Fig. 4: Polymorphism in D3-31 ERBS affects E2-mediated transcriptional activity.

a Sequencing results showing genetic variants within critical D3KV1-MF96 interval. b Detailed schematic overview of polymorphisms (denoted by red lines) in the D3KV1-MF96 interval. SNP478 denotes an AC > GG substitution on chr3:101310478-79. c ChIP-seq data from mouse uterus (extracted from SRX129062⁶³) showing Erα binding intensity to polymorphic regions listed in a. Consensus ER binding motif (UN0308.1⁶⁴) and SNP478 are highlighted in blue and red squares, respectively, where double asterisk indicates the position of SNP478. Coordinates according to mouse NCBI37/mm9 build. d Rabbit anti-mouse Erα ChIP-qPCR data confirming binding of Erα to SNP478 in spleen cells. A gene dessert was used as negative control (-ctrl) and a known Erα binding site (Csf2ra³⁰) as positive control (+ ctrl). Values are expressed as fold enrichment over rabbit IgG mock IP. Each dot represents an independent mouse biological replicate. The data shown is representative of two independent experiments with similar results. e Effect of SNP478 on the transcriptional activity of the D3KV1 Erα binding site shown in c. The candidate D3KV1 Erα binding site (chr3:101310478 ± 100 bp to each side) was cloned in its two variant forms (AC and GG) into luciferase reporter constructs. The constructs were transfected into MCF7 cells to evaluate transcriptional activity. The data shown is from a total n = 9 technical replicates pooled from two independent experiments. Data are summarised as mean (SEM). Statistical significance was evaluated using a two-sided non-parametric Mann–Whitney U test.