Adjusting for youth: updated cancer risk guidelines.

Background: Pyrethroid resistance in Anopheles funestus populations has led to an increase in malaria transmission in southern Africa. Resistance has been attributed to elevated activities of cytochrome P450s but the molecular basis underlying this metabolic resistance is unknown. Microsatellite and SNP markers were used to construct a linkage map and to detect a quantitative trait locus (QTL) associated with pyrethroid resistance in the FUMOZ-R strain of An. funestus from Mozambique. Results: By genotyping 349 F2 individuals from 11 independent families, a single major QTL, rp1, at the telomeric end of chromosome 2R was identified. The rp1 QTL appears to present a major effect since it accounts for more than 60% of the variance in susceptibility to permethrin. This QTL has a strong additive genetic effect with respect to susceptibility. Candidate genes associated with pyrethroid resistance in other species were physically mapped to An. funestus polytene chromosomes. This showed that rp1 is genetically linked to a cluster of CYP6 cytochrome P450 genes located on division 9 of chromosome 2R and confirmed earlier reports that pyrethroid resistance in this strain is not associated with target site mutations (knockdown resistance). Conclusion: We hypothesize that one or more of these CYP6 P450s clustered on chromosome 2R confers pyrethroid resistance in the FUMOZ-R strain of An. funestus. Background Anopheles funestus is widely distributed in Africa from south of the Sahara desert to northern South Africa [1]. The highly anthropophilic and endophilic behaviors of this vector make it an efficient vector of malaria, and in many places, parasite infection rates of An. funestus exceeds those of An. gambiae. In South Africa, indoor house spraying with the insecticide DDT had successfully Published: 29 January 2007 BMC Genomics 2007, 8:34 doi:10.1186/1471-2164-8-34 Received: 31 August 2006 Accepted: 29 January 2007 This article is available from: http://www.biomedcentral.com/1471-2164/8/34 © 2007 Wondji et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.