Fig. 2.

Latrotoxins experienced substantial gene duplication and diversification in cob-web weaving spiders (Theridiidae). A Bayesian 50% majority rule consensus tree rooted at the midpoint showing relationships of black widow (Latrodectus) and common house spider (Parasteatoda tepidariorum) latrotoxins, along with Diplorickettsia massiliensis bacterial proteins (indicated by an orange polygon). Nodes with posterior probability = > 0.95 indicated by gray dots; pink boxes surround functionally characterized black widow venom latrotoxins, with adjacent images representing toxicity targets (mouse for vertebrate toxin α-latrotoxin; fly for insect toxins; isopod for crustacean toxin; images from Emily Damstra). Pt = Parasteatoda tepidariorum; Pt (genomic) scaffold 111 clade includes aug3.g7859_7858 (in yellow) on a separate scaffold, sequences labeled male expressed (black star) if expression in whole males was higher than in all other tissues (venom, silk, ovaries, whole females, and two developmental stages, in TPM). Pt sequences with venom-gland biased expression indicated by green ovals. Non P. tepidariorum sequences labeled by their GenBank accession numbers. Please see Additional file 9 for a high resolution version of this figure