title: Identification of the Drosophila X chromosome: The long and short of it.
abstract: The different dose of X chromosomes in males and females produces a potentially fatal imbalance in X-linked gene products. This imbalance is addressed by dosage compensation, a process that modulates expression from an entire X chromosome in one sex. Dosage compensation acts on thousands of genes with disparate expression patterns. Both flies and mammals accomplish this with remarkable specificity by targeting epigenetic chromatin modifications to a single chromosome. Long noncoding RNAs that are expressed from the X chromosome are essential elements of the targeting mechanism in both lineages. We recently discovered that the siRNA pathway, as well as small RNA from satellite repeats that are strikingly enriched on the fly X chromosome, also promote X recognition. In this article we review the current understanding of X recognition in flies and discuss potential mechanisms by which the siRNA pathway, repetitive elements and long noncoding RNAs might cooperate to promote X recognition.
authors.affiliation: a Department of Genetics ; University of North Carolina ; Chapel Hill , NC USA.
authors.forename: Debashish U
authors.initials: DU
authors.lastname: Menon
authors.affiliation: b Department of Biological Sciences ; Wayne State University ; Detroit , MI USA.
authors.forename: Victoria H
authors.initials: VH
authors.lastname: Meller
mesh_terms: D000818:Animals; D002843:Chromatin / Q000235:genetics; D004303:Dosage Compensation, Genetic; D004331:Drosophila melanogaster; D044127:Epigenesis, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D062085:RNA, Long Noncoding / Q000096:biosynthesis / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*
chemical_list: D002843:Chromatin; D062085:RNA, Long Noncoding; D034741:RNA, Small Interfering
keywords: 1.688X repeats; 359 bp repeats; Drosophila melanogaster; X recognition; dosage compensation; roX RNA; satellite repeats; siRNA