Meiotic maturation in vitro physiology in vitro oocyte maturation techniques. Medical search. Frequent questions

Cumulus oophorus is a cluster of cells (called cumulus cells) that surround the oocyte both in the ovarian follicle and after ovulation. (wikipedia.org)
Maintenance of meiotic arrest also depends on the presence of a multilayered complex of cells, known as a follicle, that surrounds the oocyte. (wikipedia.org)
Removal of the oocyte from the follicle causes meiosis to progress in the oocyte. (wikipedia.org)
These protease-induced decreases in IGFBP-4 and -5 likely cause increased levels of bioavailable (or free) IGFs that stimulate steroidogenesis and mitogenesis in developing dominant follicles, which ultimately prepare the follicle(s) and oocyte(s) for successful ovulation and fertilization. (bioone.org)
Within the follicle, the maintenance of oocyte meiotic arrest is primarily attributed to high cytoplasmic concentrations of cyclic adenosine monophosphate (cAMP). (bvsalud.org)
The oocytes compete with one another to become the dominant follicle and eventually ovulate to be released as an egg capable of being fertilized. (medscape.com)
The aim of this study was to assess the effects of brief, intense exposure to tobacco smoke on granulosa cell number, oocyte growth, and follicle size during puberty in female Swiss mice. (biomedcentral.com)

and the development of embryos after in vitro fertilisation. (bvsalud.org)
Influence of organochlorine pesticides on development of mouse embryos in vitro . (cdc.gov)
oxidative stress is the most prominent one, which will cause damage or alter the genetic material of the sperm and reduce the quality of the oocytes, and has a crucial impact on the possibility of developing embryos even after implantation. (vetmedmosul.com)
Oocytes, sperms, and embryos are shielded from oxidative stress in their natural environment by free radical scavengers found in oviductal and follicular fluids. (vetmedmosul.com)
Oocytes and embryos are not provided with this level of protection when in vitro production (9). (vetmedmosul.com)
Melatonin supplementation has been shown to promote bovine and porcine oocytes' maturation rate and increase their blastocyst of IVF embryos (16). (vetmedmosul.com)
We found that women with BRCA mutations had much fewer oocytes and much lower numbers of embryos. (hstalks.com)

Decline in the Number of Oocytes from Birth to Menopause. (ldysinger.com)
The decline in the number of oocytes begins at 20 weeks' gestation when the female fetus has approximately 6-7 million oogonia (largest lifetime endowment). (medscape.com)

Further, melatonin and its receptors play a significant role in antioxidant defense mechanism of ovary for follicular growth and maturation. (jrhm.org)
Prior to the onset of menopause (10-15 y), menstrual cycles shorten and rapid follicular loss occurs because more oocytes are being recruited. (medscape.com)

These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. (wikipedia.org)
For several primary oocytes that complete meiosis I each month, only one or a few functional oocyte, the dominant follicles, completes maturation and undergoes ovulation. (wikipedia.org)
As follicles grow, they acquire receptors for luteinizing hormone, a pituitary hormone that reinitiates meiosis in the oocyte and causes ovulation of a fertilizable egg. (wikipedia.org)

The primary oocyte turns into a secondary oocyte in mature ovarian follicles. (wikipedia.org)
[2] It is developed from the primary oocyte by maturation. (wikipedia.org)

Upon fertilization by sperm, the secondary oocyte continues the second part of meiosis and becomes a zygote. (wikipedia.org)

ROS are free radicals that are continuously produced by oxidative metabolic reactions and increase in vitro conditions, causing aging of both the oocyte (7) and sperm (8), as well as perhaps impairing fertilization and embryo development. (vetmedmosul.com)

After beginning the meiotic process, the oogonia (now called primary oocytes) can no longer replicate. (wikipedia.org)
Oogonia enter meiosis during embryonic development, becoming oocytes. (wikipedia.org)
Oogenesis starts with the process of developing primary oocytes, which occurs via the transformation of oogonia into primary oocytes , a process called oocytogenesis . (wikipedia.org)

When the inability of male transgenic rats to transmit the transgene is not associated with mosaicism, microinsemination techniques such as intracytoplasmic sperm injection (ICSI) and round spermatid injection (ROSI) can be used for passage of the transgenes. (go.jp)
This study was conducted to evaluate in vivo and in vitro development of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection. (bioone.org)

Oocytes were collected from slaughterhouse-derived ovaries, matured in vitro, and injected with frozen-thawed stallion sperm. (bioone.org)

In conclusion, melatonin could be a promising tool for improving sperm competence for fertilizing oocytes and embryo development in sheep. (vetmedmosul.com)
Currently, its estimation is predominantly based on morphological analysis, which is subjective and does not consistently reflect the developmental competence of the oocytes. (biomedcentral.com)
however, it is not per se sufficient to assure oocyte developmental competence [ 13 ]. (biomedcentral.com)

The results showed a decrease in oocyte numbers in the transplanted OT, abnormal endocrine function of ovarian grafts, as well as dysfunctional mitochondria and DNA damage in the oocytes, which could adversely affect subsequent embryonic development. (bvsalud.org)
1974. Pesticidal chemicals affecting some energy-linked functions of rat liver mitochondria in vitro . (cdc.gov)
In the oocyte, mitochondria play a central role in cellular metabolism providing energy for successful cytoplasm and nucleus maturation, fertilization, embryo development, calcium homeostasis, and apoptosis initiation. (biomedcentral.com)

For in vitro culture of follicles, there are various techniques to optimize the growth of follicles, including the use of defined media, growth factors and three-dimensional extracellular matrix support. (wikipedia.org)
Throughout a female's reproductive lifespan, the ovaries undergo continual structural changes that are crucial for the maturation of ovarian follicles and the production of sex steroid hormones. (mdpi.com)

11 Among women undergoing in vitro fertilization-embryo transfer in the United States, deliveries per oocyte retrieved decreased from 36.9 percent among women under the age of 35 years to 20.5 percent among women between the ages of 38 and 40 years and to 10.7 percent among women between the ages of 41 and 42 years. (ldysinger.com)
The in vitro embryo production (IVEP) is very stressful for gametes. (vetmedmosul.com)
Scientists attempting to discover the basic requirements for successful embryo development have a hurdle when using in vitro embryo manufacturing strategies (2). (vetmedmosul.com)
As a result, developing a culture medium capable of effectively reducing ROS in vitro embryo production (IVEP) protocols is of tremendous importance (10). (vetmedmosul.com)

1998. Influence of organochlorine pesticides on maturation and post-fertilization development of bovine oocytes in vitro . (cdc.gov)

thereby, oocytes and sperm are highly vulnerable to reactive oxygen species (ROS) attacks, affecting their quality and viability (6). (vetmedmosul.com)
Several physiological parameters, such as viability, mitochondrial activity, and reactive oxygen species (ROS) levels have been also reported as useful markers of oocyte quality in marine invertebrates. (biomedcentral.com)

Usage of melatonin during in vitro fertilization (IVF) procedures has been found to improve oocyte quality, survival, and fecundity. (jrhm.org)
Moreover, brief exposure during puberty may induce silent oocyte disruption, which could in turn lead to decreased fecundity rates. (biomedcentral.com)

In humans, oocytes are established in the ovary before birth and may lie dormant awaiting initiation for up to 50 years. (wikipedia.org)
After the onset of puberty and menses, the female human ovary recruits at least 30-50 oocytes during each menstrual cycle. (medscape.com)

It has been hypothesized that in gonadal dysgenesis various deletions on the X chromosome cause such rapid atresia of oocytes 5 that few girls with this condition reach puberty with functioning ovaries. (ldysinger.com)
However, it is also possible that such genetic defects result in a smaller complement of oocytes during gonadal development. (ldysinger.com)

Our ICSI procedure includes the use of a piezo-driven small-sized injection pipette (2-4 μm in diameter), isolated sperm heads, and freshly ovulated oocytes. (go.jp)
These microinsemination techniques can be combined with cryopreservation of sperm and spermatid cells, leading to successful transmission of transgenes carried in male gametes. (go.jp)
For this purpose, we have incubated ram sperm using four different treatments in terms of antioxidants: melatonin, cysteamine, vitamin C, and vitamin E. They were incubated by the standard methods of maturation and capacitation of sperm. (vetmedmosul.com)
In the last decade, in vitro fertilization and sperm capacitation techniques have significantly advanced. (vetmedmosul.com)
To fertilize the oocytes, sperm must undergo a series of physiological and biochemical alterations in vitro (3). (vetmedmosul.com)
Oxidative stress is one of the key factors contributing to a decrease in sperm quality during the maturation and capacitation of the sperm (5). (vetmedmosul.com)

Each of them contains a single oocyte (immature ovum or egg cell). (wikipedia.org)
Once a month, one of the ovaries releases a mature egg (ovum), known as an oocyte. (wikipedia.org)
Diagram showing the reduction in number of the chromosomes in the process of maturation of the ovum . (wikipedia.org)
oocytogenesis , ootidogenesis , and finally maturation to form an ovum (oogenesis proper). (wikipedia.org)

[5] Because the granulosa cells and oocyte are connected by gap junctions, cyclic GMP also decreases in the oocyte, causing meiosis to resume. (wikipedia.org)
Cycle fecundability decreases as the number of oocytes decreases. (medscape.com)
The number of oocytes decreases to approximately 2-3 million at birth and decreases again to 300,000 by the time of puberty. (medscape.com)

Oocyte meiosis, important to all animal life cycles yet unlike all other instances of animal cell division, occurs completely without the aid of spindle -coordinating centrosomes . (wikipedia.org)
Female infants have 6 to 7 million oocytes at 20 weeks of gestation, when progressive atresia occurs, resulting in 1 to 2 million oocytes at birth, approximately 25,000 at the age of 37 years, and 1000 at the age of 51 years, the average age of natural menopause in the United States. (ldysinger.com)
During estrus phase in animals or the menstrual cycle in humans, the resumption of meiosis occurs in certain oocytes due to a surge of luteinizing hormone (LH) levels. (bvsalud.org)

Male European seabass, already predominant (~ 70%) in cultured stocks, show a high incidence (20-30%) of precocious sexual maturation under current aquaculture practices, leading to important economic losses for the industry. (biomedcentral.com)
In seabass aquaculture, the high incidence (20 to 30%) of precocious sexual maturation in males during the first year of life places a critical restraint to production parameters. (biomedcentral.com)

Meiosis begins with DNA replication and meiotic crossing over. (wikipedia.org)
To provide a comprehensive understanding of the recently uncovered regulatory network involved in oocyte development and maturation, the progress of the cellular and molecular mechanisms of oocyte nuclear maturation including meiosis arrest and meiosis resumption is summarized. (bvsalud.org)
Oocytes are highly specialized cells that undergo the unique processes of meiosis and fertilization and execute a molecular program for development [ 1 ]. (biomedcentral.com)

Initially the arrest is due to lack of sufficient cell cycle proteins to allow meiotic progression. (wikipedia.org)
However, as the oocyte grows, these proteins are synthesized, and meiotic arrest becomes dependent on cyclic AMP . (wikipedia.org)
In Drosophila melanogaster, 16 interconnected cells form a germline cyst, where one cell differentiates into an oocyte, while the rest become nurse cells that supply the oocyte with mRNAs, proteins, and organelles through intercellular cytoplasmic bridges named ring canals via microtubule-based transport. (bvsalud.org)

The granulosa cells produce a small molecule, cyclic GMP , that diffuses into the oocyte through the gap junctions. (wikipedia.org)

The nucleus of such an oocyte is called a germinal vesicle (see picture). (wikipedia.org)

Many investigations have been designed to gain new insights into the mechanisms underlying oocyte quality based on a differential analysis applied to molecular, biochemical, transcriptomic, or proteomic data. (biomedcentral.com)

Mammalian oocytes are maintained in meiotic prophase arrest for a very long time-months in mice, years in humans. (wikipedia.org)
In the oocyte, cyclic GMP prevents the breakdown of cyclic AMP by the phosphodiesterase PDE3, and thus maintains meiotic arrest. (wikipedia.org)

These findings are linked to melatonin's ability to reduce ROS and its adverse effects on oocytes, such as aging, apoptosis, and its capacity to bind to specific DNA sequences and interact with cytosolic molecules to regulate antioxidant genes (17). (vetmedmosul.com)

Depending on the specific species, oocytes can remain arrested for extended periods of time, ranging from months to even years. (bvsalud.org)
In many species, only one oocyte is specified among a group of interconnected germline sister cells. (bvsalud.org)
In view of the known modulation of reproductive development by swimming exercise in other teleost species, we aimed at investigating the effects of sustained swimming on reproductive development in seabass males during the first year of life in order to determine if swimming could potentially reduce precocious sexual maturation. (biomedcentral.com)

As atresia continues, both the number and quality of oocytes fall below a critical level, and the rate of aneuploidy increases - a finding that is related at least in part to problems of the meiotic spindle 15 , 16 resulting in nondisjunction. (ldysinger.com)
Additionally, the advancements in understanding the molecular cytoplasmic events occurring in oocytes, such as maternal mRNA degradation, posttranslational regulation, and organelle distribution associated with the quality of oocyte maturation, are reviewed. (bvsalud.org)
The number and quality of a woman's oocytes declines with age. (medscape.com)
This stress correlates with declining egg quality, impacting assisted reproductive techniques' success. (novoslabs.com)
Despite several recent studies investigating molecular markers related to oocyte quality, methods currently available for their determination pose various technical challenges and limitations. (biomedcentral.com)
Oocyte quality has been defined as the ability of oocytes to be fertilized and produce viable progeny. (biomedcentral.com)
Hence, to date, an effective and simple proxy of oocyte quality parameters has not been established yet making difficult for an accurate assessment of the female gamete quality before fertilization. (biomedcentral.com)
Nevertheless, the complexity of the techniques applied to assess gene expression and protein profile is a major bottleneck for the use of molecular markers in the oocyte quality assessment [ 12 ]. (biomedcentral.com)

In vivo development was assessed after transfer of injected oocytes to the oviducts of recipient mares. (bioone.org)
Relating in vitro to in vivo exposures with physiologically-based tissue dosimetry and tissue response models. (cdc.gov)

Further knowledge of the integrin-mediated regulation of cell growth and cell survival may facilitate our understanding of many key aspects of development and physiology in reproduction. (go.jp)

[5] The cyclic AMP is generated by the oocyte by adenylyl cyclase in the oocyte membrane. (wikipedia.org)

Precocious maturation of males, already predominant in the fish stock (up to 70%), results in non-marketable fish due to the fact that growth and feed utilization are negatively affected by the energy invested in the production of gametes. (biomedcentral.com)

Thus, the Msps-dynein duo creates a positive feedback loop, ensuring oocyte fate maintenance by promoting high microtubule polymerization activity in the oocyte, and enhancing dynein-dependent nurse cell-to-oocyte transport. (bvsalud.org)

The oocytes were fertilized by spermatozoa that had been capacitated with two groups of fertilization media, the first group containing melatonin and the second group containing cysteamine. (vetmedmosul.com)

In the case of ROSI, round spermatids are injected into Sr 2+ -activated oocytes using a piezo-driven middle-sized pipette (5-6 μm in diameter). (go.jp)

The progressive loss of oocytes from fetal life through menopause is a normal process. (ldysinger.com)
Any factor interfering with this process may lead to impaired oocyte maturation, which in turn affects female reproductive function. (bvsalud.org)

Knockdown of msps blocks the oocyte growth and causes gradual loss of oocyte determinants. (bvsalud.org)

Extensive research has unraveled a niche for melatonin that is of great significance for the female reproductive physiology. (jrhm.org)

This study aimed to determine the influence of antioxidants on the achievement of In vitro culture (IVC) and sperm's ability to adhere to and penetrate further into In vitro maturated oocytes. (vetmedmosul.com)

This review describes the available information regarding the role of integrins in human reproductive physiology and discusses their clinical implications. (go.jp)

For this reason, they have been very important in elucidating chromosome fine structure and physiology, especially in diptera. (scielo.br)

In normal women, at approximately 37.5 years of age, an accelerated atresia of the oocytes begins 1 , 2 ( Figure 1 ). (ldysinger.com)

Translated Msps stimulates microtubule polymerization in the oocyte, causing more microtubule plus ends to grow from the oocyte through the ring canals into nurse cells, further enhancing nurse cell-to-oocyte transport by dynein. (bvsalud.org)

In this study, we find that a microtubule polymerase Mini spindles (Msps), the Drosophila homolog of XMAP215, is essential for maintenance of the oocyte specification. (bvsalud.org)

Anatomy6

Organisms3

Chemicals and Drugs3

Analytical, Diagnostic and Therapeutic Techniques and Equipment4

Phenomena and Processes6

Disciplines and Occupations1

Information Science1

Follicle7

Embryos7

Decline in the Number of Oocytes2

Follicular2

Ovulation3

Primary oocyte2

Secondary oocyte1

Fertilization and embryo development1

Oogonia3

Intracytoplasmic sperm inj2

Frozen-thawed1

Competence3

Mitochondria3

Follicles2

Embryo4

Bovine1

Viability2

Fecundity2

Ovary2

Gonadal2

Sperm6

Ovum4

Decreases3

Occurs3

Aquaculture2

Meiosis3

Proteins3

Granulosa1

Nucleus1

Biochemical1

Arrest2

Apoptosis1

Species3

Quality8

Vivo2

Development1

Cyclic1

Gametes1

Fate1

Spermatozoa1

Diameter1

Process2

Growth1

Female1

Influence1

Implications1

Important1

Begins1

Cells1

Maintenance1