Hormonal signals produced by DAF-9/cytochrome P450 regulate C. elegans dauer diapause in response to environmental cues.
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 TGFbeta 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.
Gerisch
Birgit
B
Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany.
Antebi
Adam
A
D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D007814:Larva / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; C410905:DAF-12 protein, C elegans; D009479:Neuropeptides; D018160:Receptors, Cytoplasmic and Nuclear; D016212:Transforming Growth Factor beta; D003577:Cytochrome P-450 Enzyme System; C075027:diapause hormone; C486228:DAF-9 protein, C elegans; D006152:Cyclic GMP