Differential expression analysis with only FPKM matrix available from total newbie in R
1
0
Entering edit mode
@48da0fb9
Last seen 4 months ago
South Korea

Hi everyone,

I am new to R and have been tasked with analyzing a dataset that only provides FPKM (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE223176). I know that FPKM is not meaningful for sample-wise comparison but it seems they only give the FPKM data.

I have been reading threads regarding this topic but could not figure out a detailed pipeline and input code that I need to use to solve the task. All that I know is it is better to transform the data to log2(FPKM+0.1) and apply limma-trend. However, when I try to follow the user guide of Limma, it seems they only use the integral-number-count-table.

Could someone help me by providing a source that I can read or some example code? I truly appreciate any help since I have no clue what should I do now...

FPKM RNASeqData DEAnalysis limma • 1.2k views
ADD COMMENT
1
Entering edit mode
ATpoint ★ 4.0k
@atpoint-13662
Last seen 22 hours ago
Germany

limma-trend can accept FPKM on log scale but it's not optimal, see Differential expression of FPKM from RNA-seq data using limma and voom()

Since this is only eight samples you could use the sra-explorer.info website to get download links for the fastq files and then do a quantification with salmon as described here: https://master.bioconductor.org/packages/release/workflows/vignettes/rnaseqGene/inst/doc/rnaseqGene.html Basically you could follow the linked workflow, and then decide whether you want to use edgeR, limma, DESeq2, they all are established and do well.

ADD COMMENT
2
Entering edit mode

Agree with ATpoint

Salmon is really easy to run, you can even run it on your laptop if you aren't familiar with using a computer cluster. You can download a recent binary (v1.10) here:

https://github.com/COMBINE-lab/salmon/releases/tag/v1.10.0

After decompressing, you can directly execute the Salmon program on Linux or Mac.

It's worth learning these basic steps to process RNA-seq data.

ADD REPLY
0
Entering edit mode

Thank you so much for your answer. I will try to do as your suggestion.

ADD REPLY

Login before adding your answer.

Traffic: 598 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