Distribution of coding mutations found in Tlr4 of 35 Mus musculus strains. All coding mutations reside within exon 3. Most occupy portions of the gene corresponding to the extracellular domain. The transmembrane domain is denoted by a blue-green bar. Mutations occurring at sites that are relatively conserved among species (only one or two forms among six species) are shown in blue; those occurring at sites that are less conserved (three to five forms among six species) are shown in black.