Characterisation of tissue-specific promoter regions within Aedes aegypti

Vector-borne illnesses make up 17% of global infections, with Aedes aegypti playing a significant role in their spread. Current genetic population control strategies function inter-generationally — suppressing future mosquito generations once released —allowing for extended periods of disease spread before population suppression occurs. A new methodology, toxic male technique (TMT), utilises tissue-specific expression of ion-channel targeting venom peptides within insect seminal fluid — transferred to females via mating — inducing female lethality. A proof of concept for TMT has been demonstrated in Drosophila melanogaster and modelling its implementation in Ae. aegypti indicates more rapid population suppression and bloodmeal reduction compared to other biocontrol methods.

Engineering TMT within Ae. aegypti requires characterisation of promoters specific to the male accessory glands (MAGs), organs responsible for production of seminal fluid proteins (SFPs), transferred from males to females via mating. We characterised promoters of three, possibly four SFP encoding genes, AAEL024630, AAEL023599, AAEL013449, and AAEL006418, demonstrating a range of expression levels and tissue-specificity within the MAGs of Ae. aegypti. We accomplished this through engineering transgenic mosquito lines to express a reporter gene under control of a promoter candidate, using fluorescence microscopy and western immunoblotting to screen for presence and tissue-specificity. Successful characterisation brings intra-generational biocontrol in mosquitoes one step closer.