Hormonal signals produced by DAF-9/cytochrome P450 regulate C. elegans dauer diapause in response to environmental cues

• Published in: Development (Cambridge) Vol. 131; no. 8; pp. 1765 - 1776
• Main Authors: Gerisch, Birgit, Antebi, Adam
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Limited 01.04.2004
• Subjects: Animals; Caenorhabditis elegans; Caenorhabditis elegans - enzymology; Caenorhabditis elegans - growth & development; Caenorhabditis elegans Proteins - metabolism; Cyclic GMP - metabolism; Cytochrome P-450 Enzyme System - metabolism; Larva - metabolism; Neuropeptides - metabolism; Promoter Regions, Genetic; Receptors, Cytoplasmic and Nuclear - metabolism; Transforming Growth Factor beta - metabolism
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.01068

In response to the environment, the nematode C. elegans must choose between arrest at a long-lived alternate third larval stage, the dauer diapause, or reproductive development. This decision may ultimately be mediated by daf-9 , a cytochrome P450 related to steroidogenic hydroxylases and its cognate nuclear receptor daf-12 , implying organism-wide coordination by lipophilic hormones. Accordingly, here we show that daf-9(+) works cell non-autonomously to bypass diapause, and promote gonadal outgrowth. Among daf-9 -expressing cells, the hypodermis is most visibly regulated by environmental inputs, including dietary cholesterol. On in reproductive growth, off in dauer, hypodermal daf-9 expression is strictly daf-12 dependent, suggesting feedback regulation. Expressing daf-9 constitutively in hypodermis rescues dauer phenotypes of daf-9 , as well as insulin/IGF receptor and TGFβ mutants, revealing that daf-9 is an important downstream point of control within the dauer circuits. This study illuminates how endocrine networks integrate environmental cues and transduce them into adaptive life history choices.