Graphing DEseq2 Normalized Counts using ggplot2
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jackafiore • 0
@e819932a
Last seen 18 days ago
United States

I've been working with DEseq2 for a while now, and have been going about plotting the normalized counts for a couple genes I found.

I'm following the vignette subsection "Plot counts", to plot the counts using ggplot2, but I noticed the authors used a specific set of values for scaling their y axis (25,100,400).

I'm wondering if there is a best practice for choosing the scale of the y-axis here, or if these values were chosen based on how DEseq calculates normalized counts as well? Including link to specific section on the vignette below as well.

https://www.bioconductor.org/packages/release/bioc/vignettes/DESeq2/inst/doc/DESeq2.html#plot-counts

genex <- "ENSMPUG00000004881"
x <- plotCounts(dds, gene=genex, intgroup="dpi", main = "ENSMPUG00000004881", returnData = TRUE)
y <- plotCounts(dds, gene=genex, intgroup="severity", main = "ENSMPUG00000004881", returnData = TRUE)
x$severity <- y$severity

plot <- ggplot(x, aes(x=dpi, y=count, color=severity)) +
geom_point(position=position_jitterdodge(jitter.width=0.25), size=5) +
scale_color_manual(values = c("darkgreen", "gold", "darkred")) +
scale_y_log10(breaks=c(25,100,400)) + # Why 25,100,400 ???
geom_smooth(aes(group=severity),method="loess",se=TRUE,fullrange=TRUE) +
ggtitle("ACCS3")+
xlab("Day(s) Post Infection")+
ylab("DESEQ2 Normalized Counts")+
labs(color="Severity")+
theme_bw()
sessionInfo( )

DESeq2 Normalization RNASeq • 217 views
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ATpoint ★ 3.9k
@atpoint-13662
Last seen 19 minutes ago
Germany

It's just visualization. Don't overthink it and choose what you feel is appropriate to send the message for your analysis. I doubt that there is a gold standard answer for this other than "it looks good". Generally, the only rule I know of is that you should not mess with axis limits to mislead the reader, for example making limits very small so that tiny differences look big.

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Thank you!