Each cell exists in duplicate in a human being: one transmitted by the father and the other by the mother. The parental imprint is a “mechanism via which some genetic sequences remain silent, i.e. are not expressed, depending on whether they come from the mother or the father“. This is responsible for several genetic disorders such as Prader Willi syndrome “caused in 70% of cases by an abnormal paternal copy of chromosome 15“.
Difficult to study, Professor Nissim Benvenisty’s team at the Hebrew University of Jerusalem is interested in this syndrome and has succeeded in modelling it using induced pluripotent stem cells (IPS). These cells were originally obtained from “the skin cells of people affected by [Prader-Willi] syndrome“. They were then genetically modified to become pluripotent.
Scientists have shown “that the parental imprint caused a significant reduction in virtually all of the maternal genes present in a chromosome adjacent to chromosome 15, namely chromosome 14. This inhibition is due to the synthesis of a small quantity of RNA from the paternal gene, which alters the maternal gene in chromosome 14“.
Although other studies will be required, this one has nevertheless highlighted “the interest of modelling using induced pluripotent stem cells“.