The Glossina Genome Cluster: Comparative Genomic Analysis of the Vectors of African Trypanosomes

Abstract

Background: Tsetse flies (Glossina sp.) are the sole vectors of human and animal trypanosomiasis throughout sub-Saharan Africa. Tsetse are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young (obligate viviparity), a vertebrate blood specific diet by both sexes and obligate bacterial symbiosis. This work describes comparative analysis of six Glossina genomes representing three sub-genera: Morsitans (G. morsitans morsitans (G.m. morsitans), G. pallidipes, G. austeni), Palpalis (G. palpalis, G. fuscipes) and Fusca (G. brevipalpis) which represent different habitats, host preferences and vectorial capacity. Results: Genomic analyses validate established evolutionary relationships and sub-genera. Syntenic analysis of Glossina relative to Drosophila melanogaster shows reduced structural conservation across the sex-linked X chromosome. Sex linked scaffolds show increased rates of female specific gene expression and lower evolutionary rates relative to autosome associated genes. Tsetse specific genes are enriched in protease, odorant binding and helicase activities. Lactation associated genes are conserved across all Glossina species while male seminal proteins are rapidly evolving. Olfactory and gustatory genes are reduced across the genus relative to other characterized insects. Vision associated Rhodopsin genes show conservation of motion detection/tracking functions and significant variance in the Rhodopsin detecting colors in the blue wavelength ranges. Conclusions: Expanded genomic discoveries reveal the genetics underlying Glossina biology and provide a rich body of knowledge for basic science and disease control. They also provide insight into the evolutionary biology underlying novel adaptations and are relevant to applied aspects of vector control such as trap design and discovery of novel pest and disease control strategies.

Sequence-Based Prediction of Olfactory Receptor Responses

“…With lowering costs of sequencing, the sequences of ORs are rapidly becoming available for various organisms, including multiple species of fruit flies (Drosophila 12 Genomes Consortium 2007;Gardiner et al 2008;Ramasamy et al 2016), mosquitoes (Leal et al 2013;Neafsey and Waterhouse 2015;Lombardo et al 2017), bees (Elsik et al 2016;Karpe et al 2017), and tsetse flies (Attardo et al 2019). However, experimental data about odor responses are available for relatively few ORs.…”

Diaci v3.0: Chromosome-level assembly,de novotranscriptome and manual annotation ofDiaphorina citri,insect vector of Huanglongbing

“…Since the DNA binding specificity of 'oc' has already been experimentally determined, and the cutoff for the Homeodomain family of TFs is 70 %, we can infer that Dcitr04g16960.1.1 will have the same binding specificity as 'oc' (Supplementary File 1). WGCNA [138] was conducted according to methods previously adapted to examine gene expression patterns in relation to TF binding predictions [44,139,140]. Enriched TF binding motifs were identified in the 500 and 2000 bp regions upstream of the putative transcription start site using the HOMER tool as in previous studies examining the dynamics between TFs and expression patterns in insects [45].…”

Matrotrophic viviparity constrains microbiome acquisition during gestation in a live‐bearing cockroach, Diploptera punctata

“…This is exemplified in tsetse flies and other members of Hippoboscoidea, where mothers utilize nutritive secretions as a mechanism to transfer required symbiotic bacteria to their intrauterine developing larvae (Douglas, ; Morse et al, ; Snyder & Rio, ; Wang et al, ; Weiss et al, ). For tsetse flies, symbiotic bacteria, specifically Wigglesworthia , provide key B vitamins that are low in their food source (blood) or within milk transferred to the developing intrauterine larva and are critical to immune function (Akman et al, ; Attardo et al, ; Benoit et al, ; Rio et al, ). Here, we examine shifts in the microbiome of the live‐bearing cockroach, Diploptera punctata , during pregnancy and development.…”