Proteomic investigation of brain, liver and intestine in high feed intake and low feed intake Chinook salmon (Oncorhynchus tshawytscha)

<p>In groups of fish, there is often interindividual and intraindividual variation in feed intake. To better understand mechanisms that underpin feed intake, the <a href="/topics/agricultural-and-biological-sciences/proteomics">proteomic</a> profiles of brain, liver, and intestine in high feed intake (HFI) and low feed intake (LFI) Chinook salmon (<em><a href="/topics/agricultural-and-biological-sciences/oncorhynchus-tshawytscha">Oncorhynchus tshawytscha</a></em>) were investigated. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify 2520 liver, 2783 intestine, and 4052 brain proteins in twenty-seven fish (12 HFI and 15 LFI individuals). Using a population of fish held in tanks, feed intake groups were selected from individual feed intake (%body weight/day (%BW/day)) measured in the meal prior to sampling (HFI: 1.01%BW/day, LFI: 0.41%BW/day). Growth rate and <a href="/topics/agricultural-and-biological-sciences/feed-conversion-ratio">feed conversion ratio</a> were not significantly different between HFI and LFI fish. <a href="/topics/agricultural-and-biological-sciences/protein-synthesis">Protein synthesis</a> in both the intestine and liver of HFI was enriched, indicating increased cellular production in these tissues. In HFI fish, <a href="/topics/agricultural-and-biological-sciences/lipid-metabolism">lipid metabolism</a> was the most enriched pathway in the brain. Share of the meal (SM%), calculated as the share of the total feed supplied to the tank, was significantly higher in the HFI (1.59 ± 0.25%) than the LFI (0.72 ± 0.06%) group. This distribution of SM% may suggest that individuals in the HFI and LFI groups were dominant or subordinate, respectively. The LFI group may have suffered from internal or external stressors and accordingly, <a href="/topics/agricultural-and-biological-sciences/proteolysis">proteolysis</a> and stress response were activated. This is the first study comparing individual fish with different measured feed intakes at the proteomic level and the outputs provide a preliminary insight into the fundamental molecular landscape of feed intake in Chinook salmon.</p>