The centrosome in vertebrates: more than microtubule-organizing center

The somatic cells of all higher animals contain a single minute organelle c alled the centrosome. For years, the functions of the centrosome were thoug ht to revolve around its ability to nucleate and organize the various micro tubule arrays seen in interphase and mitosis. But the centrosome is more th an just a microtubule-organizing center. Recent work reveals that this orga nelle is essential for cell-cycle progression and that this requirement is independent of its ability to organize microtubules. Here, we review the va rious functions attributed to the centrosome and ask which are essential fo r the survival and reproduction of the cell, the organism, or both.