Genetical Research
- Genetical Research / Volume 70 / Issue 03 / December 1997, pp 195-204
- 1997 Cambridge University Press
- DOI: http://dx.doi.org/ (About DOI), Published online: 08 September 2000
Pleiotropy of adaptive changes in populations: comparisons among insecticide resistance genes in Culex pipiens
AbstractResistance to toxicants is a convenient model for investigating whether adaptive changes are associated with pleiotropic fitness costs. Despite the voluminous literature devoted to this subject, intraspecific comparisons among toxicant resistance genes are rare. We report here results on the pleiotropic effect on adult survival of Culex pipiens mutants involved in the same adaptation: the resistance to organophosphorus insecticides. This field study was performed in southern France where four resistance genes sequentially appeared and increased in frequency in response to intense insecticide control. By repeated sampling of overwintering females through winter, we analysed the impact of each of three resistance genes on adult survival. We showed that (i) the most recent gene seems to be of no disadvantage during winter, (ii) the oldest affects survival in some environmental conditions, and (iii) the third induces a constant, severe and dominant survival cost. Such variability is discussed in relation to the physiological changes involved in resistance. (Received February 18 1997)(Received July 24 1997) (Revised August 28 1997) Correspondence: c1 Corresponding author. Fax: +33 4 67 14 36 22. e-mail: chevillo@isem.univ.montp2.fr. |
