Question: Phyloseq to DESeq2 for 16s amplicon sequencing data
0
gravatar for Bioinfonext
4 months ago by
Bioinfonext150
Korea
Bioinfonext150 wrote:

Hi,

I am trying to use DESeq2 for amplicon data analysis, but I am getting some problem.

Details of the analysis:

here is the summary of data, I do have three tissue: soil, root, and shoot sample collected from different villages.

and we have given three treatment to each soil, root and shoot sample in each village: TREATMENT T1, T2 AND T3.

Now, the aim is to find which microbial species or genus are more abundant in Treatment T1 and Treatment T3 in comparison to T2 and how T3 microbial abundance is different from T1 Treatment.

I tried to pass the phyloseq object into DESeq2

# Phyloseq to Deseq

psfdds<-phyloseqtodeseq2(ps0, ~1) # I just pass 1 as design here, because at later step I am going to pass again group as design.

#Group Tissue and Tremant variable into one varibale

psfdds$group <- factor(paste0(psfdds$Tissue,psfdds$Treatment))
#  group used as design again
design(psfdds) <- ~ group


 #Deseq 
    psfdds <- DESeq(psfdds, test="Wald", fitType="parametric")
    estimating size factors
    estimating dispersions
    gene-wise dispersion estimates
    mean-dispersion relationship
    final dispersion estimates
    fitting model and testing
    -- replacing outliers and refitting for 10886 genes
    -- DESeq argument 'minReplicatesForReplace' = 7
    -- original counts are preserved in counts(dds)
    estimating dispersions
    fitting model and testing

resultsNames(psfdds)
[1] "Intercept" "group_LeafT2_vs_LeafT1" "group_LeafT3_vs_LeafT1"
[4] "group_RootT1_vs_LeafT1" "group_RootT2_vs_LeafT1" "group_RootT3_vs_LeafT1"
[7] "group_SoilT1_vs_LeafT1" "group_SoilT2_vs_LeafT1" "group_SoilT3_vs_LeafT1"

# Now extracting result for soil in Treatment1_vs_Treatment2



 res_soil.T1_soil.T2_new <- results(psfdds, contrasts=c("group","TissueSoil.TreatmentT1","TissueSoil.TreatmentT2"))



# but when I look at summary of result of any comparison it give same value as shown below
summary(ressoil.T1_soil.T2_new)
out of 59297 with nonzero total read count
adjusted p-value < 0.1
LFC > 0 (up) : 58684, 99%
LFC < 0 (down) : 3, 0.0051%
outliers [1] : 0, 0%
low counts [2] : 3004, 5.1%
(mean count < 0)

But it seems like there is some problem as it is showing the same result after passing anything.

Could anyone please suggest how can I resolve it.

I will be very thankful to you.

bioconducter R • 310 views
ADD COMMENTlink modified 4 months ago • written 4 months ago by Bioinfonext150

Could you please format your code? After highlighting the text you want to format, use the icon below:

ScreenCap

ADD REPLYlink written 4 months ago by h.mon26k
Please log in to add an answer.

Help
Access

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.
Powered by Biostar version 2.3.0
Traffic: 2219 users visited in the last hour