API

This Event is licensed under the Creative Commons BY-SA license. This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.

Event: 1695

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Impaired ovulation

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Impaired ovulation
Explore in a Third Party Tool

Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization
Organ

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Organ term
female gonad

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; https://aopwiki.org/info_pages/2/info_linked_pages/7#List). Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
ovulation Ovum decreased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE.Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
Luteinizing hormone receptor antagonism KeyEvent Young Jun Kim (send email) Under Development: Contributions and Comments Welcome
Decreased GnRH release leading to increased E2 KeyEvent Martina Panzarea (send email) Under development: Not open for comment. Do not cite

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
mammals mammals NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
Adults

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Female

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

For rodent studies, a few methods of measurement of ovulation are available.

Vaginal cytology is a method to assess the stage in the estrous cycle. This is done by flushing the vagina or collecting a vaginal swab followed by staining to observe cytology and determine the stage.

Another determinant of ovulation is the presence of corpus lutea. After sacrifice of the female mouse or rat, sections of the reproductive organs are stained, and histological examination is performed to count and identify corpus luteum.

Finally, the most direct method is the flushing of the oviduct. Once the estrous stage is determined, female mice can be placed in presence of males to induce ovulation. This is determined the next morning due to the presence of a vaginal plug. The mice are then euthanized, and the oviducts are flushed. The number of ova (mature oocytes) are counted to determine the quality of ovulation. The number of females that have ova in the oviduct is an additional measurement that may be taken into account (Ajayi and Akhigbe, 2020; Byers et al., 2012; Caligioni, 2009).

Regarding in vitro studies, involving human or rat granulosa cells for example, ovulation is not measured the same way since it does not occur in these systems. However, mRNA expression and profiles of ovulation markers can be investigated. Certain genes are overexpressed during ovulation and are considered markers of ovulation, such as AREG and EREG, shown in many studies (Fa et al., 2013; Pogrmic-Majkic et al., 2018).

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

While in many species, ovulation is dependent on LH surge, some species differences exist in regulation of this process. Ovulation is applicable to females starting from puberty and during adult life.

References

List of the literature that was cited for this KE description. More help

Ajayi AF and Akhigbe RE, 2020. Staging of the estrous cycle and induction of estrus in experimental rodents: an update. Fertil Res Pract, 6:5. doi: 10.1186/s40738-020-00074-3

Byers SL, Wiles MV, Dunn SL and Taft RA, 2012. Mouse estrous cycle identification tool and images. PLoS One, 7:e35538. doi: 10.1371/journal.pone.0035538

Caligioni CS, 2009. Assessing reproductive status/stages in mice. Curr Protoc Neurosci, Appendix 4:Appendix 4I. doi: 10.1002/0471142301.nsa04is48

Fa S, Pogrmic-Majkic K, Samardzija D, Glisic B, Kaisarevic S, Kovacevic R and Andric N, 2013. Involvement of ERK1/2 signaling pathway in atrazine action on FSH-stimulated LHR and CYP19A1 expression in rat granulosa cells. Toxicol Appl Pharmacol, 270:1-8. doi: 10.1016/j.taap.2013.03.031

Pogrmic-Majkic K, Samardzija D, Stojkov-Mimic N, Vukosavljevic J, Trninic-Pjevic A, Kopitovic V and Andric N, 2018. Atrazine suppresses FSH-induced steroidogenesis and LH-dependent expression of ovulatory genes through PDE-cAMP signaling pathway in human cumulus granulosa cells. Mol Cell Endocrinol, 461:79-88. doi: 10.1016/j.mce.2017.08.015