Discovery of functional noncoding elements by digital analysis of chromatin structure.
We developed a quantitative methodology, digital analysis of chromatin structure (DACS), for high-throughput, automated mapping of DNase I-hypersensitive sites and associated cis-regulatory sequences in the human and other complex genomes. We used 19/20-bp genomic DNA tags to localize individual DNase I cutting events in nuclear chromatin and produced approximately 257,000 tags from erythroid cells. Tags were mapped to the human genome, and a quantitative algorithm was applied to discriminate statistically significant clusters of independent DNase I cutting events. We show that such clusters identify both known regulatory sequences and previously unrecognized functional elements across the genome. We used in silico simulation to demonstrate that DACS is capable of efficient and accurate localization of the majority of DNase I-hypersensitive sites in the human genome without requiring an independent validation step. A unique feature of DACS is that it permits unbiased evaluation of the chromatin state of regulatory sequences from widely separated genomic loci. We found surprisingly large differences in the accessibility of distant regulatory sequences, suggesting the existence of a hierarchy of nuclear organization that escapes detection by conventional chromatin assays.
Sabo
Peter J
PJ
Department of Molecular Biology, Regulome, 2211 Elliott Avenue, Suite 600, Seattle, WA 98121, USA.
Hawrylycz
Michael
M
Wallace
James C
JC
Humbert
Richard
R
Yu
Man
M
Shafer
Anthony
A
Kawamoto
Janelle
J
Hall
Robert
R
Mack
Joshua
J
Dorschner
Michael O
MO
McArthur
Michael
M
Stamatoyannopoulos
John A
JA
D002843:Chromatin / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D020014:K562 Cells; D005810:Multigene Family; D011487:Protein Conformation; D012045:Regulatory Sequences, Nucleic Acid
D002843:Chromatin