Crispr Interference
Crispr Interference - Related Videos
07:27
CRISPR Interference-Based Gene Silencing: A Technique for Targeted Repression of Gene Function in Pathogenic Leptospira
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2025
This video demonstrates a CRISPR interference-based gene silencing in pathogenic Leptospira. Targeted repression of gene expression using a CRISPR/Cas system that blocks mRNA formation helps identify candidate genes for pathological and pharmacological studies.
02:18
Interference and Diffraction
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2020
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other. Alternatively, if the two waves coincide and interact in a way such that the trough of one wave coincides with the peak of the other (in an out of phase manner), the resultant wave will...
08:41
Interference and Diffraction
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2023
Source: Yong P. Chen, PhD, Department of Physics & Astronomy, College of Science, Purdue University, West Lafayette, IN Interference and diffraction are characteristic phenomena of waves, ranging from water waves to electromagnetic waves such as light. Interference refers to the phenomenon of when two waves of the same kind overlap to give an alternating spatial variation of large and small wave amplitude. Diffraction refers to the phenomenon of when a wave passes through an aperture or...
02:53
CRISPR and crRNAs
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2020
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea. The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
14:49
Application of CRISPR Interference (CRISPRi) for Gene Silencing in Pathogenic Species of Leptospira
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Cited by 9 •
2021
Here, the application of CRISPR interference (CRISPRi) for specific gene silencing in Leptospira species is described. Leptospira cells are transformed by conjugation with plasmids expressing dCas9 (catalytically "dead" Cas9) and a single-guide RNA (sgRNA), responsible for base pairing to the desired genomic target. Methods to validate gene silencing are presented.
FAQs
The guide RNA directs a catalytically inactive Cas protein to a selected DNA region. Once positioned, the bound complex can obstruct RNA polymerase, preventing effective transcription, or recruit regulatory factors that repress transcription. These mechanisms reduce gene expression while preserving the underlying DNA sequence, allowing researchers to examine gene function without making a permanent sequence change.
Catalytic inactivity separates DNA targeting from DNA modification. The Cas protein still provides a programmable platform for guide RNA-directed binding, but it does not create the sequence changes associated with active genome editing. This distinction lets investigators reduce expression and study regulatory effects while retaining the original genetic sequence for comparison or later analysis.
The guide RNA determines which DNA region the Cas protein-bound complex will recognize. Changing the guide sequence therefore provides a way to redirect repression toward a different gene or regulatory location. This programmability supports targeted investigations of individual genes and enables broader experiments that examine how selected genes contribute to regulatory networks.
CRISPRi changes gene expression rather than permanently changing the DNA sequence, and its repression can be reversible and tunable. Permanent editing approaches are useful when a lasting sequence alteration is desired, whereas CRISPRi supports controlled perturbations that can be adjusted or removed. This makes it valuable for distinguishing immediate regulatory effects from consequences of permanent genetic change.
A typical application begins by selecting the gene or DNA region whose expression will be examined, then using a guide RNA to direct a catalytically inactive Cas protein to that site. The resulting complex represses transcription through physical obstruction or regulatory-factor recruitment. Researchers can then interpret the reduced expression in relation to the gene’s function or pathway role.
CRISPRi is useful when researchers need targeted reduction of many genes or want to examine gene function without permanently editing each locus. Its programmable targeting supports loss-of-function screens, while reversible and tunable repression allows perturbations to be adjusted. These properties help investigators analyze gene regulatory networks and compare the effects of reducing different genes.
By selectively reducing expression of chosen genes, CRISPRi enables researchers to examine how those genes influence broader regulatory networks. The same approach can be used to control metabolic or other cellular pathways, linking expression changes with pathway behavior. In genetics, these experiments help connect individual gene activity to coordinated cellular functions and regulatory relationships.