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

动物是如何决定何时停止生长并成为成年动物的？体型对动物生物学的许多方面都有深远的影响，然而，动物决定其成年体型的机制仍然是发育生物学中尚未解决的基本问题。全变态昆虫--研究动物大小调节的主要模型--不会作为成虫生长，因此幼虫开始变态的大小决定了它们的成虫大小。最近一个突出的假说是，“在幼虫发育期间设定大小限制的最接近的机制可能是细胞缺氧的开始”，推测是因为氧气需求超过了供应能力。这项研究将通过检测大气氧气水平对果蝇生长、变态时间和神经内分泌功能的影响，来测试氧气在果蝇成体大小确定中的作用。此外，还将进行表观遗传学分析，以测试候选信号通路的作用，氧气感应可能通过这些通路控制发育时间和体型。理解如何确定体型是生物学的一个基本问题，因为体型影响生理、生态和进化的许多方面。体型对动物的食物需求、竞争和繁殖能力、作为资源的价值、药物清除率和应激耐受性有很大影响。然而，对于任何动物来说，确定动物何时从生长的幼体转变为生殖的成体所涉及的机制都不是很清楚。除了提供关于这个主题的可能对动物普遍适用的新信息外，这项针对果蝇的研究还可能在农业昆虫控制和疾病预防方面有特定的应用。这项研究将通过资助本科生、研究生和博士后实习生的研究经验，为科学培训做出贡献。最后，该项目将通过发展一个在线生物实验室和与当地一所以生物科学为重点的高中联系来支持中等教育。该项目的成果还将通过同行评议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).