Pollen cells keep memory to control jumping genes
In any living organism, all cells have the same DNA, but each cell's identity is defined by the combination of genes that are turned on or off, any given moment in time. In animals, this cellular memory is erased between generations, so that the new egg has no memory and, as such, has the potential to become any type of cell. In flowering plants, on the contrary, cellular memory passes from generation to generation, with potentially harmful implications for the development of new plants. In the latest issue of the journal Cell*, scientists from Instituto Gulbenkian de Ciência (IGC), in Portugal, and Cold Spring Harbor Laboratory (CSHL), in the USA, describe a novel mechanism whereby potentially mutagenic sequences of mobile DNA are silenced in the pollen grain and in seeds, thus avoiding damage to new plants.