Bacteria-like information processing in ancestral mitochondria

线粒体是所有真核生物（动物包括人类、真菌、植物和大量多样的原生动物/原生生物）细胞内的一种器官样结构（细胞器）。虽然线粒体通常被称为细胞的发电站，但它也起着重要的代谢作用：它们为整个细胞提供各种构建模块（碳水化合物，氨基酸，核苷酸，脂肪酸和铁硫化合物）。我们现在知道，线粒体拥有自己的基因组和特定的机制，用于细胞器分裂，DNA复制，基因转录为信使RNA，以及信使RNA翻译为蛋白质（细胞膜和酶的材料）。线粒体的这种半自主性是它们祖先的遗迹：它们起源于大约10亿年前在真核细胞中居住的内共生细菌。 在从共生细菌到细胞器的最初过渡阶段，原线粒体基因组必须编码一千多个指定线粒体蛋白质的基因，并遵守细菌在基因组组织，RNA转录和蛋白质翻译方面的惯例。然而，在今天的动物、真菌和植物线粒体中，基因组织和基因表达几乎没有细菌过去的痕迹。 我们的研究计划旨在阐明参与内共生细菌祖先的“驯化”的步骤，并追踪线粒体的前身转化为真核细胞器的过程。这些问题现在可以通过我们的发现有效地解决-在单细胞，有鞭毛的原生动物称为jakobids-线粒体DNA类似于微型细菌基因组。在我们项目的前五年，我们计划研究线粒体信息处理（从基因到RNA到蛋白质）在多大程度上类似于细菌或我们从动物，真菌和植物中所知道的“现代”线粒体。我们的方法将结合联合收割机经典生物化学，新一代基因组学方法和生物信息学，并为各级学生提供充足的多学科培训机会。

HOW MITOCHONDRIA CAME ABOUT Mitochondria are an organ-like structure (organelle) within the cells of all eukaryotes (animals including humans, fungi, plants, and the large and diverse assemblage of protozoans/protists). While usually referred to as the cell's powerhouse, mitochondria play also an import metabolic role: they supply the entire cell with various building blocks (carbohydrates, amino acids, nucleotides, fatty acids, and iron-sulfur compounds). We now know that mitochondria possess their own genome and particular machineries for organelle division, DNA replication, transcription of genes into messenger RNAs, and translation of messenger RNAs into proteins (the material from which cellular membranes and enzymes are made). This semi-autonomy of mitochondria is a vestige of their ancestry: they originate from endosymbiotic bacteria that took up residence in the eukaryotic cell about a billion years ago. In the initial transition phase from a symbiotic bacterium to an organelle, the proto-mitochondrial genome must have encoded more than a thousand genes specifying mitochondrial proteins, and adhered to bacterial conventions with respect to genome organization, RNA transcription and protein translation. However, in present-day mitochondria from animals, fungi and plants, gene organization and gene expression bear little traces of their bacterial past. Our research program aims at elucidating the steps that were involved in the 'domestication' of the endosymbiotic bacterial ancestor, and tracing the processes by which the predecessor of mitochondria was transformed into a eukaryotic organelle. These questions can now be tackled effectively through our discovery --in unicellular, flagellated protozoans called jakobids-- of mitochondrial DNAs resembling bacterial genomes in miniature. In the first five years of our program, we propose to investigate to which degree mitochondrial information processing, from gene via RNA to protein, resembles that of bacteria or rather 'modern' mitochondria as we known them from animals, fungi, and plants. Our approach will combine classical biochemistry, new generation genomics methodologies and bioinformatics, and provide ample multi-disciplinary training opportunities for students at all levels.