A composition of a female germinal cell (egg) extract of pluricellular organisms in M-phase of the cell cycle, the extract being used for a mitotic remodeling of chromosomes of donor cells of pluricellular organisms, wherein the mitotic remodeling confers to the nucleus of the donor cells the ability to adapt themselves to the early embryonic development, in particular to the replication phases, in order to carry out the embryonic development or to obtain stem cells.