Fig. 2. Histological and morphological examination of Lfng^–/– ovaries. (A) Ovaries from 4-week-old Lfng^+/– and Lfng^–/– mice; null ovaries are smaller and developing follicles are obvious in both. (B) The reproductive tracts of 7-week-old Lfng^+/– and Lfng^–/– mice; all structures were present and no gross abnormalities were noted. (C,D) Histological sections of neonatal ovaries stained with Hematoxylin and Eosin. Primordial follicles are evident; however, the Lfng null ovary (C) is smaller than the Lfng^+/– ovary (D) and the morphology is not as well organized. (E-J) Histological sections of ovaries from 42-day-old Lfng^–/– mice. Many abnormal follicles were noted. Some large follicles had smaller follicles within their boundaries (E, black arrow). There were follicles that shared theca or had incomplete theca (F, black arrowheads). There were polyovular follicles containing two or three oocytes (F, red arrows; G,H). There were also many large lutealinized follicles with trapped oocytes (I,J). Scale bars: 100 µm.