A single-cell survey of Drosophila blood

Elife. 2020 May 12;9:e54818. doi: 10.7554/eLife.54818.

Abstract

Drosophila blood cells, called hemocytes, are classified into plasmatocytes, crystal cells, and lamellocytes based on the expression of a few marker genes and cell morphologies, which are inadequate to classify the complete hemocyte repertoire. Here, we used single-cell RNA sequencing (scRNA-seq) to map hemocytes across different inflammatory conditions in larvae. We resolved plasmatocytes into different states based on the expression of genes involved in cell cycle, antimicrobial response, and metabolism together with the identification of intermediate states. Further, we discovered rare subsets within crystal cells and lamellocytes that express fibroblast growth factor (FGF) ligand branchless and receptor breathless, respectively. We demonstrate that these FGF components are required for mediating effective immune responses against parasitoid wasp eggs, highlighting a novel role for FGF signaling in inter-hemocyte crosstalk. Our scRNA-seq analysis reveals the diversity of hemocytes and provides a rich resource of gene expression profiles for a systems-level understanding of their functions.

Keywords: D. melanogaster; blood; developmental biology; hemocytes; immune response; immunology; inflammation; scRNA-seq; wasp infestation; wounding.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Communication
  • Cell Lineage
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / immunology*
  • Drosophila melanogaster / metabolism
  • Drosophila melanogaster / parasitology
  • Fibroblast Growth Factors / metabolism
  • Genes, Insect
  • Hemocytes / cytology*
  • Hemocytes / immunology
  • Hemocytes / metabolism*
  • Host-Parasite Interactions
  • Immunity
  • Larva / genetics
  • Larva / immunology
  • Larva / metabolism
  • Larva / parasitology
  • RNA-Seq
  • Signal Transduction
  • Single-Cell Analysis
  • Transcription, Genetic
  • Transcriptome
  • Wasps

Substances

  • Drosophila Proteins
  • Fibroblast Growth Factors

Associated data

  • GEO/GSE146596
  • GEO/GSE93823