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Insect pests have been posing threats to human health and the agricultural industry worldwide. To tackle this problem, pesticides and synthetic chemicals were deployed in the past decades; yet abusive use of these chemicals could lead to severe environmental problems. As an alternative strategy to cope with the deteriorating situation, we aim to engineer a novel yeast strain that could detect, attract and eliminate pests. We envision that it would become a substitute for pesticides in the future.

The whole project comprises of mainly three parts: (1) Odorant sensing (2) Coupled production of chemical attractant and (3) Production of pest-killing toxin.

  (1) Odorant sensing would be achieved by expressing an engineered heterologous chimera G-protein coupled receptor (GPCR) responsive to volatile odorant in yeast, where the receptor is coupled to the endogenous mating pathway through an engineered Gα subunit.

  (2) Attractant production would be achieved by induced over-expression of an aromatic amino-transferase, an endogenous yeast metabolic enzyme that can catalyze a reaction to yield a volatile insect attractant — 2-phenylethanol, when the downstream signal from the GPCR is activated.

   (3) Binary toxin widely used for pest control in agriculture would also be constitutively expressed in the yeast. When the insects are attracted to the yeast and ingest the cells, the toxin will poison the animals leading to their death. The toxicity of the toxin would be demonstrated by deploying fruit flies as our model test organisms.

Our vision is that this project can be applied in both basic scientific research and industrial application. It is going to serve as a modeling system to screen for GPCRs that bind to certain ligands. It will also mark the start of creating yeast strains that would help curb specific insect vectors, such as mosquitoes and cockroaches. Our system will be easy to maintain at low cost. Thus, it is likely that it will benefit under-developed countries where economic incentive is essential for adopting environmental friendly alternatives of pesticides. As a result, this project provides a viable solution to a better environment for our future generations.