Figure 1: Alignment of the four groups (GP1, GP2, GP3, and GP4) of C. s. scutulatus metalloproteinase genomic DNA sequences. Assignment of exon and intron (underlined) regions was made by comparing metalloproteinase cDNA sequences from C. atrox [7] and A. contortrix [12, 30] with metalloproteinase genomic DNA sequences from C. s. scutulatus obtained in this study. Differences among the DNA sequences are denoted by an asterisk (*).