Genetic and behavioral analysis of developmental ethanol exposure in Drosophila

描述（由申请人提供）：拟建研究的目的是将黑腹果蝇作为研究胎儿酒精综合征的动物模型。先前的研究表明，遗传因素可以调节酒精致畸风险的程度，但影响发育乙醇毒性的特定基因的鉴定一直难以捉摸。拟议的研究将描述果蝇在发育性乙醇暴露后发生的发育、行为和神经解剖学变化，并确定改变发育性乙醇毒性的新基因产物。初步数据显示，食用5%乙醇食物的苍蝇的存活率是对照动物的一半，而且发育时间明显推迟。此外，乙醇饲养的果蝇成年后对汽化乙醇的运动刺激作用更为敏感，这表明乙醇饲养会导致永久性的行为改变。为了确定乙醇致死性的阶段和乙醇毒性的临界时间窗，我们将在不同的发育阶段用0%和5%乙醇饲养动物进行一系列实验。通常与胎儿酒精综合征相关的行为缺陷，如学习和记忆缺陷、运动功能障碍、昼夜节律失调以及饮食和睡眠障碍，将在乙醇饲养和未暴露的对照成年苍蝇中进行评估。胎儿酒精综合征的行为障碍被认为是由乙醇引起的中枢神经系统损伤引起的。因此，我们将分别使用免疫细胞化学和GAL4/UAS双表达系统来检查胚胎和成人中枢神经系统在发育性乙醇暴露后的神经解剖学损伤和/或改变。最后，修饰乙醇致畸的基因产物将使用候选基因方法和单基因插入突变的无偏倚前向遗传筛选来鉴定。调节乙醇致畸的基因的功能分析将通过分子、行为和遗传方法的结合进行。

DESCRIPTION (provided by applicant): The goal of the proposed studies is to develop Drosophila melanogaster as an animal model to investigate fetal alcohol syndrome. Previous studies indicate that genetic factors can modulate the degree of alcohol teratogenic risk, yet the identification of specific genes that influence developmental ethanol toxicity has been elusive. The proposed research will both characterize the developmental, behavioral and neuroanatomical changes that occur upon developmental ethanol exposure in flies, and identify novel gene products that alter developmental ethanol toxicity. Preliminary data has shown that flies reared on 5% ethanol food are half as viable compared to control animals and significantly delayed in developmental time. In addition, ethanol-reared flies are more sensitive, as adults, to the locomotor-stimulant effects of vaporized ethanol, indicating that ethanol rearing causes permanent behavioral changes. To define the stage of ethanol-induced lethality and the critical time window of ethanol toxicity, a series of experiments will be performed rearing animals on 0% and 5% ethanol food during discrete developmental stages. Behavioral deficits commonly associated with fetal alcohol syndrome, such as learning and memory deficits, motor dysfunction, circadian rhythm deregulation, as well as eating and sleeping disturbances will be evaluated in both ethanol-reared and unexposed control adult flies. The behavioral disorders of fetal alcohol syndrome are thought to be caused by ethanol-induced injury to the developing central nervous system. Therefore, neuroanatomical damage and/or alterations following developmental ethanol exposure will be examined in both the embryonic and adult central nervous system using immunocytochemistry and the GAL4/UAS binary expression system, respectively. Finally, gene products that modify ethanol teratogenesis will be identified using both a candidate gene approach and an unbiased, forward genetic screen of single gene insertional mutations. Functional analysis of genes that modulate ethanol teratogenesis will be through a combination of molecular, behavioral and genetic approaches. Relevance to Public Health: The prevalence of fetal alcohol syndrome in the world is one to three per 1,000 births, indicating a serious health problem. Using the fruit fly to study the precise mechanisms of fetal alcohol syndrome has the potential to promote a better understanding of the actions of alcohol during development and to point the way to developing strategies that prevent (or mitigate) the damages of prenatal alcohol exposure.