Submitted to: International Congress on the Biology of Fish
Publication Type: Abstract Only
Publication Acceptance Date: April 11, 2012
Publication Date: July 20, 2012
Citation: Cleveland, B.M., Weber, G.M. 2012. Effects of phytoestrogens on protein turnover in rainbow trout primary myocytes. International Congress on the Biology of Fish. 912.
Soybean-derived ingredients used in aquaculture feeds may contain phytoestrogens, but it is unknown if these compounds can mimic the catabolic effects of estradiol in fish muscle. Six day-old rainbow trout primary myocytes were exposed to increasing concentrations (10 nM – 100 µM) of either genistein or diadzein for 24 hrs. Effects of phytoestrogens on the expression of twenty four proteolysis-related genes were determined by multiplex RT-PCR analysis. Genistein resulted in a linear, dose-dependent increase in expression of ubiquitin ligase genes fbxo32 (atrogin-1) and fbxo25, cathepsin D (ctsd), autophagy-related genes atg12, lc3b, and gabarapl1, and the proteasome components psma5 and psmd6. Diadzein resulted in a linear, dose-dependent increase in fbxo25 expression. Genistein affected protein turnover by decreasing rates of protein synthesis and increasing rates of protein turnover. These results suggest a potential negative effect of dietary phytoestrogens, especially genistein, on the accumulation of protein in white muscle in rainbow trout.