daf-7 Antibody
Description
Definition and Target Specificity
The DAF-7 antibody (cN-14, sc-9249) is an affinity-purified goat polyclonal antibody raised against a peptide mapping within an internal region of the DAF-7 protein in C. elegans . DAF-7 is a homolog of mammalian TGF-β, playing essential roles in developmental regulation, environmental response, and neuronal signaling .
Biological Role of DAF-7 in C. elegans
DAF-7 is a TGF-β ligand secreted primarily by the ASI ciliated neurons under favorable environmental conditions . Its signaling cascade involves:
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Phosphorylation of R-SMADs (DAF-8, DAF-14), which translocate to the nucleus to inhibit the DAF-3/DAF-5 repressor complex .
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Regulation of processes such as dauer formation, synaptic glutamate receptor (GLR-1) abundance, and germline stem cell maintenance .
Neurological Regulation
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The DAF-7 antibody has been instrumental in identifying DAF-7’s role in modulating GLR-1 glutamate receptor levels. Mutations in the DAF-7 pathway increase GLR-1 transcription and synaptic abundance, altering locomotion behavior .
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DAF-7 detection via immunofluorescence confirmed its expression in ASI neurons, which is suppressed under stress (e.g., low food, high pheromones) .
Developmental and Environmental Signaling
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Transcriptomic profiling using DAF-7 pathway mutants (daf-1, daf-3) revealed that DAF-7 suppresses genes involved in molting, stress response, and pathogen defense .
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In germline regulation, DAF-7 promotes lag-2/Notch ligand expression in distal tip cells via DAF-3 repression, influencing stem cell pool expansion .
Autophagy and Systemic Signaling
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DAF-7 acts as a systemic signal for autophagy activation. Antibody-based assays showed that DAF-7 secretion from ASI neurons regulates SQST-1::GFP aggregation in distal tissues .
Experimental Validation and Limitations
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Specificity: The antibody’s epitope lies within an internal region of DAF-7, and its specificity is confirmed through blocking peptide competition .
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Limitations: While effective for C. elegans, cross-reactivity with mammalian TGF-β isoforms has not been reported.
Future Directions
The DAF-7 antibody remains pivotal for exploring:
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
Under harsh environmental conditions, C. elegans larvae enter a developmentally arrested dauer stage. The TGF-β-like protein DAF-7 inhibits dauer formation and promotes larval growth. It may function as a ligand for the DAF-4 cell surface receptor. DAF-7 acts as a negative regulator of dauer development by transducing chemosensory information from ASI neurons and influences sensitivity to CO2 levels. In AWC neurons, DAF-7 promotes expression of srsx-3, a G protein-coupled receptor (GPCR).
DAF-7 Function and Regulation:
- DAF-7 expression declines with age in adult C. elegans, contributing to reduced sensitivity to dietary restriction in older animals. (PMID: 28107363)
- In animals with mutant daf-28/IGF, wild-type DAF-7 protein mislocalizes and accumulates in the ASI neuron's proximal axon. Activation of the unfolded protein response modulates both the developmental phenotype and DAF-7 mislocalization, but through distinct mechanisms. (PMID: 27926939)
- glr-1 gene expression and GLR-1 protein levels are elevated in the neurons of daf-7 mutants. (PMID: 26054666)
- DAF-7 plays a role in larval development, specifically affecting molting and excretory canal development. (PMID: 23526825)
- Genetic analysis of aggregation and bordering behaviors identified a new gene affecting the daf-7 pathway: the GABA receptor exp-1. (PMID: 23284308)
