Identification and characterization of the major Drosophila melanogaster mating plug protein

Insect Biochem Mol Biol. 2001 Apr 27;31(6-7):543-51. doi: 10.1016/s0965-1748(00)00154-5.


In many insects, semen coagulates into a mating plug at the distal part of the female's genital tract. Mating plugs have been proposed to facilitate sperm movement or to prevent subsequent matings or sperm loss. The molecular constituents of insect mating plugs have not previously been characterized. Here we report that an abundant autofluorescent protein made by the Drosophila melanogaster male's ejaculatory bulb is a major constituent of the posterior region of the mating plug. Identities in size, chromosomal location and expression pattern indicate that the autofluorescent protein is PEB-me, an abundant ejaculatory bulb protein reported by Ludwig et al. [Biochem. Genet. 29 (1991) 215]. We cloned and sequenced the RNA encoding this protein. The transcript, which is male-specific and expressed only in the ejaculatory bulb, encodes a 377 a.a. predicted secreted protein with PGG repeats similar to those in homopolymer-forming proteins found in spider silk.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Drosophila Proteins*
  • Drosophila melanogaster / anatomy & histology
  • Drosophila melanogaster / chemistry*
  • Drosophila melanogaster / genetics
  • Expressed Sequence Tags
  • Female
  • Fluorescence
  • Glycine
  • Insect Proteins / analysis*
  • Insect Proteins / genetics
  • Male
  • Molecular Sequence Data
  • Proline


  • Drosophila Proteins
  • Ebp protein, Drosophila
  • Insect Proteins
  • Proline
  • Glycine