February 17, 2016

expert reaction to review article discussing the potential of CRISPR/Cas9 and gene drive as possible methods of mosquito population control

The ongoing outbreak of Zika virus has brought up a number of suggestions with the aim of controlling its spread, and the use of genome editing and gene drive techniques to control mosquito populations, and hence limit the spread of the diseases which they carry, is the subject of an article in the journal Trends in Parasitology.

All our previous output on the Zika virus outbreak can be seen here.

Prof. Michael Bonsall, Professor of Mathematical Biology, University of Oxford, said:

“Gene editing methods such as CRISPR may have the potential to introduce alterations to mosquitoes that would spread through mosquito populations to reduce mosquito population sizes or prevent the spread of disease. These methods have potential application as reducing mosquito population sizes is an important factor in reducing disease spread. There were two pieces of work published late last year (one in PNAS and one in Nature Biotechnology) that showed homology directed repair using CRISPR in the Anophelese mosquito, the mosquitoes that transmit malaria – these were proof of principle studies in the lab. The mosquito vector of the current Zika outbreak in Brazil is Aedes aegypti – CRISPR has not yet been tried in Aedes, so the relevance of this to vector control for the Zika outbreak is very interesting but at this stage hypothetical.

“In this review paper the authors explore the potential for altering the sex determining genes in mosquitoes to change the sex ratio of offspring – actually to produce more males. This is a nice idea, and the CRISPR method is an efficient way to drive genes across chromosomes and affect mosquito biology.

“Currently CRISPR is a new approach to gene editing and there is still some way to go to make the technology fully effective. However, we need to be developing all of these lines of inquiry to develop a greater ability to reduce mosquito transmitted diseases.”

‘Control of mosquito-borne infectious diseases: sex and gene drive’ by Zach N. Adelman and ZhijianTu published in Trends in Parasitology on Wednesday 17 February 2016. 

Declared interests

Prof. Michael Bonsall: “I was the Specialist Adviser to the inquiry on Genetically Modified Insects by the House of Lords Science and Technology Committee, and am a member of ACRE (Defra’s committee on releases into the environment).  The Advisory Committee on Releases to the Environment is independent scientific committee that through EU derivatives and national UK legislation is mandated to provide the UK government/ministers with advice on the environmental risks (to wider receiving environments/human health) of non-native and GM releases. I have been a member of this committee since December 2007.  I have carried out occasional consultancy work for WHO, NIH, and EFSA, including work on GM-based control methods for mosquitoes.  I have received research funding from BBSRC (including working with Oxitec on GM insects), Oxford Martin School, NERC, the Royal Statistical Society, and the Royal Entomological Society.  For full details of all my interests, please see: http://www.parliament.uk/documents/lords-committees/science-technology/GMInsects/michael-bonsall-specialist-adviser-interests.pdf”