Genome features of “Dark-fly”, a Drosophila line reared long-term in a dark environment

To address the molecular mechanisms underlying environmental adaptation, we studied a Drosophila melanogaster line, termed Dark-fly, which has been maintained in constant dark conditions for 57 years (1400 generations).The structural gene copy number changes between the dark fly and its control were assessed by aCGH array. The comparison showed that hundreds of genes in the dark fly bear duplications or deletions relative to the control line. The copy number increase and decrease in the dark flies were determined by two-channel array hybridization with the control line. In addition to biological replicates, a Cy5-Cy3 dye swap was performed.Self-hybridization was also conducted to serve as a quality control.