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Other genomic arrays: Methylation, chIP on chip… UBio Training Courses
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SNP-arrays and copy number Genotyping arrays can detect CNVs
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Copy numbers from SNP arrays
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Illumina SNP arrays: Hybridization to Universal IllumiCode TM Intensity Copy number Illumina uses the same technology for methylation arrays (bi-sulfited nucleotides are like SNPs)
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Calculation of aCGH-like ratios Median R CEPHIndividual R cell line (NCI60)
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Methylation arrays
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BeadArrays o Until 12 samples per chip. o 27,578 CpG loci, >14.000 genes o 2 beads per locus (methylated/no methylated) o Random distribution (50 mer) o Input: Bisulphyted DNA o Includes probes for the promoter regions of miRNA 110 genes METHYLATION MICROARRAYS Infinium HumanMethylation27 BeadChip
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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
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SOFTWARE Lumi package (Import, background correction, normalization) Beadarray package (Import, QC) Methylumi (Import, QC,normalization, differential meth.) Bead Studio Genome Studio Methylation module http://www.illumina.com/pages.ilmn?ID=196 METHYLATION MICROARRAYS
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DIFFERENTIAL METHYLATION METHYLATION MICROARRAYS Bead Studio Genome Studio Methylation module http://www.illumina.com/pages.ilmn?ID=196 Beta values: β = I methylated /I methylated +I no_methylated β 1 0 Hypermethylated Hypomethylated 0.7 0.3
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NORMALIZATION METHYLATION MICROARRAYS Methylumi normalization 1)Calculate medians for Cy3 and Cy5 at high an low betas 2)Cy5 medians adjusted to Cy3 channel (dye bias) 3)Recalculate betas with new intensities
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DIFFERENTIAL METHYLATION METHYLATION MICROARRAYS Wilcoxon rank-test (UBio) Limma (Pomelo) Permutations (Pomelo) βsβs FDR<0.05 Median β s class A Median β s class B + Differentially methylated genes
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ChIP on chip
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ChIP on Chip We thank Chris Glass lab, UCSD, for the original slide
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Discover protein/DNA interactions!! ChIP on Chip
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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
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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(X neighb ) = Positive signals in a probe should be corroborated by the signals of probes that are its genomic neighbors, provided they are close enough P(X neighb ) 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
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ChIP on Chip software Chip Analytics WORKFLOW III. 4. Segment identification (clusters of enriched probes) 5. Gene identification -Segment, Gene or Probe report (Gene or probe ID, Chr, Start, End, p(X)…) bp
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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.
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UBio training courses: See “Course on Introduction to Sequence Analysis” 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)
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http://bioinfo.cnio.es/ Visit UBio web ! Thanks !
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