Fig. 4.

Determination of the DUX4 mRNA 5′ and 3′ends. (a) Schematic representation of the DUX4 promoter with the putative CATT, GC, TACAA, and E boxes, the ATG translation start codon, and the primers used in 5′-RACE (arrows, nos. 68 and 73). The two 5′ ends found previously in total RNAs of C2C12 cells transfected with pGEM42 are indicated. One of these is identical to the single transcription start site determined here on total RNAs of FSHD and control primary myoblasts (*). (b Upper) Scheme of the EcoRI genomic fragment end as cloned in pGEM42 with the stop codon of the DUX4 ORF and the pLAM region. The KpnI and EcoRI restriction sites, the polyA addition signal (ATTAAA), and the primers used in 3′-RACE (arrows, nos. 94 and 95) are indicated. (Lower) Mapping of the ends obtained by 3′-RACE, with introns A and B.