The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

daf-9  -  Protein DAF-9

Caenorhabditis elegans

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

High impact information on daf-9

  • However, the ligand extended the lifespan of germ-line ablated daf-9 and daf-36 mutants, showing that it is "antiaging" in the germ-line longevity pathway [1].
  • Thus, daf-9 may integrate outputs from daf-2 and daf-7 signaling pathways to relay neuroendocrine signals through synthesis of a lipophilic hormone [2].
  • Furthermore, constitutive expression of daf-9 in the hypodermis suppresses dauer arrest of daf-7 mutant animals and inhibits dauer remodelling of some tissues in daf-2 mutant animals [2].
  • A rescuing daf-9::GFP fusion gene driven by the daf-9 promoter is expressed in two head cells at all stages, in the hypodermis from mid-second larval stage (L2) to the fourth larval stage (L4), and in the spermatheca of the adult hermaphrodite [2].
  • Loss-of-function mutations in the cytochrome P450 gene daf-9 also cause dauer arrest and defects in cell migration [2].

Biological context of daf-9

  • Mutations in daf-9 result in transient dauer-like larval arrest, abnormal reproductive development, molting defects and increased adult longevity [3].
  • These extracts are also able to rescue the lethal dauer phenotype of daf-9 mutants, which lack a P450 steroid hydroxylase thought to be involved in the synthesis of the DAF-12 ligand; extracts, however, have no effect on a DAF-12 ligand binding domain mutant that is predicted to be ligand insensitive [4].
  • This is exemplified by genetic alterations in Caenorhabditis elegans where homologues of the HPG axis pathways, as well as the daf-2 and daf-9 pathways, all converge on daf-16, the homologue of human Forkhead that functions in the regulation of cell cycle events [5].

Anatomical context of daf-9

  • The surprising cellular specificity of daf-9 expression (predominantly in two sensory neurons) supports a previously unrecognized role for these cells in neuroendocrine control of larval development, reproduction and life span [3].

Associations of daf-9 with chemical compounds

  • Genetic tests show that daf-9 is upstream of daf-12 in the genetic pathways for larval development and adult longevity. daf-9 encodes a cytochrome P450 related to those involved in biosynthesis of steroid hormones in mammals [3].
  • Sterols may be the daf-9 substrate and daf-12 ligand because cholesterol deprivation phenocopies mutant defects [6].

Other interactions of daf-9

  • Using a candidate ligand approach we find that the C27 bile acid cholestenoic acid (5-cholesten-3beta-ol-(25S)-carboxylic acid) promotes reproductive growth in dauer-constitutive mutants in a daf-9- and daf-12-dependent manner [7].
  • Epistasis analyses, together with the relationship between sdf-9 mutations and daf-9 expression, suggested that SDF-9 increases the activity of DAF-9 or helps the execution of the DAF-9 function [8].
  • Double mutants carrying both daf-9 and daf-15 are more resistant to detergent than either single mutant [9].


  1. A bile acid-like steroid modulates Caenorhabditis elegans lifespan through nuclear receptor signaling. Gerisch, B., Rottiers, V., Li, D., Motola, D.L., Cummins, C.L., Lehrach, H., Mangelsdorf, D.J., Antebi, A. Proc. Natl. Acad. Sci. U.S.A. (2007) [Pubmed]
  2. Intercellular signaling of reproductive development by the C. elegans DAF-9 cytochrome P450. Mak, H.Y., Ruvkun, G. Development (2004) [Pubmed]
  3. DAF-9, a cytochrome P450 regulating C. elegans larval development and adult longevity. Jia, K., Albert, P.S., Riddle, D.L. Development (2002) [Pubmed]
  4. Lipophilic regulator of a developmental switch in Caenorhabditis elegans. Gill, M.S., Held, J.M., Fisher, A.L., Gibson, B.W., Lithgow, G.J. Aging Cell (2004) [Pubmed]
  5. Living and dying for sex. A theory of aging based on the modulation of cell cycle signaling by reproductive hormones. Bowen, R.L., Atwood, C.S. Gerontology. (2004) [Pubmed]
  6. A hormonal signaling pathway influencing C. elegans metabolism, reproductive development, and life span. Gerisch, B., Weitzel, C., Kober-Eisermann, C., Rottiers, V., Antebi, A. Dev. Cell (2001) [Pubmed]
  7. DAF-12-dependent rescue of dauer formation in Caenorhabditis elegans by (25S)-cholestenoic acid. Held, J.M., White, M.P., Fisher, A.L., Gibson, B.W., Lithgow, G.J., Gill, M.S. Aging Cell (2006) [Pubmed]
  8. SDF-9, a protein tyrosine phosphatase-like molecule, regulates the L3/dauer developmental decision through hormonal signaling in C. elegans. Ohkura, K., Suzuki, N., Ishihara, T., Katsura, I. Development (2003) [Pubmed]
  9. Mutants of Caenorhabditis elegans that form dauer-like larvae. Albert, P.S., Riddle, D.L. Dev. Biol. (1988) [Pubmed]
WikiGenes - Universities