Ikeda S.et al.
Diverse environmental conditions surrounding preimplantation embryos, including available nutrients, affect their metabolism and development in both short- and long-term manner. Thioredoxin-interacting protein (TXNIP) is a possible marker for preimplantation stress that is implicated in in vitro fertilization- (IVF) induced long-term DOHaD effects. B vitamins, as participants in one-carbon metabolism, may affect preimplantation embryos by epigenetic alterations of metabolically and developmentally important genes. In vitro-produced bovine embryos were cultured with or without Roswell Park Memorial Institute 1640 vitamin mixture, containing B vitamins and B vitamin-like substances, from day 3 after IVF and we evaluated blastocyst development and TXNIP messenger RNA (mRNA) expression in the blastocysts by reverse transcription-quantitative polymerase chain reaction. The degree of trimethylation of histone H3 lysine 27 (H3K27me3) at TXNIP promoter was examined semi-quantitatively by chromatin immunoprecipitation polymerase chain reaction. Total H3K27me3 were also compared between the groups by Western blot analysis. The vitamin treatment significantly increased the rates of blastocyst development (P<0.05) and their hatching (P<0.001) from the zona pellucida by day 8. The mRNA expression of TXNIP was lower (P<0.01) in blastocysts in the vitamin-mixture-treated group concomitant with higher (P<0.05) level of H3K27me3 of its promoter compared with the control group. The total H3K27me3 in the vitamin-mixture-treated group was also higher (P<0.01) than that in the control group. The epigenetic control of genes related to important metabolic processes during the periconceptional period by nutritional conditions in utero and/or in vitro may have possible implication for the developmental programming during this period that may impact the welfare and production traits of farm animals.