Figure 3.

Histological of analysis of control, Bmpr1a cKO, Bmpr1b^−/−, and Bmpr1a Bmpr1b dKO ovaries. Ovaries were collected from 3-month-old control and experimental mice and stained with periodic acid-Schiff and hematoxylin (n ≥ 5 mice of each genotype). A, Normal histology of Bmpr1a^Flox/− ovary containing follicles in all stages of development, including primary follicles (PF), secondary follicles (SF), and antral follicles (AF) as well as corpora lutea (CL); B, ovary from a Bmpr1a cKO female containing a large number of growing follicles and relatively few large antral follicles or corpora lutea; C and E, ovary from a Bmpr1b^−/− female with follicles in all stages of development and containing a MOF (E, arrow); D and F, ovary from a Bmpr1a Bmpr1b dKO female with features of both Bmpr1a cKO and Bmpr1b^−/− ovaries, including more growing follicles relative to antral follicles or corpora lutea, MOFs (arrow), ZPRs (white arrowheads), and abnormal follicle-like lesions (black arrowheads); G and H, phospho-histone H3 staining of control (G) and Bmpr1a Bmpr1b dKO ovaries (H) demonstrates proliferating granulosa cells in follicles of Bmpr1a Bmpr1b dKO ovaries but absence of proliferation in the follicle-like lesions (arrowheads). Magnification, ×25 (A–D; scale bar, 200 μm) and ×100 (E–H; scale bar, 100 μm).