The worm solution: a chromosome-full of condensin helps gene expression go down.
Dosage compensation in the nematode Caenorhabditis elegans is achieved by the binding of a condensin-like dosage compensation complex (DCC) to both X chromosomes in hermaphrodites to downregulate gene expression two-fold. Condensin I(DC), a sub-part of the DCC, differs from the mitotic condensin I complex by a single subunit, strengthening the connection between dosage compensation and mitotic chromosome condensation. The DCC is targeted to X chromosomes by initial binding to a number of recruiting elements, followed by dispersal or spreading to secondary sites. While the complex is greatly enriched on the X chromosomes, many sites on autosomes also bind the complex. DCC binding does not correlate with DCC-mediated repression, suggesting that the complex acts in a chromosome-wide manner, rather than on a gene-by-gene basis. Worm dosage compensation represents an excellent model system to study how condensin-mediated changes in higher order chromatin organization affect gene expression.
Csankovszki
Györgyi
G
Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA. gyorgyi@umich.edu
Petty
Emily L
EL
Collette
Karishma S
KS
D000251:Adenosine Triphosphatases / Q000235:genetics*; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D046912:Multiprotein Complexes / Q000235:genetics*; D014960:X Chromosome
D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C108312:condensin complexes; D000251:Adenosine Triphosphatases