Collaborative Research: Is hypoxia a critical cue for molting in Drosophila?

动物如何决定何时停止生长并成为成年人？身体大小深刻地影响着动物生物学的许多方面，但动物决定其成年大小的机制仍然是发育生物学未解决的基本问题之一。全变态昆虫是研究动物体型调节的主要模型，它们不像成虫那样生长，因此幼虫开始变态的大小决定了它们成虫的大小。最近一个重要的假设是，“在[幼虫]发育过程中限制大小的最接近机制可能是细胞缺氧的开始”，大概是由于氧气需求超过供应能力。本研究将通过检查大气氧水平对生长、变态时间和神经内分泌功能的影响，来测试氧在确定果蝇（Drosophila melanogaster）成年体型中的作用。此外，还将进行表观遗传分析，以测试候选信号通路的作用，通过这些信号通路，氧感可能控制发育时间和身体大小。了解身体大小是如何决定的是生物学的一个基本问题，因为身体大小影响生理学，生态学和进化的许多方面。身体大小强烈影响动物的食物需求、竞争和生殖能力、资源价值、药物清除率和应激耐受力。然而，决定动物何时从生长中的幼年形态转变为生殖性成年形态的机制对任何动物都没有很好的理解。除了提供关于这一主题的新信息外，果蝇的这项研究可能具有与农业昆虫控制和疾病预防相关的特定应用。这项研究将通过资助本科生、研究生和博士后学员的研究经验，为科学培训做出贡献。最后，该项目将通过开发一个在线生物实验室和向当地一所以生物科学为重点的高中推广，支持中等教育。 这一项目的成果还将通过同行审查的出版物和在区域或国家科学会议上的介绍加以传播。 与每份出版物相关的数据将发布在Dryad（www.datadryad.org）上。

How do animals decide when to stop growing and become adults? Body size profoundly affects many aspects of animal biology, yet the mechanisms by which animals determine their adult size remain among the fundamental unsolved problems of developmental biology. Holometabolous insects - the primary model for the study of size regulation in animals - do not grow as adults, so the size at which larvae initiate metamorphosis determines their adult size. A recent prominent hypothesis is that "the proximate mechanism setting limits to size during [larval] development is probably the onset of cellular hypoxia", presumably due to oxygen demand outstripping supply capacity. This research will test the role of oxygen in determination of adult body size in the fruit fly, Drosophila melanogaster, by examining the effect of manipulation of atmospheric oxygen levels on growth, timing of metamorphosis, and neuroendocrine function. In addition, epigenetic analyses will be conducted to test the role of candidate signaling pathways by which oxygen sensing might control developmental timing and body size.Understanding how body size is determined is a fundamental question of biology because body size affects so many aspects of physiology, ecology and evolution. Body size strongly affects food requirements, competitive and reproductive capacities, value as a resource, drug clearance rates, and stress-tolerance of an animal. Yet, the mechanisms involved in determining when animals switch from the growing juvenile form to the reproductive adult form are not well-understood for any animal. In addition to providing new information on this topic that may be general for animals, this research with Drosophila may have specific applications relevant to insect control for agriculture and disease-prevention. This research will contribute to science training by funding research experiences for undergraduate, graduate and postdoctoral trainees. Finally, this project will support secondary education by development of an on-line biology laboratory and outreach to a local bioscience-focused high school. Results from this project will also be disseminated through peer reviewed publications and presentations at regional or national scientific meetings. Data associated with each publication will be posted on Dryad (www.datadryad.org).