Liver Protein Comparisons of Warm‐adapted Versus Cold‐adapted Populations of Threespine Sticklebacks (Gasterosteus aculeatus)

Abstract

This study investigated the molecular phenotypes of a warm‐adapted population of threespine sticklebacks (Gasterosteus aculeatus). We created a liver protein assay consisting of 1,016 proteins with Skyline (MacCoss Lab) from four populations (N=24) using data dependent acquisition (DDA) shotgun proteomics. This assay will be used to perform targeted proteomics on future comparisons, which will allow for more precise identification and quantification of the targeted proteins. A population of sticklebacks from Baja California, Mexico is surviving and breeding at temperatures near 30 degrees Celsius, which is close to the upper thermal limit for this species. Understanding what this population is doing at the molecular level to function at these high temperatures may give insight into mechanisms that have allowed for their survival, as well as the potential for other populations to adapt to higher temperatures. Livers from sticklebacks of the Baja California population were then compared to three cold‐adapted populations using gel‐free quantitative proteomics by liquid chromatography‐mass spectrometry (LC‐MS/MS). A resident marine population (Bodega Harbor, CA), a freshwater population (Lake Solano, CA), and an anadromous population (Anchorage, Alaska) were used in these comparisons. Six Baja California threespine sticklebacks and six fish from each of the other three groups were compared in four separate sets (N=96). Approximately 20 proteins were significantly more abundant in the Baja California population than the other three populations across all four sets. Our results suggest that certain molecular chaperones and redox/antioxidant proteins may contribute to the survival of the Baja California population. Our study lays the foundation for highly accurate quantification of protein differences in future comparisons using targeted proteomics. This study also highlights proteins that are consistently found at higher abundance in the warm‐adapted population and thus may be important for liver adaptation to warmer temperatures.Support or Funding InformationFunded by NSF Grant IOS‐1355098.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.