CD Biosynsis offers high-precision Chlamydomonas reinhardtii Gene Knock-in Services, providing stable, site-specific integration of exogenous DNA into the nuclear or chloroplast genomes of this versatile green alga. Unlike random integration, which often suffers from low expression levels due to the host's robust gene silencing machinery, our CRISPR-Cas9/HDR-mediated knock-in platform ensures consistent, predictable transgene performance. This service is essential for applications such as metabolic pathway assembly, endogenous protein tagging, and the development of algal strains for recombinant protein secretion or biofuel optimization. We provide comprehensive solutions, from donor template design and codon optimization to final clone verification in this premier photosynthetic model.
Get a QuoteAchieving stable and high-level transgene expression in Chlamydomonas reinhardtii is notoriously difficult due to position effects and transcriptional silencing. Our platform utilizes the high-fidelity Homology-Directed Repair (HDR) pathway stimulated by CRISPR-Cas9 or Cas12a nucleases. By designing donor templates with optimized homology arms, we facilitate the integration of your gene of interest into pre-validated Genomic Safe Harbors or specific endogenous loci. This precision avoids the disruption of essential genes and ensures that the integrated cassette remains transcriptionally active across multiple growth cycles, making it the superior choice for synthetic biology and industrial biotechnology.
We provide a wide array of knock-in options tailored to address the unique GC-rich genome and compartmentalized biology of Chlamydomonas.
Validated Loci Targeting
Targeting well-characterized genomic regions (e.g., COP1 or specific intergenic regions) known for stable expression and minimal impact on growth or photosynthetic efficiency.
Codon Optimization
Utilizing proprietary algorithms to optimize the GC-content (typically ~64%) and codon usage of your transgene to maximize translation efficiency in the algal nucleus.
C/N-terminal Fusion
Precise insertion of fluorescent markers (e.g., mCherry, CrGFP) or affinity tags (e.g., FLAG, HA) at the native locus to study protein dynamics, flagellar transport, or metabolic flux under physiological regulation.
Biallelic Control
Ensuring complete conversion in the vegetative haploid stage for immediate phenotypic screening and biochemical characterization.
Poly-cistronic Assembly
Integration of multi-gene pathways into the chloroplast genome, leveraging its ability to express operon-like clusters for complex metabolic engineering.
Biolistic Delivery
Utilizing high-velocity micro-projectile bombardment to deliver donor DNA directly into the chloroplast, achieving high-frequency site-specific integration.
1. Design & Codon Optimization
2. Donor & RNP Preparation
3. Transformation & Selection
4. Clonal Verification
Selection of the target locus and bioinformatic gRNA design. Full sequence optimization of the transgene to match the Chlamydomonas 64% GC bias.
Synthesis of HDR donor templates (plasmids or linear DNA) with high-fidelity homology arms. Preparation of high-purity Cas9 protein and validated gRNAs.
Junction PCR: Verification of site-specific integration at both 5' and 3' ends.
Sequencing: Sanger or NGS confirmation of the full transgene sequence and genomic context.
Phenotypic Validation: Analysis of protein expression (Western Blot) and functional stability over passages.
Stable Expression
By targeting validated Safe Harbor loci, we minimize the risk of gene silencing and ensure long-term expression stability over multiple growth cycles.
DNA-Free RNP Delivery
Use of RNPs for the nuclease component reduces off-target effects and eliminates the integration of Cas9 DNA, resulting in "cleaner" engineered strains.
Optimized Algal Vectors
Our vectors include native algal promoters, terminators, and introns (e.g., RBCS2 intron 1) proven to enhance nuclear transgene expression levels.
Compartment Specificity
Expertise in both nuclear and chloroplast engineering allows for the strategic placement of pathways based on metabolic requirements and PTM needs.
1. Why is codon optimization so critical for Chlamydomonas?
Chlamydomonas has an extremely high GC-bias (~64%). Transgenes with standard eukaryotic or bacterial codons are often poorly translated or targeted by silencing mechanisms. Our optimization ensures high translational throughput.
2. What is the difference between nuclear and chloroplast knock-in?
Nuclear integration is standard for most proteins but can suffer from silencing. Chloroplast integration offers high expression levels and allows for poly-cistronic (operon-like) multi-gene expression but has limited post-translational modifications.
3. How do you verify that the integration is site-specific?
We perform junction PCR using one primer located outside the homology arm in the native genome and another within the integrated cassette. Amplification at both ends confirms precise, site-specific knock-in.
4. Can you perform marker-free knock-in?
Yes. We can utilize transient selection markers or co-transformation strategies followed by screening to produce "clean" strains without permanent antibiotic resistance markers.
5. What is a Genomic Safe Harbor (GSH)?
A GSH is a specific site in the genome where a transgene can be integrated and expressed without adversely affecting the host's fitness and where the transgene itself is protected from silencing.
6. How long does a typical knock-in project take?
A standard nuclear knock-in project, from design to verified monoclonal line delivery, typically takes between 14 to 20 weeks.
7. Do you provide protein expression validation?
Yes, we offer additional services including Western Blot, LC-MS/MS, or fluorescence quantification to confirm your transgene is producing the protein at the expected levels.
8. What is the success rate for chloroplast knock-in?
Biolistic-mediated chloroplast transformation is highly robust in Chlamydomonas. We achieve nearly 100% homoplasmy (all chloroplast copies modified) through several rounds of selective plating.
CRISPR-Cas9 technology represents a transformative advancement in gene editing techniques. The main function of the system is to precisely cut DNA sequences by combining guide RNA (gRNA) with the Cas9 protein. This technology became a mainstream genome editing tool quickly after its 2012 introduction because of its efficient, simple and low-cost nature.
The CRISPR gene editing system with its Cas9 version stands as a vital instrument for current biological research. CRISPR technology enables gene knockout (KO) through permanent gene expression blockage achieved by sequence disruption. Various scientific domains including disease modeling and drug screening employ this technology to study gene functions. CRISPR KO technology demonstrates high efficiency and precision but requires confirmation and verification post-implementation because unsatisfactory editing may produce off-target effects or incomplete gene knockouts which impact experimental result reliability. For precise and efficient Gene Editing Services - CD Biosynsis, Biosynsis offers comprehensive solutions tailored to your research needs.
The CRISPR-Cas9 knockout cell line was developed using CRISPR/Cas9 gene editing to allow scientists to remove genes accurately for research on gene function and disease models and pharmaceutical discovery. Genetic research considers this technology essential due to its high efficiency together with simple operation and broad usability.
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CD Biosynsis is a leading customer-focused biotechnology company dedicated to providing high-quality products, comprehensive service packages, and tailored solutions to support and facilitate the applications of synthetic biology in a wide range of areas.