Related Experiment Video
Updated: Jun 5, 2026
10:24
Evaluation of Intracellular Location of Reactive Oxygen Species in Solea Senegalensis Spermatozoa
Published on: March 11, 2018
Reactive oxygen species are indispensable in ovulation
Ketty Shkolnik1, Ari Tadmor, Shifra Ben-Dor
1Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel.
Summary
Reactive oxygen species (ROS) are crucial for ovulation, mimicking luteinizing hormone (LH) effects. Blocking ROS impairs ovulation, suggesting ROS are essential signaling molecules in the preovulatory process.
Area of Science:
- Reproductive biology
- Endocrinology
- Cell signaling
Background:
- Ovulation is triggered by a luteinizing hormone (LH) surge.
- The ovulatory process shares characteristics with inflammation.
- The role of reactive oxygen species (ROS) in ovulation is not well understood.
Purpose of the Study:
- To investigate the involvement of ROS in LH-induced ovulation.
- To determine if ROS are necessary signaling molecules for ovulation.
Main Methods:
- Administration of ROS scavengers to hormonally induced ovulating mice.
- In vivo and ex vivo assessment of cumulus expansion and progesterone production.
- Analysis of gene expression and signaling pathway activation (EGF receptor, p42/44 MAPK).
Main Results:
- ROS scavengers significantly reduced ovulation rates in mice.
- Antioxidants inhibited LH-induced cumulus expansion and progesterone production.
- Hydrogen peroxide (H2O2) mimicked LH-induced cumulus expansion.
- ROS ablation attenuated LH-stimulated gene expression and signaling pathway activation.
Conclusions:
- Ovarian ROS production is an essential signaling event during ovulation, likely triggered by LH.
- ROS play a critical role in cumulus expansion, progesterone production, and gene regulation necessary for ovulation.
Related Concept Videos
01:22Oogenesis
Oogenesis, the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
02:07Oogenesis
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
01:29Oxygen Requirements and Growth Patterns
Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...
01:30Hormonal Control of the Ovarian Cycle
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
01:17Oxidation of Phenols to Quinones
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
01:27Ovarian Cycle
The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle length...