Sex and the single cell. II. There is a time and place for sex

PLoS Biol. 2010 May 4;8(5):e1000365. doi: 10.1371/journal.pbio.1000365.

Abstract

The Drosophila melanogaster sex hierarchy controls sexual differentiation of somatic cells via the activities of the terminal genes in the hierarchy, doublesex (dsx) and fruitless (fru). We have targeted an insertion of GAL4 into the dsx gene, allowing us to visualize dsx-expressing cells in both sexes. Developmentally and as adults, we find that both XX and XY individuals are fine mosaics of cells and tissues that express dsx and/or fruitless (fru(M)), and hence have the potential to sexually differentiate, and those that don't. Evolutionary considerations suggest such a mosaic expression of sexuality is likely to be a property of other animal species having two sexes. These results have also led to a major revision of our view of how sex-specific functions are regulated by the sex hierarchy in flies. Rather than there being a single regulatory event that governs the activities of all downstream sex determination regulatory genes-turning on Sex lethal (Sxl) RNA splicing activity in females while leaving it turned off in males-there are, in addition, elaborate temporal and spatial transcriptional controls on the expression of the terminal regulatory genes, dsx and fru. Thus tissue-specific aspects of sexual development are jointly specified by post-transcriptional control by Sxl and by the transcriptional controls of dsx and fru expression.

Publication types

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

MeSH terms

  • Animals
  • DNA-Binding Proteins* / genetics
  • DNA-Binding Proteins* / metabolism
  • Drosophila Proteins* / genetics
  • Drosophila Proteins* / metabolism
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / metabolism
  • Drosophila melanogaster / physiology*
  • Female
  • Gene Expression Regulation, Developmental*
  • Male
  • Nerve Tissue Proteins* / genetics
  • Nerve Tissue Proteins* / metabolism
  • Organ Specificity
  • RNA-Binding Proteins* / genetics
  • RNA-Binding Proteins* / metabolism
  • Sex Characteristics
  • Sex Differentiation*
  • Transcription Factors* / genetics
  • Transcription Factors* / metabolism

Substances

  • DNA-Binding Proteins
  • DSX protein, Drosophila
  • Drosophila Proteins
  • Nerve Tissue Proteins
  • RNA-Binding Proteins
  • Sxl protein, Drosophila
  • Transcription Factors
  • fru protein, Drosophila