Evolution of primary microcephaly genes and the enlargement of primate brains
Evolution of primary microcephaly genes and the enlargement of primate brains
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DOI：
10.1016/j.gde.2005.04.009
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发表时间：
2005-06-01
影响因子：
4
通讯作者：
Jackson, AP
中科院分区：
文献类型：
--
作者：
Ponting, C;Jackson, AP
在哺乳动物的进化过程中，大脑的大小与身体的大小有着显著的差异。特别是，大的大脑皮层是人类区别于其他灵长类动物的一个特征。这种解剖学上的变化必须有遗传改变的基础，但所涉及的分子过程尚未确定。然而，克隆两个人类疾病基因的最新进展有望在这一重要领域取得进展。小头症（MCPH1）和异常纺锤状小头症相关（ASPM）是原发性小头症（一种人类神经发育障碍）中的基因突变。在这种“返祖”的情况下，大脑体积缩小到与早期原始人类相当的大小。因此，有人提出，这些基因随着灵长类动物大脑大小的增加而适应性地进化。随后的研究支持了这一假设，表明这两种基因在类人猿进化过程中都经历了积极的选择。对它们蛋白质的进一步功能表征将有助于理解决定人脑大小的分子和进化过程。
Brain size, in relation to body size, has varied markedly during the evolution of mammals. In particular, a large cerebral cortex is a feature that distinguishes humans from our fellow primates. Such anatomical changes must have a basis in genetic alterations, but the molecular processes involved have yet to be defined. However, recent advances from the cloning of two human disease genes promise to make inroads in this important area. Microcephalin (MCPH1) and Abnormal spindle-like microcephaly associated (ASPM) are genes mutated in primary microcephaly, a human neurodevelopmental disorder. In this 'atavistic' condition, brain size is reduced in volume to a size comparable with that of early hominids. Hence, it has been proposed that these genes evolved adaptively with increasing primate brain size. Subsequent studies have lent weight to this hypothesis by showing that both genes have undergone positive selection during great ape evolution. Further functional characterisation of their proteins will contribute to an understanding of the molecular and evolutionary processes that have determined human brain size.