Genetic and Cellular Analysis of C. elegans Exposed to Anoxia

因为真核生物的生命需要氧气，所以缺氧影响它们的生长和发育可能并不令人惊讶。然而，发育过程中缺乏氧气并不总是致命的。事实上，包括线虫、斑马鱼、咸虾和果蝇在内的几种生物在缺氧时会阻止发育和细胞周期的发展。线虫，秀丽线虫，暴露在缺氧中，显著阻止发育和细胞周期进程长达4天。这种停滞在再次暴露于氧气时是可逆的，因此被称为缺氧诱导的暂停生命。真核生物中缺氧诱导的暂停生命的保守性表明可逆性停滞在生物体中具有重要的作用。然而，由于对缺氧引起的悬吊现象还没有很好的研究，因此还不清楚，本研究的重点是线虫胚胎如何在缺氧状态下存活。长期的研究目标是识别和表征线虫中发生的阻止发育和细胞过程对缺氧做出反应的分子机制。基因和细胞生物学研究的结合将被用来检验线虫具有发育依赖的遗传和细胞机制以在缺氧中生存的假设。线虫缺氧生存所需的基因已经确定，并将在分子水平上进行进一步研究。具体地说，纺锤体检查点基因，SAN-1和MDF-2，在缺氧诱导的暂停生命中的作用将被调查。此外，RNA干扰屏幕的扩展将用于识别胚胎在缺氧状态下存活所需的其他基因。这项拟议的项目意义重大，因为它将确定线虫胚胎缺氧生存所需的遗传途径。了解缺氧对生物体的影响将有助于更好地理解环境如何影响发育中的胚胎。最后，拟议的项目将通过研究生和本科生的参与将研究和教育结合起来。

Because eukaryotic organisms require oxygen for life it is probably not surprising that oxygen deprivation influences their growth and development. However, the absence of oxygen during development is not always fatal. It fact, several organisms, including nematodes, zebrafish, brine shrimp, and fruit flies arrest developmental and cell cycle progression in response to oxygen deprivation. The nematode, Caenorhabditis elegans, exposed to anoxia remarkably arrests developmental and cell cycle progression for up to 4 days. This arrest is reversible upon reexposure to oxygen, and is thus referred to as anoxia-induced suspended animation. The conservation of anoxia-induced suspended animation in eukaryotes suggests that reversible arrests have a significant role in organisms. However the phenomenon of anoxia-induced suspended animation has not been well studied and therefore is not understood, The proposed research focuses on how C. elegans embryos survive anoxia. The long-term research goal is to identify and characterize the molecular mechanisms that occur in nematodes to arrest developmental and cellular processes in response to anoxia. A combination of genetic and cell biological studies will be used to test the hypothesis that nematodes have developmentally dependent genetic and cellular mechanisms to survive anoxia. Genes required for nematodes to survive anoxia have been identified and will be further studied at the molecular level. Specifically, the role of spindle checkpoint genes, san-1 and mdf-2, in anoxia induced suspended animation will be investigated. Additionally, expansion of an RNA interference screen will be used to identify additional genes required for embryos to survive anoxia. The proposed project is significant because it will identify genetic pathways required for nematode embryos to survive anoxia. Understanding the effect oxygen deprivation has on organisms will lead to a greater understanding of how the environment effects developing embryos. Finally, the proposed project will integrate research and education by having the involvement of students at both the graduate and undergraduate level.