DISSERTATION RESEARCH: Molecular Evolution of Extracellular Hemoglobins in the Vestimentiferan Tubeworm Ridgeia piscesae

东北太平洋热液喷口的管虫Ridgeia piscesae利用细胞外血红蛋白将环境中的硫化物传递给细胞内细菌，而细胞内细菌又利用硫化物为宿主制造糖。根据喷口流体的温度和化学性质，双鱼鲷表现出几种不同的生长形式。双鱼的生长形式在基因上是相同的，但为什么双鱼在不同的环境中表现出体型的变化是一个谜。本研究将对两种鱼类生长形式中血红蛋白亚基的序列多样性和基因表达差异进行表征，以确定该候选分子是否对硫化物水平的环境变化做出反应。绘制管虫基因组中珠蛋白基因的位置将有助于更好地了解这些基因是如何被调控的。热液喷口是地球上独特的环境，因为生物利用化学能而不是阳光驱动生态系统。对双鱼脊的遗传研究将为生物体如何适应极端环境提供更多的见解。这项研究将提供一个独特的机会来了解基因表达是否受到环境的影响。阐明珠蛋白基因的DNA序列变异模式也将增加我们对环境如何影响进化模式的理解。

The tubeworm Ridgeia piscesae of the hydrothermal vents in the northeast Pacific Ocean uses extracellular hemoglobins to deliver environmental sulfide to intracellular bacteria, which in turn uses sulfide to create sugars for the host. R. piscesae displays several different growth forms depending on the temperature and chemistry of vent fluids. The growth forms of R. piscesae are genetically identical, but why R. piscesae shows variation in body shape in different environments is a mystery. This research will characterize sequence diversity and gene expression differences of hemoglobin subunits in two R. piscesae growth forms to determine if this candidate molecule responds to environmental variation in sulfide levels. Mapping the location of globin genes within the tubeworm genome will provide a better understanding of how these genes are regulated.Hydrothermal vents are unique environments on this planet because organisms use chemical energy rather than sunlight drives the ecosystem. Genetic studies of Ridgeia piscesae will provide more insight into how organisms adapt to extreme environments. This research will provide a unique opportunity to learn if gene expression is influenced by the environment. Elucidating patterns of DNA sequence variation in globin genes will also increase our understanding of how environments influence patterns of evolution.