Differential allelic expression is common In addition to studying gene expression patterns, RNA sequencing can also reveal differences in allelic expres sion. Allelic expression analysis can reveal functional excellent validation regulatory variants. Within an individual both alleles are subjected to same environmental conditions and feed back control. Any bias in the expression of two alleles indicates presence of nearby cis variants. In RNA se quencing experiments read counts at the polymorphic sites provide allelic abundance and simple statistical tests of differences in read counts at polymorphic sites allow the detection of biases in allelic expression. Allelic expression imbalance is generally measured by genotyping or sequencing SNPs in individual cDNA samples.

However, high throughput sequencing methods have recently been used for studying AEI. While sequencing individual samples for AEI analysis is a powerful Inhibitors,Modulators,Libraries approach for detecting subtle dif ferences in allelic expression, it is expensive to sequence individual samples separately. Next generation sequen cing of pooled samples provides cost effective method for estimating allele frequencies at genome wide scale. Pooling and sequencing RNA samples is an effi cient way to detect cis regulatory polymorphisms at genome wide scale. Sequencing RNA samples pooled from 100 adipose and islet tissues of F2 mice, Babak et al. found several genes showing AEI. They found a significant overlap between the genes showing AEI and cis eQTL genes obtained from microarray ana lysis of the same F2 population, indicating Inhibitors,Modulators,Libraries the robustness of this approach.

While differential allelic expression Inhibitors,Modulators,Libraries from RNA sequencing of pooled samples may not indi cate the presence of cis acting variants, the correlation of allelic expression with total gene expression Inhibitors,Modulators,Libraries may indi cate the presence of nearby cis acting variants. We used pooled RNA samples to identify Inhibitors,Modulators,Libraries SNPs in this study. Allelic expression of about 52 % of significant var iants correlated with differential gene expression between control and stress treatments. These variants therefore may represent cis acting regulatory variants controlling gene expression or these variants may occur in high LD with regulatory variants in adjacent intronic, untranslated and promoter sequences. Recent genome wide association studies have demonstrated that genetic variation in regulatory regions is more important than coding regions in affecting complex traits.

Identifica tion of regulatory polymorphisms is therefore crucial for understanding the control of complex traits. Allelic expression was shown to influence gene expres sion and phenotype in several plant Vismodegib buy species. Drought stress was shown to induce allele specific expression in barley hybrids. Allelic expression may also by caused by differential methylation of alleles.