Question: genes symbol in RangedSummarizedExperiment object and add GRangesList to DESeqDataSet object in DESeq2
gravatar for layal8785
14 months ago by
layal87850 wrote:

I hope I can get clear answer, because I didn't come here to ask till I've struggled for few days.

1) I wanted to get the fpkm counts from the DESeqDataSet object I created it from DESeqDataSetFromMatrix,but a column basepairs is not present in mcols(dds) (mcols of DESeqDataSet object after applying DESeq() ) so we need to calculated from the rowRanges of the dds object.. But it doesn't have GRangesList information.

So the question was how to get the the GRangesList.

2) get the GRanges from Genomic Feature package:

gtffile <- file.path("PATH/Mus_musculus.GRCm38.86.gtf")
txdb <- makeTxDbFromGFF(gtffile, format="gtf", circ_seqs=character())
ebg <- exonsBy(txdb, by="gene")
se <- summarizeOverlaps(features=ebg, bamfiles,
                        fragments=TRUE )

How to get the gene symbol instead of the ensemble ID ?

I tried to set use.names = TRUE in exonBy() function but it is not possible to set the use.names to TRUE  when grouped by "gene"... I tried to group it by transcript and get the transcript name it didn't work

In the function summarizeOverlaps no argument could be used to get the gene symbol

since I got the GRangesList (ebg) how to add it to dds (which I have) as it recommended in reference Manual

" If a user wants to store metadata columns about the rows of the countData, but does not have GRanges or GRangesList information, first construct the DESeqDataSet without rowRanges and then add the DataFrame with mcols(dds)"

ADD COMMENTlink modified 14 months ago • written 14 months ago by layal87850

I created the count matrix from featureCount

FC_countreads <- featureCounts(files="pathes to 12bam files",
                               isPairedEnd=TRUE, annot.ext= "pathsToGeneAnnotation/Mus_musculus.GRCm38.86.gtf",
                               isGTFAnnotationFile=TRUE, GTF.featureType="exon", GTF.attrType="gene_name")

countdata <- FC_countreads$counts

#Set new names to countdata matrix

New_names <- c("DayZero_R1","DayZero_R2","DayZero_R3" , "DayThree_R1","DayThree_R2","DayThree_R3","DaySix_R1","DaySix_R2","DaySix_R3", "DayTwelve_R1", "DayTwelve_R2", "DayTwelve_R3")
colnames(countdata) <- New_names

condition <- factor(c(rep("DayZero", 3),rep("DayThree",3),rep("DaySix",3),rep("DayTwelve",3)))
coldata <- data.frame(row.names = colnames(countdata), condition)
dds <- DESeqDataSetFromMatrix(countData = countdata, colData = coldata, design = ~ condition)



ADD REPLYlink written 14 months ago by layal87850
gravatar for Michael Love
14 months ago by
Michael Love17k
United States
Michael Love17k wrote:

Let's take a step back, how did you generate the count matrix you used to create the dds object?

ADD COMMENTlink written 14 months ago by Michael Love17k

The output from featureCounts should have a list element called annotation with information about each gene's length. See the help page: ?featureCounts.

ADD REPLYlink written 14 months ago by Michael Love17k
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