Fig. 4

Phylogenetic analysis of P. ulmi putative GSTs. A set of P. ulmi, P. citri, T. urticae, Ixodes scapularis, Sarcoptes scabiei, Dermatophagoides pteronyssinus GST protein sequences were aligned using MUSCLE and subjected to a maximum-likelihood analysis using Treefinder. The tree was midpoint rooted and numbers at the branch point of each node represent the bootstrap value resulting from 1000 pseudoreplicates (LR-ELW). Tetranychid GSTs clustered within classes: δ, delta class, ζ, zeta class, ω, omega class and μ, mu class. Colour and shape codes are as follows: P. ulmi, green triangle, P. citri, yellow triangle, T. urticae, red square, purple dot, I. scapularis, blue rhombus, S. scabiei and pink rhombus, Dermatophagoides pteronyssinus. GST protein sequences and accession numbers can be found in Additional file 10