Histone modification of embryonic stem cells produced by somatic cell nuclear transfer and fertilized blastocysts

ABSTRACT

Nuclear transfer-embryonic stem cells [NT-ESCs] are genetically identical to the donor's cells; provide a renewable source of tissue for replacement, and therefore, decrease the risk of immune rejection. Trichostatin A [TSA] as a histone deacetylase inhibitor [HDACi] plays an important role in the reorganization of the genome and epigenetic changes. In this study, we examined whether TSA treatment after somatic cell nuclear transfer [SCNT] can improve the developmental rate of embryos and establishment rate of NT-ESCs line, as well as whether TSA treatment can improve histone modification in NT-ESCs lines. In this experimental study, mature oocytes were recovered from BDF1 [C57BL/6xDBA/2] mice and enucleated by micromanipulator. Cumulus cells were injected into enucleated oocytes as donor. Reconstructed embryos were activated in the presence or absence of TSA and cultured for 5 days. Blastocysts were transferred on inactive mouse embryonic fibroblasts [MEF], so ESCs lines were established. ESCs markers were evaluated by reverse transcription-polymerase chain reaction [RT-PCR]. Histone modifications were analyzed by enzyme linked immunosorbent assay [ELISA]. Result of this study showed that TSA treatment after SCNT can improve developmental rate of embryos [21.12 +/- 3.56 vs.8.08 +/- 7.92], as well as establishment rate of NT-ESCs line [25 vs.12.5]. We established 6 NT-ESCs in two experimental groups, and three embryonic stem cells [ESCs] lines as control group. TSA treatment has no effect in H3K4 acetylation and H3K9 tri-methylation in ESCs. TSA plays a key role in the developmental rate of embryos, establishment rate of ESC lines after SCNT, and regulation of histone modification in NT-ESCs, in a manner similar to that of ESCs established from normal blastocysts