Cellular immune response to parasitization in Drosophila requires the EBF orthologue collier

PLoS Biol. 2004 Aug;2(8):E196. doi: 10.1371/journal.pbio.0020196. Epub 2004 Aug 17.


Drosophila immune response involves three types of hemocytes ('blood cells'). One cell type, the lamellocyte, is induced to differentiate only under particular conditions, such as parasitization by wasps. Here, we have investigated the mechanisms underlying the specification of lamellocytes. We first show that collier (col), the Drosophila orthologue of the vertebrate gene encoding early B-cell factor (EBF), is expressed very early during ontogeny of the lymph gland, the larval hematopoietic organ. In this organ, Col expression prefigures a specific posterior region recently proposed to act as a signalling centre, the posterior signalling centre (PSC). The complete lack of lamellocytes in parasitized col mutant larvae revealed the critical requirement for Col activity in specification of this cell type. In wild-type larvae, Col expression remains restricted to the PSC following parasitization, despite the massive production of lamellocytes. We therefore propose that Col endows PSC cells with the capacity to relay an instructive signal that orients hematopoietic precursors towards the lamellocyte fate in response to parasitization. Considered together with the role of EBF in lymphopoiesis, these findings suggest new parallels in cellular immunity between Drosophila and vertebrates. Further investigations on Col/EBF expression and function in other phyla should provide fresh insight into the evolutionary origin of lymphoid cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Crosses, Genetic
  • Drosophila / embryology
  • Drosophila / parasitology*
  • Drosophila Proteins / metabolism
  • Drosophila Proteins / physiology*
  • Evolution, Molecular
  • Gene Expression Regulation, Developmental*
  • Hemocytes / immunology*
  • Hemocytes / parasitology
  • Immune System / pathology
  • In Situ Hybridization
  • Insect Proteins / metabolism
  • Lymph Nodes / pathology
  • Models, Biological
  • Receptors, Notch / metabolism
  • Signal Transduction
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*
  • Transgenes
  • Wasps


  • Drosophila Proteins
  • Insect Proteins
  • Receptors, Notch
  • Transcription Factors
  • kn protein, Drosophila