The Caenorhabditis elegans heterochronic gene lin‐14 coordinates temporal progression and maturation in the egg‐laying system

Heterochronic genes function to ensure the timing of stage‐specific developmental events in C. elegans. Mutations in these genes cause certain developmental programs to be executed in a precocious or retarded manner. Canonical precocious (loss‐of‐function) and retarded (gain‐of‐function) mutations in the lin‐14 gene lead to elimination or reiteration of larval stage‐specific cellular events. Here, we describe a hypomorphic, missense allele of lin‐14, sa485. lin‐14(sa485) hermaphrodites pass through normal larval stages, but exhibit asynchrony between vulval and gonadal maturation in the L4 larval stage. We show that a subtly precocious morphogenetic event in the vulva disrupts tissue synchrony and is followed by retarded vulval eversion. Additionally, uterine uv1 cell differentiation is retarded in lin‐14(sa485) animals that exhibit delayed vulval eversion. Together, these experiments outline a function for LIN‐14 in coordinating the temporal progression of development, which is separable from its role in regulating stage‐specific events during C. elegans postembryonic development. Developmental Dynamics 238:394–404, 2009. © 2009 Wiley‐Liss, Inc.