These duplications were generated by transgenic methods. They are useful for mapping, gene rescue and changing the dosage of genes on chromosome 3.

The majority of the duplications (those with "GV" in the symbol name) were made by Graeme Mardon and GenetiVision Corporation. Most carry insertions from the CH321 BAC library made by Venken et al., (2009) and are approximately 80 kb in size. Some are from the CH322 library (ibid.) and are approximately 20 kb in size.  The BACs were made using genomic DNA from the line used to generate the reference genome sequence.