ABSTRACT

One of the big challenges in the postgenome era is the better understating of the gene regulation process. Recently developed high-throughput genotyping and gene expression platforms have enabled a powerful new tool: expression quantitative trait loci (eQTL) analysis, where loci or markers on the genomes are associated with variations in gene expression. In such studies, gene expression is treated as a quantitative trait. DNA polymorphism at the gene, binding site or regulatory proteins, such as transcription factors

T&F Cat # C6847 Chapter: 10 page: 205 date: August 5, 2009

T&F Cat # C6847 Chapter: 10 page: 206 date: August 5, 2009

(TFs), transcription association proteins and signaling proteins, is likely to affect the expression level of the gene in an inheritable way (Monks et al., 2004; Brem and Kruglyak, 2005; Petretto et al., 2006b). Hence, a significant statistical association between a locus and the expression level of a gene suggests that the locus might regulate the gene. Since the early work of Jansen and Nap (2001), eQTL has become a widespread technique to identify such regulatory associations and has been applied to a number of species including yeast (Yvert et al., 2003; Brem and Kruglyak, 2005; Brem et al., 2005), Arabidopsis (DeCook et al., 2006), maize (Schadt et al., 2003), Drosophila (Jin et al., 2001), mouse (Klose et al., 2002; Bystrykh et al., 2005; Chesler et al., 2005), rat (Petretto et al., 2006a) and human (Monks et al., 2004; Cheung et al., 2005; Stranger et al., 2005). Many of them used the strategy of genome-wide association study (GWAS), considering loci covering the whole genome and expression profiles of all or nearly all genes identified in the organism.