GO:0022602 ovulation cycle process: Physiology, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0022602 (ovulation cycle process) describes the recurring female sexual cycle, including the estrous cycle in rodents and the menstrual cycle in humans, with physiologic changes in the endometrium that recur at regular intervals during reproductive years.
• The process is driven by coordinated hypothalamic-pituitary-ovarian signaling, ovarian folliculogenesis, ovulation, and luteal-phase endocrinology.
• Single-cell atlases of the cycling murine ovary have revealed dynamic cell-type-specific gene expression across the cycle, providing a blueprint for functional studies.
• Disruption of the ovulation cycle process is linked to stress-related menstrual dysfunction, endometriosis, and ovulatory disorders.
• Key genes and pathways include gonadotropins, steroidogenic enzymes, and local ovarian factors that regulate follicle activation, ovulation, and corpus luteum function.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) enable causal testing of candidate genes in ovulation cycle biology.
Description
The ovulation cycle process (GO:0022602) is a biological process that encompasses the recurring sexual cycle in females, often with physiologic changes in the endometrium that recur at regular intervals during reproductive years. This term includes both the estrous cycle in non-human mammals and the menstrual cycle in humans, and it is central to reproductive biology, endocrinology, and women's health research. Understanding this process is essential because it integrates hypothalamic-pituitary signaling, ovarian folliculogenesis, ovulation, and luteal function, all of which are required for fertility. Disruptions in the ovulation cycle process are associated with stress-related menstrual disturbances, ovulatory disorders, and endometriosis, making it a high-priority area for mechanistic and translational studies. Recent single-cell transcriptomic atlases of the cycling murine ovary have provided unprecedented resolution of the cell types and gene expression programs that orchestrate this process. These resources, combined with functional genomics, are accelerating the discovery of causal genes and regulatory networks.
ovulation cycle process At A Glance
| GO ID | GO:0022602 |
|---|---|
| GO term | ovulation cycle process |
| Ontology | biological_process |
| Synonym | estrous cycle process; menstrual cycle process |
| Major function | Coordinates recurring female reproductive cycles, including follicular development, ovulation, and endometrial changes |
| Related processes | Ovarian folliculogenesis, luteal-phase endocrinology, ovulation |
| Key cell types | Granulosa cells, theca cells, oocyte, luteal cells, endometrial cells |
| Research relevance | Fertility, ovulatory disorders, endometriosis, stress-related menstrual dysfunction |
What Is GO:0022602?
According to the Gene Ontology, GO:0022602 (ovulation cycle process) is defined as a process involved in the sexual cycle seen in females, often with physiologic changes in the endometrium that recur at regular intervals during the reproductive years. It includes the estrous cycle process and the menstrual cycle process as synonyms. This term captures the cyclic series of hormonal and physiological events that prepare the female reproductive system for potential pregnancy, from follicular development through ovulation to luteal maintenance or regression.
Why Is ovulation cycle process Important in Cell Biology?
The ovulation cycle process is fundamental to female fertility and reproductive health, and its dysregulation underlies common clinical conditions such as ovulatory disorders, stress-related menstrual irregularities, and endometriosis. Because the process involves tightly coordinated endocrine and local ovarian signaling, it serves as a model system for studying cyclic gene expression, cell-cell communication, and hormone-responsive tissues. Advances in single-cell technologies and functional genomics have made it possible to dissect the molecular players that drive each phase of the cycle, offering new opportunities for therapeutic target discovery.
• Essential for female fertility and successful reproduction.
• Dysregulation is linked to stress-related menstrual cycle and ovulation disturbances.
• Implicated in endometriosis and ovulatory menstruation pathology.
• Provides a paradigm for hormone-driven cyclic gene expression.
• Ovarian folliculogenesis is a key component and target for fertility research.
• Luteal-phase endocrinology is critical for implantation and early pregnancy.
• Single-cell atlases enable cell-type-specific functional studies.
• CRISPR screens can identify novel regulators of ovulation.
• Menstrual synchrony debates highlight the complexity of cycle regulation.
• Model organisms (e.g., mouse) allow genetic dissection of the cycle.
What Happens During ovulation cycle process?
Hypothalamic-Pituitary-Ovarian Axis Activation
In simple terms: The brain and pituitary gland send hormonal signals to the ovaries to start the cycle.
The ovulation cycle process begins with pulsatile gonadotropin-releasing hormone (GnRH) from the hypothalamus, which stimulates follicle-stimulating hormone (FSH) and luteinizing hormone (LH) release from the pituitary. These hormones act on the ovary to recruit follicles and drive steroidogenesis. Stress can disrupt this axis, leading to menstrual cycle and ovulation disturbances.
Ovarian Folliculogenesis and Follicle Selection
In simple terms: Immature eggs in the ovary grow and mature inside follicles.
Under FSH stimulation, a cohort of follicles enters the growing pool, but typically only one dominant follicle is selected for ovulation. This involves granulosa cell proliferation, antrum formation, and oocyte maturation. Preovulatory follicles can also participate in the activation of primordial follicles, as shown in mouse studies.
Ovulation and Oocyte Release
In simple terms: The mature egg is released from the ovary.
An LH surge triggers the final maturation of the dominant follicle and rupture of the follicular wall, releasing the oocyte. This process involves proteolytic enzymes, inflammatory mediators, and vascular changes in the ovary. New insights into the human ovulatory process highlight the roles of cumulus cells and extracellular matrix remodeling.
Luteal Phase and Endometrial Changes
In simple terms: After ovulation, the remaining follicle becomes a corpus luteum that prepares the uterus for pregnancy.
The ruptured follicle transforms into the corpus luteum, which secretes progesterone to support a potential pregnancy. If implantation does not occur, the corpus luteum regresses, progesterone levels fall, and the endometrium is shed during menstruation. Luteal-phase endocrinology is critical for cycle regularity and fertility.
Cycle Regression and Renewal
In simple terms: If pregnancy does not happen, the cycle resets and a new one begins.
The decline in progesterone leads to endometrial breakdown and the onset of a new cycle. This cyclic renewal involves coordinated changes in gene expression across ovarian and endometrial cells, as revealed by single-cell atlases of the cycling murine ovary. Menstrual synchrony and its determinants remain debated, reflecting the complexity of cycle regulation.
Key Genes Involved in GO:0022602 ovulation cycle process
The following genes and proteins are central to the regulation and execution of the ovulation cycle process, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| FSHB | Follicle-stimulating hormone beta subunit; stimulates follicular growth | Target for fertility and ovulatory disorder studies |
| LHB | Luteinizing hormone beta subunit; triggers ovulation | Key regulator of ovulation timing |
| GNRHR | Gonadotropin-releasing hormone receptor; mediates GnRH signaling | Central to hypothalamic-pituitary control |
| CYP19A1 | Aromatase; converts androgens to estrogens | Steroidogenesis marker in granulosa cells |
| CYP17A1 | 17α-hydroxylase; androgen synthesis in theca cells | Theca cell function and steroidogenesis |
| STAR | Steroidogenic acute regulatory protein; cholesterol transport | Rate-limiting for progesterone synthesis |
| INHA | Inhibin alpha; feedback regulation of FSH | Follicle development and cycle regulation |
| AMH | Anti-Müllerian hormone; regulates follicle recruitment | Ovarian reserve and folliculogenesis |
| ESR1 | Estrogen receptor alpha; mediates estrogen actions | Endometrial and ovarian responses |
| PGR | Progesterone receptor; mediates progesterone effects | Luteal phase and endometrial receptivity |
| PTGS2 | Cyclooxygenase-2; prostaglandin synthesis | Ovulation and inflammation-like processes |
| MMP2 | Matrix metalloproteinase-2; extracellular matrix remodeling | Follicular rupture and ovulation |
| VEGFA | Vascular endothelial growth factor A; angiogenesis | Follicular and luteal vascularization |
| LHCGR | Luteinizing hormone/choriogonadotropin receptor | Ovulation and luteal function |
| FSHR | Follicle-stimulating hormone receptor | Follicle recruitment and growth |
| AR | Androgen receptor; mediates androgen signaling | Folliculogenesis and ovulatory function |
| BMP15 | Bone morphogenetic protein 15; oocyte-derived growth factor | Follicle development and ovulation |
| GDF9 | Growth differentiation factor 9; oocyte-derived growth factor | Folliculogenesis and cumulus expansion |
How Is ovulation cycle process Regulated?
The ovulation cycle process is regulated by a complex interplay of endocrine, paracrine, and autocrine signals. The hypothalamic-pituitary-ovarian axis provides the central drive through GnRH, FSH, and LH, while ovarian steroids (estradiol and progesterone) exert feedback regulation. Local factors such as inhibin, activin, and anti-Müllerian hormone modulate follicle recruitment and selection. Stress pathways can disrupt this regulation, leading to menstrual cycle and ovulation disturbances. Single-cell studies have revealed dynamic changes in gene expression across cell types during the cycle, highlighting the role of cell-cell communication in coordinating ovulation and luteal function.
ovulation cycle process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FSHB | Ovulatory disorders, infertility | Knockout mouse, point mutation in FSHR |
| LHB | Anovulation, luteal phase defect | Knock-in of human LHB variants |
| CYP19A1 | Aromatase deficiency, PCOS | Conditional knockout in granulosa cells |
| PGR | Endometriosis, implantation failure | Knockout and point mutation models |
| AMH | Ovarian insufficiency, PCOS | Overexpression and knockout models |
Stress-Related Menstrual and Ovulatory Dysfunction
Psychological and physiological stress can disrupt the hypothalamic-pituitary-ovarian axis, leading to irregular menstrual cycles and anovulation. This has been described as a silent pandemic of stress affecting menstrual cycle and ovulation. Understanding the molecular mechanisms linking stress to ovulatory dysfunction is critical for developing interventions.
Endometriosis and Ovulatory Menstruation
Endometriosis is a chronic inflammatory condition that is closely linked to ovulatory menstruation. Recent perspectives suggest that the pathophysiology extends beyond retrograde menstruation (Sampson principle), involving ovulatory and menstrual factors. Studying the ovulation cycle process can provide insights into endometriosis onset and progression.
Ovulatory Disorders and Infertility
Disorders of ovulation, such as polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea, are major causes of infertility. These conditions involve dysregulation of folliculogenesis, steroidogenesis, and ovulation. Research into the ovulation cycle process is essential for identifying therapeutic targets.
From ovulation cycle process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate ovulation timing? | Knockout mouse with timed mating |
| Does a specific point mutation in gene Y affect luteal function? | Point-mutation knock-in mouse |
| Can overexpression of gene Z rescue ovulatory defects? | Transgenic overexpression |
| What is the cell-type-specific role of gene A in the ovary? | Conditional knockout (Cre-lox) |
| How does gene B affect folliculogenesis? | Knock-in reporter for lineage tracing |
| Does gene C influence stress-induced anovulation? | Knockout combined with stress paradigms |
How to Study the ovulation cycle process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Single-cell RNA-seq | Cell-type-specific gene expression | Ovary atlas across cycle |
| CRISPR knockout screen | Gene function in ovulation | Identify novel regulators |
| Hormone profiling | FSH, LH, estradiol, progesterone levels | Assess endocrine axis |
| Histology/immunohistochemistry | Follicle morphology and protein localization | Validate ovarian phenotypes |
| Intravital imaging | Real-time ovulation events | Study follicular rupture |
| Proteomics | Protein abundance and modifications | Discover biomarkers |
| Metabolomics | Metabolite changes in follicular fluid | Assess oocyte quality |
| Flow cytometry | Immune cell populations in ovary | Study inflammation in ovulation |
Single-Cell Transcriptomics
Single-cell RNA sequencing of the cycling ovary enables the identification of cell-type-specific gene expression programs across the estrous cycle. This approach has been used to build a comprehensive atlas of the murine ovary, revealing dynamic changes in granulosa, theca, and luteal cells.
Functional Genomics and CRISPR Screens
CRISPR-based knockout and activation screens can systematically test the function of candidate genes in ovulation and folliculogenesis. These screens are particularly powerful when combined with single-cell readouts to link genotype to phenotype.
Hormone Profiling and Endocrine Assays
Measuring serum levels of FSH, LH, estradiol, and progesterone across the cycle provides functional readouts of the hypothalamic-pituitary-ovarian axis. These assays are essential for validating genetic models of ovulatory dysfunction.
Imaging and Histology
Ovarian histology and intravital imaging allow visualization of follicle development, ovulation, and corpus luteum formation. These methods complement molecular studies by providing spatial and temporal context.
How CRISPR Can Be Used to Study GO:0022602 ovulation cycle process
Knockout
CRISPR knockout of candidate genes in mouse models or ovarian cell lines can reveal their requirement for ovulation cycle progression. For example, knockout of steroidogenic enzymes or gonadotropin receptors leads to arrested folliculogenesis or anovulation.
Point Mutation
Introducing precise point mutations that mimic human variants allows testing of specific amino acid changes in genes such as LHCGR or FSHR. This approach can uncover gain-of-function or loss-of-function effects on ovulation.
Knock-in
Knock-in of reporter genes (e.g., fluorescent proteins) or humanized alleles enables lineage tracing and functional studies of ovulation cycle genes. Tagged knock-ins can also facilitate protein interaction studies.
Overexpression
Overexpression of candidate genes in transgenic models can test sufficiency for ovulation or luteal function. For instance, overexpression of growth factors like BMP15 or GDF9 can alter folliculogenesis.
How EDITGENE Supports ovulation cycle process Research
Researchers studying ovulation cycle process-related genes often need to determine whether a candidate gene is causally involved in folliculogenesis, ovulation, or luteal function. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this discovery, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for ovulation cycle process research.
Frequently Asked Questions About ovulation cycle process
What is GO:0022602 ovulation cycle process?
GO:0022602 is a Gene Ontology biological process term that describes the recurring female sexual cycle, including the estrous cycle and menstrual cycle, with physiologic changes in the endometrium that recur at regular intervals during reproductive years.
What genes are involved in the ovulation cycle process?
Key genes include FSHB, LHB, GNRHR, CYP19A1, CYP17A1, STAR, INHA, AMH, ESR1, PGR, PTGS2, MMP2, VEGFA, LHCGR, FSHR, AR, BMP15, and GDF9, among others.
How is the ovulation cycle process regulated?
It is regulated by the hypothalamic-pituitary-ovarian axis through GnRH, FSH, and LH, with feedback from ovarian steroids and local factors such as inhibin and AMH.
What happens during ovulation?
An LH surge triggers final follicle maturation and rupture, releasing the oocyte through processes involving proteases, prostaglandins, and vascular changes.
What is the difference between estrous cycle and menstrual cycle?
The estrous cycle occurs in non-human mammals and the menstrual cycle in humans; both are covered by GO:0022602 and share core hormonal and ovarian events.
How does stress affect the ovulation cycle?
Stress can disrupt the hypothalamic-pituitary-ovarian axis, leading to irregular cycles and anovulation, as described in recent reviews.
What is the role of the corpus luteum in the ovulation cycle?
The corpus luteum forms after ovulation and secretes progesterone to support early pregnancy; its regression triggers menstruation if implantation fails.
Can CRISPR be used to study ovulation cycle genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to test gene function in ovulation and folliculogenesis.
What diseases are linked to ovulation cycle dysfunction?
Conditions include stress-related menstrual disorders, endometriosis, polycystic ovary syndrome, and ovulatory infertility.
What research methods are used to study the ovulation cycle process?
Methods include single-cell RNA-seq, CRISPR screens, hormone profiling, histology, and imaging.
Conclusion
The ovulation cycle process (GO:0022602) is a cornerstone of female reproductive biology, integrating endocrine, ovarian, and endometrial events that recur cyclically. Its dysregulation contributes to infertility, stress-related menstrual disorders, and endometriosis, making it a critical area for mechanistic and translational research. Advances in single-cell genomics and CRISPR functional screens are rapidly expanding our understanding of the genes and pathways that control ovulation, offering new avenues for therapeutic intervention.
References
- 1. Saadedine M et al.. 2025. The silent pandemic of stress: impact on menstrual cycle and ovulation.. Stress 28(1):2457767 PMID: 39862134
- 2. Morris ME et al.. 2022. A single-cell atlas of the cycling murine ovary.. Elife 11 PMID: 36205477
- 3. Rimon-Dahari N et al.. 2016. Ovarian Folliculogenesis.. Results Probl Cell Differ 58:167-90 PMID: 27300179
- 4. Jo M et al.. 2025. New insights into the ovulatory process in the human ovary.. Hum Reprod Update 31(1):21-47 PMID: 39331957
- 5. Bulun SE. 2025. Endometriosis and ovulatory menstruation: beyond the Sampson principle.. J Clin Invest 135(13) PMID: 40590223
- 6. Zhang J et al.. 2024. Participation of preovulatory follicles in the activation of primordial follicles in mouse ovaries.. Int J Biol Sci 20(10):3863-3880 PMID: 39113716
- 7. Messinis IE et al.. 2009. Luteal-phase endocrinology.. Reprod Biomed Online 19 Suppl 4:4314 PMID: 20034416
- 8. McClintock MK. 1998. Whither menstrual synchrony?. Annu Rev Sex Res 9:77-95 PMID: 10349026
