question: What is the Drosophila melanogaster Groucho protein?
answer: Groucho proteins are abundant and broadly expressed nuclear factors that lack intrinsic DNA-binding activity but can interact with a variety of DNA-binding proteins. The recruitment of Groucho to specific gene regulatory sequences results in transcriptional repression.
  Groucho (Gro) is a Drosophila melanogaster transcriptional corepressor.