Multiplexing: An efficient way of genetic monitoring of laboratory mice using microsatellite markers

Inbred strains of laboratory mice have been widely used in biomedical research. An inbred strain is the one which has been maintained by sibling mating for twenty or more consecutive generations. Except for the sex difference, an inbred strain is homozygous at all loci. Most of the traits are consistent, do not vary in offspring and respond to experimental procedures uniformly. This enables researchers to produce reliable data for therapeutic purposes, hence inbred strain must be genetically pure over the generation.

A total of 20 mice samples from 10 inbred strains i.e., A/J, BALB/c, C3H/J, CD1, C57BL/6, DBA/2, FVB/NJ, ICRC, Swiss Webster and Swiss/Ba were screened for their genetic purity with the help microsatellite markers. Tail DNA was isolated using Proteinase/K-Phenol-chloroform extraction method and quantified by Nanodrop. DNA obtained was used for microsatellite marker analysis by standardizing multiplex-PCR. Seven multiplex (duplex) panels were successfully established by optimizing various reaction conditions to analyse any deviation in the genetic profile.

Upon comparing genetic profiles obtained in multiplex PCR with the information available on Mouse Genome Informatics database, it was concluded that most of the inbred mice are genetically consistent as they showed zero divergence in observed base pair size mainly due to stringent breeding protocol and optimum living conditions. The work done also signifies a cost-effective, time saving, high throughput and robust method of genetic monitoring of laboratory mice strains.