Comparative linkage mapping of the upper end of chromosome 6 in Iron Mountain M. guttatus hybrids. In a freely recombining cross (left: IM179 × IM767 F₂; n = 86), this region spans ∼40 cM, whereas recombination is highly suppressed in all three F₂ mapping populations segregating for the inv6 haplotype (right; c3 map shown). Marker names are to the right, and centimorgans are to the left of bar. Shared markers are highlighted in italic red type.