Totipotency is the capacity of a single cell to generate all cell types of an organism and occurs naturally for a short time window at the onset of vertebrate development. The generation of totipotent cells in the laboratory holds enormous promises to regenerative medicine since it would enable replacing ‘sick’ cells with ‘healthy’ cells.
Vertebrate eggs have the remarkable ability to reprogram cell fates upon somatic cell nuclear transfer (SCNT), whereby the nucleus of a somatic cell (donor) gets transferred into an enucleated egg. The resulting nuclear transfer embryo is able to erase the memory of the somatic cell identity. This allows the establishment of totipotency in the laboratory.
However, the reprogramming efficiency of SCNT is very low since some donors are resistant to reprogramming. Previously, Dr. Eva Hörmanseder could show that the cellular memory of resistant donors is stabilized by a specific epigenetic mark, the prominent histone modification H3K4 methylation. To investigate whether histone modifications, in particular H3K4 methylation, can act as epigenetic barriers for reprogramming and how these barriers can be manipulated in Xenopus NT-embryos, she received funding from the DFG. This includes also two PhD positions. The research of the Hörmanseder lab will provide fundamental insights into how reprogramming efficiencies can be improved and will promote the progress of the techniques, that allow the generation of totipotent cells in a petri dish.