Allotransplantation of cryopreserved prepubertal mouse ovaries restored puberty and fertility without affecting methylation profile of Snrpn-DMR.

OBJECTIVE: To evaluate the genetic safety of vitrification on the methylation imprints and the development and fertility potential of prepubertal mouse ovaries.

DESIGN: Experimental animal study.

SETTING: University-based fertility center.

ANIMAL(S): Institute of Cancer Research (ICR) 10-day-old female mice, 10-week-old adult female mice, and 12-week-old adult male mice.

INTERVENTION(S): Vitrification of juvenile mouse ovaries was performed using ED20 and EG5.5/30 solutions followed by retrieval of fresh and vitrified-warmed germinal vesicle (GV) oocytes for Snrpn differentially methylated regions (DMR) methylation analyses, collection of mature oocytes from superovulated ovarian grafts, in vitro fertility(IVF), and early embryonic development after heterotopic allotransplantation.

MAIN OUTCOME MEASURE(S): Analysis of methylation status of Snrpn-DMR, percentage of fertilization, and blastocysts formation.

RESULT(S): Methylation status of Snrpn-DMR from vitrified-warmed GV oocytes did not show significant alteration compared with that of controls, although a significant reduction of viable oocytes was observed. Puberty as well as endocrine function was restored, and no significant difference was shown in number of follicles, percentage of mice retaining fertility, and blastocyst formation among three groups.

CONCLUSION(S): Our study proved that vitrification of prepubertal mouse ovaries did not alter the methylation profile of Snrpn-DMR and subsequent allotransplantation; IVF could restore the development and fertility potential.