By Geert Kops, University Medical Center Utrecht
This year, 2014, marks the 100th anniversary of an astonishing prediction by one of the great biologists of the past. Theodor Boveri had been observing the many ways in which the development of a sea urchin embryo could go awry when an egg was fertilized by multiple sperm cells. He noticed that those eggs made many errors in how they distributed the chromosomes during the first cell divisions and he deduced that the problems with development were caused by the wrong combination of chromosomes ending up in cells of the embryo. Surely, he thought, these chromosomes must contain information that dictates how a cell should behave. Knowing that another German biologist, David von Hansemann, had seen tumor cells with abnormal amounts of chromosomes, Boveri did what all great scientist do: he merged the two seemingly unrelated observations. Boveri realized that tumor cells might be tumor cells because they lost certain chromosomes that carried information on how to behave.