Dot plot of the Sp185/333 gene cluster shows gene and segment duplication. The Sp185/333 gene cluster of 34 kB is plotted against itself. The colored pentagrams indicate the positions of each of the Sp185/333 genes. Matching sequence appears as diagonal lines of dots indicating similar sequences are present in the same or opposite orientation. The genes plus a short region upstream of each of the genes are conserved. The dotted box illustrates the region of segmental duplications as indicated by the length and number of parallel, diagonal lines. The total length of the segmental duplications is ~13.7 kb and consists of three segments that each include a D1 gene (yellow, green and blue).