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bioRxiv · 10.1101/2023.09.26.559639

Novel Epidermal Oxysterols Function as Alarm Substances in Zebrafish

Li, Y.·Yan, Z.·Lin, A.·Yang, X.·Li, X.·Yin, X.·Li, W.·Li, K.
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Abstract

Aquatic animals often use chemical cues to signal predation risk. When injured, shoaling fish skins release alarm substances that induce intense fear and a suite of anti-predator behaviors in other shoal members. However, the chemical nature of alarm substances remains largely unknown. Here we show that zebrafish alarm substance comprises 24-methyl-5-cholestane-3,7,12,24,28-pentahydroxy 28-sulfate, a novel oxysterol sulfate, and 5-cyprinol sulfate. These compounds are present in zebrafish skin extract and, at concentrations of less than one nanomolar, each induces anti-predator behaviors and increases cortisol levels. Their mixture, at its natural ratio, replicates the skin extract in eliciting the full suite of anti-predator behavior patterns. Our findings reveal a molecular-level mechanism whereby fish signal predation danger.

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Li, Y., Yan, Z., Lin, A., Yang, X., Li, X., Yin, X., Li, W., Li, K.. 2023-09-29. Novel Epidermal Oxysterols Function as Alarm Substances in Zebrafish. https://doi.org/10.1101/2023.09.26.559639

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