Follicular development in transplanted fetal and neonatal mouse ovaries is influenced by the gonadal status of the adult recipient

Ovary grafting is not only a method of investigating follicle and oocyte development, but also a useful model to explore the possibility of the re-establishment of the reproductive axis in male-to-female sexual reversal. This study investigated ovary survival and follicle development after mouse ovaries were transplanted into immune-intact castrated male mice. Ten-day-old mouse ovaries were transplanted into the back muscle of adult outbred castrated male mice treated with immunosuppressants. Twenty-two days later, the ovary structure and the number of follicles present was examined by hematoxylin and eosin staining. The oocytes were harvested, and then used for in vitro maturation (IVM) and IVF. The results showed that primordial and antral follicles were mainly found in the grafts, and there were obvious differences compared with 32-day-old fresh ovaries (P!0.05). Embryos were derived from collected oocytes after IVM and IVF with a 72.4% cleavage rate and 7.9% blastocyst rate; 12 live pups were generated by embryo transfer. The hormone assay showed that plasma concentrations of both estrogen and progesterone increased after ovarian transplantation (P!0.01). In conclusion, immune-intact adult castrated male mice can support ovary survival and further development of follicles with endocrine function after ovarian transplantation.

Section: Discussionsupporting

confidence: 91%

Follicle growth and oocyte development after ovary transplantation into back muscle of immune-intact adult castrated male mice

Li¹,

Tao²,

Zhang³

et al. 2010

“…Support for the persistence of primordial follicle numbers in the postnatal Balb/c mouse ovary is available from the studies by Cox et al (2000). When fetal ovaries were transplanted under the kidney capsule of intact or bilaterally ovariectomized adult female mice, all grafted ovaries showed follicle maturation, yet the mean numbers of primordial follicles per ovary in the transplants did not decline from 2 to 8 weeks following transplantation.…”

Section: Discussionmentioning

confidence: 99%

Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply

Kerr¹,

Duckett²,

Myers³

et al. 2006

193

180

Proliferation and partial meiotic maturation of germ cells in fetal ovaries is believed to establish a finite, non-renewable pool of primordial follicles at birth. The supply of primordial follicles in postnatal life should be depleted during folliculogenesis, either undergoing atresia or surviving to ovulation. Recent studies of mouse ovaries propose that intra-and extraovarian germline stem cells replenish oocytes and form new primordial follicles. We quantified all healthy follicles in C57BL/6 mouse ovaries from day 1 to 200 using unbiased stereological methods, immunolabelling of oocyte meiosis (germ cell nuclear antigen (GCNA)) and ovarian cell proliferation (proliferating cell nuclear antigen (PCNA)) and electronmicroscopy. Day 1 ovaries contained 7924G1564 (S.E.M.) oocytes or primordial follicles, declining on day 7 to 1987G203, with 200-800 oocytes ejected from individual ovaries on that day and day 12. Discarded oocytes and those subjacent to the surface epithelium were GCNA-positive indicating their incomplete meiotic maturation. From day 7 to 100 mean numbers of primordial follicles per ovary were not significantly depleted but declined at 200 days to 254G71. Mean numbers of all healthy follicles per ovary were not significantly different from day 7 to 100 (range 2332G349-3007G322). Primordial follicle oocytes were PCNA-negative. Occasional unidentified cells were PCNA-positive with mitotic figures observed in the cortex of day 1 and 12 ovaries. Although we found no evidence for ovarian germline stem cells, our data support the hypothesis of postnatal follicle renewal in postnatal and adult ovaries of C57BL/6 mice. Reproduction (2006) 132 95-109

“…Ovarian grafting was performed using a standard procedure (Cox et al 2000, Snow et al 2002. In brief, tissue transplant recipients (8-10-week-old female SCID mice) were anesthetized (Avertin (20 mg/ml 2, 2, 2-tribromoethanol and 2% v/v tert-amyl alcohol), 0.4 mg/g body weight, i.p).…”

Section: Ovariectomy and Transplantationmentioning

confidence: 99%

Live offspring from vitrified blastocysts derived from fresh and cryopreserved ovarian tissue grafts of adult mice

Wang¹,

Catt²,

Pangestu³

et al. 2009

Ovarian tissue cryopreservation and transplantation can be used to preserve fertility for cancer patients. In this study, we assessed the viability and function of ovarian tissue from adult mice that was cryopreserved by solid surface vitrification or traditional slow-cooling using various in vitro and in vivo techniques, including allotransplantation, in vitro oocyte maturation, embryo culture in vitro, blastocyst cryopreservation, embryo transfer, and development. The importance of cumulus cells for oocyte maturation, fertilization, and embryo development was investigated. Graft recovery, follicle survival, and oocyte retrieval was similar in control, vitrified, and slow-cooled groups. High rates of oocyte maturation, cleavage, and blastocyst formation were achieved, with no significant differences between the control, vitrified or slow-cooled ovarian tissue grafts. The presence of cumulus cells was important for oocyte maturation, fertilization, and subsequent development. Cumulus-oocyte complexes with no surrounding cumulus cells (N-COCs) or with an incomplete layer (P-COCs) had significantly lower rates of oocyte maturation and blastocyst formation than cumulus-oocyte complexes with at least one complete layer of cumulus cells (F-COCs; maturation rate: 63, 78 vs 94%; blastocyst rate: 29, 49 vs 80%). Live births were achieved using vitrified blastocysts derived from oocytes taken from vitrified and slow-cooled ovarian tissue heterotypic allografts. Successful production of healthy offspring from these vitrified blastocysts suggests that this technique should be considered as a useful stage to pause in the assisted reproduction pathway. This provides an alternative protocol for restoring fertility and offering cancer patients a better indication of their chances of pregnancy and live birth.