A fateful age gap

Abstract

When a stem cell divides, one sister cell differentiates and the other retains its stem-cell identity. Differences in the age of an organelle — the centriole — inherited at cell division may determine these differing fates. The centrosome is the main microtubule-organizing centre in animal cells. Its intrinsic asymmetry, made up as it is of centrioles formed at different stages of the cell cycle, is an important factor in stem cell division. Now a study in mouse embryos shows that the process that accounts for nearly all neurogenesis in the developing mammalian neocortex — asymmetric division of radial glia progenitors — is also regulated by asymmetric inheritance of centrioles. Now a study of the embryonic mouse neocortex shows that the process that accounts for nearly all neurogenesis in the developing mammalian neocortex — asymmetric division of radial glia progenitors — is also regulated by asymmetric inheritance of centrioles. Daughter cells receiving the older of the two centrioles in the main remain in the ventricular zone of the brain's neocortex to replenish the progenitor pool, while daughter cells receiving the new, duplicated centriole tend to migrate into the cortex to differentiate into a neuron.