Emerging technologies for gene manipulation in Drosophila melanogaster

Key Points Many genetic tools have been developed over the past 100 years to manipulate the genome of the fruitfly Drosophila melanogaster ; despite the success of most of these methods, some limitations need to be overcome. The past 3 years have seen the introduction of several new technologies that allow flies to be manipulated more easily than any other multicellular organism. The new methods include the ability to create molecularly designed deletions, improved genetic-mapping technologies, strategies for creating targeted mutations, new transgenic approaches and the ability to manipulate large fragments of DNA. Two transposable elements, P -elements and piggyBac s, each having different properties and mobilization characteristics, are being used to generate insertions in every gene of the D. melanogaster genome. Two P -elements, located at different positions in cis or in trans on the same homologous pair of chromosomes, can be used to generate transposon-induced deficiencies. A P -element that contains an internal hobo transposable element allows nested deletions to be generated from a common starting point ('deletion-generator' technology). Two transposons, each of which contains an FRT site, are used to create molecularly defined deletions through Flp-mediated excision of the intervening sequence. SNPs and molecularly defined P -element insertions improve and accelerate gene-mapping efforts. 'Ends-out replacement gene targeting' removes a desired genomic sequence through homologous recombination. Target-induced local lesions in genomes (TILLING), a technique that was first applied in Arabidopsis thaliana , quickly and efficiently identifies single-nucleotide changes in specific genes and might allow the isolation of an allelic series for structure–function analysis. The bacteriophage φC31 efficiently integrates DNA at defined loci in the fly genome. Recombineering facilitates gap-repair-mediated subcloning and the subsequent mutagenesis of large DNA fragments. The popularity of Drosophila melanogaster as a model for understanding eukaryotic biology over the past 100 years has been accompanied by the development of numerous tools for manipulating the fruitfly genome. Here we review some recent technologies that will allow Drosophila melanogaster to be manipulated more easily than any other multicellular organism. These developments include the ability to create molecularly designed deletions, improved genetic mapping technologies, strategies for cre