CD Biosynsis offers specialized Phaeodactylum tricornutum CRISPR Interference (CRISPRi) Services, providing a powerful, non-mutagenic platform for tunable and reversible gene knockdown. While traditional knockouts are effective for complete loss-of-function, many genes in this model diatom—especially those involved in the central carbon metabolism, photosynthesis, and cell wall formation—are essential for viability. Our CRISPRi platform utilizes a catalytically inactive or "dead" Cas9 (dCas9) to sterically block the transcription machinery at the DNA level. This allows researchers to suppress gene expression without introducing permanent double-strand breaks, making it the tool of choice for functional genomics and metabolic pathway balancing in marine biotechnology.
Our CRISPRi solutions for P. tricornutum are specifically engineered to navigate the diatom's complex regulatory environment. We utilize codon-optimized dCas9 variants and high-efficiency guide RNA (gRNA) design tailored to the transcription start sites (TSS) of the diatom genome. By bypassing the limitations of traditional RNAi, which often suffers from inconsistent silencing and off-target effects, our CRISPRi platform provides highly specific and predictable repression. This service is essential for researchers looking to identify metabolic bottlenecks, study essential gene function, or redirect carbon flux from primary growth toward high-value molecules like EPA and fucoxanthin without compromising the overall fitness of the algal culture.
Get a QuoteCRISPRi represents a major leap forward in the genetic manipulation of diatoms, offering a level of control that was previously unattainable. The mechanism relies on the targeting of the dCas9-gRNA complex to the promoter or the 5' untranslated region (UTR) of a gene, where it acts as a physical barrier to RNA polymerase. In Phaeodactylum tricornutum, we have optimized this system to achieve significant repression of both reporter genes and endogenous metabolic targets.
A key advantage of our platform is the ability to perform "multiplexed knockdown." By delivering multiple gRNAs, we can simultaneously repress several genes within a branched pathway, allowing for sophisticated redirection of metabolic energy. Furthermore, the integration of dCas9 into episomal vectors allows for the removal of the repression machinery once the study is complete, providing a flexible and reversible tool for marine synthetic biology. Our data-driven approach ensures that gRNAs are placed in the optimal window relative to the TSS to maximize repression efficiency while minimizing non-specific effects.
We provide multiple CRISPRi configurations designed to meet the varying requirements of basic research and industrial strain optimization.
Strong Algal Promoters
Utilizing robust diatom promoters like FCP (Fucoxanthin Chlorophyll a/c-binding Protein) to drive continuous dCas9 expression for long-term gene silencing.
Stable Episomal Delivery
Leveraging CEN/ARS-based episomes to maintain the CRISPRi machinery without the genomic instability of random integration.
Pathway Rerouting
Simultaneously targeting multiple competitive enzymes (e.g., those involved in storage carbohydrate synthesis) to favor the production of lipids or pigments.
gRNA Arrays
Implementation of poly-cistronic gRNA arrays processed by endogenous RNases or Csy4 endonucleases to ensure balanced repression across multiple targets.
TSS Window Mapping
Fine-tuning the level of repression by shifting gRNA targets across the -50 to +200 bp region of the transcription start site to achieve specific expression "set points."
Epigenetic Fusions
Utilizing dCas9 fusions with transcriptional repressor domains (e.g., KRAB-like) optimized for the diatom chromatin environment to enhance the depth of knockdown.
Our systematic workflow ensures high-precision knockdown with quantitative verification of mRNA reduction.
1. TSS Identification & gRNA Design
2. Cassette Assembly & Codon Optimization
3. Transformation & Monoclonal Isolation
4. Quantitative Validation
Utilizing P. tricornutum genome databases to map the exact Transcription Start Site (TSS). Design of multiple gRNAs per gene to identify the most effective repression site.
Assembly of dCas9 expression vectors featuring diatom-specific regulatory parts. Full codon optimization of dCas9 and nuclear localization signals (NLS) to ensure nuclear import and activity.
qPCR Validation: Measurement of target gene mRNA levels to confirm the percentage of knockdown. Phenotypic Assessment: Analysis of growth, lipid composition (GC-MS), or photosynthetic efficiency (PAM). Delivery of verified strains.
Study Essential Genes
Enables the functional analysis of genes that cannot be knocked out due to lethality, providing a vital tool for understanding core diatom physiology.
Tunable Suppression
By varying the gRNA location, we can achieve different degrees of silencing, allowing for the identification of metabolic "sweet spots" for bioproduct yield.
High Specificity
Unlike RNAi, which relies on the complex RNA-induced silencing complex (RISC), CRISPRi acts directly on DNA with significantly lower off-target risks.
Pathways Engineering
Ideal for complex metabolic engineering where multiple genes must be downregulated simultaneously to redirect resources toward target metabolites.
1. How does CRISPRi differ from traditional RNAi in diatoms?
RNAi targets mRNA for degradation in the cytoplasm, which can be inconsistent in P. tricornutum. CRISPRi acts at the DNA level by blocking the initiation or elongation of transcription, providing more stable and targeted repression.
2. Can CRISPRi achieve 100% silencing of a gene?
While CRISPRi is highly effective, it typically achieves a 60% to 95% reduction in mRNA levels. This "knockdown" rather than "knockout" is actually beneficial for studying essential genes that the cell needs to survive.
3. Is the gene repression reversible?
Yes. If the dCas9 machinery is delivered on an episomal vector, curing the vector from the cell will restore wild-type levels of gene expression. This is ideal for studying temporal gene functions.
4. How do you choose the best gRNA for repression?
We target the Transcription Start Site (TSS) window. Generally, gRNAs targeting the non-template strand near the TSS provide the most robust steric hindrance to RNA polymerase.
5. Can you target multiple genes at the same time?
Yes, we can deliver a poly-cistronic gRNA array that targets multiple steps in a metabolic pathway, providing a systems-level approach to gene regulation.
6. What type of validation data is provided?
We provide RT-qPCR data to quantify the percentage of mRNA reduction compared to a control strain. We can also provide Western Blot data if a suitable antibody is available for your target protein.
7. Is codon optimization necessary for dCas9 in diatoms?
Absolutely. Diatoms have specific codon usage patterns. We utilize dCas9 sequences that have been fully optimized for P. tricornutum to ensure high translational efficiency and nuclear import.
8. What is the typical turnaround time for a CRISPRi project?
A standard CRISPRi project from design to verified monoclonal knockdown strain delivery typically takes 14 to 18 weeks.
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.