FIG. 1.

Typical morphology of primary (75–99 μm, A), early secondary preantral (100–125 μm, B), and late secondary preantral (126–180 μm, C) follicles retrieved from ovaries of deer mice using the mechanical method together with that of early secondary preantral follicle (D) obtained using the enzymatic method: the follicles retrieved by the mechanical method have an intact outer membrane of TC and an intact layer of GC in the middle together with a primary Oo in the center. In contrast, the middle and particularly, the outer layer of the follicles retrieved by the enzymatic method were severely compromised. Scale bar: 50 μm. TC, theca cells; GC, granulosa cells; Oo, oocyte.