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Updated: Jul 27, 2025
High Throughput Microinjections of Sea Urchin Zygotes
Published on: January 21, 2014
Trifluoperazine-Sensitive Step during Sea Urchin, Echiuroid and Pelecypod Egg Activation:
Laurent Meijer1, François Dube1,2, Pierre Guerrier1
1Station Biologique de Roscoff, 29211 Roscoff, France.
Abstract:
Trifluoperazine, a calmodulin-antagonist, is shown to inhibit egg activation by ionophore A 23187 in sea urchin (I50 : 43 μM), by trypsin in echiufoids (I50 : 22 μM) and by KCl in bivalves (I50 : 34 μM). In each case the inhibition could be reversed by washing the eggs and the trifluoperazine-sensitive period was clearly limited. In Barnea and Urechis, trifluoperazine inhibits calcium uptake. A common trifluoperazine-sensitive step, possibly involving calmodulin, may thus be shared by a variety of animal groups during egg activation.
Insights
Trifluoperazine, a calmodulin antagonist, inhibits sea urchin, echiufoid, and bivalve egg activation. This effect, reversible by washing, suggests a common calmodulin-involved step in diverse animal egg activation.
Area of Science:
- Reproductive biology
- Cell signaling
- Biochemistry
Background:
- Egg activation is a critical step in sexual reproduction.
- Calmodulin is a key calcium-binding protein involved in cellular processes.
- Understanding the molecular mechanisms of egg activation is crucial for developmental biology.
Purpose of the Study:
- To investigate the role of calmodulin in egg activation across different animal groups.
- To determine if trifluoperazine, a calmodulin antagonist, inhibits egg activation.
- To identify potential common molecular pathways in egg activation.
Main Methods:
- Utilized trifluoperazine as a calmodulin antagonist.
- Tested inhibition of egg activation induced by ionophore A 23187 (sea urchin), trypsin (echiufoids), and KCl (bivalves).
- Assessed reversibility of inhibition and calcium uptake in specific species.
Main Results:
- Trifluoperazine inhibited egg activation in sea urchin (I50: 43 μM), echiufoids (I50: 22 μM), and bivalves (I50: 34 μM).
- Inhibition was reversible upon washing, indicating a time-sensitive process.
- Trifluoperazine was shown to inhibit calcium uptake in Barnea and Urechis.
Conclusions:
- A common, trifluoperazine-sensitive step, potentially involving calmodulin, is implicated in egg activation across various animal phyla.
- Calmodulin may play a conserved role in regulating calcium dynamics during fertilization.
- This study highlights a shared molecular mechanism in a fundamental reproductive process.
