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Other genomic arrays: Methylation, chIP on chip …. U B io Training Courses. SNP-arrays and copy number. Genotyping arrays can detect CNVs. Copy numbers from SNP arrays. Illumina SNP arrays: Hybridization to Universal IllumiCode TM. Illumina uses the same technology for methylation arrays
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Other genomic arrays: Methylation, chIP on chip… UBio Training Courses
SNP-arrays and copy number Genotyping arrays can detect CNVs
Illumina SNP arrays: Hybridization to Universal IllumiCodeTM Illumina uses the same technology for methylation arrays (bi-sulfited nucleotides are like SNPs) Intensity <-> Copy number
Calculation of aCGH-like ratios Median R CEPH Individual R cell line (NCI60)
METHYLATION MICROARRAYS • BeadArrays • Until 12 samples per chip. • 27,578 CpG loci, >14.000 genes • 2 beads per locus (methylated/no methylated) • Random distribution (50 mer) • Input: Bisulphyted DNA • Includes probes for the promoter regions of miRNA 110 genes Infinium HumanMethylation27 BeadChip
METHYLATION MICROARRAYS Illumina Golden Gate Assay • Until 147,456 DNA methylation measures simultaneously. • Resolution: 1 CpG • Until 96 samples simultaneously • GoldenGate Methylation Cancer Panel I 1,505 CpG loci selected from 807 gene • Allows custom designs
METHYLATION MICROARRAYS SOFTWARE Bead Studio Genome Studio Methylation module http://www.illumina.com/pages.ilmn?ID=196 Lumi package (Import, background correction, normalization) Beadarray package (Import, QC) Methylumi (Import, QC ,normalization, differential meth.)
METHYLATION MICROARRAYS DIFFERENTIAL METHYLATION Bead Studio Genome Studio Methylation module http://www.illumina.com/pages.ilmn?ID=196 Beta values: β= Imethylated/Imethylated+Ino_methylated Hypermethylated Hypomethylated β 0 1 0.3 0.7
METHYLATION MICROARRAYS NORMALIZATION Methylumi normalization • Calculate medians for Cy3 and Cy5 at high an low betas • Cy5 medians adjusted to Cy3 channel (dye bias) • Recalculate betas with new intensities
METHYLATION MICROARRAYS DIFFERENTIAL METHYLATION Wilcoxon rank-test (UBio) Limma (Pomelo) Permutations (Pomelo) βs Median βs class A Median βs class B FDR<0.05 + Differentially methylated genes
ChIP on Chip We thank Chris Glass lab, UCSD, for the original slide
ChIP on Chip Discover protein/DNA interactions!!
ChIP on Chip software Chip Analytics WORKFLOW I. 1. Pre-normalization. Background substraction: Foreground – background Default: Median blank substraction Each channel – median negative controls 2. Normalization (dye-byas and interarray normalization) Default : Median dye-byas, median interarray. Recommended: Loess
ChIP on Chip software Chip Analytics WORKFLOW II. 3. Error modelling To identify which probes are most representative of binding events: P(X)=P-value of a single probe matching event P(Xneighb)= Positive signals in a probe should be corroborated by the signals of probes that are its genomic neighbors, provided they are close enough P(Xneighb) follows a Gaussian distribution Both the P(X) and the P(Xneighb) values of a probe need to satisfy significance thresholds in order for a probe to be considered as representing a binding event
ChIP on Chip software Chip Analytics WORKFLOW III. 4. Segment identification (clusters of enriched probes) bp 5. Gene identification -Segment, Gene or Probe report (Gene or probe ID, Chr, Start, End, p(X)…)
CoCas http://www.ciml.univ-mrs.fr/software/cocas/index.html Agilent platform Normalization QC Report Genome Visualization Peak Finder Benoukraf et al. Bioinformatics 2009.
Weeder: Motif discovery in sequences from co-regulated genes (single specie). WeederH: Motif discovery in sequences from homologous genes. Pscan: Motif discovery in sequences from co-regulated genes (JASPAR,TRANSFAC matrices) UBio training courses: See “Course on Introduction to Sequence Analysis”
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