TY  - JOUR
A1  - Khulan, Batbayar
A1  - Thompson, Reid F.
A1  - Ye, Kenny
A1  - Fazzari, Melissa J.
A1  - Suzuki, Masako
A1  - Stasiek, Edyta
A1  - Figueroa, Maria E.
A1  - Glass, Jacob L.
A1  - Chen, Quan
A1  - Montagna, Cristina
A1  - Hatchwell, Eli
A1  - Selzer, Rebecca R.
A1  - Richmond, Todd A.
A1  - Green, Roland D.
A1  - Melnick, Ari
A1  - Greally, John M.
T1  - Comparative isoschizomer profiling of cytosine methylation: The HELP assay
Y1  - 2006/08/01 
JF  - Genome Research 
JO  - Genome Research 
SP  - 1046 
EP  - 1055 
DO  - 10.1101/gr.5273806 
VL  - 16 
IS  - 8 
UR  - http://genome.cshlp.org/content/16/8/1046.abstract 
N2  - The distribution of cytosine methylation in 6.2 Mb of the mouse genome was tested using cohybridization of genomic representations from a methylation-sensitive restriction enzyme and its methylation-insensitive isoschizomer. This assay, termed HELP (HpaII tiny fragment Enrichment by Ligation-mediated PCR), allows both intragenomic profiling and intergenomic comparisons of cytosine methylation. The intragenomic profile shows most of the genome to be contiguous methylated sequence with occasional clusters of hypomethylated loci, usually but not exclusively at promoters and CpG islands. Intergenomic comparison found marked differences in cytosine methylation between spermatogenic and brain cells, identifying 223 new candidate tissue-specific differentially methylated regions (T-DMRs). Bisulfite pyrosequencing confirmed the four candidates tested to be T-DMRs, while quantitative RT-PCR for two genes with T-DMRs located at their promoters showed the HELP data to be correlated with gene activity at these loci. The HELP assay is robust, quantitative, and accurate and is providing new insights into the distribution and dynamic nature of cytosine methylation in the genome. 
ER  -