eQTL Studies: from Bulk Tissues to Single Cells

TL;DR

This paper reviews the development of statistical methods for detecting cell-type-specific and context-dependent eQTLs, emphasizing the transition from bulk tissue studies to single-cell analyses to better understand gene regulation.

Contribution

It provides a comprehensive overview of methods enabling eQTL detection at single-cell resolution and discusses current limitations and future research directions.

Findings

Recent studies highlight the importance of cell-type-specific eQTLs.

Methods have evolved to detect eQTLs from single-cell data.

Current techniques face limitations in sensitivity and resolution.

Abstract

An expression quantitative trait locus (eQTL) is a chromosomal region where genetic variants are associated with the expression levels of certain genes that can be both nearby or distant. The identifications of eQTLs for different tissues, cell types, and contexts have led to better understanding of the dynamic regulations of gene expressions and implications of functional genes and variants for complex traits and diseases. Although most eQTL studies to date have been performed on data collected from bulk tissues, recent studies have demonstrated the importance of cell-type-specific and context-dependent gene regulations in biological processes and disease mechanisms. In this review, we discuss statistical methods that have been developed to enable the detections of cell-type-specific and context-dependent eQTLs from bulk tissues, purified cell types, and single cells. We also discuss the limitations of the current methods and future research opportunities.