Inhibition of touch cell fate by egl-44 and egl-46 in C-elegans

In wild-type Caenorhabditis elegans, six cells develop as receptors for gentle touch. In eg1-44 and eg1-46 mutants, two other neurons, the FLP cells, express touch receptor-like features. eg1-44 and eg1-46 also affect the differentiation of other neurons including the HSN neurons, two cells needed for egg laying, eg1-44 encodes a member of the transcription enhancer factor family. The product of the eg1-46 gene, two Drosophila proteins, and two proteins in human and mice define a new family of zinc finger proteins. Both eg1-44 and eg1-46 are expressed in FLP and HSN neurons (and other cells); expression of eg1-46 is dependent on eg1-44 in the FLP cells but not in the HSN cells. Wild-type touch cells express egl-46 but not eg1-44. Moreover, ectopic expression of eg1-44 in the touch cells prevents touch cell differentiation in an egl-46-dependent manner. The sequences of these genes and their nuclear location as seen with FLP fusions indicate that they repress transcription of touch cell characteristics in the FLP cells.