DESeq2 error on analyzing microbiome data
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Entering edit mode
zhigang.li • 0
@zhigangli-21311
Last seen 6 weeks ago
United States

Hi There,

I am trying to do a differential abundance analysis with microbiome sequencing data suing DESeq2 package, but I keep getting errors after trying different approaches within the package. The data is a 50 by 501 matrix with each row being a sample and the first column being the group indicator and the other 500 columns are sequencing reads for 500 taxa. No missing data in the data set. I can upload the data, but I don't know how to do that. Below is the R script for the analysis. Please help. Thanks a lot!

class(data) [1] "data.frame"

# make data in the format for DESeq2

countsData=t(data[,-1])+1

rownames(countsData)=colnames(data)[-1]

class(countsData)

[1] "matrix"

print(dim(countsData))

[1] 500 50

print(countsData[1:5,1:5]

                  [,1] [,2] [,3] [,4] [,5]

rawCount1 8 8 10 11 9

rawCount2 8 9 8 7 8

rawCount3 36 34 30 36 33

rawCount4 7 8 6 5 8

rawCount5 10 7 63 13 64

# get predictor data and annotate the predictor data

xData=as.data.frame(data[,1])

colnames(xData)=colnames(data)[1]

xData[,"x"]=as.factor(xData[,"x"])

class(xData)

[1] "data.frame"

print(dim(xData))

[1] 50 1

print(xData[1:5,])

[1] 0 0 1 0 1

Levels: 0 1

# prepare for analysis

dds <- DESeqDataSetFromMatrix(countData=countsData,colData=xData,design=~x)

# run analysis

suppressWarnings(runDeseq<- try(DESeq(dds, quiet = TRUE), silent = TRUE))

if (inherits(runDeseq, "try-error")) {

# If the parametric fit failed, try the local.

suppressWarnings(runDeseq<- try(DESeq(dds, fitType = "local", quiet = TRUE), 
                                silent = TRUE))

 if (inherits(runDeseq, "try-error")) {

   # If local fails, try the mean

   suppressWarnings(runDeseq<- try(DESeq(dds, fitType = "mean", quiet = TRUE), 
                                  silent = TRUE))
   }

   if (inherits(runDeseq, "try-error")) {

     # If still bad, quit with error.

     stop("DESeq1 fail")
     }

}

When I dig into the error message, it says "simpleError in estimateDispersionsFit(object, fitType = fitType, quiet = quiet): all gene-wise dispersion estimates are within 2 orders of magnitude from the minimum value, and so the standard curve fitting techniques will not work. One can instead use the gene-wise estimates as final estimates: dds <- estimateDispersionsGeneEst(dds) dispersions(dds) <- mcols(dds)$dispGeneEst ...then continue with testing using nbinomWaldTest or nbinomLRT".

So I tried

dds <- DESeqDataSetFromMatrix(countData=countsData,colData=xData,design=~x)

dds <- estimateDispersionsGeneEst(dds)

but it gave me another error message: "Error in .local(object, ...) : first calculate size factors, add normalizationFactors, or set normalized=FALSE".

Here is some session info:

sessionInfo()

R version 3.6.1 (2019-07-05)

Platform: x86_64-w64-mingw32/x64 (64-bit)

Running under: Windows 10 x64 (build 16299)

packageVersion("DESeq2")

[1] ‘1.24.0’

deseq2 microbiome sequencing • 1.2k views
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0
Entering edit mode
@mikelove
Last seen 15 hours ago
United States

The second error seems easy to overcome. Did you try following the advice printed there, that is “first estimate size factors...”? See estimateSizeFactors().

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Entering edit mode
zhigang.li • 0
@zhigangli-21311
Last seen 6 weeks ago
United States

Thanks a lot for your help. I tried estimateSizeFactors() and changed the code a little bit. Now it is working. Here is my new code for the analysis. Does it look correct to you? Thanks!

run analysis

suppressWarnings(runDeseq<- try(DESeq(dds, quiet = TRUE), silent = TRUE))

if (inherits(runDeseq, "try-error")) {

# If the parametric fit failed, try the local.

suppressWarnings(runDeseq<- try(DESeq(dds, fitType = "local", quiet = TRUE), 
                                silent = TRUE))

 if (inherits(runDeseq, "try-error")) {

   # If local fails, try the mean

   suppressWarnings(runDeseq<- try(DESeq(dds, fitType = "mean", quiet = TRUE), 
                                  silent = TRUE))
 }

 if (inherits(runDeseq, "try-error")) {

   dds <- estimateSizeFactors(dds)

   dds <- estimateDispersionsGeneEst(dds)

   dispersions(dds) <- mcols(dds)$dispGeneEst

   runDeseq <- try(nbinomWaldTest(dds, quiet = TRUE),silent = TRUE)
   }

}

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