title: Does timing matter in pesticide resistance? One splice form variant of MDR49 provides early, but not late, 'protection' to DDT
organism: Drosophila melanogaster
description: The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R.
attributes.tag: isolate
attributes.value: 91-R
attributes.tag: host
attributes.value: Drosophilamelanogaster
attributes.tag: collection_date
attributes.value: 2015-07
attributes.tag: geo_loc_name
attributes.value: USA: Illinois
attributes.tag: tissue
attributes.value: Whole body
attributes.tag: BioSampleModel
attributes.value: Invertebrate