Two classes of dosage compensation complex binding elements along Caenorhabditis elegans X chromosomes.
Dosage compensation equalizes X-linked gene products between the sexes. In Caenorhabditis elegans, the dosage compensation complex (DCC) binds both X chromosomes in XX animals and halves the transcription from each. The DCC is recruited to the X chromosomes by a number of loci, rex sites, and is thought to spread from these sites by an unknown mechanism to cover the rest of the chromosome. Here we describe a novel class of DCC-binding elements that we propose serve as "way stations" for DCC binding and spreading. Both rex sites and way stations comprise strong foci of DCC binding on the native X chromosome. However, rex sites maintain their ability to bind large amounts of DCC even on X duplications detached from the native X, while way stations do not. These results suggest that two distinct classes of DCC-binding elements facilitate recruitment and spreading of the DCC along the X chromosome.
Blauwkamp
Timothy A
TA
Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, USA.
Csankovszki
Gyorgyi
G
D000818:Animals; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000235:genetics*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism* / Q000502:physiology; D004303:Dosage Compensation, Genetic; D005260:Female; D005786:Gene Expression Regulation; D017238:Genes, Helminth; D050172:Genes, X-Linked; D009687:Nuclear Proteins / Q000378:metabolism* / Q000502:physiology; D021381:Protein Transport; D050436:Regulatory Elements, Transcriptional; D014158:Transcription, Genetic; D014960:X Chromosome
D002868:Chromosomal Proteins, Non-Histone; D009687:Nuclear Proteins