From DNA to Diversity, Molecular Genetics and the Evolution of Animal Design, 2nd edition

Abstract

Background Biological timing mechanisms that integrate cyclical and successive processes are not well understood. C. elegans molting cycles involve rhythmic cellular and animal behaviors linked to the periodic reconstruction of cuticles. Molts are coordinated with successive transitions in the temporal fates of epidermal blast cells, which are programmed by genes in the heterochronic regulatory network. It was known that juveniles molt at regular 8–10 hr intervals, but the anticipated pacemaker had not been characterized.