Epigenetic regulation of metabolism in Drosophila

描述（由申请人提供）：全球人群中糖尿病和肥胖症频率的惊人上升促使公共政策发生重大变化，生物医学研究也转向提高我们对代谢失调如何导致疾病的理解。这种代谢紊乱流行病的核心是父母和他们后代的代谢健康之间的惊人相关性。有大量的文献 在大鼠和小鼠中描述了这一现象，证明了父母一代的暂时营养变化可能对维持正常饮食的成年后代的代谢状态产生重大影响。这包括患2型糖尿病和肥胖症的风险增加。沿着，对1944年荷兰饥饿冬季出生的成年人进行的流行病学研究以及其他相关研究表明，在人类中也可以看到类似的代谢遗传效应。分子研究表明，后代表观遗传染色质标记的变化与亲代饮食的变化有关，为解释遗传对代谢的影响提供了潜在的分子机制。然而，尽管有这些广泛的研究，这一领域的研究仍然是相关的。只有少数遗传学方法已被用于表征代谢状态的遗传，并没有明确的分子机制来解释这种关联。我们已经发现果蝇具有将父母的代谢状态与后代联系起来的能力， 可以通过雄性和雌性生殖系观察到这种传播，代谢功能障碍会持续到F2和F3代，并且表型与啮齿动物和人类研究中报告的表型相似。我们已经确定了一个核受体，有助于这种反应，DHR 96，并已表明，表观遗传状态的遗传变化可能会导致后代的代谢功能障碍。我们在这里提出两个具体目标，以扩大这些初步意见。首先，我们将定义在成年后代的父母受到不同的短暂的饮食治疗的生理和代谢缺陷。这些实验将包括代谢组学分析，通过RNA-seq进行的转录分析，组织特异性和性别特异性遗传研究，以及测试不同的饮食治疗。其次，我们将通过确定经历不同饮食的野生型亲本的亲本种系和成熟成年后代中关键组蛋白修饰的全基因组变化来表征跨代代谢控制的表观遗传调节。我们还将进行集中的遗传研究，以测试由这项工作引起的代谢功能障碍的特定模型。我们在这项研究中的目标是利用果蝇的遗传优势进行代谢调节和表观遗传控制的研究，首次提供一个简单的模型系统来定义控制跨代代谢遗传的分子机制。

DESCRIPTION (provided by applicant): The alarming rise in the frequency of diabetes and obesity in worldwide populations has prompted major changes in public policy as well as a shift in biomedical research toward improving our understanding of how misregulation of metabolism can lead to disease. Central to this epidemic of metabolic disorders is the striking correlation between the metabolic health of the parents and that of their offspring. There is a vast literature describing this phenomenon in rats and mice, demonstrating that temporary nutritional changes in the parental generation can have major effects on the metabolic status of their adult offspring maintained on a normal diet. This includes an increased risk for developing type 2 diabetes and obesity. Epidemiological studies of adults born during the Dutch Hunger Winter of 1944, along with other more correlative studies, have demonstrated that similar inherited effects on metabolism can be seen in humans. Molecular studies have shown that changes in epigenetic chromatin marks in offspring are associated with changes in parental diet, providing a potential molecular mechanism to explain the inherited effects on metabolism. In spite of these extensive studies, however, the research in this area remains correlative. Only a few genetic approaches have been used to characterize the inheritance of metabolic state, and there is no defined molecular mechanism to explain this association. We have discovered that the fruit fly Drosophila shares the ability to link the metabolic status of parents with that of their offspring, that transmission can be seen through both the male and female germline, that metabolic dysfunction carries through to the F2 and F3 generations, and that the phenotypes are similar to those reported in rodent and human studies. We have identified a nuclear receptor that contributes to this response, DHR96, and have shown that genetic changes in epigenetic state can lead to metabolic dysfunction in the offspring. We propose here two specific aims to extend these initial observations. First, we will define the physiological and metabolic defects seen in the adult offspring of parents subjected to different transient dietary treatments. These experiments will include metabolomic profiling, transcriptional profiling by RNA-seq, tissue-specific and sex-specific genetic studies, and testing different dietary treatments. Second, we will characterize the epigenetic regulation of transgenerational metabolic control by determining the genome- wide changes in key histone modifications in the parental germline and mature adult offspring of wild-type parents subjected to different diets. We will also perform focused genetic studies to test specific models for metabolic dysfunction that arise from this work. Our goal in this research is to exploit the genetic strengths of Drosophila for studies of metabolic regulation and epigenetic control, providing, for the first time, a simple model system to define the molecular mechanisms that control transgenerational metabolic inheritance.