CD Biosynsis offers specialized Nannochloropsis spp. CRISPR Interference (CRISPRi) services, providing a powerful, non-mutagenic platform for the tunable and reversible knockdown of target genes. While traditional knockouts are highly effective, many metabolic nodes in Nannochloropsis—particularly those involved in central carbon metabolism, nitrogen assimilation, and cell division—are essential for survival. Our CRISPRi platform utilizes a catalytically inactive "dead" Cas9 (dCas9) to sterically block the transcription machinery, allowing researchers to explore the function of essential genes and balance metabolic flux without the lethality of a permanent knockout.
Our CRISPRi solutions are specifically engineered for the unique regulatory landscape of the Nannochloropsis genus, including N. oceanica and N. gaditana. We utilize codon-optimized dCas9 variants and high-efficiency guide RNA (gRNA) design tailored to the transcription start sites (TSS) of the algal genome. This technology is instrumental for industrial applications, such as redirecting carbon from biomass production to lipid biosynthesis during different growth phases. By bypassing the limitations of RNAi, which often suffers from incomplete silencing and off-target effects in microalgae, our CRISPRi platform provides a highly specific and predictable tool for rational algal strain optimization.
Get a QuoteCRISPRi functions by targeting the dCas9-gRNA complex to the promoter or the 5' untranslated region (UTR) of a gene, creating a physical "roadblock" that prevents RNA polymerase from initiating or elongating transcription. In Nannochloropsis, we have optimized this system to achieve significant repression of both reporter genes and endogenous metabolic targets. This approach is particularly valuable for metabolic engineering, where the goal is often to "dim" rather than "darken" a specific pathway to maintain cellular health while maximizing the yield of target bioproducts like EPA.
A major advantage of our platform is its multiplexing capability. By delivering multiple gRNAs, we can simultaneously repress several genes within a branched pathway, allowing for sophisticated control over the metabolic network. Because dCas9 does not cut the DNA, the genetic integrity of the strain is maintained. Furthermore, the use of inducible promoters to drive dCas9 expression allows for temporal control over gene repression, enabling researchers to trigger metabolic shifts (such as the transition from growth to lipid accumulation) at the optimal time in a photobioreactor cultivation cycle.
We provide multiple CRISPRi configurations to meet the diverse needs of functional genomics and industrial strain engineering.
Strong Algal Promoters
Utilizing robust native promoters (e.g., vcp, eIF4A) to drive continuous expression of dCas9 for long-term silencing of competitive metabolic pathways.
Stable Episomes
Leveraging replicative episomal vectors to maintain the CRISPRi machinery without the variable effects of random genomic integration.
Chemical Induction
Utilizing inducible systems (e.g., nitrate or heat-shock inducible promoters) to activate gene repression at specific time points, such as during the onset of stationary phase.
Reversible Design
The non-mutagenic nature of CRISPRi allows for the restoration of wild-type expression levels simply by turning off dCas9 expression or curing the episome.
gRNA Arrays
Expression of poly-cistronic gRNA arrays to downregulate multiple enzymes in a single biosynthetic route (e.g., starch biosynthesis) to force carbon flux into lipids.
Fine-Tuning
Varying the target sites of gRNAs relative to the TSS to achieve different levels of repression, from moderate to strong silencing.
Our systematic workflow ensures high-precision knockdown with quantitative verification of transcriptional repression.
1. TSS Mapping & gRNA Design
2. Vector Build & Optimization
3. Transformation & Selection
4. qPCR Validation
Utilizing Nannochloropsis genome databases to map the exact Transcription Start Site (TSS). Design of multiple gRNAs targeting the -50 to +150 bp window relative to the TSS for optimal steric hindrance.
Construction of dCas9 vectors with algal-specific regulatory elements. Full codon optimization of dCas9 and nuclear localization signals (NLS) to ensure high nuclear accumulation.
Quantitative Verification: Measurement of target gene mRNA levels via RT-qPCR to confirm the degree of repression. Physiological analysis: Monitoring of lipid accumulation (GC-MS) and growth kinetics. Delivery of verified strains.
Target Essential Genes
Enables the study of vital metabolic nodes that cannot be completely knocked out, providing insights into core algal survival mechanisms.
Non-Mutagenic Precision
Avoids the double-strand breaks and random indels of standard CRISPR, preserving the genomic integrity and stability of the production strain.
Tunable Suppression
Repression levels can be adjusted by gRNA positioning or promoter choice, allowing for the discovery of the metabolic "sweet spot" for bioproduction.
Multiplexing Support
Ideal for complex engineering where multiple genes must be downregulated simultaneously to optimize carbon and energy flux distribution.
1. How effective is CRISPRi compared to RNAi in Nannochloropsis?
CRISPRi targets DNA directly and is generally more stable and specific than RNAi, which relies on the variable efficiency of the cytoplasmic RNA-induced silencing complex (RISC).
2. Can I achieve a complete "knockout-like" effect with CRISPRi?
While CRISPRi is a knockdown tool, we can often achieve >90% repression of mRNA levels, which for many genes is sufficient to replicate a loss-of-function phenotype.
3. Is the repression permanent?
It is as stable as the expression of the dCas9 and gRNA. If delivered via an episomal vector, curing the vector will restore the wild-type phenotype, making the system reversible.
4. How do you select the best target site for repression?
We target the Transcription Start Site (TSS). Generally, targeting the non-template strand just downstream of the TSS provides the strongest steric hindrance to RNA polymerase.
5. Do you provide validation of mRNA levels?
Yes, every CRISPRi project includes RT-qPCR analysis to quantify the exact percentage of gene knockdown achieved in the monoclonal strains.
6. Can you target chloroplast genes with CRISPRi?
Yes, we offer specialized organelle-targeted repression services by utilizing dCas9 variants equipped with chloroplast transit peptides.
7. What is the benefit of inducible CRISPRi?
It allows for the growth of a healthy algal culture before triggering the metabolic shift needed for production, which is essential for genes that might otherwise slow growth.
8. What is the typical turnaround time for a CRISPRi project?
A standard project from design to delivery of verified monoclonal knockdown strains 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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