CREB mediates theC. elegansdauer polyphenism through direct and cell-autonomous regulation of TGF-β expression

AbstractAnimals can adapt to dynamic environmental conditions by modulating their developmental programs. Understanding the genetic architecture and molecular mechanisms underlying developmental plasticity in response to changing environments is an important and emerging area of research. Here, we show a novel role of cAMP response element binding protein (CREB)-encodingcrh-1gene in developmental polyphenism ofC. elegans. Under conditions that promote normal development in wild-type animals,crh-1mutants inappropriately form transient pre-dauer (L2d) larva and express the L2d marker gene. L2d formation incrh-1mutants is specifically induced by the ascaroside pheromone ascr#5 (asc-ωC3; C3), andcrh-1functions autonomously in the ascr#5-sensing ASI neurons to inhibit L2d formation. Moreover, we find that CRH-1 directly binds upstream of thedaf-7TGF-β locus and promotes its expression in the ASI neurons. Taken together, these results provide new insight into how animals alter their developmental programs in response to environmental changes.