Sequential histone-modifying activities determine the robustness of transdifferentiation

Epigenetics direct transdifferentiation To make an entire animal, many and varied cell types form and interact. Some of these differentiated cells take a U-turn and can de-differentiate or transdifferentiate to another cell fate. Although relatively rare in nature, Zuryn et al. followed such a program in the tiny roundworm Caenorhabditis elegans , where a rectal cell–to–motor neuron conversion is seen. Transcription factors with conserved roles in cell plasticity and terminal fate selection partner up with specific histone-modifying enzymes in discrete steps to specify separate sequential phases of cell identity. Science , this issue p. 826