Regulation of apoptosis of rbf mutant cells during Drosophila development

Dev Biol. 2009 Feb 15;326(2):347-56. doi: 10.1016/j.ydbio.2008.11.035. Epub 2008 Dec 10.

Abstract

Inactivation of the retinoblastoma gene Rb leads to defects in cell proliferation, differentiation, or apoptosis, depending on specific cell or tissue types. To gain insights into the genes that can modulate the consequences of Rb inactivation, we carried out a genetic screen in Drosophila to identify mutations that affected apoptosis induced by inactivation of the Retinoblastoma-family protein (rbf) and identified a mutation that blocked apoptosis induced by rbf. We found this mutation to be a new allele of head involution defective (hid) and showed that hid expression is deregulated in rbf mutant cells in larval imaginal discs. We identified an enhancer that regulates hid expression in response to developmental cues as well as to radiation and demonstrated that this hid enhancer is directly repressed by RBF through an E2F binding site. These observations indicate that apoptosis of rbf mutant cells is mediated by an upregulation of hid. Finally, we showed that bantam, a miRNA that regulates hid translation, is expressed in the interommatidial cells in the larval eye discs and modulates the survival of rbf mutant cells.

Publication types

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

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Animals
  • Apoptosis / physiology*
  • Base Sequence
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / anatomy & histology
  • Drosophila melanogaster / embryology*
  • Drosophila melanogaster / physiology*
  • E2F Transcription Factors / genetics
  • E2F Transcription Factors / metabolism
  • Enhancer Elements, Genetic
  • Gene Expression Regulation, Developmental*
  • Genes, Reporter
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Photoreceptor Cells, Invertebrate / cytology
  • Photoreceptor Cells, Invertebrate / physiology
  • Retinoblastoma Protein / genetics*
  • Retinoblastoma Protein / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Drosophila Proteins
  • E2F Transcription Factors
  • MicroRNAs
  • Rbf protein, Drosophila
  • Retinoblastoma Protein
  • Transcription Factors
  • bantam microRNA, Drosophila