Beetle defence may save lives

New antibiotic and anti-cancer chemicals may one day be synthesized using biotechnology, following CSIRO’s discovery of the three genes that combine to provide soldier beetles with their potent predator defence system. The three genes that combine to make the fatty acid soldier beetles use to ward off predators has been replicated. Because of its anti-microbial properties, the substance may be synthesised to develop antibiotics and anti-cancer chemicals for human consumption. The team found this fluid contains an exotic fatty acid called dihydromatricaria acid, or DHMA, which is one of a group called polyynes that have known anti-microbial and anti-cancer properties. While DHMA and similar polyne fatty acids are found in a wide variety of plants, fungi, liverworts, mosses, marine sponges and algae, these compounds have proved very difficult to manufacture using conventional chemical processes. However, Dr Haritos and her team have developed a way to achieve this.

Soldier beetles are the only animals reported to contain DHMA. This, together with the observation that  the beetles forage on plants (such as daisies) which contain a lot of these types of fatty acids, led to previous incorrect conclusions that the DHMA in soldier beetles was derived from their diet. "Through our research and the gene differences we have discovered, we now know soldier beetles have evolved this same defensive compound entirely independently of its production in plants and fungi," Dr Haritos said.