title: Unique inbred strain MSM/Ms established from the Japanese wild mouse.
abstract: Most laboratory mice belong to a species of house mouse, Mus musculus. So far, at least three subspecies groups have been recognized; domesticus subspecies group (DOM) distributed in western Europe, musculus subspecies group (MUS) distributed in eastern Europe and northeast Asia, and castaneus subspecies group (CAS) found in southwest and southeast Asia including southern China. These subspecies are estimated to have branched off roughly one million years ago. Genetic comparison between subspecies' groups and common inbred strains (CIS) have revealed that the genetic background of CIS is derived mainly from DOM. This shows the importance of non-DOM wild mice as valuable genetic resources. We started to establish our unique strain, MSM/Ms, from MUS in Japan in 1978. In the beginning, we kept wild mice trapped in Mishima in large plastic buckets. In 1979, breeding by sister-brother mating started. The MSM/Ms inbred strain was established in 1986 and 21 years later it reached F(100). During breeding, no significant fluctuations in litter size and sex ratios have been observed. Extensive genetic analyses of chromosome C-banding pattern, biochemical markers and microsatellite DNA (MIT) markers of this strain have demonstrated the characteristics of MUS. A phylogenetic tree constructed from MIT markers has confirmed the MUS nature of MSM strain. Taken together with its genetic remoteness from CIS, MSM appears to maintain many valuable alleles for investigation of biological functions and diseases. Some of these alleles have avoided selection during breeding as either fancy mice or laboratory mice. The MSM-specific genetic traits discovered to date are discussed.
authors.affiliation: National Institute of Genetics, Mishima, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Moriwaki
authors.forename: Nobumoto
authors.initials: N
authors.lastname: Miyashita
authors.forename: Akihiko
authors.initials: A
authors.lastname: Mita
authors.forename: Hideo
authors.initials: H
authors.lastname: Gotoh
authors.forename: Kimiyuki
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Hideki
authors.initials: H
authors.lastname: Kato
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Mekada
authors.forename: Chikako
authors.initials: C
authors.lastname: Noro
authors.forename: Satoshi
authors.initials: S
authors.lastname: Oota
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshiki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Obata
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yonekawa
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiroishi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001947:Breeding / Q000379:methods*; D002871:Chromosome Banding; D003433:Crosses, Genetic; D005260:Female; D006799:Housing, Animal; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains / Q000097:blood / Q000502:physiology*; D018895:Microsatellite Repeats / Q000235:genetics; D010802:Phylogeny; D013045:Species Specificity
chemical_list: D015415:Biomarkers