Gene Expression in Individual Bovine Somatic Cell Cloned Embryos at the 8-cell and Blastocyst Stages of Preimplantation Development

Abstract

Abstract. Aberrant gene expression in somatic cell nuclear-transferred (NT) embryos due to abnormal epigenetic modifications of the donor nucleus likely accounts for much of the observed diminished viability and developmental abnormalities. We compared the expression of 13 developmentally important genes in individual 8-cell and blastocyst stage NT embryos produced from adults female cumulus cells and adult male skin fibroblast cells with low and high incidences of neonatal abnormalities [1,2]. In vitro-fertilized (IVF) embryos were used as control embryos. Among the genes tested, the relative abundance of Glut-1, IGF-1R, E-cad, and Cx43 transcripts varied significantly between the two types of NT embryos at the 8-cell stage. The relative abundance of manganese super oxide dismutase (MnSOD) and Stat3 transcripts was significantly higher in IVF embryos compared with both types of NT embryos. At the blastocyst stage, there was a significant difference in the relative expression of only one gene, Bcl-2, between the two types of NT embryos. Although the level of Glut-1 expression did not vary between the two types of NT blastocysts, its expression in both types of NT blastocysts was significantly lower than that in IVF blastocysts. The MnSOD expression level tended to be higher in NT blastocysts. The gene expression profile for any single gene, however, was highly variable among individual embryos and was independent of embryo morphology. The present study demonstrated that the expression profiles of the 13 genes examined in Day 9 NT blastocysts produced from two different types of donor cells with different incidences of neonatal abnormalities are largely indistinguishable.

Differences in developmental competence and gene expression profiles between buffalo (Bubalus bubalis) preimplantation embryos cultured in three different embryo culture media

“…In several studies, mRNA expression levels of BAX have been used to evaluate embryo quality developed in vitro (Amarnath et al 2007;Mundim et al 2009;Shiqiang et al 2010;Kim et al 2012;Sadeesh et al 2015b). Data from the current study indicate that BAX expression was greater (P \ 0.05) in embryos produced from undefined media-containing serum than those produced in its absence, suggesting that over expression of the BAX gene, in the cellular apoptotic pathway takes place (Yang and Rajamahendran 2002;Opiela et al 2008).…”

“…It is possible that gene expression analysis at different stages of preimplantation development in the present study correspond to gene expression analysis before and after maternal to zygotic transition (MZT) stage. The genes under study were selected because they participate in key cellular processes during preimplantation development and have been reported to become transcriptionally active during preimplantation stages (Li et al 2006;Amarnath et al 2007;Wrenzycki et al 2007;Sadeesh et al 2015a, b). The genes evaluated include genes involved in embryo metabolism (GLUT-1), stress response (MnSOD), pro-apoptosis (BAX), anti-apoptosis (BCL-2), imprinting (IGF-2, IGF-2R), DNA methylation (DNMT-3A) and quality (IFNT).…”

“…In the present study, irrespective of whether culture took place in defined or undefined medium, abundance of MnSOD mRNA tended to be non-significant from the 4-cell to 8-to 16-cell stage and expression of MnSOD was greater (P \ 0.05) in embryos from undefined media at 2-cell, morula and hatched blastocyst stages compared to defined medium. In cattle, greater expression of MnSOD compared to IVF embryos has been noted, despite the acknowledged poor in vivo development potential of SCNT embryos (Amarnath et al 2007). On the other hand, contradictory results have been observed more recently by Kim et al (2012) who described no differences in expression levels of MnSOD between bovine SCNT and IVF embryos.…”

A comparative study on expression profile of developmentally important genes during pre-implantation stages in buffalo hand-made cloned embryos derived from adult fibroblasts and amniotic fluid derived stem cells

“…To the best of our knowledge, this is perhaps, the first report comparing mRNA expression patterns of development-related genes among pre-implantation buffalo NT embryos with different developmental potentials. The genes under study were selected because they participate in key cellular processes during pre-implantation development and have been reported to become transcriptionally active during preimplantation stage (Li et al 2006a, b;Amarnath et al 2007;Wrenzycki et al 2007). The genes evaluated include genes involved in pluripotency and transcription (OCT4, NANOG and STAT3), chromatin structure (HDAC2), DNA methylation (DNMT1 and DNMT3A), imprinting (IGF2 and IGF2R), pro-apoptosis (BAX); anti-apoptosis (BCL2), oxidative stress (MnSOD), and metabolism (GLUT1).…”

“…Only a very few reports are available on the comparison of gene expression in NT embryos produced from different types of somatic cells (Li et al 2006a, b;Amarnath et al 2007;Beyhan et al 2007), and they were reported that there was differential expressions of genes between SCNT embryos produced from different types of donor cells. Although, no particular donor cell type has been established to be superior in overcoming the problem associated with the epigenetic reprogramming after NT and cell potential of different donors to develop normal embryos.…”