The determination of expression quantitative trait loci (eQTL) epistasis - a form of functional interaction between genetic loci that affect gene expression - is an important step toward the thorough understanding of gene regulation. Since gene expression has emerged as an "intermediate" molecular phenotype eQTL epistasis might help to explain the relationship between genotype and higher level ...

In genomewide mapping of expression quantitative trait loci (eQTL), it is widely believed that thousands of genes are trans-regulated by a small number of genomic regions called "regulatory hotspots," resulting in "trans-regulatory bands" in an eQTL map. As several recent studies have demonstrated, technical confounding factors such as batch effects can complicate eQTL analysis by causing many ...

Quantitative genetics and quantitative trait locus (QTL) mapping have undergone a revolution in the last decade. Progress in the next decade promises to be at least as rapid, and strategies for fine-mapping QTLs and identifying underlying genes will be radically revised. In this Commentary we address several key issues: first, we revisit a perennial challenge--how to identify individual genes a...

Cheverud and Buikstra (1981) demonstrated a tendency for nonmetric traits representing the number of foramina to have lower heritabilities than those representing hyperstotic or hypostotic traits in a sample of rhesus macaques. Based on this observation, Cheverud and Buikstra hypothesize that differences in the heritability of the two sets of traits may be due to differences in trait etiology. ...