Fig. 1

Genomic organization of ESR1, ESR2 and PGR. a Upstream exons and corresponding transcription start sites (TSSs) of ESR1. The upstream exons are shown by boxes and the corresponding TSSs are indicated by arrows. The numbers show the positions of the 5′ start sites of the upstream exons with respect to the start site of upstream Exon A. The different start sites correspond to the mature ESR1 mRNAs, called variant 1, 2 and 3. All 5′ upstream exons are spliced at the common acceptor splice site (+ 163 bp). b Exons, transcription start sites and transcription end sites of ESR2-variant a and b. The numbers of Exon 9 indicate the distances from the transcription start sites of each variant. c Exons, transcription start sites of PGR-variant 1 and 2. The numbers associated with Exon 1 of variants 1 and 2 indicate the 5′ start sites with respect to the distance from the start site of variant 1 (+ 1). The locations of the primer pairs used in qRT-PCR are indicated by the arrows