Details of Award
NERC Reference : NE/L008793/1
Genetic control of avian disease vector mosquitoes for conservation
Training Grant Award
- Lead Supervisor:
- Dr S Wigby, University of Oxford, Zoology
- Grant held at:
- University of Oxford, Zoology
- Science Area:
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Biodiversity
- Global Change
- Natural Resource Management
- Science Topics:
- None
- Abstract:
- Genetic control of bird disease vector mosquitoes for conservation Human activities can have dramatic effects on the ability of wild animals to survive, and extinction threatens a large number of species, particularly those that are found in only a few places in the world. One dramatic example of this is in the Hawaiian islands, which were once home to over a hundred species of birds that were found no where else on Earth ("endemic" species). Since the arrival of Europeans in the Hawaiian Islands, a remarkable 71 out of 113 endemic bird species there have become extinct, and 32 are currently endangered or threatened. A major obstacle in the conservation and restoration of the existing species are diseases transmitted by mosquitos to birds: avian malaria and pox, which were accidently introduced by people to the islands, along with non-native mosquitos. The mosquito Culex quinquefasciatus is the main source of these diseases in Hawaiian birds. Current methods of mosquito control, such as insecticide sprays or biological control (using other species that eat or harm the mosquitos), are impractical and/or environmentally damaging. One promising approach for the control of bird diseases is the use of genetically manipulated mosquitos, and in particular a technique called RIDL (Release of Insects carrying a Dominant Lethal). This technique introduces a gene that makes mosquito larvae die unless they receive a chemical antidote in their food when reared in captivity. The offspring of these mosquitoes are therefore not able to survive to adulthood in the wild, where the antidote is not available. If enough RIDL male mosquitoes are released over a period of time, and mate with wild females, few offspring survive and the pest population falls. As recently shown against the dengue virus carrying mosquito, Aedes aegypti, multiple releases of male RIDL mosquitoes leads to substantial reduction of the target mosquito population. Such mosquitoes are therefore genetically sterile, and the use of RIDL mosquitos is a major improvement on the use of radiation-sterilised insects (the Sterile Insect Technique) which has been used for many years to control pest insect populations. RIDL relies on mating between males and females of the same species, so does not effect other species; and the mate-seeking behaviour of male mosquitoes offers high potential against difficult-to-reach and low-density target insect pests. The trait is also self-limiting, because carriers of the RIDL gene die in the wild. A RIDL variant, in which larval death is female-specific (fsRIDL), allows convenient production of large male-only cohorts (the females blood-feed); so-called "genetic sexing". This project will seek to extend RIDL to C. quinquefasciatus, and generate fsRIDL strains using existing genetics or by utilising novel manipulations of sex determining genes, as has previously been achieved in fruit flies and moths. C. quinquefasciatus mosquitos have previously been successfully genetically manipulated, so this species is a promising target for this research, which nonetheless represents the cutting edge of insect biology. Successfully genetically manipulated RIDL mosquitos will undergo assessment of biological performance such as mating competitiveness and longevity in large cages. The proportion of strain insects showing RIDL trait will also be assessed in recently colonised wild-type C. quinquefasciatus strains in the laboratory, and mass-rearing methods will be investigated. The anticipated project outcome is a RIDL strain of C. quinquefasciatus ready for field-testing, with the potential to provide effective pest control of this non-native wildlife disease carrying insect in the Hawaiian Islands. Success would represent the first use of transgenic animals for species conservation.
- NERC Reference:
- NE/L008793/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Industrial CASE
This training grant award has a total value of £83,515
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £16,225 | £11,001 | £56,290 |
If you need further help, please read the user guide.