A controlled change to a genetic system used to test a functional hypothesis. Its interpretation depends on specificity, timing and controls for secondary effects.
Modification or design of a protein to change its properties. Rational design, library construction and directed evolution offer complementary ways to test sequence–function relationships.
Design of a protein catalyst using computational models of structure and chemistry. Experimental screening and directed evolution test and improve the proposed catalytic arrangement.
An unintended effect outside the nominated molecular target. Independent reagents, verified target changes and functional rescue help distinguish target-specific consequences from these effects.
A genetic intervention eliminating functional output of a gene. A targeted insertion or deletion is not by itself proof of knockout: remaining alleles, reading frame and functional protein must be checked.
Targeted alteration of a genome using a guide-directed CRISPR system. Independent targeting reagents, verification of the resulting alleles and functional rescue help distinguish an intended effect from unrelated damage.
Sequence-targeted fluorescent localization of chromosomal sites using a nuclease-inactive targeting system. Colocalization with a protein is evidence of shared location, not necessarily direct molecular contact.
A guide-directed bacterial DNA-recognition and cleavage system. Catalytically inactive dCas9 retains targeting functions used in imaging and transcriptional regulation.
Guide-directed recruitment of transcriptional activation machinery to increase endogenous gene expression. Unlike a promoter-replacing knock-in, it need not change the target sequence.
Guide-directed reduction of gene expression using nuclease-inactive DNA targeting. In mammalian cells, dCas9 fused to a repressor can reduce transcription without requiring a DNA break.
A guide-directed DNA nuclease. Target recognition depends on a guide RNA and an appropriate protospacer adjacent motif; cleavage is followed by cellular repair, so cleavage alone does not specify the final allele.
A catalytically inactive form of Cas9 retaining guide-directed DNA binding. Recruitment of regulatory domains makes it a platform for CRISPR interference and CRISPR activation.
A short target-adjacent DNA motif recognized by a CRISPR-associated nuclease. The motif requirement depends on the nuclease; the commonly used Cas9 from Streptococcus pyogenes recognizes NGG.
An RNA molecule whose complementary sequence directs a targeting complex to a nucleic-acid sequence. In CRISPR genome editing, guide complementarity and a compatible protospacer adjacent motif jointly constrain targeting.
Optogenetics uses genetically introduced light-responsive components to perturb or monitor biological processes with spatial and temporal control. Light-only, construct-only and expression-matched controls help distinguish the intended response from phototoxicity.
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Genetic engineering, also known as genetic modification or gene editing, is a biotechnological process that involves the direct manipulation of an organism's genes. This can include altering, removing, or adding specific segments of DNA in an organism's genome to achieve desired traits or characteristics. Genetic engineering is employed across various fields, including agriculture, medicine, and research.