FIG. 1.
Transcript levels within and flanking the human β-globin locus. (A) Arrowheads represent individual globin genes in the human β-globin and indicate the direction of transcription. Vertical black arrows represent the LCR and locus flanking DNase I hypersensitive sites. Odorant receptor genes in flanking sequences are represented by black squares. Gaps in the sequence diagram are denoted by double-hashed lines representing gaps of 21 kb (left) or 40 kb (right). Vertical bars below the diagram represent the locations of the TaqMan probes. (B) Total RNA from K562 cells was isolated, and transcript levels at specific regions were assayed by RT-qPCR and compared to a genomic DNA control of known concentration by the comparative CT method (n = 2). Probes within γ-globin coding sequences do not distinguish between the Gγ and Aγ genes but probes up- and downstream and between these genes amplify unique sequences. Black bars, with reverse transcriptase; gray bars, without reverse transcriptase. Controls include necdin (brain specific) and ζ-globin (unlinked α-like embryonic globin). (C) The data of panel B are presented at an expanded scale. Error bars indicate standard errors of the means (n = 3).