The Drosophila don juan (dj) gene encodes a novel sperm specific protein component characterized by an unusual domain of a repetitive amino acid motif

Mech Dev. 1997 Jun;64(1-2):19-30. doi: 10.1016/s0925-4773(97)00031-2.


We identified and characterized the don juan gene (dj) of Drosophila melanogaster. The don juan gene codes for a sperm specific protein component with an unusual repetitive six amino acid motif (DPCKKK) in the carboxy-terminal part of the protein. The expression of Don Juan is limited to male germ cells where transcription of the dj gene is initiated during meiotic prophase. But Western blot experiments indicate that DJ protein occurs just postmeiotically. Examination of transgenic flies bearing a dj-promoter-lacZ reporter construct revealed lacZ mRNA distribution resembling the expression pattern of the endogenous dj mRNA in the adult testes, whereas beta-galactosidase expression is exclusively present in postmeiotic germ cells. Thus, these observations strongly suggest that dj transcripts are under translational repression until in spermiogenesis. To study the function and subcellular distribution of DJ in spermiogenesis we expressed a chimaeric dj-GFP fusion gene in the male germline exhibiting strong GFP fluorescence in the liver testes, where only elongated spermatids are decorated. With regard to the characteristic expression pattern of DJ protein and its conspicuous repeat units possible functional roles are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Base Sequence
  • DNA, Complementary / genetics
  • Drosophila Proteins*
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / metabolism
  • Gene Expression Regulation, Developmental
  • Genes, Insect*
  • Green Fluorescent Proteins
  • Insect Proteins / genetics*
  • Insect Proteins / metabolism
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Male
  • Molecular Sequence Data
  • Oligonucleotide Probes / genetics
  • Protein Biosynthesis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Repetitive Sequences, Nucleic Acid
  • Spermatids / metabolism
  • Spermatogenesis / genetics
  • Spermatozoa / metabolism*


  • DNA, Complementary
  • Drosophila Proteins
  • Insect Proteins
  • Luminescent Proteins
  • Oligonucleotide Probes
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • dj protein, Drosophila
  • Green Fluorescent Proteins

Associated data

  • GENBANK/U90537