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Updated: Jun 30, 2026

Zygote Microinjection for Creating Gene Cassette Knock-in and Flox Alleles in Mice
Published on: June 24, 2022
Cautionary insights on knockout mouse studies: the gene or not the gene?
Amy F Eisener-Dorman1, David A Lawrence, Valerie J Bolivar
1Wadsworth Center, 120 New Scotland Avenue, David Axelrod Institute, Albany, NY 12208, USA.
Abstract:
Gene modification technologies play a vital role in the study of biological systems and pathways. Although there is widespread and beneficial use of genetic mouse models, potential shortcomings of gene targeting technology exist, and are not always taken into consideration. Oversights associated with the technology can lead to misinterpretation of results; for example, ablation of a gene of interest can appear to cause an observed phenotype when, in fact, residual embryonic stem cell-derived genetic material in the genetic background or in the area immediately surrounding the ablated gene is actually responsible. The purpose of this review is to remind researchers, regardless of scientific discipline, that the background genetics of a knockout strain can have a profound influence on any observed phenotype. It is important that this issue be appropriately addressed during data collection and interpretation.
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