C. elegans pha-4 Functional Gene Editing Service

Service Overview Precision editing of PHA-4 in a premier genetic model for mitochondrial, dietary-restriction, and longevity research

pha-4 encodes the single C. elegans FoxA-family forkhead transcription factor and is the master effector of the dietary-restriction longevity program. When nutrient intake falls, PHA-4 activates the gene battery that reprograms metabolism, induces autophagy, and raises stress resistance, producing the extended lifespan characteristic of DR.

Because FoxA factors are conserved regulators of fasting metabolism and of hepatic and pancreatic development, pha-4 links a worm longevity program directly to mammalian metabolic disease. CD BioSciences delivers custom pha-4 alleles — reduction-of-function and DNA-binding-domain point mutants, conditional and tissue-specific configurations, and GFP knockins — with full verification.

About the Target Gene: pha-4 Key biological and practical facts to inform your edit design

Gene symbol	pha-4 (FoxA-family forkhead transcription factor)
Protein product	PHA-4 — FoxA-family forkhead transcription factor
Mammalian homolog	FOXA1 / FOXA2 / FOXA3 (FoxA family)
Biological role	A FoxA-family forkhead transcription factor that acts as the master effector of the dietary-restriction longevity program. Under reduced nutrient intake, PHA-4 turns on the gene battery that reprograms metabolism, autophagy, and stress resistance to extend lifespan.
Loss-of-function phenotype	Loss of pha-4 abolishes the lifespan extension normally produced by dietary restriction, including in eat-2 mutants, while leaving insulin/IGF-dependent longevity largely intact. Strong loss-of-function is lethal or severely disrupts pharyngeal development, so reduction-of-function or conditional designs are used.
Why edit it	pha-4 was the first transcription factor shown to be specifically required for DR-induced longevity, demonstrating that DR is an active transcriptional program rather than passive under-nutrition. Mammalian FoxA factors are central regulators of fasting metabolism and of liver, pancreas, and metabolic disease.
Recommended background	N2 (wild type). Because null alleles disrupt pharyngeal organogenesis, reduction-of-function (e.g. zu225) or conditional / tissue-specific configurations are recommended for adult lifespan work.
Representative allele	zu225 (canonical reduction-of-function reference allele); conditional and tissue-specific configurations recommended.

Fig. 1 The FoxA-dependent transcriptional program required for dietary-restriction longevity in C. elegans. The highlighted (amber) node marks the editing target.

pha-4 at a glance: pha-4/FoxA is required for dietary-restriction longevity; its loss abolishes DR lifespan extension. Editing pha-4 alone is a powerful way to dissect PHA-4 function in vivo, with conserved relevance to human FOXA1 biology.

Our pha-4 Editing Strategies Choose the allele that matches your experimental question

Gene Knockout

gRNA-guided Cas9 cutting with NHEJ repair to introduce frameshift indels, generating premature stop codons and null / strong-loss-of-function pha-4 alleles.

Knockin & Tagging

Homology-directed repair (HDR) inserts GFP / HA / FLAG or other tags at the pha-4 locus for endogenous expression and subcellular localization studies.

Point Mutation

Introduce specific amino-acid substitutions to dissect functional domains and separate catalytic from scaffolding roles of PHA-4.

Conditional & Reporter Alleles

Build tissue-specific, inducible, or temperature-sensitive configurations and reporter lines for spatiotemporal analysis of PHA-4 function.

Workflow of Our pha-4 Editing Service From sequence to validated strain in a streamlined pipeline

Strategy Design

Define target (knockout / knockin / point mutation), select gRNA(s) and HDR template, confirm against the latest genome build.

gRNA Synthesis

Design, validate, and synthesize high-specificity guide RNAs targeting the pha-4 locus.

Vector & Template Construction

Build Cas9 / gRNA delivery construct and, for knockin, the homology-arm repair template.

Microinjection

Perform gonadal microinjection of N2 animals with CRISPR components and co-CRISPR selection markers.

Screening & Verification

PCR, Sanger / sequencing, and phenotype confirmation to isolate edited animals and verify alleles.

Delivery & Report

Provide homozygous / balanced pha-4 strains plus a full genotype and methods report.

Key Features Why researchers choose CD BioSciences for C. elegans editing

High-efficiency, optimized CRISPR / Cas9 platform for C. elegans.
Whole-process technical traceability and transparent timelines.
Flexible editing: knockout, knockin, tagging, and point mutation.
Full genotype verification before strain delivery.
One-stop model development integrated with our C. elegans portfolio.
Competitive pricing and short turnaround.
Direct access to scientists and prompt inquiry response.
Reliable, convenient global shipping of frozen stocks.

Applications Where a custom pha-4 model adds value

Master transcriptional control of dietary-restriction longevity.
Autophagy, proteostasis, and metabolic reprogramming in aging.
FoxA biology: fasting metabolism and metabolic disease.
Epistasis with eat-2 and other DR models.
Separating DR longevity from insulin/IGF-dependent longevity.
Chromatin and target-gene analysis (ChIP, reporter validation).
DR-mimetic and metabolic compound screening.

Deliverables What you receive with every project

Genetically verified pha-4 edited strain(s) (homozygous or balanced).
Detailed genotyping report (editing strategy, allele sequence, verification data).
Methods summary and rearing / storage recommendations.
Optional: crosses into reporter, lifespan-assay, or co-CRISPR selection backgrounds.
Optional: phenotype confirmation, lifespan assay setup, and imaging support.

Frequently Asked Questions

What type of pha-4 allele will I get from a knockout project?

Standard knockout projects deliver a frameshift indel allele predicted to produce a premature stop and a loss-of-function phenotype. We confirm the edit by sequencing and, where relevant, by characteristic phenotype assays.

Can you add a GFP or epitope tag to endogenous pha-4?

Yes. Using HDR with a designed repair template, we can insert GFP, HA, or FLAG tags at the C- or N-terminus while preserving endogenous promoter and regulation.

How long does a typical pha-4 editing project take?

Timelines vary with editing type and validation needs, but our optimized pipeline and co-CRISPR selection typically shorten turnaround versus conventional approaches. Contact us with your design for a project-specific estimate.

Can I use a pha-4 null allele for adult lifespan assays?

Generally not recommended. Strong loss of pha-4 causes severe pharyngeal and developmental defects, and null animals are difficult to maintain and to interpret in lifespan assays. Reduction-of-function alleles such as zu225, or conditional / tissue-specific knockdown configurations, give clean adult-stage results.

Start Your pha-4 Editing Project

CD BioSciences is committed to convenient, efficient, and cost-effective C. elegans model customization. Tell us your target design — knockout, knockin, tagging, or point mutation — and our scientists will respond with a tailored plan and quote.

References
1. Kim H. M., Colaiácovo M. P. CRISPR-Cas9-guided genome engineering in C. elegans. Current Protocols in Molecular Biology, 2016, 115(1): 31.7.1–31.7.18.
2. Panowski S. H., Wolff S., Aguilaniu H., Durieux J., Dillin A. PHA-4/Foxa mediates diet-restriction-induced longevity of C. elegans. Nature, 2007, 447(7144): 550–555.

For research use only.