Genetic Studies of Alcohol Tolerance

描述(由申请人提供)：发生酒精中毒的一个重要的遗传风险因素是对急性剂量的酒精的不同敏感性。急性酒精反应是初始敏感性和急性功能耐受性(AFT)综合作用的函数，两者都受到遗传因素的影响。使用近亲交配的小鼠品系，我们一直在使用一种被称为快速耐受性的范式-在一次接触酒精后24小时内产生耐受性-作为研究急性酒精反应的遗传学的工具。我们发现近交系的长睡眠小鼠和短睡眠小鼠(ILS和ISS)在快速耐受能力上有很大的不同，用翻正反射丧失试验(LORR)作为敏感性的衡量标准。这种依赖于菌株的差异似乎至少部分是通过对AFT的差异效应来调节的。我们假设，快速耐受性的遗传差异是由于基线基因表达和酒精介导的基因表达效应的基因型相关差异所致。因此，我们建议利用快速耐受模型，使用“基因基因组学”方法来检查急性反应的分子和遗传基础，这是一个将连锁分析与高通量基因表达技术相结合的新兴研究领域。使用从ILS和ISS衍生的LXS重组近交系(RI)小鼠品系，将研究快速耐受性、初始敏感性和AFT的遗传学，以及导致行为反应遗传差异的假定基因表达事件。将使用Affymetrix小鼠外显子微阵列进行表达谱分析，利用该微阵列可以研究对选择性剪接以及转录本丰度的影响。提出了以下五个特定目标来检验这一假设：1)确定LXS RIS对LORR反应的初始敏感性、AFT和快速耐受性之间的关系；2)定位目标1中确定的反应的数量性状基因座(QTL)；3)在LXS RIS的小脑和纹状体中进行表达谱分析，以识别其表达与行为反应共同分离的基因；4)定位目标3中确定的基因和目标2中确定的QTL区间内的基因的表达QTL；5)确认AIMS 3和AIMS 4中确定的基因的表达结果。我们认为，这些实验的结果将为深入了解急性酒精敏感性的遗传变异的本质提供依据。这反过来将有助于更深入地了解人类酗酒的遗传风险。与公众健康的相关性酒精中毒的发生和维持既受环境因素的影响，也受遗传因素的影响。该项目旨在识别影响急性酒精敏感性变异的基因，这一特征被认为是导致酒精中毒的遗传风险。这些知识对于全面了解酒精中毒的分子基础以及开发新的或改进的治疗策略是必不可少的。

DESCRIPTION (provided by applicant): An important genetic risk factor for the development of alcoholism is differential sensitivity to an acute dose of alcohol. Acute alcohol responses are a function of the combined effects of initial sensitivity and acute functional tolerance (AFT), both of which are influenced by genetic factors. Using inbred mouse strains, we have been using a paradigm known as rapid tolerance - tolerance that develops within 24 hrs following a single exposure to alcohol - as a tool to investigate the genetics of acute alcohol responses. We have found that the Inbred Long and Short Sleep mouse strains (ILS and ISS) differ considerably in their ability to develop rapid tolerance using the loss of righting reflex test (LORR) as the measure of sensitivity. This strain- dependent difference appears to be mediated at least partly by differential effects on AFT. We hypothesize that genetic variance in rapid tolerance occurs as a result of genotype-dependent differences in baseline gene expression and in alcohol-mediated effects on gene expression. Thus, we propose to exploit the rapid tolerance model to examine the molecular and genetic basis of acute responses using a "genetical genomics" approach, an emergent area of research that combines linkage analysis with high- throughput gene expression technologies. The genetics of rapid tolerance, initial sensitivity, and AFT, and of the postulated gene expression events that contribute to genetic variance for the behavioral responses will be investigated using the LXS recombinant inbred (RI) mouse strain panel which was derived from the ILS and ISS. Expression profiling will be conducted with Affymetrix Mouse Exon microarrays with which it is possible to investigate effects on alternative splicing as well as on transcript abundance. The following five Specific Aims are being proposed to test the hypothesis: 1) determine relationships between initial sensitivity, AFT, and rapid tolerance for the LORR response in the LXS RIs; 2) map quantitative trait loci (QTL) for the responses determined in Aim 1; 3) conduct expression profiling in the cerebellum and striatum of the LXS RIs to identify genes whose expression co-segregates with the behavioral responses; 4) map expression QTL for genes identified in Aim 3 and for genes that occur within QTL intervals determined in Aim 2; and 5) confirm expression results for genes identified in Aims 3 and 4. We propose that the results of these experiments will offer insight into the nature of genetic variance for acute alcohol sensitivity. This in turn will contribute to a deeper understanding of genetic risk for human alcoholism. PUBLIC HEALTH RELEVANCE The initiation and maintenance of alcoholism is influenced by both environmental and genetic factors. This project aims to identify genes that influence variation in acute alcohol sensitivity, a trait that is thought to contribute to genetic risk for alcoholism. Such knowledge is essential for a complete understanding of the molecular basis of alcoholism and for the development of new or improved strategies for its treatment.