Chronic social stress alters protein metabolism in juvenile rainbow trout, Oncorhynchus mykiss.

When confined in pairs, juvenile rainbow trout (Oncorhynchus mykiss) form dominance hierarchies in which subordinate fish exhibit characteristic physiological changes including reduced growth rates and chronically elevated plasma cortisol concentrations. We hypothesized that alterations in protein metabolism contribute to the reduced growth rate of socially stressed trout, and predicted that subordinate trout would exhibit reduced rates of protein synthesis coupled with increases in protein degradation. Protein metabolism was assessed in dominant and subordinate fish after 4 days of social interaction, and in fish that were separated after 4 days of interaction for a 4 days recovery period, to determine whether effects on protein metabolism recovered when social stress was alleviated.

Meta-analysis of differentially-regulated hepatic microRNAs identifies candidate post-transcriptional regulation networks of intermediary metabolism in rainbow trout.

MicroRNAs (miRNAs) are small non-coding RNAs which act as post-transcriptional regulators by decreasing targeted mRNA translation and stability. Principally targeting small 3' UTR elements of protein-coding mRNAs through complementary base-pairing, miRNAs are promiscuous regulators of the transcriptome. While potent roles for hepatic miRNAs in the regulation of energy metabolism have emerged in rodent models, comparative roles in other vertebrates remain largely unexplored.

Correction: Social status regulates the hepatic miRNAome in rainbow trout: Implications for posttranscriptional regulation of metabolic pathways.

[This corrects the article DOI: 10.1371/journal.pone.

Glucagon regulation of carbohydrate metabolism in rainbow trout: glucose fluxes and gene expression.

Glucagon increases fish glycaemia, but how it affects glucose fluxes has never been characterized. The goal of this study was to test the hypothesis that glucagon stimulates hepatic glucose production (rate of appearance, ) and inhibits disposal (rate of disposal, ) in rainbow trout. Changes in the mRNA abundance of key proteins involved in glycolysis, gluconeogenesis and glycogen breakdown were also monitored.