Genetic control of mosquitoes

1. HEALTHY PEOPLE HEALTHY ENVIRONMENT Genetic control of mosquitoes Luke Alphey, Founder and Chief Scientific Officer Visiting Professor in Zoology, University of Oxford

2. Oxitec Ltd Based in Oxford, UK,30 employees Founded in 2002 to commercialise new technology from Oxford University Control of insects Agricultural pests Public Health (mosquitoes) Injecting DNA into mosquito eggs

3. Introduction Why? Pest insects cause $$bn damage and transmit major diseases How? Engineered sterile males RIDL®: Release of Insects carrying a Dominant Lethal genetic system Genetics, molecular biology When? Initial strains successfully tested in field Marker-only moth: USA 2006 RIDL mosquitoes: Cayman Islands 2009, Malaysia 2010, Brazil 2011

4. Increased Risk of Vector Borne Disease Dengue - growing global pandemic Over 100 million cases annually Severity increasing No specific medication or vaccine Chikungunya - emerging threat 1.8 million cases in last 6 years (WHO) Reunion (2005) had 266,000 cases and 254 deaths Italy (2007) – 197 cases and I death Oxitec/Nimmo

5. WHO Dengue control

7. RIDL®

8. RIDL

9. A Genetic Solution Release engineered sterile males to prevent mosquito reproduction and so control dengue “birth control for mosquitoes” Sterile male mosquitoes actively seek females Find mosquitoes better than human inspectors WHO • Based on Sterile Insect Technique • How it works • Rear millions of insects • Sterilise with irradiation • Release over wide area • Sterile males mate with wild females: progeny don’t survive • Pest population declines • Species-specific • Used for over 50 years

10. New World Screwworm Eradicated

11. X Bi-sex lethal X RIDL: fail-safe / replacing radiation • RIDL insects are genetically sterile • Repressible • Release homozygous males Female-specific lethal Introgression of genes through male line

12. Antidote (Tc) death Female death Female specificity RIDL®: molecular biology • Controllable Gene Expression tTA effector promoter tetO Thomas et al. 2000 Science 287: 2474-6Fu et al. 2010 PNAS 107: 4550-4

13. OX3545F Act4-tTA + tetO-DsRed (DsRed) tTA effector promoter Act4 tetO + promoter Flight muscles only

14. OX3604C RIDL mosquitoes Males Females Flightless mosquitoes cannot survive in wild (or find hosts). Unable to mate even in laboratory. Males have normal flight ability, as have females given antidote as larvae.

15. fsRIDL phased trials – large lab cage trials RIDL cage trials performed in Colorado State University (Megan Wise, Bill Black)showing suppression of target population

16. X Bi-sex lethal X RIDL: fail-safe / replacing radiation • RIDL insects are genetically sterile • Repressible • Release homozygous males Female-specific lethal Introgression of genes through male line

17. Development trials • First open release Grand Cayman 2009 • mating of RIDL males to local females • excellent mating competitiveness • provided data for suppression trial 2010 0 10km • Each Area approx 16 Ha (40 acres) • No conventional control forAedes aegypti • Release period May-Oct 2010 with pre- and post-release monitoring 500m

18. Cayman field trial 2010 0 • Trial was complete success; all endpoints met • Clear suppression from early August • Sustained release of RIDL OX513A males can suppress a field population of Aedes aegypti mosquitoes • Maximum degree of suppression limited by immigration • GM mosquitoes can perform successfully in the field 500m

19. Bringing new technology to the field RIDL Nature

20. Regulatory Progress • The USDA completed (2008) an Environmental Impact Statement (EIS) on the use of autocidal technology (RIDL) in fruit flies and PBW • Record of Decision: this is the environmentallypreferred alternative • North American Plant Protection Organization (NAPPO) standard signed late 2007 • MosqGuide: WHO/TDR develop guidance for use of GM mosquitoes for disease control • Oxitec transgenic insect approvals • Multiple movement and contained trial approvals (Medfly, Mexfly, pink bollworm, Aedes aegypti, Ae. albopictus) • Open field release approvals in the USA (PBW 2006,7,8) • Released 15 million Oxitec pink bollworm from aircraft over 2500 acres (2008)

21. Community Engagement Focus Group: reactions to Oxitec approach breakthrough! good news kills larvae good – something worth trying going forward provides immediate solution / result in preventing Dengue seen as a long term solution cf other methods which are all seen as short term some even welcome the research team to test the technique in their community From TNS Malaysia Community engagement • Malaysian Health Minister Datuk Seri Liow Tiong Lai “We see it as the most efficient and fastest way in eradicating Aedes mosquitoes from our local environment,” Liow said, adding that Aedes is not a species endemic [native] to Malaysia. Monday 11th Oct 2010

22. Frequently Asked Questions Will the genetic modification spread outside the release area? The released mosquitoes and their progeny will die so this is a ‘self limiting’ approach, with no permanent change to the wild mosquito population. The large fitness cost (and no component advantage) also prevents spread. Do mosquitoes provide valuable ecosystem services (e.g. food chain, pollinators)? Aedes aegypti originated in Africa and only achieved pan-tropical distribution in the 1930s. Therefore in most countries it is not a native species. There are no birds, fish or other insects that feed exclusively on it and therefore reducing the number of Aedes aegypti is most unlikely to have negative impacts on the environment. If one mosquito suppressed, will a worse one replace (niche replacement)? Aedes aegypti it occupies an unusual, human-associated niche normally empty in its absence. Aedes albopictus, a potential alternative, is an inferior vector of dengue. RIDL strains are also available for Aedes albopictus. Can we release enough (feasibility, economics)? Long history of success and data from SIT implies ‘yes’, as do modelling and data so far.

23. Acknowledgements HEALTHY PEOPLE HEALTHY ENVIRONMENT Angi Harris Bill Petrie Greg Simmons Bob Staten (rtd) Tom Miller (UCR) IMR, Malaysia Lee Han Lim PI: Tony James PI: John Mumford

24. Thank you…