The Hox gene Abdominal-B uses Doublesex F as a cofactor to promote neuroblast apoptosis in the Drosophila central nervous system

Development. 2019 Aug 22;146(16):dev175158. doi: 10.1242/dev.175158.

Abstract

Highly conserved DM domain-containing transcription factors (Doublesex/MAB-3/DMRT1) are responsible for generating sexually dimorphic features. In the Drosophila central nervous system, a set of Doublesex (Dsx)-expressing neuroblasts undergo apoptosis in females whereas their male counterparts proliferate and give rise to serotonergic neurons crucial for adult mating behaviour. Our study demonstrates that the female-specific isoform of Dsx collaborates with Hox gene Abdominal-B (Abd-B) to bring about this apoptosis. Biochemical results suggest that proteins AbdB and Dsx interact through their highly conserved homeodomain and DM domain, respectively. This interaction is translated into a cooperative binding of the two proteins on the apoptotic enhancer in the case of females but not in the case of males, resulting in female-specific activation of apoptotic genes. The capacity of AbdB to use the sex-specific isoform of Dsx as a cofactor underlines the possibility that these two classes of protein are capable of cooperating in selection and regulation of target genes in a tissue- and sex-specific manner. We propose that this interaction could be a common theme in generating sexual dimorphism in different tissues across different species.

Keywords: Abdominal-B; Apoptosis; Doublesex; Drosophila; Neuroblast; Sexual dimorphism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis* / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Drosophila / cytology*
  • Drosophila / embryology
  • Drosophila / genetics*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / physiology*
  • Female
  • Gene Expression Regulation, Developmental
  • Genes, Homeobox*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / physiology*
  • Male
  • Neural Stem Cells / cytology*
  • Protein Isoforms / genetics
  • Protein Isoforms / physiology
  • Sex Characteristics

Substances

  • Abd-B proteins, Drosophila
  • DNA-Binding Proteins
  • DSX protein, Drosophila
  • Drosophila Proteins
  • Homeodomain Proteins
  • Protein Isoforms