Best way of presenting "absolute" expression values (edgeR)
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Sindre ▴ 110
@sindre-6193
Last seen 4.3 years ago
Hi! We want to classify a new type of glands by ranking genes by expression level using RNAseq. We don't have any good controls, so we just want to see a ranked list of genes. I have used Cufflinks RPKM values, but if I want to use edgeR, is this a valid way of doing it using featureCounts: fc <- featureCounts(files=targets$Targets,nthreads=8, isGTFAnnotationFile=TRUE, GTF.attrType="gene_id", GTF.featureType="exon", useMetaFeatures=TRUE, annot.ext="genes.gtf") x <- DGEList(counts=fc$counts, genes=fc$annotation) expr <- calcNormFactors(x) expr_norm <- rpkm(expr, log=FALSE,gene.length=x$genes$Length) # Getting gene length from FeatureCounts, using rkpm() in the edgeR package, not Rsubread.. Then just write out this table.. Thanks!
RNASeq edgeR RNASeq edgeR • 2.5k views
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Hi! I know a lot of people do the following: 1. Take a list of differentially expressed genes 2. Fetch the FASTA files for protein coding genes 3. Predict if secretory by using SignalP My question is, does it exist a list/database of known/predicted secretory protein coding genes from hg19? That would be much more efficient than many people predicting the same proteins a lot of times..
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@gordon-smyth
Last seen 14 hours ago
WEHI, Melbourne, Australia

Yes, your code is fine for getting normalized RPKM from featureCounts and edgeR.

Your code is similar to the public case study: https://bioinf.wehi.edu.au/RNAseqCaseStudy

In the latest version of edgeR, you can even simplify the code to

expr_norm <- rpkm(expr)

Gordon

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