Modification Visualization
Metagene Plots with Guitar
r
library(Guitar)
library(TxDb.Hsapiens.UCSC.hg38.knownGene)
# Load m6A peaks
peaks <- import('m6a_peaks.bed')
# Create metagene plot
# Shows distribution relative to transcript features
GuitarPlot(
peaks,
txdb = TxDb.Hsapiens.UCSC.hg38.knownGene,
saveToPDFprefix = 'm6a_metagene'
)
Custom Metagene with deepTools
bash
# Create bigWig from IP/Input ratio
bamCompare -b1 IP.bam -b2 Input.bam \
--scaleFactors 1:1 \
--ratio log2 \
-o IP_over_Input.bw
# Metagene around stop codons
computeMatrix scale-regions \
-S IP_over_Input.bw \
-R genes.bed \
--regionBodyLength 2000 \
-a 500 -b 500 \
-o matrix.gz
plotProfile -m matrix.gz -o metagene.pdf
Browser Tracks
bash
# Create normalized bigWig for genome browser
bamCoverage -b IP.bam \
--normalizeUsing CPM \
-o IP_normalized.bw
# Peak BED to bigBed
bedToBigBed m6a_peaks.bed chrom.sizes m6a_peaks.bb
Heatmaps
r
library(ComplexHeatmap)
# m6A signal around peaks
Heatmap(
signal_matrix,
name = 'm6A signal',
cluster_rows = TRUE,
show_row_names = FALSE
)
Related Skills
- •epitranscriptomics/m6a-peak-calling - Generate peaks for visualization
- •data-visualization/genome-tracks - IGV, UCSC integration
- •chip-seq/chipseq-visualization - Similar techniques