A set of over 400 interchromosomal duplications tiling the majority of the second and third chromosomes from Drosophila melanogaster. The transgenic lines were created via site-specific transgenesis mediated by phiC31 integrase and confirmed by PCR genotyping using clone-specific primers. All second chromosome BACs are inserted at the VK31 docking site on the third chromosome, while all third chromosome BACs are inserted at VK37 on the second chromosome. This set of BACs overlap by an average of 5-10 kb and are primarily >80 kb in size (BAC ID starts with CH321), although some 20 kb BACs (BAC ID starts with CH322) are also present in this collection.