Experts in the safety of genetically modified (GM) organisms have expressed concern over the release of GM mosquitoes into the wild on the Cayman Islands, which was publicised internationally only last month — a year after their initial release.
The trial of the OX513A strain of the dengue-carrying Aedes aegypti mosquito, developed by UK biotechnology company Oxitec, was carried out on Grand Cayman island by the Cayman Islands’ Mosquito Research and Control Unit (MRCU) in 2009, followed by a bigger release between May and October this year. Together they represent the first known release of GM mosquitoes anywhere in the world.
Unpublished results of the trials, showing that the GM male mosquitoes competed with wild males, were presented at the American Society of Tropical Medicine and Hygiene annual meeting in the United States, last week (4 November).
The male GM mosquitoes mate with normal females to produce larvae that die unless the antibiotic tetracycline is present. In tetracycline’s absence an enzyme accumulates to a toxic level, killing the larvae. The developers hope the strategy could be combined with other mosquito control methods to reduce transmission in dengue-prone areas.by