Resiliency of equid H19 imprint to somatic cell reprogramming by oocyte nuclear transfer and genetically induced pluripotency†.

The research article represents an investigation into the resiliency of the H19 gene imprint within horse cells during the process of somatic cell nuclear transfer and generating induced pluripotent stem cell (iPSC) lines. The study reflects that equine cells display considerable resistance to epigenetic modifications in the H19 gene, contrary to what occurs in several other mammalian species.

Research Scope

• The aim of this research was to examine the equid H19 gene to ascertain if its imprinting is disrupted in somatic cell nuclear transfer-derived conceptuses and induced pluripotent stem cell lines.
• This study was conducted using a mule hybrid model.

Research Methodology

• The team identified a CpG-rich region encompassing five CTCF binding sites upstream of the equine H19 gene. This region was examined using bisulfite sequencing.
• Across parent-specific and global H19 transcript analysis, the researchers found that the imprinted H19 gene maintains its monoallelic status.

Research Findings

• Contrary to many other mammalian species, the average methylation levels of both parental differentially methylated regions within embryonic and extra-embryonic SCNT tissues as well as iPSC lines were unaltered by reprogramming.
• The equid somatic cells showed significant resilience to epigenetic changes to the H19-imprinted locus throughout the SCNT and iPSC reprogramming process.

Research Implications

• The findings suggest that cloned horses exhibit normal size, with no obvious abnormalities with their placenta, which possibly indicates that H19/IGF2 imprinting is likely to be epigenetically stable after reprogramming in equids.
• This comparative resilience to epigenetic modifications within the H19 gene in horse cells could have significant implications for the process of cell reprogramming and related applications within the field of veterinary medicine and associated fields.