Study design.

<p>(A) F0 and F1 mice were generated via the depicted crosses. The schematic diagram illustrates example expression patterns for a <i>cis</i> effect, <i>trans</i> effect, and parent-of-origin effect. For a <i>cis</i> effect, in the F1 hybrids, the Cast/EiJ allelic expression relative to the C57BL/6J allelic expression recapitulates the ratio of gene expression levels in the F0 homozygotes. For a <i>trans</i> effect, the F1 hybrids express the Cast/EiJ and C57BL/6J alleles equally. For a parent-of-origin effect, there is preferential expression of the maternal allele (as depicted) or the paternal allele, as seen by comparison of the reciprocal F1 hybrids. (B) An overview of the workflow is shown.