Ectopic DJ arrays target perinucleolar heterochromatin. Positioning of DJ BAC arrays. 3D FISH was performed on AMD-treated cells from clones 1 and 2 with rDNA (red) and DJ BAC CT476834 (green) probes. The large green hybridization signals identified by arrowheads indicate the ectopic DJ array. Endogenous DJ signals are also visible. Classification of ectopic DJ arrays as nucleolar associated, partially associated, or nonassociated is indicated by white, yellow, and orange arrowheads, respectively, and is quantified below.