Molecular evolution and ecological adaptation of male- and female-transmitted mtDNA genomes in bivalves

我的长期目标是了解在双壳类软体动物中存在的一个非常不寻常的线粒体DNA遗传系统的起源和维持因素。这种系统被称为线粒体DNA的“双单代遗传”（DUI）。与所有其他动物不同，许多双壳类动物拥有两种不同的与性别相关的mtDNA谱系，而不仅仅是单一的、雌性传播的mtDNA谱系。我的短期目标是测试各种假说，这些假说被提出来解释与男性和女性传播DNA基因组的发育控制和进化动力学相关的因素。这些假设包括酒后驾车允许自然选择提高这些贻贝的精子性能，或者这些与性别相关的基因组可能在性别决定中发挥作用。在海洋贻贝中发现的独特的雄性和雌性传播的mtDNA基因组也经历了重组，这种现象直到最近才被认为发生在动物mtDNA基因组中。我研究这种不寻常的线粒体DNA遗传系统的方法包括精子活力分析、全线粒体基因组测序分析和生物信息学/计算机分析的组合。我的研究的预期结果是促进我们对基本生物过程的理解，主要是在双壳类动物中，但这些知识也将适用于其他动物群体。我的研究将促进我们对基本细胞过程的理解，并将引起遗传学家、无脊椎生物学家和动物学家的普遍兴趣和价值。在双壳类性别决定领域的纯知识的进步可能在水产养殖领域和通过人工控制性别比例来开发入侵淡水贻贝物种的生物控制方面具有应用价值。我的研究对解释线粒体DNA的进化也有广泛的意义。例如，我的研究项目将为解释一个被称为Cox1的特定基因的DNA序列提供必要的数据，这是“生命条形码联盟”倡议的基础。这是一项尝试，利用DNA序列数据，通过一种简单、廉价的测试来识别世界上所有的动物物种。由于海洋和淡水贻贝面临着全球气候变化和双壳类入侵物种全球迁移的威胁，对其DNA条形码的正确解读将变得越来越重要。

My long-term objectives are to understand the origin and factors maintaining a highly unusual system of mitochondrial DNA inheritance present in bivalve mollusks. This system is called “doubly uniparental inheritance” (DUI) of mitochondrial DNA. Unlike all other animals, many groups of bivalves possess two distinct sex-associated mtDNA lineages rather than just a single, female-transmitted mtDNA lineage. My short-term objectives are to test various hypotheses that have been proposed to explain factors associated with the developmental controls and evolutionary dynamics of the male- and female-transmitted DNA genomes. These hypotheses include the proposal that DUI allows for natural selection to improve sperm performance in these mussels, or that these gender-associated genomes might play a role in sex determination. The distinct male and female transmitted mtDNA genomes found in marine mussels also undergo recombination, a phenomenon that was, until recently, not thought to occur in animal mtDNA genomes. My approach to studying this unusual system of mitochondrial DNA inheritance includes a combination of sperm motility analyses, whole mitochondrial genome sequencing assays, and bioinformatics/in silico analyses. The anticipated outcome of my research is to advance our understanding of basic biological processes, primarily in bivalves, but this knowledge will also apply to other animal groups. My research will advance our understanding of fundamental cellular processes and will be of general interest and value to geneticists, invertebrate biologists and zoologists. The advancement of pure knowledge in the area of sex determination in bivalves may have applications in the field of aquaculture and in the development of biological controls for invasive freshwater mussel species through artificial control of sex ratios. My research also has broad implications for interpreting the evolution of mitochondrial DNA. For example, my research program will provide essential data for interpreting DNA sequences for a particular gene known as Cox1, which is used as the basis of the "Consortium for the Barcode of Life" initiative. This is an attempt to use DNA sequence data to identify all species of animals in the world using a simple, inexpensive test. The correct interpretation of DNA Barcodes of native marine and freshwater mussels will be increasingly important as these species face threats from global climate change and global transport of invasive bivalve species.