Fig 1. Irisin was detected in the heart and skeletal muscle of zebrafish by Western blot analyses.

(A) Western blot showing irisin in different concentrations of total protein extract from heart and skeletal muscle of untreated zebrafish (tissue name, and concentration of protein loaded in brackets), and siRNA treated zebrafish (labeled siRNA-heart; siRNA-muscle), and synthetic irisin (positive control); (B) pre-absorption control using total protein as indicated in A (age: 2 months; n = 6 zebrafish). Fig (C) shows the internal control (β-tubulin) expression in the above tissues. Western blot detected irisin protein at 23 kDa (A) while no protein was detected in the preabsorption control (B) in skeletal muscle and heart tissues of zebrafish. A band representing beta tubulin was detected in all tissue samples tested.