A Pedigree and Southern Blot Results in Humans Are Shown

A pedigree and Southern blot results in humans are shown in the following figure. Filled-in figures represent individuals expressing a dominant trait (hypothetical) for blue tongue. What can you say about the potential linkage relationship between the allele responsible for the trait? Shaded regions within the homologs represent sequences that hybridize to the probe used for the Southern analysis. Arrows indicate cleavage sites used for the Southern analysis.