Analysis of DEXI/Dexi refines the organization of the mouse 7C and human 15q11-->q13 imprinting clusters

Identification of imprinted genes in the Prader-Willi/Angelman syndrome deletion region is complicated by the presence of large flanking repeats. While inactive copies of DEXI are located within the repeats, we have now localized the active DEXI gene to 15q11-->q13 outside the PWS/AS deletion and Dexi to mouse chromosome 16, suggesting complex evolution of this genomic region in both species.