knockin
The insertion of a specific exogenous DNA sequence into a defined genomic locus, typically via HDR-mediated repair of a CRISPR-induced break. Written as one word.
Full Definition
A knockin (KI) involves the targeted insertion of a foreign or modified sequence—such as a reporter gene, tag, or therapeutic transgene—into a specific genomic site using CRISPR-Cas9 coupled with a donor template for HDR. Unlike a knockout, which disrupts gene function, a knockin can add or replace genetic information. Editors should write it as one word ('knockin'), consistent with 'knockout' and 'knockdown'. Hyphenated forms ('knock-in') and spaced verb forms ('knock in') are also encountered; the verb uses the two-word form.
Usage
Usage note: One word as noun/modifier: 'knockin'. Two words as verb: 'to knock in'. Some journals prefer 'knock-in'; confirm house style. Contrast with 'knockout' (disruption) and 'knockdown' (expression reduction).
In Context
- "A GFP knockin at the endogenous ACTB locus was used to track beta-actin localisation in live cells." — Methods section
- "The paper used 'knock-in', 'knockin', and 'KI' inconsistently; all were standardised to 'knockin'." — Copy-editing note