Figure 1.

Sodium channel expression and phylogenetic relationships of 10 teleost fish species. The families represented here span almost the entire teleost clade. The relative expression in skeletal muscle of the voltage-gated sodium channel genes Scn4aa and Scn4ab is represented with pie charts for each of the 10 species. Thick red segments on the branches leading to the two electric fish Eigenmannia veriscens and Gnathonemus petersii indicate the likely times when electric organs evolved and Scn4aa neofunctionalized (Arnegard et al. 2010; Betancur-R et al. 2013).