An X/Y DNA segment from an early stage of sex chromosome differentiation in the fly Megaselia scalaris

Genome. 1998 Apr;41(2):289-94. doi: 10.1139/g98-015.


The sex chromosomes of the Megaselia scalaris wild-type strain Wien are homomorphic. We studied a roughly 1.8 kb X/Y DNA segment of this strain. It includes, at one end, the first part of a coding sequence for a protein of the vespid antigen 5 family. Molecular differentiation between the X and Y chromosomes has commenced, but homology, even of short DNA stretches, is still assessable beyond doubt. The most conspicuous differences between the X and the homologous Y segment were insertions/deletions in the noncoding region: among them, deletions, a duplication, and an insertion of a mobile element. These structural changes grossly disrupted homology. In comparison, base substitutions, though more numerous, contributed little to the differentiation of the X/Y DNA segment.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chromosome Mapping
  • Diptera / genetics*
  • Female
  • Male
  • Molecular Sequence Data
  • Open Reading Frames
  • Polymorphism, Restriction Fragment Length
  • Sequence Alignment
  • Sex Determination Processes*
  • X Chromosome*
  • Y Chromosome*

Associated data

  • GENBANK/AJ000510