Figure 4.

Substrains with mild, or no, change in iris appearance. Coat color (left column), broadbeam illumination of iris (middle column), and transilluminating view of iris (right column). (A–C) chocolate mice have a modest alteration in coat color and mild transillumination defects that tended to increase peripherally. These transillumination defects did not worsen with increasing age among the mice examined. In contrast, other strains with similarly modest alterations in coat color maintain completely normal irides; including, (D–F) leaden mice have slightly diluted coats and normal appearing irides (the leaden substrain utilized here also carried the fuzzy allele, so it can additionally be concluded that fuzzy does not influence the iris), and (G–I) gunmetal mice have slightly diluted coats and normal appearing irides. Two substrains with mutations that do not influence adult coat color at all, but do influence melanosomes in other tissues were also examined; including, (J–L) As adults, pale ear mice have normal coat color but irides that appear slightly darker (note that the ears and tail of pale ear mice are also light colored), and (M–O) shaker 1 mice have normally colored coats and normal appearing irides. All mice were homozygous for the indicated mutations and were maintained on a C57BL/6J genetic background.