Sequence, Evolution and Expression of Mitochondrial Genomes in the Genus Zea

在植物和动物的细胞中，线粒体帮助将食物转化为化学能。虽然细胞核包含了细胞的绝大多数基因，但线粒体有自己的DNA，编码对细胞生存至关重要的蛋白质。在动物和大多数植物中，线粒体基因只能通过雌性（卵子）亲本遗传。植物的线粒体基因组通常比动物的线粒体基因组大得多，也更多变。植物的线粒体编码更多的蛋白质，包括那些可以干扰花粉发育的蛋白质。这种类型的不育（不影响花的雌性部分）被称为细胞质雄性不育（CMS）。该性状可用于生产更强、产量更高的杂交植株。尽管它们的大小和重要性相对较小，但很少有植物线粒体基因组被测序。线粒体蛋白编码基因在不同类型的植物中似乎非常相似；然而，大部分线粒体DNA位于基因之间，其功能和起源尚不清楚。此外，这些“基因间”DNA序列在不同的植物中似乎没有什么共同之处。因此，为了了解植物线粒体DNA的快速变化是如何发生的，我们需要分析非常接近的物种的线粒体基因组。我们将对四种栽培玉米及其一种野生近缘种，以及另外两种亲缘较远的单子叶作物品种驼草（trisacum dactyloides）和高粱的线粒体基因组进行测序。我们将识别所有潜在的基因，并研究它们在不同组织和发育阶段中的表达方式。该项目将有助于了解线粒体基因组的内容、组织、表达和进化

Mitochondria help to turn food into chemical energy in cells of plants and animals. Although the nucleus contains the vast majority of the cell's genes, mitochondria have their own DNA, coding for proteins vital for the survival of cells. In animals and most plants, mitochondrial genes are inherited only through the female (egg) parent. Plant mitochondrial genomes are generally much larger and more variable than those of animals. Plant mitochondria code for more proteins, including ones that can interfere with the development of pollen. This type of infertility (which does not affect female parts of flowers) is called cytoplasmic male sterility (CMS). The CMS trait can be exploited in the production of stronger and higher-yielding hybrid plants. Despite their relatively small sizes and importance, very few plant mitochondrial genomes have been sequenced. Mitochondrial protein-coding genes appear to be very similar in different types of plants; however, most of the mitochondrial DNA lies between genes and its function and origin is unknown. Furthermore, it appears that these "intergenic" DNA sequences have little in common in different plants. Therefore, in order to understand how rapid changes occur in plant mitochondrial DNA, we need to analyze mitochondrial genomes from very closely related species. We will sequence the mitochondrial genomes from four types of cultivated maize and one of its close wild relatives, as well as from two other more distantly related monocot crop species, Tripsacum dactyloides (eastern gamma grass) and sorghum. We will identify all the potential genes and look at how they are expressed in different tissues and stages of development. The project will contribute to an understanding of the content, organization, expression and evolution of mitochondrial genomes i