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Event: 285

Key Event Title

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

Reduction, Vitellogenin synthesis in liver

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

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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
Tissue

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
liver

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
gene expression	vitellogenins	decreased
protein secretion	vitellogenins	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
Aromatase inhibition leading to reproductive dysfunction	KeyEvent	Cataia Ives (send email)	Open for citation & comment	WPHA/WNT Endorsed
Androgen receptor agonism leading to reproductive dysfunction	KeyEvent	Evgeniia Kazymova (send email)	Open for citation & comment	WPHA/WNT Endorsed
Estrogen receptor antagonism leading to reproductive dysfunction	KeyEvent	Evgeniia Kazymova (send email)	Open for citation & comment	Under Review
Prolyl hydroxylase inhibition	KeyEvent	Allie Always (send email)	Under Development: Contributions and Comments Welcome
Unknown MIE leading to reprodl	KeyEvent	Evgeniia Kazymova (send email)	Under Development: Contributions and Comments Welcome
AHR mediated epigenetic reproductive failure	KeyEvent	Arthur Author (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
Pimephales promelas	Pimephales promelas	High	NCBI
Fundulus heteroclitus	Fundulus heteroclitus	High	NCBI
Oryzias latipes	Oryzias latipes	High	NCBI
Danio rerio	Danio rerio	High	NCBI

Life Stages

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

Life stage	Evidence
Adult, reproductively mature	High

Sex Applicability

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

Term	Evidence
Unspecific	Not Specified
Female	High

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

Vitellogenin is an egg yolk precursor protein synthesized by hepatocytes of oviparous vertebrates. In vertebrates, transcription of vitellogenin genes is predominantly regulated by estrogens via their action on nuclear estrogen receptors. During vitellogenic periods of the reproductive cycle, when circulating estrogen concentrations are high, vitellogenin transcription and synthesis are typically orders of magnitude greater than during non-reproductive conditions.

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

Relative abundance of vitellogenin transcripts or protein can be readily measured in liver tissue (e.g., (Biales et al. 2007)) or whole body (H Holbech et al. 2001) from organisms exposed in vivo, or in liver slices (e.g., (Schmieder et al. 2000) or hepatocytes (e.g., (Navas and Segner 2006) exposed in vitro, using real-time quantitative polymerase chain reaction (PCR; transcripts) or enzyme linked immunosorbent assay (ELISA; protein).

Domain of Applicability

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

Oviparous vertebrates. Although vitellogenin is conserved among oviparous vertebrates and many invertebrates, liver is not a relevant tissue for the production of vitellogenin in invertebrates (Wahli 1988)

References

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

Biales AD, Bencic DC, Lazorchak JL, Lattier DL. 2007. A quantitative real-time polymerase chain reaction method for the analysis of vitellogenin transcripts in model and nonmodel fish species. Environ Toxicol Chem 26(12): 2679-2686.
Navas JM, Segner H. 2006. Vitellogenin synthesis in primary cultures of fish liver cells as endpoint for in vitro screening of the (anti)estrogenic activity of chemical substances. Aquat Toxicol 80(1): 1-22.
Schmieder P, Tapper M, Linnum A, Denny J, Kolanczyk R, Johnson R. 2000. Optimization of a precision-cut trout liver tissue slice assay as a screen for vitellogenin induction: comparison of slice incubation techniques. Aquat Toxicol 49(4): 251-268.
Wahli W. 1988. Evolution and expression of vitellogenin genes. Trends in Genetics. 4:227-232.
H Holbech, L Andersen, G I Petersen, B Korsgaard, K L Pedersen, P Bjerregaard, Development of an ELISA for vitellogenin in whole body homogenate of zebrafish (Danio rerio), Comp Biochem Physiol C Toxicol Pharmacol. 2001, 130(1):119-31