"In almost all treatment paradigms, over-expression of
hlh-1 resulted in widespread myogenesis; most cells had adopted a muscle-like fate. The muscle marker routinely used to assay myogenesis was myosin heavy chain A [MHC A (Miller et al., 1986) Fig. 1]. Although high levels of MHC A were detected, filaments were disorganized and these muscle-like cells fail to contract. To determine the extent to which these cells adopted a true muscle-like fate, we tested several additional muscle markers, including several structural proteins. The muscle-like cells resulting from heat shock-induced HLH-1 activated a
myo-3::gfp reporter gene (Fire and Waterston, 1989) and were positive for filamentous actin, UNC-89 (Benian et al., 1996), UNC-98 (Mercer et al., 2003) and PAT-3 (Gettner et al., 1995; Francis and Waterston, 1985) (data not shown)."