Nina Alphey

Research Associate, Mathematical Ecology Research Group

 

Research Interests

Pest insects do enormous damage to human health (transmitting diseases such as dengue fever and malaria) and to agriculture (damaging crops or livestock).  Controlling pest species while minimising the adverse consequences to the environment is a major challenge for sustainable agricultural production and for public health.  Novel genetics-based methods are being developed to mitigate the harm done by insects.  My research uses mathematical modelling to analyse the many interesting issues raised by these new biological approaches.

I have focussed mainly on  population suppression strategies, where the aim is to reduce the number of pest insects using genetic constructs, particularly a self-limiting system called RIDL (Release of Insects carrying a Dominant Lethal), which was developed originally in the University of Oxford’s Department of Zoology and now at Oxitec Ltd, a biotechnology spin-out.  This strategy is based on the Sterile Insect Technique, an area-wide method of biological pest control in which large numbers of sterile pest insects are released; these mate with wild insects, but no offspring result, so the population’s reproductive potential is reduced and numbers are suppressed.  Genetic engineering has enabled improvements and variations and I develop theoretical frameworks and mathematical models to investigate the effect of applying these techniques.

We explore the effects of density dependent processes and the community ecology implications using competition/interaction models.  We developed models to assess the cost-effectiveness of novel vector control strategies for reducing the burden of dengue, a major mosquito-borne viral disease. Using population genetic and population dynamic models, we assess the circumstances under which hypothetical resistance to the lethal mechanism might pose a significant challenge to the effectiveness of releases for population control.

With collaborators at the University of Exeter (formerly at Imperial College), we are combining theoretical and experimental approaches, building on my earlier models, to examine the use of RIDL releases to enhance other pest control methods by managing resistance.  Releasing insecticide-susceptible males carrying a genetic construct with female-specific lethality kills female progeny, thereby reducing the reproductive potential of the population, and introgresses susceptible alleles through male progeny, thus diluting resistance in the target population.

Future directions: while sterile insect methods are undergoing or approaching field trials in several species, and there is much still to explore, another generation of gene-editing technologies are in development.  These include a system using homing endonuclease genes to drive genetic traits into populations (I have modelled a simple version reducing survival, variants reducing female fertility or producing male bias in populations are also in development), and techniques such as engineered under-dominance are proposed to drive genes into a mosquito population that will render the vectors incapable of transmitting disease. Many interesting research questions are amenable to mathematical modelling in respect of these systems.

 

Additional Information

  • Science Media Centre, BBSRC Press Office and Sense About Science contact for journalists and others
  • Fellow of the Institute of Chartered Accountants in England and Wales (FCA)
  • Member of MPLS division Skills Training Group 2011-2013
  • Judge for Debating Matters, the national sixth form debating competition run by the Institute of Ideas, 2011 to date

 

Contacts

Email: nina.alphey@zoo.ox.ac.uk
 

Websites

 

Selected Publications

  • Benjamin Watkinson-Powell and Nina Alphey (2017) Resistance to genetic insect control: Modelling the effects of space. Journal of Theoretical Biology 413(1): 72-85.  doi:10.1016/j.jtbi.2016.10.014

  • Harvey-Samuel, T.D., N.I Morrison, A.S. Walker, T. Marubbi, J. Yao, H. Collins, K. Gorman, T.G.E. Davies, N. Alphey, S. Warner, A.M. Shelton and L. Alphey (2015) Pest control and resistance management through releases of insects carrying a male-selecting transgene. BMC Biology, 13:49.  doi:10.1186/s12915-015-0161-1

  • Alphey, L. and N. Alphey (2014) Five things to know about genetically modified (GM) insects for vector control. PLOS Pathogens 10: e1003909.  doi:10.1371/journal.ppat.1003909

  • Alphey N and Bonsall MB. (2014) Interplay of population genetics and dynamics in the genetic control of mosquitoes, Journal of the Royal Society Interface 11: 20131071. doi:10.1098/rsif.2013.1071

  • Alphey N, Alphey L, Bonsall MB. (2011) A model framework to estimate impact and cost of genetics-based sterile insect methods for dengue vector control, PLoS ONE 6(10): e25384. doi:10.1371/journal.pone.0025384.

  • Nina Alphey, Michael B. Bonsall and Luke Alphey. (2011) Modeling resistance to genetic control of insects, Journal of Theoretical Biology 270(1):42-55. doi:10.1016/j.jtbi.2010.11.016.

  • Nina Alphey, Michael B. Bonsall and Luke Alphey. (2009) Combining pest control and resistance management: synergy of engineered insects with Bt crops, Journal of Economic Entomology 102(2):717-732. doi:10.1603/029.102.0233.

  • Nina Alphey, Paul G. Coleman, Michael B. Bonsall and Luke Alphey. (2008) Proportions of different habitat types are critical to the fate of a resistance allele, Theoretical Ecology 1(2):103-115. doi:10.1007/s12080-008-0010-8.

  • Michael P. Atkinson, Zheng Su, Nina Alphey, Luke Alphey, Paul G. Coleman, Lawrence M. Wein. (2007) Analyzing the Control of Mosquito-borne Diseases by a Dominant Lethal Genetic System, Proceedings of the National Academy of Sciences 104(22):9540-9545. doi:10.1073/pnas.0610685104.