Fig. 1 Analysis of cathepsin D (CTSD) localization at the ovary interface of "Qianbei Ma" goat. Sections of ovarian tissue were prepared and stained for CTSD with a nonspecific immunoglobulin G (IgG) as negative staining control. (a) Primordial follicles; (b) Primary follicle; (c) Corpus luteum; (d) Secondary follicle; (e) Granulosa and theca cells in the antral follicle; (f) Negative control. Scale bar=400 μm.