Box and whisker plots for Dayhoff PAM 250 scores determined by ClustalX alignment of full-length mouse PSGs with full-length human PSGs. At each position in the alignment, the Dayhoff PAM250 log score was determined for pairwise comparisons of each sequence in the set of mouse PSGs against all sequences in the set of human PSGs. Mouse Psg24, Psg30 and Psg31 along with human PSG2 and PSG5 were omitted from the analysis due to expansions or contractions of total domain complement which would complicate generation of the initial clustalX alignment. The scores were split into five groups, according to domain structure, and used to generate a box and whisker plot. Domain name abbreviations shown on the X-axis correspond to the following domain comparisons: L/L, human L versus mouse L domain; N/N1, human N versus mouse N1 domain; A1/N2, human A1 versus mouse N2 domain; A2/N3, human N2 versus mouse N3 domain; B2/A, human B2 versus mouse A domain. Significant differences of p < 0.0001 were observed for the N/N1 domain comparison when tested against the A1/N2 and A2/N3 data, and p < 0.0005 when tested against the B2/A data.