Proteomics of hyposaline stress in blue mussel congeners (genus Mytilus): implications for biogeographic range limits in response to climate change

Climate change is affecting species' physiology, pushing environmental tolerance limits and shifting distribution ranges. In addition to temperature and ocean acidification, increasing levels of hyposaline stress due to extreme precipitation events and freshwater runoff may be driving some of t...

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Bibliographic Details
Published in:Journal of Experimental Biology
Main Authors: Tomanek, Lars, Zuzow, Marcus J., Hitt, Lauren, Serafini, Loredana, Valenzuela, Jacob J.
Format: Text
Language:English
Published: Company of Biologists 2012
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Online Access:http://jeb.biologists.org/cgi/content/short/jeb.076448v1
https://doi.org/10.1242/jeb.076448
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Summary:Climate change is affecting species' physiology, pushing environmental tolerance limits and shifting distribution ranges. In addition to temperature and ocean acidification, increasing levels of hyposaline stress due to extreme precipitation events and freshwater runoff may be driving some of the reported recent range shifts in marine organisms. Using 2D gel electrophoresis and tandem mass spectrometry, we characterized the proteomic responses of the cold-adapted blue mussel species Mytilus trossulus , a native to the Pacific coast of North America, and the warm-adapted M. galloprovincialis , a Mediterranean invader that has replaced the native from the southern part of its range, but may be limited from expanding north due to hyposaline stress. After exposing laboratory-acclimated mussels for 4 h to two different experimental treatments of hyposaline conditions and one control treatment (24.5 and 29.8 and 35.0 psu, respectively) followed by a 0 and 24 h recovery at ambient salinity (35 psu), we detected changes in the abundance of molecular chaperones of the endoplasmic reticulum (ER), indicating protein unfolding, during stress exposure. Other common responses included changes in small GTPases of the Ras-superfamily during recovery, which suggest a role for vesicle transport, and cytoskeletal adjustments associated with cell volume, as indicated by cytoskeletal elements such as actin, tubulin, intermediate filaments and several actin-binding regulatory proteins. Changes of proteins involved in energy metabolism and scavenging of reactive oxygen species (ROS) suggest a reduction in overall energy metabolism during recovery. Principal component analyses of protein abundances suggest that M. trossulus is able to respond to a greater hyposaline challenge (24.5 psu) than M. galloprovincialis (29.8 psu), as shown by changing abundances of proteins involved in protein chaperoning, vesicle transport, cytoskeletal adjustments by actin-regulatory proteins, energy metabolism and oxidative stress. While proteins involved ...