Gene expression in reproductive organs of tsetse females \u2013 initial data in an approach to reduce fecundity

Emanuel Procházka,George Tsiamis,Ivana Daubnerová,Peter Klepsatel,Peter Takáč,Veronika Michalková,Dušan Žitňan,Ladislav Roller

doi:10.1186/s12866-018-1294-5

Emanuel Procházka, George Tsiamis + Show 6 more

Open Access

https://doi.org/10.1186/s12866-018-1294-5

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Abstract

BackgroundTsetse flies are vectors of African trypanosomes, and their vectorial capacity results in a major public health emergency and vast economic losses in sub-Saharan Africa. Given the limited ability of trypanosome prevention and eradication, tsetse vectors remain major targets of control efforts. Larvae of all three instars are developed in mothers’ uteri, nourished through milk, and ‘larviposited’ shortly before pupation. The past few years have witnessed the emergence of approaches based on knockdown of genes involved in milk production, resulting in a significant reduction of fecundity.ResultsIn order to identify further genes applicable in the control of tsetse flies, we determined the expression of protein-coding genes in ovaries and uteri from both virgin and heavily pregnant Glossina morsitans morsitans females. Comparison of expression profiles allowed us to identify candidate genes with increased expression in pregnant individuals. Lists with the highest increases include genes involved in oocyte and embryonic development, or nourishment. Maximum ovarian fold change does not exceed 700, while the highest uterine fold change reaches to more than 4000. Relatively high fold changes of two neuropeptide receptors (for corazonin and myosuppressin) propose the corresponding genes alternative targets.ConclusionsGiven the higher fold changes in the uterus, targeting gene expression in this tissue may result in a more evident reduction of fecundity. However, ovaries should not be neglected, as manifested by several genes with top fold changes involved in early developmental stages. Apart from focusing on the highest fold changes, neuropeptide receptors with moderate increases in expression should be also verified as targets, given their roles in mediating the tissue control. However, this data needs to be considered initial, and the potential of these genes in affecting female fecundity needs to be verified experimentally.

Highlights

Tsetse flies are vectors of African trypanosomes, and their vectorial capacity results in a major public health emergency and vast economic losses in sub-Saharan Africa
We determined the expression of protein-coding genes in ovaries and uteri from both virgin and heavily pregnant G. m. morsitans flies
Resulting reads that uniquely mapped to the genome were further trimmed to remove reads that did not map to annotated genes, or were mapped to them ambiguously

Summary

Introduction

Tsetse flies are vectors of African trypanosomes, and their vectorial capacity results in a major public health emergency and vast economic losses in sub-Saharan Africa. Given the limited ability of trypanosome prevention and eradication, tsetse vectors remain major targets of control efforts. Larvae of all three instars are developed in mothers’ uteri, nourished through milk, and ‘larviposited’ shortly before pupation. Human (HAT) and animal (AAT) African trypanosomiases are serious diseases caused by unicellular protozoan parasites belonging to the genus Trypanosoma. Some livestock breeds and wild animals are trypanotolerant, but in humans, untreated HAT eventually leads to death [1, 2]. Trypanosomes use tsetse flies from Glossina genus (Diptera: Glossinidae) to accomplish their transmission. Tsetse flies are obligatory blood feeders, and they acquire the pathogens while feeding on infected animals (livestock, wildlife) or humans. As only a single offspring is produced during each gonotrophic cycle, each female gives birth to 8–10 progeny during her life (reviewed in [12])

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