Genetics of gene expression, also referred to as "genetical genomics" or expression quantitative trait loci (eQTLs) analyses are studies linking gene variation and expression data (Damerval et al. 1994; Jansen and Nap, 2001; Brem & Kruglyak, 2005; Brem 2002; Emilsson et al., 2008; Schadt et al., 2003).
Expression quantitative trait loci (eQTLs) are genomic loci that contribute to variation in expression levels of mRNAs.
Mapping expression quantitative trait loci (eQTLs) aims at identifing genomic regions that regulats gene expression. In 2002, Brem and colleagues carried out the first genome-wide study of gene expression in yeast. Many other research teams have performed genetics of gene expression studies in plants, animals, and humans. Initially these eQTL studies used microarrays to measure genome-wide gene expression. More recent studies have employed massively parallel RNA sequencing (RNA-Seq) technology.
cis and trans eQTLs
eQTLs may act in cis (local eQTLs or cis eQTLs) or in trans (distant eQTLs or trans eQTLs) to a gene [Michaelson et al. 2009]."Static" and "dynamic" eQTLs
Some eQTLs are identified in many tissues, others are tissue-specific. cis eQTLs are detected in many tissue types. Gerrits et al. studied eQTLs across different cellular differentiation states and found "dynamic" eQTL that are cell-type-dependent.
Key words : quantitative trait loci, eQTL, genetics of gene expression, cis eQTL, trans eQTL, local eQTLs,distant eQTLs, eSNP.
Related Web pages : GWAS