Additional file 6: Figure S3. of Transcription analysis of neonicotinoid resistance in Mediterranean (MED) populations of B. tabaci reveal novel cytochrome P450s, but no nAChR mutations associated with the phenotype

Amino acid alignment of B. tabaci nAChR subunits. Protein sequence alignment of B. tabaci nAChR subunits with D_a1 subunit of D. melanogaster. The numbers on the right indicate the amino acid position. The N-terminal signal peptides, the N-terminal region encompassing the six conserved domains loops (A-F) and the transmebrane domains were predicted by sequence similarity and using the SignalP4.1 [123] and TMHMM softwares [124]. Predicted N-terminal signal peptide leader sequences are shaded in yellow while the six ligand-binding loops (D, A, E, B, F, C) and the four transmembrane domains (TM1-4) are shaded in grey and green respectively. Alignment of predicted protein sequences (aa sequence average length for all subunits except α6 = 457; for α6 = 115) shows that all subunits possess two Cys separated by 13 residues, typical of LGIC subunits, as well as six conserved Loops (Loops A-F) located at the N-terminal domain. All subunits carry a predicted signal peptide at the N-terminus and four transmembrane motifs (TM1–TM4) at the C-terminal domain, which are involved in forming an ion channel. Loops between TM3 and TM4 were highly variable. The YxCC and GEK motifs are shaded in black. Amino acid mutations involved in imidacloprid resistance (R81T (M. persicae numbering), Y151S (N. lugens numbering)) are marked by inverted red triangle while non-synonymous SPNs found in B. tabaci strains are shaded in blue and marked with asterisk. (PDF 39 kb