Genetic quality: a complex issue for experimental study reproducibility

Abstract

Laboratory animal research involving mice, requires consideration of many factors to be controlled. Genetic quality is one factor that is often overlooked but is essential for the generation of reproducible experimental results. Whether experimental research involves inbred mice, spontaneous mutant, or genetically modified strains, exercising genetic quality through careful breeding, good recordkeeping, and prudent quality control steps such as validation of the presence of mutations and verification of the genetic background, will help ensure that experimental results are accurate and that reference controls are representative for the particular experiment. In this review paper, we will discuss various techniques used for the generation of genetically altered mice, and the different aspects to be considered regarding genetic quality, including inbred strains and substrains used, quality check controls during and after genetic manipulation and breeding. We also provide examples for when to use the different techniques and considerations on genetic quality checks. Further, we emphasize on the importance of establishing an in-house genetic quality program.

Keywords: Genetic modification; Genetic monitoring; Genetic quality; Reproducibility.

Fig. 1

Schematic image of agarose gel of Multiplex PCR test result to detect marker genes widely used in genetically altered mice. The Tfrc gene as internal control was commonly detected in all strains A-D

Fig. 2

Genetic quality of mouse strains in Japan

Fig. 3

PCR tests for genetically altered mouse strains

Fig. 4

The first triple transgenic line of Tg1 x Tg2 x Tg3-TETX was generated to demonstrate that the action of tetanus toxin (TeTX) blocks neurotransmission in specific neurons in the hippocampus when Dox is not administered. Administration of Dox can reversibly release this blockade of neurotransmission. The second crossbred of Tg1 x Tg2 x Tg3-GFP was to visualize neurons with GFP in the dentate gyrus (DG) of the hippocampus and the pyramidal neurons of CA3, and the expression of GFP disappeared by administration of Dox