properties against reactive oxygen species (ROS) and an anti-apoptotic effect through enhancing the transcription of some related genes such as superoxide dismutase, prostaglandin synthase, glutathione peroxidase, peroxiredoxins, and heme oxygenase. Therefore, the current review concludes that an addition of RA (up to 50 nM) has the potential to improve the oocyte maturation media of various species of livestock due to its antioxidant activity.

Molecular Mechanisms of Plant Regeneration

2019 ◽  
Vol 70 (1) ◽  
pp. 377-406 ◽  
Author(s):  
Momoko Ikeuchi ◽  
David S. Favero ◽  
Yuki Sakamoto ◽  
Akira Iwase ◽  
Duncan Coleman ◽  
...  
Keyword(s):  
Cell Fate ◽  
Molecular Mechanisms ◽  
Normal Development ◽  
Somatic Cells ◽  
Cell Fates ◽  
Developmental Programs ◽  
Hormonal Responses ◽  
Wound Stress ◽  
Directional Transport

Plants reprogram somatic cells following injury and regenerate new tissues and organs. Upon perception of inductive cues, somatic cells often dedifferentiate, proliferate, and acquire new fates to repair damaged tissues or develop new organs from wound sites. Wound stress activates transcriptional cascades to promote cell fate reprogramming and initiate new developmental programs. Wounding also modulates endogenous hormonal responses by triggering their biosynthesis and/or directional transport. Auxin and cytokinin play pivotal roles in determining cell fates in regenerating tissues and organs. Exogenous application of these plant hormones enhances regenerative responses in vitro by facilitating the activation of specific developmental programs. Many reprogramming regulators are epigenetically silenced during normal development but are activated by wound stress and/or hormonal cues.

scholarly journals Maturation of human oocytes in vitro and their developmental competence

Reproduction ◽  
2001 ◽  
pp. 51-75 ◽  
Author(s):  
A Trounson ◽  
C Anderiesz ◽  
G Jones
Keyword(s):  
Embryo Development ◽  
Oocyte Maturation ◽  
Growth Phase ◽  
Developmental Competence ◽  
Minimum Size ◽  
Success Rates ◽  
Human Oocytes ◽  
Maturation In Vitro

Complete maturation of oocytes is essential for the developmental competence of embryos. Any interventions in the growth phase of the oocyte and the follicle in the ovary will affect oocyte maturation, fertilization and subsequent embryo development. Oocyte size is associated with maturation and embryo development in most species examined and this may indicate that a certain size is necessary to initiate the molecular cascade of normal nuclear and cytoplasmic maturation. The minimum size of follicle required for developmental competence in humans is 5-7 mm in diameter. Maturation in vitro can be accomplished in humans, but is associated with a loss of developmental competence unless the oocyte is near completion of its preovulatory growth phase. This loss of developmental competence is associated with the absence of specific proteins in oocytes cultured to metaphase II in vitro. The composition of culture medium used successfully for maturation of human oocytes is surprisingly similar to that originally developed for maturation of oocytes in follicle culture in vitro. The presence of follicle support cells in culture is necessary for the gonadotrophin-mediated response required to mature oocytes in vitro. Gonadotrophin concentration and the sequence of FSH and FSH-LH exposure may be important for human oocytes, particularly those not exposed to the gonadotrophin surge in vivo. More research is needed to describe the molecular and cellular events, the presence of checkpoints and the role of gene expression, translation and protein uptake on completing oocyte maturation in vitro and in vivo. In the meantime, there are very clear applications for maturing oocytes in human reproductive medicine and the success rates achieved in some of these special applications are clinically valuable.

Protein synthesis and phosphorylation during bovine oocyte maturation in vitro and in vivo,

1989 ◽  
Vol 27 ◽  
pp. 39 ◽  
Author(s):  
P.M.M. Kastrop ◽  
M.M. Bevers ◽  
O.H.J. Destrée ◽  
Th.A.M. Kruip
Keyword(s):  
Protein Synthesis ◽  
Oocyte Maturation ◽  
Bovine Oocyte ◽  
Maturation In Vitro

scholarly journals Effects of gonadotrophin in vivo and 2-hydroxyoestradiol-17β in vitro on follicular steroid hormone profile associated with oocyte maturation in the catfish Heteropneustes fossilis

2006 ◽  
Vol 189 (2) ◽  
pp. 341-353 ◽  
Author(s):  
A Mishra ◽  
K P Joy
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Hplc Method ◽  
Heteropneustes Fossilis ◽  
Germinal Vesicle Breakdown ◽  
Steroid Profile ◽  
17 Hydroxyprogesterone ◽  
Envelope Layer

An HPLC method was used to tentatively identify progesterone (P4) and its metabolites (17-hydroxyprogesterone (17-P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P)), corticosteroids (cortisol and corticosterone) and testosterone in ovary/follicular preparations of the catfish Heteropneustes fossilis associated with in vivo or in vitro oocyte maturation/ovulation. A single i.p. injection of human chorionic gonadotrophin (100 IU/fish, sampled at 0, 8 and 16 h) induced oocyte maturation and ovulation, which coincided with significant and progressive increases in 17,20β-P, and P4 and 17-P4, the precursors of the former. Both cortisol and corticosterone also increased significantly. Conversely, testosterone decreased significantly and progressively over time. Under in vitro conditions, incubation of post-vitellogenic (intact) follicles or follicular envelope (layer) with 2-hydroxyoestradiol (2-OHE2, 5 μM for 0, 6 and 24 h) elicited a sharp significant increase in 17,20β-P, the increase being higher in the follicular envelope incubate. P4 and 17-P4 also registered significant increases over the time with the peak values at 24 h. Cortisol and corticosterone increased significantly in the intact follicle, but not in the follicular envelope incubate. Testosterone decreased significantly in the intact follicle, but increased significantly (24 h) in the follicular envelope incubate. Coincident with these changes, the percentage of germinal vesicle breakdown (GVBD) increased over the time in the intact follicle incubate (48.9% at 6 h and 79.8% at 24 h). Denuded oocytes on incubation with 2-OHE2 (5 μM) did not produce any significant change in the percentage of GVBD or in the steroid profile. While corticosterone and 17,20β-P were undetected, P4, 17-P4, cortisol and testosterone were detected in low amounts. The results show that the 2-OHE2-induced GVBD response seems to be mediated through the production of 17,20β-P and corticosteroids. It is suggested that hydroxyoestrogens seem to be a component in the gonadotrophin cascade of regulation of oocyte maturation/ovulation in the catfish.

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