[
Nature,
1974]
The assembly of contractile and calcium-related regulatory proteins into functioning myofilament arrays within muscle cells and the genetic control of muscle differentiation are still largely unknown processes. Here we present evidence that a particular gene may regulate such lattice assembly in the body wall muscle cells of the nematode Caenorhabditis elegans. A temperature-sensitive mutation in this gene can prevent the appearance of normal myofilament lattices in this muscle without affecting the amounts of major contractile proteins present. The organised or defective adult structures once formed in mutant muscle are stable to changes in temperature.