Differential gene expression in the bovine transgenic nuclear transfer embryos

Abstract

The detrimental effects of gene transfection on embryo development and the molecular mechanism behind the differential expression of genes related to early embryo development were assessed in the production of transgenic cow embryos through somatic cell nuclear transfer (NT). Parthenogenetic, IVF, and transgenic NT embryos derived from α1-antitrypsin transfected ear fibroblast cells was produced. To investigate the molecular mechanism behind lower developmental competence of transgenic NT embryos, the differential mRNA expression of three genes (IFN-τ, Oct4, Fgf4) in the 3 types of embryo (Parthenogenetic, IVF, transgenic NT) was examined. RNA was extracted from ten blastocysts derived from 3 types of embryos and reverse-transcripted for synthesis of the first cDNA. The quantification of 3 gene transcripts (IFN-τ, Oct4, and Fgf4) was carried out in three replicate by quantitative real-time reverse transcriptase PCR. Expression level of IFN-τ mRNA was significantly higher in transgenic NT embryos than parthenogenetic and IVF embryos (P<0.05). However, expression level of Oct4 and Fgf4 of transgenic NT embryos was significantly lower than IVF embryos (P<0.05). Altered levels of these three mRNA transcripts may explain some of the embryonic/fetal/neonatal abnormalities observed in offspring from transgenic NT embryos.