Cyclic AMP modulators regulate epigenetic marks in preimplantation embryos from prepubertal and adult donors

Prepubertal female donors are promising to accelerate genetic gain and decrease generation intervals. Recent data indicate that cyclic AMP regulators employed during in vitro maturation (IVM) increased yields of bovine blastocyst rates in vitro. This study evaluated the effects of the cAMP modulators forskolin, 3-isobutyl-1-methylxanthine (IBMX) and cilostamide during IVM on blastocyst production, DNA methylation profiles in expanded blastocysts and pregnancy rates from prepubertal and adult Holstein-Friesian oocytes. Ovum pick-up retrieved oocytes were allocated to the following treatments: TCM24 (24h IVM, control), cAMP30 (2h pre-IVM (forskolin-IBMX), 30h IVM (cilostamide), and DMSO30 (DMSO)/ vehicle control; 2h pre-IVM, 30h IVM). In vitro matured oocytes were fertilized and presumptive zygotes were cultured in vitro until day 8. Expanded blastocysts were either frozen and submitted to bisulfite conversion, amplification, and sequencing of bovine testis satellite I and Bos taurus alpha satellite I or transferred to synchronized recipients (cAMP30 protocol). In vivo produced blastocysts were used for comparative reasons for methylation analysis. Blastocyst rates did not significantly differ among treatment groups. DNA methylation levels of blastocysts obtained from adult and prepubertal donors were similar compared to their in vivo produced counterparts when cAMP regulators were added. Preliminary data indicate that pregnancy rates were similar with oocytes from adult and prepubertal donors. Thus oocyte developmental competence in prepubertal donors can be similar to that of the adult donors without cAMP modulators addition. Modifications of epigenetic marks usually produced by assisted reproductive technologies could be reduced by supplementation of cAMP modulators during IVM. Bernal SM is supported by the DAAD (Deutscher Akademischer Austauschdienst)