API

Event: 285

Key Event Title

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Reduction, Vitellogenin synthesis in liver

Short name

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Reduction, Vitellogenin synthesis in liver

Key Event Component

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Process Object Action
gene expression vitellogenins decreased

Key Event Overview


AOPs Including This Key Event

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Stressors

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Level of Biological Organization

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Biological Organization
Tissue


Organ term

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Organ term
liver


Taxonomic Applicability

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Term Scientific Term Evidence Link
Pimephales promelas Pimephales promelas Strong NCBI
Fundulus heteroclitus Fundulus heteroclitus Strong NCBI
Oryzias latipes Oryzias latipes Strong NCBI

Life Stage Applicability

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Life stage Evidence
Adult, reproductively mature Strong

Sex Applicability

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Term Evidence
Unspecific Not Specified

How This Key Event Works

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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

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Relative abundance of vitellogenin transcripts or protein can be readily measured in liver tissue from organisms exposed in vivo (e.g., (Biales et al. 2007)), 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).


Evidence Supporting Taxonomic Applicability

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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

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  • 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.