中心体是动物细胞中的一种关键细胞器，起主要微管组织中心的作用，在细胞分裂和细胞迁移过程中有重要作用。中心体具有内在不对称性，它们似乎是由细胞周期不同阶段形成的“母”中心粒和“子” 中心粒组成的。这种内在不对称性最近被发现是干细胞分裂中的一个重要因子。

现在，对小鼠胚胎新皮层所做的一项研究表明，可解释发育中的哺乳动物新皮层中几乎全部神经发生活动（放射状胶质先祖细胞的非对称分裂）的过程也是由 中心粒的非对称遗传调控的。接受两个中心粒中较老一个的子细胞仍然留在大脑新皮层的脑室区，以补充先祖细胞数量，而接受新的、复制的中心粒的子细胞则迁移 到皮层中，分化成一个神经细胞。

Nature 461, 947-955 (15 October 2009) | doi:10.1038/nature08435

Asymmetric centrosome inheritance maintains neural progenitors in the neocortex

Xiaoqun Wang1, Jin-Wu Tsai2, Janice H. Imai1,3, Wei-Nan Lian2, Richard B. Vallee2 & Song-Hai Shi1,3

1 Developmental Biology Program, Memorial Sloan Kettering Cancer Centre, 1275 York Avenue, New York, New York 10065, USA
2 Departments of Pathology and Cell Biology, Columbia University, 630 W. 168th Street, New York, New York 10032, USA
3 BCMB Allied Program, Weill Cornell Medical College, 1300 York Avenue, New York, New York 10065, USA
Correspondence to: Correspondence and requests for materials should be addressed to S.-H.S.

Asymmetric divisions of radial glia progenitors produce self-renewing radial glia and differentiating cells simultaneously in the ventricular zone (VZ) of the developing neocortex. Whereas differentiating cells leave the VZ to constitute the future neocortex, renewing radial glia progenitors stay in the VZ for subsequent divisions. The differential behaviour of progenitors and their differentiating progeny is essential for neocortical development; however, the mechanisms that ensure these behavioural differences are unclear. Here we show that asymmetric centrosome inheritance regulates the differential behaviour of renewing progenitors and their differentiating progeny in the embryonic mouse neocortex. Centrosome duplication in dividing radial glia progenitors generates a pair of centrosomes with differently aged mother centrioles. During peak phases of neurogenesis, the centrosome retaining the old mother centriole stays in the VZ and is preferentially inherited by radial glia progenitors, whereas the centrosome containing the new mother centriole mostly leaves the VZ and is largely associated with differentiating cells. Removal of ninein, a mature centriole-specific protein, disrupts the asymmetric segregation and inheritance of the centrosome and causes premature depletion of progenitors from the VZ. These results indicate that preferential inheritance of the centrosome with the mature older mother centriole is required for maintaining radial glia progenitors in the developing mammalian neocortex.