Is the Y chromosome of Drosophila an evolved supernumerary chromosome?

Bioessays. 1996 Apr;18(4):317-23. doi: 10.1002/bies.950180410.


The Y chromosomes of most Drosophila species are necessary for male fertility but they are not involved in sex determination. They have many puzzling properties that resemble the effects caused by B chromosomes. Classical genetic and molecular studies reveal substantial affinities between Y and B chromosomes and suggest that the Y chromosomes of Drosophila are not degenerated homologues of the X chromosomes, but rather that their Y chromosomes evolved as specialized supernumeraries similar to classical B chromosomes.

MeSH terms

  • Animals
  • Drosophila / genetics*
  • Evolution, Molecular
  • Fertility
  • Heterochromatin / metabolism
  • Humans
  • Sex Chromosomes / chemistry
  • Sex Chromosomes / genetics
  • Y Chromosome / genetics*


  • Heterochromatin