Origin: TAAM Orleans (France) - 2012 

Strain name: 129S2/SvPasOrlRj 

Type: Inbred mouse 

Couleur et génotype associé : Agouti mouse with white belly, Aw/Aw - MHC: Haplotype H2b 

Breeding: Difficult to rear 

This strain was created at Columbia University in 1928 by Dunn from a crossbreed of coloured stock and chinchilla stock (Tyrc-ch) provided by Castle. In 1948, the strain was brought to the Jackson Laboratory (129/ReJ). In 1953 Stevens took it on and began by studying the genetic basis of testicular teratomas in mice from the 129 parental strain. In order to determine the cellular origin of the teratomas he worked on different crossbreeds of 129 stock. His research work resulted in the creation of the substrains “Steel” and “Ter”. The 129S2/SvPasOrl strain is a substrain of Steel, resulting from crossbreeding with the C3H-MgfSl-J, followed by 12-14 generations of further crossbreeding with 129/Sv stock. This resulted in mice with agouti pigmentation and white bellies. The steel-J mutation increases the incidence of tertomas by 10%. This strain was brought to Dr J.L. Guenet at the Institut Pasteur in 1970. The 129 family is made up of 3 sub-families with a significant genetic variation. In order to differentiate these sub-families, the new nomenclature in 1999, completed their code by adding a letter for each strain. As such, the parental substrain is now 129P, the Steel substrain, 129S and the “teratoma” (ter) substrain, 129T.