Fig. 1

Differential chromatin accessibility in the Nr5a1 locus during gonadotrope specification. a The Nr5a1 locus displays differential local chromatin accessibility depending on gonadotrope differentiation stage in vitro. Chromatin accessibility was investigated by assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) in αT1–1, αT3–1 and LβT2 gonadotrope cell lines. ATAC-seq tracks are shown for 45 Kb of the Nr5a1 locus. Accessible chromatin regions identified from ATAC-seq results are shown for each cell line under each track (respectively, in gray, blue and yellow). In the last lane are summarized in black the potential regulatory regions, based on accessible chromatin sequences identified in at least one cell line. b Nr5a1 potential regulatory regions show differential chromatin accessibility depending on gonadotrope differentiation stage in vivo. ATAC assay followed by real-time PCR quantification (ATAC-qPCR) was performed on pituitary cells dispersed from developing glands of E12.5, E13.5 and E14.5 mouse embryos. Quantitative PCR was performed using sets of primers targeting the potential cis-regulatory regions. Raw qPCR data were normalized to control region (see “Materials and Methods”) and to E12.5 stage of development. At this stage, Nr5a1 gene is not expressed and the locus is expected to be in a closed chromatin conformation. Results are the mean ± SEM of three independent experiments. Change in chromatin accessibility between E12.5 and E13.5 or E12.5 and E14.5 embryonic stages is compared using a Mann–Whitney test. Significant difference with E12.5 stage: “a” p < 0.05; “b” p < 0.01; “c” p < 0.001