Across eukaryotes, most genes required for mitochondrial function have been transferred to, or otherwise acquired by, the nucleus. Encoding genes in the nucleus has many advantages. So why do mitochondria retain any genes at all? Why does the set of mtDNA genes vary so much across different species? And how do species maintain functionality in the mtDNA genes they do retain? In this review, we will discuss some possible answers to these questions, attempting a broad perspective across eukaryotes. We hope to cover some interesting features which may be less familiar from the perspective of particular species, including the ubiquity of recombination outside bilaterian animals, encrypted chainmail-like mtDNA, single genes split over multiple mtDNA chromosomes, triparental inheritance, gene transfer by grafting, gain of mtDNA recombination factors, social networks of mitochondria, and the role of mtDNA dysfunction in feeding the world. We will discuss a unifying picture where organismal ecology and gene-specific features together influence whether organism X retains mtDNA gene Y, and where ecology and development together determine which strategies, importantly including recombination, are used to maintain the mtDNA genes that are retained.

中文翻译：

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真核生物线粒体 DNA 基因含量的进化和维持。


在真核生物中，线粒体功能所需的大多数基因都已转移到细胞核或由细胞核获得。在细胞核中编码基因有很多优点。那么为什么线粒体会保留任何基因呢？为什么不同物种的 mtDNA 基因组差异如此之大？物种如何维持它们所保留的线粒体DNA基因的功能？在这篇综述中，我们将讨论这些问题的一些可能的答案，尝试从更广阔的角度看待真核生物。我们希望涵盖一些从特定物种的角度来看可能不太熟悉的有趣特征，包括两侧对称动物之外普遍存在的重组、加密的链甲状线粒体DNA、分裂在多个线粒体DNA染色体上的单基因、三亲遗传、通过嫁接进行的基因转移、线粒体DNA重组因子的获得、线粒体的社交网络以及线粒体DNA功能障碍在养活世界中的作用。我们将讨论一个统一的图景，其中有机体生态学和基因特异性特征共同影响有机体 X 是否保留 mtDNA 基因 Y，并且生态学和发育共同决定使用哪些策略（重要的是包括重组）来维持保留的 mtDNA 基因。