Les élèments transposables, marqueurs de différenciation génétique des populations d'Anopheles gambiae

Abstract

In Sub-Saharan Africa, Anopheles gambiae is one of the principal vectors of plasmodium, the malaria parasite. New strategies to eradicate this disease, like the construction of a genetically modified mosquito resistant to the plasmodium, are currently being developed. These strategies need a deep knowledge of the genome and population structure of anopheles. Insertion polymorphism of three transposable elements (TE) has been used to detect the structure in An. gambiae natural populations. Results show that a high genetic differentiation divides the species in two molecular forms, M and S, that segregate in African populations. These results reinforce the hypothesis of an undergoing speciation between the molecular forms. Localization on chromosome arms of insertions characteristic of each molecular form suggests that differentiation concerns a large part of the genome, where as previous studies limit the differentiated regions to some regions on chromosomes X and 2L. Transcriptional activity of the three TE differs between tissues and between populations. These results highlight the importance of tissues-specific and population-specific regulation ways of TE expression. The expression variation does not show any correlation with molecular forms, but seems to be correlated with copy number, suggesting that genome characteristics related to the molecular forms do not lead to a specific expression patternLYON1-BU.Sciences (692662101) / SudocSudocFranceF