Mouse TA muscles were transfected with GFP (A and B), eIF2Bɛ (2Bɛ) (C and D), or constitutively active eIF2Bɛ (2Bɛ-S535A) (E and F). At 7 days post-transfection, the muscles were collected and cross-sections from the mid-belly of the muscle were subjected to immunohistochemistry for GFP and laminin (A), 2Bɛ and laminin (C), or 2Bɛ-S535A and laminin (E). Scale bar = 100 μm. The CSA of transfected fibres (green bars) and non-transfected fibres (black bars) from GFP (B) 2Bɛ, (D), or 2Bɛ-S535A (F) transfected muscles was determined and plotted on a histogram (n = 285–510 transfected and 285–510 non-transfected fibres/group). H, average CSA of the transfected (+) and non-transfected (−) fibres per muscle from samples transfected with GFP, 2Bɛ, or 2Bɛ-S535A. Values are means ± SEM, n = 5–7 muscles/group. *Different from the non-transfected fibres within a given condition, P < 0.05.