Entering edit mode
Yanzhu Lin
▴
120
@yanzhu-lin-6551
Last seen 8.2 years ago
Hi Mike,
I would like to try DESeq2 package now.
My project has three factors: A with 16 levels, B with 2 levels and C
with
3 levels, in total I have 16 x 3 x 2 = 96 groups, for each group, we
have
8 biological replicates in our original experiment design, which ends
up
with
96 x 8 =768 biosamples.
I can't understand why we can't estimate any interaction terms if
there are
8 replicates per group, which was mentioned in your previous email.
Based on 8 biological replicates per group, I think we still have
enough df
to test each interaction term.
Best,
Yanzhu
Jan 15, 2014 at 11:12 AM, Michael Love <michaelisaiahlove@gmail.com>
wrote:
> hi Yanzhu,
>
> Firstly, we recommend in general moving to DESeq2, where we spend
most of
> our development effort and which will be supported going foward.
>
> The DESeq2 workflow is very similar to DESeq and is described in
detail in
> the vignette. The constructor function from a count matrix and
column data
> is DESeqDataSetFromMatrix(), see the manual page for the required
> arguments. For likelihood ratio tests, you can use the following
code:
>
> dds <- DESeqDataSetFromMatrix(counts, columndata, design = ~ A)
> dds <- DESeq(dds, test="LRT", reduced = ~ 1)
> res <- results(dds)
> res
>
> In order to give more detailed recommendations though, can you
please tell
> us more about the experimental setup and what questions you are
trying to
> answer? For instance, how are the samples distributed across groups
A, B
> and C?* I would suppose they are not 8 replicates per group, as this
> would not allow you to estimate any interaction terms.*
>
> Mike
>
>
> On Mon, Jan 13, 2014 at 2:15 PM, Yanzhu [guest]
<guest@bioconductor.org>
> wrote:
>
>>
>> Dear Community,
>>
>> I have some questions about how the DESeq r package works for
>> multi-factors expersiment. My experiment has three factors: A/B/C,
and 8
>> replicates per condition. I would like the test the significance of
the
>> main effects of factor A, B and C, the significance of the two-way
>> interaction terms: A:B, A:C and B:C, and the significance of the
three-way
>> interaction term: A:B:C. I want the table of pvalue for each term
(main
>> effects, two-way interaction terms and the three-way interaction
term) like
>> what ANOVA does for each gene.
>>
>>
>> I know to test the significance of the three-way interaction term,
we use
>> the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B+A:C+B:C+A:B:C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B+A:C+B:C)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> My Questions are: how can I test the significance of main effects
and the
>> two-way interaction terms?
>>
>> 1. To test the main effect of A, B and C
>>
>> (i) To test the main effect of A:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~1)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> (ii) To test the main effect of B:
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~B)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~1)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> OR:
>>
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B)
>> itDeSeq0<-fitNbinomGLMs(cdsFull,count~B)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> Which one is correct?
>>
>> (iii) To test the main effect of C:
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~1)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> OR:
>>
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C)
>> itDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> which one is correct?
>>
>> 2. To test the two-way interaction terms: A:B, A:C and B:C
>>
>> (i) To test the two-way interaction term: A:B
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> Is it correct?
>>
>> (ii) To test the two-way interaction term: A:C
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B+A:C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> OR:
>>
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+A:C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> Which one is correct?
>>
>> (iii) To test the two-way interaction term: B:C
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B+A:C+B:C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C+A:B+A:C)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> OR:
>>
>> Do I need to use the following coding:
>> fitDeSeq1<-fitNbinomGLMs(cdsFull,count~A+B+C+B:C)
>> fitDeSeq0<-fitNbinomGLMs(cdsFull,count~A+B+C)
>> modDeSeq<-nbinomGLMTest(fitDeSeq1,fitDeSeq0)
>>
>> Which one is correct?
>>
>> Thank you!
>>
>>
>>
>>
>>
>>
>> -- output of sessionInfo():
>>
>> sessionInfo()
>> R version 3.0.1 (2013-05-16)
>> Platform: x86_64-w64-mingw32/x64 (64-bit)
>>
>> locale:
>> [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United
>> States.1252 LC_MONETARY=English_United States.1252
>> [4] LC_NUMERIC=C LC_TIME=English_United
>> States.1252
>>
>> attached base packages:
>> [1] parallel stats graphics grDevices utils datasets
methods
>> base
>>
>> other attached packages:
>> [1] DESeq_1.12.1 lattice_0.20-15 locfit_1.5-9.1
>> Biobase_2.20.1 BiocGenerics_0.6.0 edgeR_3.2.4
>> [7] limma_3.16.8
>>
>> loaded via a namespace (and not attached):
>> [1] annotate_1.38.0 AnnotationDbi_1.22.6 DBI_0.2-7
>> genefilter_1.42.0 geneplotter_1.38.0
>> [6] grid_3.0.1 IRanges_1.18.4 MASS_7.3-26
>> RColorBrewer_1.0-5 RSQLite_0.11.4
>> [11] splines_3.0.1 stats4_3.0.1 survival_2.37-4
>> tools_3.0.1 XML_3.98-1.1
>> [16] xtable_1.7-1
>>
>> --
>> Sent via the guest posting facility at bioconductor.org.
>>
>> _______________________________________________
>> Bioconductor mailing list
>> Bioconductor@r-project.org
>> https://stat.ethz.ch/mailman/listinfo/bioconductor
>> Search the archives:
>> http://news.gmane.org/gmane.science.biology.informatics.conductor
>>
>
>
[[alternative HTML version deleted]]