There are 94 individuals from each of two interspecific backcross: (C57BL/6J x M. spretus) x C57BL/6J and (C57BL/6J x SPRET/Ei) x SPRET/Ei. They were typed at 1372 and 4913 genetic markers, respectively, with 904 markers in common.
Rowe LB, Nadeau JH, Turner R, Frankel WN, Letts VA, Eppig JT, Ko MS, Thurston SJ, Birkenmeier EH.
Maps from two interspecific backcross DNA panels available as a community genetic mapping resource
Mamm Genome. 1994 May;5(5):253-74.