Integrated GWAS of complex behavioral and gene expression traits in outbred rats

描述（由申请人提供）：我们将使用定量遗传技术来识别影响与药物滥用相关的一系列心理复杂行为表型的基因和等位基因。我们的中心利用了研究设计、下一代测序和统计方法方面的一些最新进展，共同创造了一个特殊的机会。尽管在过去的二十年里，在小鼠身上的正向（表现型到基因型）和反向（基因型到表现型）遗传研究取得了巨大的进展，但在大鼠身上发展和应用同样的技术却进展甚微。尽管在小鼠身上进行的正向和反向遗传研究都取得了丰硕的成果，但许多重要而复杂的心理过程很难或不可能在小鼠身上进行研究。出于这个原因，我们建议将我们已经在小鼠身上成功使用的各种遗传技术用于大鼠的行为研究。在目前的应用中，我们建议使用最先进的工具来阐明4,800只大鼠与药物滥用相关的各种行为的遗传基础。我们中心的一个关键优势是我们利用独特的大鼠异质库存（HS）。这些大鼠，有时被称为N/NIH，是1984年由8个近交大鼠株杂交而成的一种HS，作为近亲繁殖的种群已经维持了65代。这就产生了大量累积的重组，使它们成为进行类似于人类基因组广泛关联研究（GWAS）的研究的理想资源。值得注意的是，所有8个近交始祖菌株最近都被重新测序，鉴定出720万个snp。我们将使用一种创新的下一代基于测序的方法对这些大鼠进行基因分型，该方法以极低的成本提供约100K个snp。我们将使用这些数据推断单倍型，这将使我们能够推算出每只大鼠的所有720万个snp。除了确定这些snp与行为特征之间的关联外，我们还将研究72只行为幼稚大鼠的基因表达，重点关注4个关键大脑区域。我们将利用这些数据来鉴定表达数量性状位点（eqtl）。然后，我们将整合所有这些数据，以确定影响行为的特定基因。许多被研究的行为领域都是两性二态的；我们的研究将使用雄性和雌性大鼠，这将使我们能够通过基因型相互作用来识别性别差异和性别。我们还将确定这些性状之间的共遗传性，以及个体基因座对多个假定相关行为域的多效性。最后,

DESCRIPTION (provided by applicant): We will use quantitative genetic techniques to identify genes and alleles that influence a constellation of psychologically complex behavioral phenotypes that are associated with drug abuse. Our center capitalizes on a number of recent advances in study design, next-generation sequencing and statistical methods that together create an exceptional opportunity. Whereas the past two decades have seen enormous advances in both forward (phenotype to genotype) and reverse (genotype to phenotype) genetic studies in mice, there has been much less progress developing and applying the same techniques in rats. Although both forward and reverse genetic studies in mice have been extremely fruitful, many important but complex psychological processes are difficult or impossible to study in mice. For this reason we are proposing to adapt a variety of genetic techniques that we have already used successfully in mice, for behavioral studies in rats. In the current application, we propose to employ state-of-the-art tools to elucidate the genetic basis of a variety of behaviors that are relevant to drug abuse in 4,800 rats. A key strength of our center is that we utilize a unique rat heterogeneous stock (HS). These rats, sometimes referred to as N/NIH, are an HS that was created in 1984 by intercrossing 8 inbred rat strains and have been maintained as an outbred population for 65 generations. This has given rise to numerous accumulated recombinations that make them an ideal resource for performing studies that are analogous to human genome wide association studies (GWAS). Significantly, all 8 inbred founder strains have recently been re-sequenced, identifying 7.2 million SNPs. We will genotype these rats using an innovative next-generation sequencing-based method that provides ~100K SNPs at an extremely low cost. We will use these data to infer haplotypes, which will allow us to impute all 7.2 million SNPs in each rat. In addition to identifying associations between these SNPs and the behavioral traits, we will also examine gene expression in 72 behaviorally naive rats focusing on 4 key brain regions. We will use these data to identify expression quantitative trait loci (eQTLs). We will then integrate all of these data to identify specific genes that influece behavior. Many of the behavioral domains being studied are known to be sexually dimorphic; our study will use both male and female rats, which will allow us to identify sex differences and sex by genotype interactions. We will also identify co-heritability among these traits, as well as pleiotropic effects of individual loci on multiple putatively related behavioral domains. Finally, the proposed center includes numerous educational, career development and public outreach activities. We will implement a program to train high school and undergraduate students. In addition, technicians, graduate students, postdocs and junior faculty will receive career development advice in the form of individual development plans and research performance progress reports. Finally, we will engage in public outreach programs that will draw on diverse communities in Chicago, Buffalo and Memphis.