Fig 2. Histidine Metabolism in Affected Tissues.

Levels (median-scaled and log-transformed) of histidine and other related metabolites in breast muscle tissue samples obtained from affected (A) and unaffected (U) chickens that were sampled from two genetically distinct purebred lines (lines 1 and 2) and a commercial broiler (CB) population. Elevated histidine levels in affected tissue were accompanied by an accumulation of histamine, 1-methylhistidine, and 3-methylhistidine, which may reflect skeletal muscle degeneration and oxidative stress. In contrast, the histidine derived antioxidants carnosine and anserine, were depleted in affected breast muscle tissue suggesting altered redox homeostasis.