Maternal inheritance of mitochondrial DNA in mice after inter-species hybridization and 138 generations of backcrossing.

This study represents a continuation of a backcrossing experiment initiated in 1982 and reported on earlier after seven generations of backcrossing (Gyllensten et al. 1985) and again after 26 generations (Gyllensten et al. 1991). For the better part of 50 years, it has been demonstrated that mitochondrial DNA (mtDNA) has a largely, if not exclusively maternal mode of inheritance among the multicellular organisms studied to date (Dawid and Blackler 1972; Hutchison et al. 1974; Francisco et al. 1979; Giles et al. 1980; Reilly and Thomas 1980 as cited in Gyllensten et al. 1985). Few studies of invertebrates and no studies of vertebrates have examined maternal inheritance of mtDNA over the course of 139 generations as is the case here (Degrugillier and Newman 1993). Our initial results identify 100% conformity of mtDNA with M. spretus suggesting that any potential paternal contribution of mtDNA to this mouse lineage will require more detailed analysis to detect it.