A proteomic analysis of the statocyst endolymph in common cuttlefish (Sepia officinalis): an assessment of acoustic trauma after exposure to sound

M Monge,C Quero,M André,M Solé

doi:10.1038/s41598-019-45646-6

Abstract

Recent studies, both in laboratory and sea conditions, have demonstrated damage after sound exposure in the cephalopod statocyst sensory epithelium, which secretes endolymph protein. Here, the proteomic analysis of the endolymph was performed before and after sound exposure to assess the effects of exposure to low intensity, low frequency sounds on the statocyst endolymph of the Mediterranean common cuttlefish (Sepia officinalis), determining changes in the protein composition of the statocyst endolymph immediately and 24 h after sound exposure. Significant differences in protein expression were observed, especially 24 h after exposure. A total of 37 spots were significantly different in exposed specimens, 17 of which were mostly related to stress and cytoskeletal structure. Among the stress proteins eight spots corresponding to eight hemocyanin isoforms were under-expressed possible due to lower oxygen consumption. In addition, cytoskeletal proteins such as tubulin alpha chain and intermediate filament protein were also down-regulated after exposure. Thus, endolymph analysis in the context of acoustic stress allowed us to establish the effects at the proteome level and identify the proteins that are particularly sensitive to this type of trauma.

Highlights

The introduction of artificial sound sources in the marine environment is known to have potential negative effects on marine organisms
Given that the statocyst sensory epithelia are responsible of the secretion of statocyst endolymph protein, here we investigate if noise exposure induces proteomic changes in the endolimph by exposing N Mediterranean common cuttlefish, S. officinalis, to the same low frequency sound regime that was observed to cause physiological damage to the sensory epithelia in previous studies
Protein extracts from the endolymph of untreated and treated individuals were analysed by 2D-DIGE, allowing us to compare three protein samples simultaneously on the same gel

Summary

Introduction

The introduction of artificial sound sources in the marine environment is known to have potential negative effects on marine organisms. Cephalopods are short-lived marine invertebrates that exhibit sensitivity to environmental change and stressors[19], with complex behavioural patterns[20], and play a significant role as both prey and predator[21,22,23,24]. These characteristics allow responses to changes in the marine environment[25,26,27], including underwater noise effects, to be assessed. The whole hair cell body was ejected from the sensory epithelium (Fig. 1G) This damage resulting from exposure to artificial noise directly affected the functionality and sensitivity of the cephalopod statocysts. A comparative analysis of the cuttlefish proteome at different times after sound exposure was performed to detect differences in protein abundance with the objective of determining proteins more sensitive to acoustic related stress

Methods

Results

Discussion

Conclusion