Energetics of Protein Metabolism during Development of Antarctic Echinoderms

0130398 Manahan幼虫型在海洋环境中无脊椎动物的生活史策略中占主导地位。在南极洲，能量收支计算表明，棘皮动物的幼虫阶段有能力在没有食物的情况下生存数月至数年。这导致了一种猜测，即能量代谢机制在这些幼虫形式中更有效，这种“增强的效率”可能是极端寒冷的生命所独有的。最近对南极海洋无脊椎动物发育生理学的生物化学基础的研究揭示了寒冷环境下新陈代谢的一些新方面。与预期的低代谢和低速率的大分子合成在寒冷中，南极海胆的胚胎和幼虫具有高速率的蛋白质合成，同时保持低速率的代谢。最近的一项发现解决了这个明显的悖论，即南极海胆的蛋白质合成成本是其他动物的二十五分之一。这是动物蛋白质合成的最高效率，对寒冷环境中生长和发育的生理学具有重要意义。这种独特的生物化学效率的蛋白质合成在寒冷的主题是详细的调查，在目前的项目。该研究小组将联合收割机结合南极幼体生理学和生物化学以及海胆发育分子生物学方面的专门知识，以解决基于三个主要目标的实验计划。(1)最近发现的南极海胆幼虫蛋白质合成成本低的普遍性将通过测量其他南极棘皮动物物种发育过程中的代谢和蛋白质合成进行测试。(2)对具有低代谢成本的高蛋白质合成速率的预测是，在这样的生物体中生长效率将是高的。这将通过测量幼虫中蛋白质生长效率的生理学来测试。(3)南极海胆胚胎蛋白质合成的独特高效率将使用特定的分子生物学方法进行研究。这些定量分析的结合将使我们能够精确定位导致如此高的能量效率的蛋白质代谢的那些方面。需要了解极地生物的代谢效率，以帮助解决有关极地地区温度补偿和适应食物限制的长期问题。这里的独特方法是强调生物分析的细胞和亚细胞水平，以了解我们建议研究的南极生物体的发育，生长，代谢率，蛋白质合成速率和成本之间的关系。

0130398ManahanLarval forms are dominant in the life history strategies of invertebrates in marine environments. In Antarctica, energy budget calculations have shown that larval stages of echinoderms have the capacity to survive without food for periods of several months to years. This has led to the speculation that mechanisms of energy metabolism are more efficient in these larval forms, and that this "enhanced efficiency" might be unique to life in extreme cold. Recent studies on the biochemical bases of developmental physiology in Antarctic marine invertebrates have revealed some novel aspects of metabolism in the cold. Contrary to expectations of low metabolism and low rates of macromolecular synthesis in the cold, embryos and larvae of an Antarctic sea urchin have high rates of protein synthesis, while maintaining low rates of metabolism. This apparent paradox was resolved with the recent finding that the cost of protein synthesis in this Antarctic sea urchin is one twenty-fifth of that reported for other animals. This is the highest efficiency for protein synthesis reported for an animal and has important implications for the physiology of growth and development in cold environments. This unique biochemical efficiency of protein synthesis in the cold is the subject of detailed investigation in the current project. The research team will combine expertise in Antarctic larval physiology and biochemistry and molecular biology of sea urchin development to address an experimental plan that is based on three major objectives. (1) The generality of the recent finding of the low cost of protein synthesis in Antarctic sea urchin larvae will be tested by measuring metabolism and protein synthesis during development of other Antarctic echinoderm species. (2) The prediction of a high rate of protein synthesis with low metabolic cost is that growth efficiencies will be high in such organisms. This will be tested by measuring the physiology of protein growth efficiencies in larvae. (3) The unique high efficiency of protein synthesis in Antarctic sea urchin embryos will be studied using specific molecular biology approaches. The combination of these quantitative analyses will enable us to pinpoint those aspects of protein metabolism that result in such extremely high energy-efficiencies. Understanding metabolic efficiency in polar organisms is required to help resolve long-standing questions regarding temperature compensation and adaptations to food limitation in polar regions. The unique approach here is the emphasis on the cellular and sub-cellular levels of biological analysis to understand the relationship among development, growth, metabolic rate, and rates and costs of protein synthesis in the Antarctic organisms we propose to study.