Genetic Studies of Alcohol Tolerance

描述（由申请人提供）：酒精中毒发展的一个重要遗传风险因素是对急性剂量酒精的不同敏感性。急性酒精反应是初始敏感性和急性功能耐受性（AFT）的综合作用的函数，两者都受遗传因素的影响。使用近交系小鼠品系，我们一直在使用一种称为快速耐受性的范例-在单次暴露于酒精后24小时内发展的耐受性-作为研究急性酒精反应遗传学的工具。我们已经发现，近交长睡眠和短睡眠小鼠品系（ILS和ISS）在使用翻正反射丧失试验（LORR）作为灵敏度测量的快速耐受性方面存在显著差异。这种菌株依赖性差异似乎至少部分是通过对AFT的差异效应介导的。我们假设，快速耐受性的遗传变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依赖性差异所致。因此，我们建议利用快速耐受模型，使用“遗传基因组学”方法来检查急性反应的分子和遗传基础，这是一个新兴的研究领域，将连锁分析与高通量基因表达技术相结合。将使用源自ILS和ISS的LXS重组近交系（RI）小鼠品系组研究快速耐受性、初始敏感性和AFT的遗传学，以及导致行为反应遗传变异的假定基因表达事件的遗传学。表达谱分析将使用Affytron小鼠外显子微阵列进行，使用该微阵列可以研究对选择性剪接以及对转录本丰度的影响。提出了以下五个具体目标来检验这一假设：1）确定LXS RI中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 RI的小脑和纹状体中进行表达谱分析，以鉴定其表达与行为反应共分离的基因; 4）定位目标3中鉴定的基因和目标2中确定的QTL间隔内出现的基因的表达QTL;和5）确认目标3和4中鉴定的基因的表达结果。我们建议，这些实验的结果将提供深入了解急性酒精敏感性的遗传变异的性质。这反过来将有助于更深入地了解人类酗酒的遗传风险。 酒精中毒的发生和维持受环境和遗传因素的影响。该项目旨在确定影响急性酒精敏感性变化的基因，这种特征被认为是导致酒精中毒遗传风险的原因。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至关重要。

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.