Robustness of single-cell RNA-seq for identifying differentially expressed genes

BMC Genomics. 2023 Jul 3;24(1):371. doi: 10.1186/s12864-023-09487-y.

Abstract

Background: A common feature of single-cell RNA-seq (scRNA-seq) data is that the number of cells in a cell cluster may vary widely, ranging from a few dozen to several thousand. It is not clear whether scRNA-seq data from a small number of cells allow robust identification of differentially expressed genes (DEGs) with various characteristics.

Results: We addressed this question by performing scRNA-seq and poly(A)-dependent bulk RNA-seq in comparable aliquots of human induced pluripotent stem cells-derived, purified vascular endothelial and smooth muscle cells. We found that scRNA-seq data needed to have 2,000 or more cells in a cluster to identify the majority of DEGs that would show modest differences in a bulk RNA-seq analysis. On the other hand, clusters with as few as 50-100 cells may be sufficient for identifying the majority of DEGs that would have extremely small p values or transcript abundance greater than a few hundred transcripts per million in a bulk RNA-seq analysis.

Conclusion: Findings of the current study provide a quantitative reference for designing studies that aim for identifying DEGs for specific cell clusters using scRNA-seq data and for interpreting results of such studies.

Keywords: Gene expression; RNA-seq; Single cell; Stem cell.

MeSH terms

  • Gene Expression Profiling* / methods
  • Humans
  • Induced Pluripotent Stem Cells*
  • RNA-Seq
  • Sequence Analysis, RNA / methods
  • Single-Cell Analysis / methods
  • Single-Cell Gene Expression Analysis