The effect of amniotic membrane stem cells as donor nucleus on gene expression in reconstructed bovine oocytes

摘要

Nuclear reprogramming of a differentiated cell in somatic cell nuclear transfer (SCNT) is a major concern in cloning procedures. Indeed, the nucleus of the donor cell often fails to express the genes which are a prerequisite for normal early embryo development. This study was aimed to evaluate the developmental competence and the expression pattern of some reprogramming related genes in bovine cloned embryos reconstructed with amniotic membrane stem cells (AMSCs) in comparison with those reconstructed with mesenchymal stem cells (MSCs) and adult fibroblasts (AF) as well as with in vitro fertilized (IVF) oocytes. In vitro matured abattoir-derived oocytes were considered as recipients and a hand-made cloning technique was employed for oocyte enucleation and nuclear transfer (NT) procedures. The expression pattern of genes involved in self-renewal and pluripotency (POU5F1, SOX2, NANOG), imprinting (IGF2, IGF2R), DNA methylation (DNMT1, DNMT3A), histone deacetylation (HDAC2), and apoptosis (BAX, BCL2) were evaluated in NT and IVF derived embryos. Despite the insignificant difference in cleavage rate between reconstructed and IVF oocytes, the blastocyst rate in the IVF group was higher than that of other groups. Among reconstructed oocytes, a higher blastocysts rate was observed in MSC-NT and AMSCs-NT derived embryos that were significantly higher than AF-NT derived ones. There were more similarities in the expression pattern of pluripotency and epigenetic modification genes between MSC-NT and IVF derived blastocysts compared with other groups. In conclusion, considering developmental competence, AMSCs, as alternative donors in SCNT procedure, like MSCs, were prone to have more advantage compared with AF.