High throughput screening of eco-friendly novel repellents for tick control

As vectors of different bacteria and viruses, ticks transmit serious diseases to humans, companion animals and livestock, threatening our health and causing great economic losses in livestock industry.

Concerns are raised on the use of synthetic tick repellents such as DEET, due to the toxicological risk to human health and the environment as well as increasing resistance.

Plant-derived compounds represent promising alternative to synthetic repellents; however, the high throughput screening of such eco-friendly repellents was hampered by the lack of understanding of the targeted tick chemosensory system and the chemosensory receptor (CR) genes that are crucial for ticks to locate hosts and detect repellents.

In the proposed project, I will carry out a comprehensive comparative transcriptome analysis to identify the CR genes that are overexpressed in tick chemosensory organs.

I will define the specific CRs for DEET and key host-derived attractants in an automated voltage clamp recording system (HiClamp), and utilize the receptors as the targets to screen a large panel of plant-derived candidate repellents.

The most potent novel repellents will be validated by behavioural assay and developed to an optimized formulation with extended duration of efficacy.

Taken together, this project will not only resolve the fundamental question on molecular mechanism of tick chemosensation, but also result in an eco-friendly novel tick repellent.