Cautionary note on the use of to study muscle phenotypes caused by mutations in the human gene.

Mutations in the human gene, encoding a slow skeletal muscle/β-cardiac myosin heavy chain, cause different types of myopathies. The nematode model has frequently been employed to study the molecular and physiological consequences of mutations in muscle function by introducing mutations into the gene, the worm ortholog. We report here that the model is not appropriate for such studies if they involve expression of the UNC-54 protein (wild-type or fused to green fluorescent protein) above endogenous levels.