Modulation the effect of genomic imprinting by 5-methyl-2-deoxycytidine in parthenogenetic mouse embtyos developed in vitro and in vivo

5-methyl-2-deoxycytidine was used to modify the development of diploid parthenogenetic mouse embryos. The unfertilized eggs were derived from the hybrid mice and after activation and diploidization were cultured in vitro from 1 cell stage to blastocycyst stage. PE at 8 cell stage were treated with 5 mdC for 48h and after development to blastocyst stage they were transplanted into the uterus of pseudopregnant females. It has been shown in preimplantation stage that treatment with 0.1-0.25 microM 5 mdC improves statisticall significantly the develppment of PE with 0.1 microM or 0.25 microM 5 mdC, 78% and 65% of them developed to the blastocyst stage, against 58% in untreated PE. Treatment of PE with 0.1 microM or 0.25 microM 5 mdC of the same doses also statistically sinificantly improves their implantation, 73% and 80% of treated PE respectively being implanted, against 68% in the untreated PE. Treatment with to the blastocyst stage and 47% of them were implanted. During the postimplantation period, PE treated with 0.1 microM or 0.25 microM 5mdC developed to various somite stages - 14% or 15%, respectovely as compared with 20% in the controls. After treatment of PE with 0.1 microM or 0.25 microM 5mdC, 17% and 22%of the treated PE at somite stages continued their development up to stages of 35-50 somites at days 11 to 13. All of these advanced embryos had much better developed placenta than the untreated PE. The data demonstrate that 5 mdC significatly improves preimplantation development, implantation and postimplantation development of PE from hybrid mice. The results are in agreement with our previous findings that global changes in the methylation status of DNA in mouse PE can modulate the expression of some of the imprinted genes and thus to improve significantly the development of part of the treated PE. 5 mdCprobably promoters the repression of ome of the imprinted genes expression in a double dose in PE or compensates diminished DNA 5 mdC can modulate the effects of the genomic imprinting in a model system from PE grown in vitro and in vivo.