Upstream eventInhibition, Deiodinase 2
Reduced, Anterior swim bladder inflation
Key Event Relationship Overview
AOPs Referencing Relationship
|AOP Name||Adjacency||Weight of Evidence||Quantitative Understanding|
|Deiodinase 2 inhibition leading to reduced young of year survival via anterior swim bladder inflation||non-adjacent|
|fathead minnow||Pimephales promelas||NCBI|
Life Stage Applicability
Key Event Relationship Description
Evidence Supporting this KER
- Exposure of fathead minnows (Pimephales promelas) to the non-specific deiodinase inhibitor iopanoic acid from 6-14 dpf resulted in impaired inflation and reduced size of the anterior swim bladder. Exposure from 6-18 dpf impacted anterior chamber size, but not inflation rates. Exposure from 6-21 dpf had no effect on anterior swim bladder inflation. Together the results suggest the inhibition of DIO2 can delay, although not necessarily prevent, anterior inflation in fathead minnows (Cavallin et al., unpublished).
Uncertainties and Inconsistencies
Only few studies have been performed, of which none have been published yet.
Quantitative Understanding of the Linkage
Known modulating factors
Known Feedforward/Feedback loops influencing this KER
Domain of Applicability
The evidence for a relationship between DIO2 inhibition and inflation of the anterior chamber of the swim bladder currently comes from work on zebrafish and fathead minnow.
This KER is probably not sex-dependent since both females and males rely on activation of THs by deiodinase for anterior swim bladder inflation. Additionally, zebrafish are undifferentiated gonochorists, and gonad differentiation starts only around 23-25 dpf (Uchida et al., 2002), after the time point of anterior chamber inflation (around 21 dpf).
Uchida, D., Yamashita, M., Kitano, T., Iguchi, T., 2002. Oocyte apoptosis during the transition from ovary-like tissue to testes during sex differentiation of juvenile zebrafish. Journal of Experimental Biology 205, 711-718.