Research sheds light on how insects smell
02 October 2009
Research sheds light on how insects smell
Researchers from Birkbeck have identified a new protein structure which sheds light on how insects smell and could help develop more eco-friendly methods of pest control.
Published in the Journal of Molecular Biology, the study was carried out by Dr Jing-Jiang Zhou and colleagues at Rothamsted Research, in collaboration with Professor Nick Keep's group from the Institute of Structural and Molecular Biology at Birkbeck. The protein was identified at the UK's national Synchrotron, Diamond Light Source.
Prof Nick Keep, Professor of Biomolecular Science at Birkbeck, University of London, said; "Insects can pick up a mate or a food plant at an amazing distance from just a few scent molecules. We can see from our work how these molecules bind to the first stage of the insect's detection system. This gives us insight into how the system works and how it can be so specific. The world beating Diamond X-ray facility was a crucial tool in this work."
The importance of understanding how insects 'smell' and how the chemical signals are recognised is useful for many things, but especially for pest control in agriculture. Determining the composition and processes behind the olfactory functions of insects feeds directly in to the development and refinement of new pathways to influence insect host locating behaviours.
Plants use chemical signals to repel and attract insects and by harnessing a detailed understanding of the signals, farmers can plant companion species to create 'odours' that would make an area very unattractive or attractive to insects according to what they require. This is more commonly known as the push-pull system.
Many insects depend on chemicals like pheromones to communicate with each other and to find a suitable mate. There are two main sex pheromone components bombykol and bombykal in the silkworm moth, which was the subject in this study. Bombykol, the first insect pheromone discovered 50 years ago is the only component involved in mating behaviour whereas bombykal is an antagonist.
Dr Jing-Jiang Zhou, Senior Research Scientist in insect molecular biology at Rothamsted Research, adds: “So far, we know that odorant binding proteins [OBPs] within the organism pick up pheromones at pores on the outside of the antenna and carry them through a watery layer to the nerve endings. But it is not clear whether they simply transport and release molecules which bind to olfactory receptors or whether they form a specific OBP- pheromone complex which then activates the receptor. The structures we determined using the crystallography capabilities at Diamond give us a view of how these processes work.”
Dr Zhou concludes: "It's not just the farming community which stands to benefit from this work. These new insights will be fed into the development and refinement of biosensors where detection sensitivity is paramount in areas like blood tests. One of our spin-off companies are also investigating how bees can detect some small quantities of explosives and stand to benefit from any knowledge we generate."
Solving this protein structure also represents a significant achievement in the advance of structural biology in the UK and it marks the 100th new structure identified at Diamond since its opening in 2007. Almost £300 million has been invested in the Synchrotron and the facility represents the largest UK scientific investment for 40 years. It is a joint venture funded by the UK Government through STFC and the Wellcome Trust.
