Figure 1.

(A) Gene-rich SDHD domain is separated from a flanking gene desert by UPGL, a large non-coding RNA. The non-coding UPGL gene (CR616845) is located at the telomeric boundary of a gene-rich region containing SDHD on chromosome band 11q23. The locations of SDHD and the gene desert are indicated by arrows. (B) UPGL primary transcript is composed of two alternatively spliced exons. The first exon originates from the CGI major promoter, although rare transcripts originate from an alternative CGI promoter. Many truncated transcripts downstream of UPGL suggest alternative transcript processing at 3′-end of UPGL.