Development of hands and wings: Protein pentagone important
Whether we are talking about our own hand or something seemingly so distant from an evolutionary perspective as the wings of an insect: In order to make an organ out of a multitude of cells, the cells have to know where they are during the development of the still growing organ. Cells use this information to decide whether, for instance, they will later become a part of the thumb or the pinky finger. It has long been known that cells receive information on their position as well as growth stimuli from signaling molecules present in the cell tissue, so-called morphogens – real jacks of all trades, which are put to work again and again in the course of development. They are only produced by a small group of cells and have the ability to spread across the cell tissue in the form of a concentration gradient.