DESeq2: Contrast for two conditions combined versus one condition (A+B_vs_C)
1
0
Entering edit mode
bioinf ▴ 10
@bioinf-12080
Last seen 6 months ago
United States

Hi,

Below is my samples and conditions info:

Sample_ID        Conditions
1                        A
2                        A
3                        A
4                        B
5                        B
6                        B
7                        C
8                        C
9                        C

For A_vs_C, I followed:

res_A_vs_C= lfcShrink(dds, contrast=c("Conditions", "A", "C"), type='ashr')

Now, I want to compare samples with A and B conditions together versus condition C (A+B_vs_C). How can I do that from the above dds (if there is a way)?

Or do I need to group A+C and create a new column, and then run a new DESeq()? Please guide.

Thanks.

DESeq2 contrasts • 566 views
ADD COMMENT
2
Entering edit mode
ATpoint ★ 4.5k
@atpoint-13662
Last seen 2 days ago
Germany

See previous threads Using the "listValues" argument of DESEQ in multiple group comparisons

listValues is the keyword.

ADD COMMENT
0
Entering edit mode

Thank you ATpoint ! Considering I used C after A in my last comparison, so this one would be:

res_AB_vs_C = lfcShrink(dds, contrast = list(c("A", "B"), "C"),  listValues=c(-1/2, 1)), type='ashr')

or should I use: (will the order matter? and If so, then I will need to do res_C_vs_A instead of res_A_vs_C)

res_C_vs_AB = lfcShrink(dds, contrast = list("C", c("A", "B"),  listValues=c(1, -1/2)), type='ashr')

Thanks.

ADD REPLY
1
Entering edit mode

It should not matter, only the sign of the logFC will be other. I always adjust this to the story I want to tell. Say you do treatment vs normal then in my head treatment effects should have a positive logFC in plots etc, so I would put treatment vs (control1,control2)/2.

ADD REPLY

Login before adding your answer.

Traffic: 620 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