C. elegans unc-22 Functional Gene Editing Service

Service Overview Precision editing of unc-22 in a premier genetic model for muscle contractility, neuronal wiring, and locomotion

unc-22 encodes twitchin of Caenorhabditis elegans, a giant tandem immunoglobulin- and fibronectin-III-domain protein of the sarcomere whose closest vertebrate relative is titin. Its C-terminal kinase domain places it in the MLCK-like branch of the family.

UNC-22 sits in the A-band, where it acts simultaneously as a structural element of thick filament architecture and as a regulator of the contraction–relaxation cycle. Removing it does not abolish contraction but uncouples its timing, which is why unc-22 mutants twitch rather than simply failing to move. CD BioSciences delivers custom unc-22 alleles — knockouts, Ig-domain and Fn3 truncations, kinase-dead point mutants, conditional configurations, and tag knockins — with full genotype verification.

About the Target Gene: unc-22 Key biological and practical facts to inform your edit design

Gene symbol	unc-22 (Twitchin, a giant titin-like muscle protein combining immunoglobulin domains with a kinase domain)
Protein product	UNC-22 — twitchin, the giant immunoglobulin-domain kinase of muscle thick filaments
Mammalian homolog	TTN (titin) and related giant sarcomeric Ig-domain proteins
Biological role	Twitchin is one of the giant intracellular proteins built from tandem immunoglobulin and fibronectin-III domains, sharing that architecture with vertebrate titin. Its C-terminal region carries a kinase domain related to myosin light chain kinase, which is why the family is sometimes described as "MLCK-like". UNC-22 localises to the A-band of the sarcomere and behaves as both a structural scaffold and a signalling element: it helps set thick filament architecture and it modulates the contraction–relaxation cycle, since twitchin family members can respond to calcium-calmodulin.
Loss-of-function phenotype	The name describes the phenotype directly. Loss of UNC-22 gives animals that twitch — they show spontaneous, localised muscle contractions instead of the smooth sinusoidal wave of normal locomotion. Muscles still contract, but the regulation of relaxation is disturbed, so contraction and relaxation are no longer properly ordered.
Why edit it	Giant Ig-domain proteins are structurally hard to work with in vertebrates, and twitchin is the tractable member of that group. It is also where enough molecular genetics has accumulated to separate the protein's mechanical role from its kinase role, which is the same question that currently dominates titin biology in cardiomyopathy and muscular dystrophy.
Recommended background	N2 (wild type). Nulls are viable and give the diagnostic twitching phenotype, so scoring is straightforward. We recommend quantifying twitch frequency and waveform in addition to qualitative inspection, and combining the edit with a calcium reporter if you want to test whether the defect is in relaxation timing rather than force.
Representative allele	Reference alleles from the CGC collection together with engineered deletions; custom CRISPR nulls, A-band domain truncations, kinase-domain point mutants, conditional configurations, and fluorescent or epitope tag knockins available on request.

Fig. 1 UNC-22 / twitchin, the giant titin-like kinase that sets thick filament architecture and contraction–relaxation timing in C. elegans muscle. The highlighted (amber) node marks the editing target.

unc-22 at a glance: unc-22 sets thick filament architecture; without it muscles twitch instead of beating smoothly. Editing unc-22 alone is a powerful way to dissect UNC-22 function in vivo, with conserved relevance to human TTN biology.

Our unc-22 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 unc-22 alleles.

Knockin & Tagging

Homology-directed repair (HDR) inserts GFP / HA / FLAG or other tags at the unc-22 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 UNC-22.

Conditional & Reporter Alleles

Build tissue-specific, inducible, or temperature-sensitive configurations and reporter lines for spatiotemporal analysis of UNC-22 function.

This gene is worth flagging for a practical reason: unc-22 mutations were historically recovered as spontaneous events, largely through transposon insertion, which means an apparent spontaneous twitcher in your stock is not automatically your construct. Every line we deliver is verified by sequencing across the edited junction and outcrossed, so background insertions are excluded. For mechanism, a kinase-dead point mutant separates catalysis from the protein's scaffolding role in the A-band.

Workflow of Our unc-22 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 unc-22 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 unc-22 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 unc-22 model adds value

Thick filament architecture and A-band organisation.
Regulation of contraction and relaxation timing.
Giant immunoglobulin-domain protein structure and elasticity.
Calcium-calmodulin-dependent control of the sarcomere.
Titin-family biology in a genetically tractable system.
Locomotion waveform analysis and quantitative phenotyping.
Muscle myopathy and myotonia-like phenotype modelling.

Deliverables What you receive with every project

Genetically verified unc-22 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, muscle- or cilia-marker, and co-CRISPR selection backgrounds.
Optional: phenotype confirmation, sarcomere and axonal imaging, and locomotion analysis support.

Frequently Asked Questions

What type of unc-22 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 unc-22?

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 unc-22 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.

A twitching animal appeared in my stock unexpectedly — is it unc-22?

It is worth checking, and worth being suspicious of. Spontaneous mutations at this locus were recovered historically at an unusually high frequency, and a substantial fraction of them were caused by transposon insertion rather than by base substitution. That is a property of the locus, not a defect in any particular strain construction. The practical response is to sequence the locus and, where possible, replace the line with a defined CRISPR allele whose edits are known and whose background has been outcrossed, rather than propagating the spontaneous allele forward.

Start Your unc-22 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. Moerman D. G., Benian G. M., Barstead R. J., Schriefer L. A., Waterston R. H. Identification and intracellular localization of the unc-22 gene product of Caenorhabditis elegans. Genes & Development, 1988, 2(1): 93–105.

For research use only.