title: An evolutionary consequence of dosage compensation on Drosophila melanogaster female X-chromatin structure?
abstract: BACKGROUND
  X chromosomes are subject to dosage compensation in Drosophila males. Dosage compensation requires cis sequence features of the X chromosome that are present in both sexes by definition and trans acting factors that target chromatin modifying machinery to the X specifically in males. The evolution of this system could result in neutral X chromatin changes that will be apparent in females.
  
  
  RESULTS
  We find that the general chromatin structure of female X chromosomes is distinct from autosomes. Additionally, specific histone marks associated with dosage compensation and active chromatin marks on the male X chromosome are also enriched on the X chromosomes of females, albeit to a lesser degree.
  
  
  CONCLUSIONS
  Our data indicate that X chromatin structure is fundamentally different from autosome structure in both sexes. We suggest that the differences between the X chromosomes and autosomes in females are a consequence of mechanisms that have evolved to ensure sufficient X chromosome expression in the soma of males.
authors.affiliation: Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-8028, USA. yuzhang@niddk.nih.gov
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Brian
authors.initials: B
authors.lastname: Oliver
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry* / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D004331:Drosophila melanogaster / Q000737:chemistry* / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D006657:Histones / Q000032:analysis; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D014960:X Chromosome
chemical_list: D002843:Chromatin; D006657:Histones