[DESEQ2] When to average biological replicates for hierarchical clustering
1
0
Entering edit mode
E • 0
@3732d500
Last seen 5 months ago
United Kingdom

Hi all,

I am trying to perform hierarchical clustering on the results of DESeq2.

My experimental design has 12 different conditions, each with a number of biological replicates.

To do this, I have used vst() on my deseq object, followed by scale() to get Z-scores.

VST <- vst(dds_deseq, blind=FALSE) Counts <- assay(VST) Scaled_counts<-t(scale(t(as.matrix(Counts)), center=TRUE, scale=TRUE))

I then use hclust() to produce the dendograms.

This seems to work well and the dendograms I get in the end match my expectations, however due to the large number of biological replicates, the resulting clusters are "overly detailed" - the heatmap is huge. I would like to simplify this by averaging my biological replicates, and reperforming the clustering on those averages.

I am unsure at what point it would be appropriate to take that average (ie. I would expect that taking an average of Z-scores would distort the data).

It seems to me that there should be a way to average counts in the dds_deseq object, however I do not not know how to do this, and am unsure whether this would also skew the results.

Alternatively, should I take the average at the level of the txi object? If so, could someone suggest how I can do this?

Many thanks!

DESeq2 • 284 views
ADD COMMENT
0
Entering edit mode
@james-w-macdonald-5106
Last seen 2 days ago
United States

If you fit a cell means model, the coefficients are the average of each group. You could compute the averages from a treatments contrast parameterization as well, but it's easier to just do the former.

Login before adding your answer.

Traffic: 877 users visited in the last hour
Help About
FAQ
Access RSS
API
Stats

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

Powered by the version 2.3.6