线粒体是真核生物通过有氧呼吸过程产生生物能量的工厂。这一重要细胞器相关基因的突变或缺失会对生物体产生重要功能缺陷。Bioon
中科院昆明动物所马普进化基因组学青年科学家小组的博士生江会锋在导师王文研究员和美国康乃尔大学（Cornell University）的Gu Zhenglong教授指导下发现，在啤酒酵母的进化支系中线粒体相关基因的功能在全基因组重复后发生了功能选择性放松，并且此种放松现象和这一进化支系中新近进化出来的高效有氧发酵机制密切相关。与此相反，进行有氧呼吸过程的酵母种属中线粒体功能则是高度保守的。这一结果提示在真核生物的进化过程中这两种重要能量代谢途径可能在进化过程中存在着某种竞争机制。
该研究成果于7月30号在线发表于国际著名基因组学刊物《基因组研究》（Genome Research）（IF 11.3）上。（生物谷Bioon.com）
生物谷推荐原始出处：
Genome Research，DOI: 10.1101/gr.074674.107，Huifeng Jiang，Zhenglong Gu
Relaxation of yeast mitochondrial functions after whole-genome duplication
Huifeng Jiang1,2,3, Wenjun Guan1,4, David Pinney5, Wen Wang2,6, and Zhenglong Gu1,6
1 Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA; 2 CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), Kunming, Yunnan 650223, People’s Republic of China; 3 Graduate School of Chinese Academy Sciences, Beijing 100039, People’s Republic of China; 4 Zhejiang University, College of Life Sciences, Hangzhou 310058, People’s Republic of China; 5 Department of Mathematics, Cornell University, Ithaca, New York 14853, USA
Mitochondria are essential for cellular energy production in most eukaryotic organisms. However, when glucose is abundant, yeast species that underwent whole-genome duplication (WGD) mostly conduct fermentation even under aerobic conditions, and most can survive without a functional mitochondrial genome. In this study, we show that the rate of evolution for the nuclear-encoded mitochondrial genes was greater in post-WGD species than pre-WGD species. Furthermore, codon usage bias was relaxed for these genes in post-WGD yeast species. The codon usage pattern and the distribution of a particular transcription regulatory element suggest that the change to an efficient aerobic fermentation lifestyle in this lineage might have emerged after WGD between the divergence of Kluyveromyces polysporus and Saccharomyces castellii from their common ancestor. This new energy production strategy could have led to the relaxation of mitochondrial function in the relevant yeast species.
