The Japanese wild‐derived inbred mouse strain, msm/ms in cancer research

Abstract

MSM/Ms is a unique inbred mouse strain derived from the Japanese wild mouse, Mus musculus molossinus, which has been approximately 1 million years genetically distant from standard inbred mouse strains mainly derived from M. m. domesticus. Due to its genetic divergence, MSM/Ms has been broadly used in linkage studies. A bacterial artificial chromosome (BAC) library was constructed for the MSM/Ms genome, and sequence analysis of the MSM/Ms genome showed approximately 1% of nucleotides differed from those in the commonly used inbred mouse strain, C57BL/6J. Therefore, MSM/Ms mice are thought to be useful for functional genome studies. MSM/Ms mice show unique characteristics of phenotypes, including its smaller body size, resistance to high‐fat‐diet‐induced diabetes, high locomotive activity, and resistance to age‐onset hearing loss, inflammation, and tumorigenesis, which are distinct from those of common inbred mouse strains. Furthermore, ES (Embryonic Stem) cell lines established from MSM/Ms allow the MSM/Ms genome to be genetically manipulated. Therefore, genomic and phenotypic analyses of MSM/Ms reveal novel insights into gene functions that were previously not obtained from research on common laboratory strains. Tumorigenesis‐related MSM/Ms‐specific genetic traits have been in-tensively investigated in Japan. Furthermore, radiation‐induced thymic lymphomas and chemi-cally‐induced skin tumors have been extensively examined using MSM/Ms.