Dauer formation in Caenorhabditis elegans is induced by chemosensation of high levels of a constitutively secreted pheromone. Seven genes defined by mutations that confer a dauer-formation constitutive phenotype (Daf-c) can be congruently divided into two groups by any of three criteria. Group 1 genes (daf-11 and daf-21) are (1) strongly synergistic with group 2 genes for their Daf-c phenotype,...

Sterol-sensing nuclear receptors and insulin-like growth factor signaling play evolutionarily conserved roles in the control of aging. In the nematode Caenorhabditis elegans, bile acid-like steroid hormones known as dafachronic acids (DAs) influence longevity by binding to and regulating the activity of the conserved nuclear receptor DAF-12, and the insulin receptor (InsR) ortholog DAF-2 contro...

Parallel pathways control C. elegans reproductive development in response to environmental cues. Attenuation of daf-2 insulin-like or daf-7 TGFbeta-like signaling pathways cause developmental arrest at the stress resistant and long-lived dauer stage. Loss-of-function mutations in the cytochrome P450 gene daf-9 also cause dauer arrest and defects in cell migration. A rescuing daf-9::GFP fusion g...

The C. elegans daf-8 gene encodes an R-Smad that is expressed in a subset of head neurons, the intestine, gonadal distal tip cells and the excretory cell. We found that DAF-8, which inhibits the DAF-3 Co-Smad, is associated with DAF-3 and the DAF-14 Smad in vivo and in vitro. Overexpression of daf-8 conferred a dauer-defective phenotype and suppressed constitutive dauer formation in daf-8 and d...

The nematode Caenorhabditis elegans responds to overcrowding and scarcity of food by arresting development as a dauer larva, a nonfeeding, long-lived, stress-resistant, alternative third-larval stage. Previous work has shown that mutations in the genes daf-2 (encoding a member of the insulin receptor family) and age-1 (encoding a PI 3-kinase) result in constitutive formation of dauer larvae (Da...

The nematode Caenorhabditis elegans responds to conditions of overcrowding and limited food by arresting development as a dauer larva. Genetic analysis of mutations that alter dauer larva formation (daf mutations) is presented along with an updated genetic pathway for dauer vs. nondauer development. Mutations in the daf-2 and daf-23 genes double adult life span, whereas mutations in four other ...