Molecular Evolution of Aerobic Energy in Primates: The Cytochrome bc1 Complex

氧化能量代谢的适应性变化可能是人类起源的关键过程。细胞色素c氧化酶的亚基，在电子传递链中的末端酶复合物，和细胞色素c，细胞色素bc1和细胞色素氧化酶之间的电子载体，以前被证明都经历了灵长类动物的快速氨基酸取代的时期。这些研究现在将扩展到细胞色素bc1，一种11亚基复合物。本文将讨论两个问题，其解决方案将有助于深入了解细胞色素bc1的进化和功能及其在灵长类动物中的潜在作用：（1）细胞色素bc1亚基基因和细胞色素c将被检查，以确定编码的蛋白质是否经历了快速的氨基酸取代的爆发，导致灵长类动物的谱系。(2)将检测灵长类动物中的阳性选择变化是否不仅通过氨基酸编码区变化发生，而且还通过控制基因表达的元件中的调节变化发生。这项工作将描述一些重要的遗传变化，这些变化使大脑灵长类动物的出现成为可能。

Adaptive changes in oxidative energy metabolism may be a key process in the origins of humankind. Subunits of cytochrome c oxidase, the terminal enzyme complex in the electron transport chain, and cytochrome c, the electron carrier between cytochrome bc1 and cytochrome oxidase, were previously shown to have both undergone periods of rapid amino acid substitutions in primates. These studies will now be extended to cytochrome bc1, an 11-subunit complex. Two problems will be addressed whose solutions will help provide insights into the evolution and function of cytochrome bc1 and its potential role in anthropoid primates: (1) Cytochrome bc1 subunit genes and also cytochrome c will be examined to determine whether the encoded proteins underwent bursts of rapid amino acid substitutions in lineages leading to the anthropoid primates. (2) Positively selected changes in primates will be tested as to whether they take place not only via amino acid coding region changes but also via regulatory changes in the elements that control expression of the genes. This work will characterize some of the important genetic changes that allowed the emergence of the large-brained primates.