Figure 4. Innervation and cholinergic signaling alters the muscle mitochondrial mass and structure. Transgenes expressing daf-16 in either the muscle (A) or nervous system (B) were introduced into a daf-2 daf-16 mutant and the effects on muscle mitochondrial mass were assessed. The restoration of daf-16 in either the muscle (A) or neurons (B) can both partially restore the mitochondrial mass of the daf-2 mutant measured by the fluorescence from a muscle-expressed mitochondrial-localized GFP on the indicated days of adulthood. N >12 for all ages and genotypes. * represents p < 0.05 by t‐test. (C) The severing of motor neuron commissures via laser axotomy produces a decline in muscle mitochondrial mass in the denervated muscles as shown by the imaging and quantitation of a mitochondrial-localized GFP. * represents p < 0.05 by t‐test. (D) Disruption of cholinergic signaling in a cha-1 mutant produces aging-like changes in mitochondrial structure including the formation of abnormal GFP+ aggregates. Shown are confocal images from adult day 3 wild-type and cha-1 mutants grown at the semi-permissive temperature of 22.5ºC captured from animals expressing a mitochondrial-localized GFP to label the muscle mitochondria.