Fig. 1.

Pregnancy hormones induce robust upregulation of Casein 2 (Csn2) in post-pregnancy mammary organoid cultures. (a) Genome browser tracks showing distribution of H3K27Ac peaks at the Csn2 locus in luminal ductal MECs harvested from pre- and post-pregnancy mice at distinct pregnancy cycles. (b) mRNA levels (qPCR) of casein genes, Csn2 and Csn3, in pre- and post-pregnancy mammary organoids grown with essential medium, complete medium (supplemented with pregnancy hormones) or complete medium with FGF2 n = 2 biological replicates, with 3 technical replicates each. ***p = 0.0002, **p = 0.002, *p = 0.01 (c) Csn2 mRNA levels (2^deltadeltaCT) in pre-pregnancy mammary organoids grown with complete medium. Normalized to pre- pregnancy organoids treated with complete medium for 3 h. (d) Immunofluorescence (IF) imaging of whole mounted pre- and post-pregnancy mammary organoids before or after complete medium exposure for 12 h and 72 h. KRT8 (blue), KRT5 (red) and CSN2 (green). Scale: 100 μm. For analyses, error bars indicate standard error of the mean (SEM) across samples of same experimental group. p values were defined using Welch’s t-test