Collaborative Project: Effects of Oxygen and Temperature on Egg Mass Function of Southern Ocean Marine Invertebrates

该项目旨在了解南大洋海洋无脊椎动物生殖策略的进化生理学。南大洋的动物群在稳定的寒冷温度下进化了大约1400万年。这些条件导致了不寻常的生理和生化特性的演变，其中许多可能反映了适应相对较低的氧气供应和高幼虫的氧气需求。拟议项目的目标是了解无脊椎动物卵块功能的纬度变化与氧气供应和温度的关系。这种关系对于幼虫在高纬度低温、高氧条件下的生存至关重要。特别是，研究人员将：（1）使用第一原理模拟在环境相关温度下氧气向南极生物卵和胚胎群的扩散;（2）通过测量胚胎代谢的温度依赖性和氧气通过天然和人工凝胶的扩散率来测试模型假设;（3）通过使用氧微电极测量人工和天然卵块中的氧梯度以及通过测量在卵块中不同位置处的胚胎发育速率来测试模型预测;（4）比较南大洋和温带沃茨卵块的结构和功能。 这项研究的这些组成部分构成了对卵块结构和功能的进化生理学的综合研究。对极地特有的质量的研究将增加对卵质量在赤道到极地的温度梯度和氧分压梯度上的演变的理解。该提案将支持研究生，并将涉及几个本科生的研究。PI还将为各自机构的本科生课程设计和实施极地生物学单元。这些教育单位将集中在PI的照片，录像，实验和数据，从这个项目。PI将使用网络链接的视频和教学技术来设计和共同教授极地生态生理学的新课程，将与当地小学机构合作，让高中生参与研究，并将开发有关极地生物学的高中课程模块。

This project seeks to understand the evolutionary physiology of reproductive strategies in Southern Ocean marine invertebrates. The fauna of the Southern Ocean has evolved under stable, cold temperatures for approximately 14 million years. These conditions have led to the evolution of unusual physiological and biochemical characteristics, many of which may reflect adaptations to relatively low oxygen availability and high larval oxygen demands. The goal of the proposed projects is to understand latitudinal variation in the function of invertebrate egg masses in relation to oxygen availability and temperature. This relationship is critical to larval survival in the low-temperature, high-oxygen conditions found at high latitudes. In particular, the investigators will: (1) use first principles to model the diffusion of oxygen into egg and embryo masses of Antarctic organisms at environmentally relevant temperatures; (2) test model assumptions by measuring the temperature-dependence of embryonic metabolism and oxygen diffusivity through natural and artificial gels; (3) test model predictions by using oxygen microelectrodes to measure oxygen gradients in both artificial and natural egg masses, and by measuring developmental rates of embryos at different positions in masses; and (4) compare the structure and function of egg masses from the Southern Ocean to those from temperate waters. These components of the study constitute an integrated examination of the evolutionary physiology of egg mass structure and function. Studies of masses endemic to polar conditions will increase the understanding of egg mass evolution across equator-to-pole gradients in temperature and across gradients in oxygen partial pressure. The proposal will support graduate students and will involve several undergraduates in research. The PIs will also design and implement units on polar biology for undergraduate classes at their respective institutions. These educational units will focus on the PIs' photographs, video footage, experiments, and data from this project. The PIs will use web-linked video and instructional technologies to design and co-teach a new class on polar ecological physiology, will work with local grade school institutions to involve high school students in research, and will develop high school course modules about polar biology.