Fig. 1

ERβ is expressed in granulosa cells and some stromal cells of the ovary. A IHC with the validated antibody PPZ0506 in WT (upper panel, bar indicates 20 μm in the left panel and 50 μm in all other, black arrows indicate granulosa cells and white theca cells, n = 4) and ERβKO (lower panel, n = 4) mouse ovary. B In situ hybridization with a probe against Esr2 in WT female ovary (n = 2 mice, one representative ovary shown in image) confirms ERβ expression in granulosa cells, in cells surrounding the outer layer of theca cells, and in some stromal cells in mouse ovary. C Western blot (one of 2 replicates, each with 2 pooled ovaries), and D qPCR analysis (n = 5, paired t-test) corroborates the loss of ERβ expression in ERβKO ovaries. Both mouse ERβ isoforms (549 aa, calculated molecular weight 61.2 kDa and 567 aa ERβ_ins with 18 inserted aa,, calculated molecular weight 63.2 kDa) are visible near the expected sizes, with both bands being absent in the knockout ovary. E Assessment of ERβ protein expression by IHC in WT mice (n = 11), separated by follicular stage and each follicle scored according to staining intensity and area