Discovery of Addiction-Related Genes with Advanced Mouse Resources

 描述(由申请者提供)：我们的首要目标是发现行为易感性和成瘾发展背后的遗传和基因组机制。尽管为限制毒品的供应和使用作出了广泛努力，但吸毒成瘾仍然是世界范围内的重大社会和经济负担。吸毒成瘾的高遗传性，尤其是可卡因， 表明在初次接触后出现物质使用障碍的倾向受到遗传因素的影响。人类和动物的研究都表明，新奇追求和新奇偏好等行为特征与患上药物使用障碍的倾向密切相关，但这种关系的生物学基础尚不清楚。我们建议通过利用小鼠遗传资源的最新进展来确定成瘾和易感行为的生物学机制，这些资源包括高精度的外交(DO)小鼠种群、转基因小鼠的验证、通过RNA序列分析进行基因表达定量，以及系统遗传学中的计算和统计方法。在目标1中，我们将通过数量性状基因座(QTL)分析，在一大组DO小鼠中识别易感新奇相关性状和药物自我给药的遗传机制。其中最引人注目和最容易处理的将在以基因为靶标的小鼠模型中得到验证。静脉给药(IVSA)范式被认为是临床前研究中评估成瘾的金标准，它将能够量化成瘾的核心特征，包括强制药物使用、难以限制药物摄入以及极高的吸毒动机。在目标2中，我们将量化基因表达的遗传变异，定位表达QTL，并使用RNAseq在药物未成熟的DO小鼠亚群中识别易感行为的遗传相关性，并通过广泛使用的信息学资源传播这些结果。药物幼稚小鼠的基因表达分析能够从药物暴露的生物后遗症中分离出容易上瘾的生物底物。通过使用RNA测序，我们将能够在面对遗传多样性的情况下量化异构体和等位基因变异。在目标3中，我们将利用易感行为特征作为参考，解决将药物幼稚个体基因表达的遗传变异与药物自我给药行为的遗传变异联系起来的根本问题。这将通过使用多变量统计方法来实现，我们将这种方法称为“参考性状遗传学”。这一策略利用一个共同的表型集合，将两组独立的小鼠之间不同和不相容的措施联系起来。这项技术在成瘾研究方面的发展将使近亲繁殖群体的应用扩大到在健康和疾病方面的广泛应用。每个目标都将独立地提供成瘾生物学家感兴趣的基础研究成果和资源，包括基因表达QTL、成瘾相关遗传位点和成瘾相关行为的表达相关因素。AIMS之间的协同作用将揭示从多态到成瘾相关行为的网络。

 DESCRIPTION (provided by applicant): Our overarching goal is to discover the genetic and genomic mechanisms underlying behavioral predisposition and development of addiction. Addiction remains a substantial worldwide social and economic burden despite extensive efforts to curb drug availability and use. The high heritability of drug addiction, especially for cocaine, indicates that the propensity to develop a substance use disorder after initial exposure is genetically influenced. Both human and animal studies indicate that behavioral traits such as novelty seeking and novelty preference are strongly correlated with the propensity to develop a substance use disorder, but the biological basis of this relationship is unknown. We propose to identify biological mechanisms of addiction and predisposing behavior by harnessing recent advances in mouse genetic resources, including the high-precision Diversity Outbred (DO) mouse population, validation in genetically modified mice, gene expression quantitation through RNA sequence analysis, and computational and statistical methods in systems genetics. In Aim 1 we will identify genetic mechanisms underlying predisposing novelty-related traits and drug self-administration through quantitative trait locus (QTL) analysis in a large set of DO mice. The most compelling and tractable of these will be validated in gene targeted mouse models. The intravenous drug-self administration (IVSA) paradigm, considered the gold standard for the assessment of addiction in preclinical research will enable quantification of the core features of addiction including compulsive drug use, difficulty limiting drug intake, and an extremely high motivation to take the drug. In Aim 2 we will quantify gene expression genetic variation, map expression QTLs and identify genetic correlates of predisposing behavior using RNAseq in a drug-naïve subset of DO mice, and disseminate these results through widely used informatics resources. Gene expression analysis in drug-naïve mice enables separation of the biological substrates of predisposition to addiction from the biological sequelae of drug exposure. By using RNA sequencing, we will be able to quantify isoforms and allelic variants in the face of genetic diversity. In Aim 3, we will address the fundamental problem of relating genetic variation in gene expression in drug-naïve individuals to genetic variation in drug self-administration behavior by utilizing predisposing behavioral traits as a reference. This will be accomplished through the use of multivariate statistical methods in an approach we term "reference trait genetics". This strategy makes use of a common collection of phenotypes to relate disparate and incompatible measures across two independent sets of mice. Development of this technique in the context of addiction research will extend the application of outbred populations to a wide range of applications in health and disease. Each aim will independently deliver basic research results and resources of interest to addiction biologists, including gene expression QTLs, addiction related genetic loci, and expression correlates of addiction related behavior. Synergy among the aims will reveal networks from polymorphism to addiction related behavior.