| Title: | Assessing the acoustic behaviour of Anopheles gambiae (s.l.) dsxF mutants: implications for vector control |
| Author(s): | Su MP; Georgiades M; Bagi J; Kyrou K; Crisanti A; Albert JT; |
| Address: | "Ear Institute, University College London, 332 Grays Inn Road, London, WC1X 8EE, UK. The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK. Division of Biological Science, Nagoya University, Nagoya, 464-8602, Japan. Department of Life Sciences, Imperial College London, London, UK. Ear Institute, University College London, 332 Grays Inn Road, London, WC1X 8EE, UK. joerg.albert@ucl.ac.uk. The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK. joerg.albert@ucl.ac.uk" |
| DOI: | 10.1186/s13071-020-04382-x |
| ISSN/ISBN: | 1756-3305 (Electronic) 1756-3305 (Linking) |
| Abstract: | "BACKGROUND: Release of gene-drive mutants to suppress Anopheles mosquito reproduction is a promising method of malaria control. However, many scientific, regulatory and ethical questions remain before transgenic mosquitoes can be utilised in the field. At a behavioural level, gene-drive carrying mutants should be at least as sexually attractive as the wildtype populations they compete against, with a key element of Anopheles copulation being acoustic courtship. We analysed sound emissions and acoustic preference in a doublesex mutant previously used to collapse Anopheles gambiae (s.l.) cages. METHODS: Anopheles rely on flight tones produced by the beating of their wings for acoustic mating communication. We assessed the impact of disrupting a female-specific isoform of the doublesex gene (dsxF) on the wing beat frequency (WBF; measured as flight tone) of males (XY) and females (XX) in homozygous dsxF(-) mutants (dsxF(-/-)), heterozygous dsxF(-) carriers (dsxF(+/-)) and G3 dsxF(+) controls (dsxF(+/+)). To exclude non-genetic influences, we controlled for temperature and wing length. We used a phonotaxis assay to test the acoustic preferences of mutant and control mosquitoes. RESULTS: A previous study showed an altered phenotype only for dsxF(-/-) females, who appear intersex, suggesting that the female-specific dsxF allele is haplosufficient. We identified significant, dose-dependent increases in the WBF of both dsxF(-/-) and dsxF(+/-) females compared to dsxF(+/+) females. All female WBFs remained significantly lower than male equivalents, though. Males showed stronger phonotactic responses to the WBFs of control dsxF(+/+) females than to those of dsxF(+/-) and dsxF(-/-) females. We found no evidence of phonotaxis in any female genotype. No male genotypes displayed any deviations from controls. CONCLUSIONS: A prerequisite for anopheline copulation is the phonotactic attraction of males towards female flight tones within mating swarms. Reductions in mutant acoustic attractiveness diminish their mating efficiency and thus the efficacy of population control efforts. Caged population assessments may not successfully reproduce natural mating scenarios. We propose to amend existing testing protocols to better reflect competition between mutants and target populations. Our findings confirm that dsxF disruption has no effect on males; for some phenotypic traits, such as female WBFs, the effects of dsxF appear dose-dependent rather than haplosufficient" |
| Keywords: | "Acoustics Animal Communication Animals Animals, Genetically Modified/genetics/physiology *Anopheles/genetics/physiology Flight, Animal Gene Drive Technology/methods Hearing Mosquito Control/*methods Mosquito Vectors/genetics/physiology Mutagenesis Mutatio;" |
| Notes: | "MedlineSu, Matthew P Georgiades, Marcos Bagi, Judit Kyrou, Kyros Crisanti, Andrea Albert, Joerg T eng AV/PP/0028/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom 648709/H2020 European Research Council/ England 2020/10/09 Parasit Vectors. 2020 Oct 7; 13(1):507. doi: 10.1186/s13071-020-04382-x" |
