New research from the University of Exeter has shown that the sexually antagonistic gene for resistance to the pesticide DDT, which increases fitness in female flies but simultaneously decreases fitness in male flies, helps to maintain genetic variation. The findings contribute to the understanding of evolutionary dynamics and have important implications for pest management.
The researchers used a genetic model and multiple experimentally evolving populations of the fly Drosophila melanogaster to test whether sexual conflict can maintain genetic variation. Their findings show that sexually antagonistic selection is able to maintain genetic variation and also broadly explains the genetic patterns seen in nature.
Professor David Hosken from the Centre for Ecology and Conservation at the University of Exeter's Cornwall Campus in Penryn said: "Our results show the potential value for insect resistance systems to not only play a part in applied pest management but also shed light on fundamental evolutionary questions."
Sexual conflict occurs whenever males and females differ in their optimal values for shared traits. In humans, wider hips are favoured in females to accommodate child birth, but are less of a benefit in males because they lead to increased mobility costs. The way that genetic variation - essential for species adaptation - is maintained under such conditions has so far been unclear.
The results of this study provide an explanation for why, although the DDT resistant gene variant which was present before pesticide use, and is known to improve numbers of and survival of offspring, did not increase in frequency until widespread DDT use.
Although now banned for agricultural uses, DDT is still produced in relatively small quantities to control the populations of animals known to be disease vectors, for example in mosquito control to limit the spread of malaria.
The study was funded by NERC, The Royal Society and the University of Exeter.
Sexual conflict maintains variation at an insecticide resistance locus by Wayne G. Rostant, Caroline Kay, Nina Wedell and David J. Hosken is published today in the journal BMC Biology. http://www.
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About the University of Exeter
The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 19,000 students and is ranked 7th in The Times and The Sunday Times Good University Guide league table, 10th in The Complete University Guide and 9th in the Guardian University Guide 2015. In the 2014 Research Excellence Framework (REF), the University ranked 16th nationally, with 98% of its research rated as being of international quality. Exeter was The Sunday Times University of the Year 2012-13.
The University has four campuses. The Streatham and St Luke's campuses are in Exeter and there are two campuses in Cornwall, Penryn and Truro. The 2014-2015 academic year marks the 10-year anniversary of the two Cornwall campuses. In a pioneering arrangement in the UK, the Penryn Campus is jointly owned and managed with Falmouth University. At the campus, University of Exeter students can study programmes in the following areas: Animal Behaviour, Conservation Biology and Ecology, English, Environmental Science, Evolutionary Biology, Geography, Geology, History, Human Sciences, Marine Biology, Mining and Minerals Engineering, Politics and International Relations, Renewable Energy and Zoology.
The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the past few years; including landmark new student services centres - the Forum in Exeter and The Exchange at Penryn - together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.
About the University of Exeter's Centre for Ecology and Conservation (CEC)
Staff at the Centre for Ecology and Conservation, based on the Penryn Campus, undertake cutting-edge research that focusses on whole organism biology. The CEC has three interlinked research groups: Behaviour, Ecology and Conservation, and Evolution which constitute 40 academics and over 100 early career researchers. It engages widely with businesses, charities and government agencies and organisations in Cornwall, the Isles of Scilly and beyond to translate its research into societal impact. Staff at the CEC deliver educational programs to some 500 undergraduate and 100 postgraduate students.
A new £5.5 million Science and Engineering Research Support Facility (SERSF) is currently under construction at the Penryn Campus. The facility will bring pioneering business, science and engineering together and will provide space for the growing CEC alongside the University of Exeter Business School, which is expanding into Cornwall, and the University's Marine Renewables team.
The University of Exeter and Falmouth University are founding partners in the Combined Universities in Cornwall (CUC), a unique collaboration between six universities and colleges to promote regional economic regeneration through Higher Education, funded mainly by the European Union (Objective One and Convergence), the South West Regional Development Agency and the Higher Education Funding Council for England, with support from Cornwall Council.