The predicted secondary structure of Domains IV and V of the mt 16S rRNA gene for haplotype Is-1 of I. scapularis . Open circles indicate putative nucleotides within other domains of the gene . Closed circles indicate deletions in the sequence of haplotype Is-1 compared to the DNA sequences some other haplotypes of I. scapularis (see Table 2). Solid arrows indicate purine and pyrimidine transitional changes, while open arrows indicate transversional mutations, multiple changes, or indels in the DNA sequences of the other 16S haplotypes detected in this study relative to the DNA sequence of haplotype Is-1. The box indicates the hypervariable region as defined by Smith and Bond .