Effect of Akt gene ablation on Akt phosphorylation and expression in extensor digitorum longus muscles (EDL). EDL muscles were isolated intact from WT and Akt null (Akt1−/−, Akt2−/−) mice and incubated in vitro as described in methods. Muscle extracts were prepared and Akt was assessed by immunoblotting with a pThr308 Akt, pSer473 Akt, Akt1, and Akt2 antibodies (A). The pThr308 Akt, pSer473 Akt, Akt1, and Akt2 immunoreactive bands were quantified, and data were normalized to total amounts of α-tubulin (B–E). The number of muscles per group is 4–8. *Significantly different from all other groups. +Significantly different from WT mice. #Significantly different from Akt1−/− mice.