Phylogenetic analysis of aphid GLUT-like sugar transporters. Neighbor-joining phylogenetic tree of GLUT-like transporters from A. pisum (red), N. lugens (orange), T. castaneum (light blue), A. mellifera (green), D. melanogaster (blue), P. humanus (purple) and H. sapiens (brown). Putative sugar transporters identified by the presence of a TIGRFAMs sugar porter motif (TIGR00879) were included in the analysis. The reliability of the tree was determined using 1000 bootstrap replications. Bootstrap values >90% (black circle) and >70% (grey circle) are indicated at each node. The phylogenetically well-supported insect/mammalian GLUT clade (red outline) contains aphid glucose/fructose transporter ApST4, ACYPI001980 (red box) and human GLUT class I and II transporters (shaded grey). Red arrows indicate aphid gut expressed transporters: ApST1, ACYPI001780; ApST3, ACYPI004204 ; and ApST9, ACYPI001077. Orange arrows indicate functionally characterized N. lugens sugar transporter transporters (NlST): NlST1, AB549994 [14, 23] and NlST6, AB54999 . All sequences are available from NCBI using the accession numbers in the phylogenetic tree. Scale bar represents 0.1 substitutions per amino acid site.