Backcross design.

<p>Schematic illustration of the experimental set-up used to breed reciprocal crosses that enabled identification of parent-or-origin effects. EAE-susceptible DA and -resistant PVG strains were backcrossed to heterozygous F1 (DAxPVG) hybrids to generate two experimental populations, DABC and PVGBC, respectively. Within each population, two reciprocal crosses were established by breeding F1 hybrids to DA mothers (DAxF1) or fathers (F1xDA) in DABC and PVG mothers (PVGxF1) or fathers (F1xPVG) in PVGBC. Transmission of autosomal chromosomes (one pair of autosomes is represented by vertical lines) and mitochondria (represented by circle) is shown in the upper panel. Transmission of sex chromosomes is shown in the lower panel. DA and PVG alleles are indicated with D and P, respectively, and the maternally and paternally inherited alleles are indicted with m and p, respectively.