Figure 5.—

Postulated evolution of the segment of repeats in the involucrin gene of the mouse. The common precursor is likely to have contained 20 repeats of the constant region. A plus sign indicates repeat additions and a minus sign indicates repeat deletions, virtually all of which occurred in the variable region. Numbers in boldface type along the branches of the tree indicate the number of repeats added or deleted to each lineage. Numbers within parentheses show the number of repeats in each allele. Arrows show admixture of the DIK-L ancestor, which is of M. m. musculus origin, into M. m. domesticus and of PWK, which is of M. m. domesticus origin, into M. m. musculus. The points of closer similarity among the three major lineages are summarized. The points of closer similarity among minor lineages can be found in the results.