TABLE 2.
Tsetse fly symbionts, main features of the association, and symbiont role in the modulation of host biology.
| Microorganism | Features of the acquisition and association with the flies | Present in all flies? | Role in host biology | Relevant bibliography about its role in the host |
| Wiggleworthia (Fam. Enterobacteriaceae) | • Maternally transmitted bacterial endosymbiont • Localized in the cytosol of bacteriocytes adjacent to anterior midgut and also contained in milk gland secretions • Obligate mutualist |
Yes | • Nutritional function (these symbionts are equipped with the biosynthetic pathways to produce vitamins essential for the host requirements) • Immunological function |
Rio et al. (2019) Wang J. et al. (2013) Weiss et al. (2011, 2013) |
| Sodalis (Fam. Enterobacteriaceae) | • Maternally transmitted bacterial symbiont • Located both intra- and extra-cellularly different tissues including midgut, fat body, milk gland and salivary glands • Commensal symbiont |
No | • Unknown | Toh et al. (2006) Wang J. et al. (2013) Weiss et al. (2012, 2013) |
| Wolbachia (Fam. Rickettsiaceae) | • Bacterial endosymbiont transovarically transmitted via germ line cells • Exclusively localized in germ line tissues • Parasitic symbiont |
No | • Manipulation of host reproduction by different mechanisms (e.g., cytoplasmic incompatibility) | Wang J. et al. (2013) Weiss et al. (2012, 2013) Doudoumis et al. (2013) |
| SGHV1 (Fam. Hytrosaviridae) | • Horizontally transmitted during feeding • Located in salivary glands |
No | • Replication causes the swelling of salivary glands (hypertrophy) • In the presence of the virus, tsetse flies may be symptomatic or asymptomatic |
Wang J. et al. (2013) Kariithi et al. (2018) |
1Acronym for salivary gland hypertrophy virus.