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Drosophila, a-Esterase-7, Mutant Insecticide, Proteomics, Fat body
Abstract:
Carboxylesterases constitute a large enzyme family in insects, which is involved in diverse functions such
as xenobiotic detoxi
fi
cation, lipid metabolism and reproduction. Phylogenetically, many insect carbox-
ylesterases are represented by multienzyme clades, which are encoded by evolutionarily ancient gene
clusters such as the
a
-Esterase
cluster. Much in contrast to the vital importance attributed to carbox-
ylesterases in general, the
in vivo
function of individual
a
-Esterase
genes is largely unknown. This study
employs a functional proteomics approach to identify esterolytic enzymes of the vinegar
fl
y
Drosophila
melanogaster
fat body. One of the fat body carboxylesterases,
a
-Esterase-7
, was selected for mutational
analysis by gene targeting to generate a deletion mutant
fl
y. Phenotypic characterization of
a
-Esterase-7
null mutants and transgenic
fl
ies, which overexpress a chimeric
a
-Esterase-7:EGFP
gene, reveals
important functions of
a
-Esterase-7
in insecticide tolerance, lipid metabolism and lifespan control. The
presented
fi
rst deletion mutant of any
a
-Esterase
in the model insect
D. melanogaster
generated by gene
targeting not only provides experimental evidence for the endogenous functions of this gene family. It
also offers an entry point for
in vivo
structure-function analyses of
a
-Esterase-
7, which is of central
importance for naturally occurring insecticide resistance in wild populations of various dipteran insect species.
