Fig. 2

Neighbor joining tree for N-terminal MiSp encoding sequences demonstrates variation within and among species. Variants are shown for L. hesperus (Lh) and TOPO clones from L. tredecimguttatus (Lt), L. geometricus (Lg), and S. grossa (Sg). Units are number of substitutions. Latrodectus clones are arbitrarily numbered, except that Lt M1-7 and Lg M1-5 resulted from amplification with primers designed from L. hesperus, while higher clone numbers resulted from amplification with species-specific primers. S. grossa TOPO clones resulted from two separate PCR reactions, which are indicated here as “A#” and “B#”. Completely sequenced clones are indicated by bolded names. See Table 1 and Additional file 1: Table S4 for accession numbers. Boxes indicate distinct clusters identified in neighbor joining trees based on N-terminal sequences including adjacent repetitive sequences and in C-terminal and adjacent repetitive region encoding sequences (Additional file 1: Figures S2 and S3)