Ovarian fragmentation and grafting promoted follicle growth in mice. Paired ovaries from juvenile mice were grafted into kidneys of adult ovariectomized mice (intact, IN; pieces, PI). Hosts were injected with FSH daily for 5 d before graft retrieval. (A) Morphology of paired ovarian grafts with or without fragmentation into three pieces. (A, Upper) Grafts inside kidney capsules. (A, Lower) Isolated paired grafts. (B) Weights of paired ovaries following fragmentation into 2–4 pieces from day 10 (D10) mice and incubated for 1–24 h before grafting. Ovarian weights before grafting (D10) and at 5 d after grafting with (D15 FSH) or without FSH treatment (D15) served as controls; n = 8–22. (C) Follicle dynamics before and after grafting of intact and fragmented (three pieces) ovaries from day 10 mice. (C, Left) Total follicle numbers. (C, Right) Follicle dynamics; n = 5. Pmd, primordial; Prm, primary; Sec, secondary; PO, preovulatory. (D) Weights of paired ovaries from mice at different ages following fragmentation into 3–4 pieces and grafting. Mean ± SEM; *P < 0.05; n = 8–22.