Genetically modified mice are mainstream tools for medical research. The background
strains used to generate transgenic and knockout mice have been studied extensively. In
many instances, the background strain used to create the genetic modification is
inappropriate for phenotypic analysis of the mutation. In such cases it is useful to develop a
congenic strain of the transgenic mouse line in which the mutation is introduced into a more
suitable genetic background. In this review, the approaches to generate congenic strains of …