Distinct landscapes of PWS regions across species. (A) Comparison of PWS region sno-lncRNAs and its parent SNURF-SNRPN exons in different species. Conserved SNURF-SNRPN exons were manually linked between human (black boxes of top panel) and rhesus (grey boxes of middle panel), and SNORD116 cluster snoRNAs (dark and light blues bars for human and rhesus, respectively) were located in introns. Note that several non-SNURF-SNRPN exons were annotated in mouse (empty boxes). The homogenous SNURF-SNRPN exons in rhesus are based on sequence homology and/or expression signals (Additional file 6). (B) Enrichment of Fox binding sites in PWS region sno-lncRNAs. Potential Fox protein binding sites were predicted in five human and two rhesus sno-lncRNAs.