Phylogeny of sensory neuron membrane proteins.

Both clades I and II show one to one orthology of the specific SNMP from different insect species. Different symbols depict SNMPs from the different species at the terminal nodes: Glossina austeni (red*), Glossina brevipalpis (purple*), Glossina fuscipes fuscipes (pink*), Glossina morsitans morsitans (dark blue*), Glossina pallidipes (light orange*), Drosophila melanogaster (black*), Anopheles gambiae (sky blue*) and Musca domestica (lime green*). The symbol * represents the name of the specific SNMP. Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship was inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Phylogenetic relationships of GRs identified in Glossina genes and their homologs in An. gambiae, D. melanogaster and M. domestica are shown in Fig 6. In all the tsetse species, there was expansion of Gr21a, associated with CO₂ detection in fruit fly and mosquitoes [64,65]. Similarly, expansion of CO2 receptors was noted in An. gambiae which has expanded Gr63a, a protein co-expressed with Gr21a and involved in CO₂ detection [65]. No homologs to sugar receptors in D. melanogaster [66] were identified in any of the five Glossina species (Fig 6). Similarly, D. melanogaster Gr43a, implicated in internal fructose sensing [67] was absent in all tsetse species.