assignTSSByCage {ORFik}R Documentation

Input a txdb and add a 5' leader for each transcript, that does not have one.

Description

For all cds in txdb, that does not have a 5' leader: Start at 1 base upstream of cds and use CAGE, to assign leader start. All these leaders will be 1 exon based, if you really want exon splicings, you can use exon prediction tools, or run sequencing experiments.

Usage

assignTSSByCage(txdb, cage, extension = 1000, filterValue = 1,
  restrictUpstreamToTx = FALSE, removeUnused = FALSE)

Arguments

txdb

a TxDb file or a path to one of: (.gtf ,.gff, .gff2, .gff2, .db or .sqlite)

cage

Either a filePath for CageSeq file, or already loaded CageSeq peak data as GRanges.

extension

The maximum number of basses upstream of the TSS to search for CageSeq peak.

filterValue

The minimum number of reads on cage position, for it to be counted as possible new tss. (represented in score column in CageSeq data) If you already filtered, set it to 0.

restrictUpstreamToTx

a logical (FALSE), if you want to restrict leaders to not extend closer than 5 bases from closest upstream leader, set this to TRUE.

removeUnused

logical (FALSE), remove leaders that did not have any cage support. (standard is to set them to original annotation)

Details

Given a TxDb object, reassign the start site per transcript using max peaks from CageSeq data. A max peak is defined as new TSS if it is within boundary of 5' leader range, specified by 'extension' in bp. A max peak must also be higher than minimum CageSeq peak cutoff specified in 'filterValue'. The new TSS will then be the positioned where the cage read (with highest read count in the interval).

Value

a TxDb obect of reassigned transcripts

See Also

Other CAGE: reassignTSSbyCage, reassignTxDbByCage

Examples

 ## Not run: 
 library(GenomicFeatures)
 # Get the gtf txdb file
 txdbFile <- system.file("extdata", "hg19_knownGene_sample.sqlite",
 package = "GenomicFeatures")
 cagePath <- system.file("extdata", "cage-seq-heart.bed.bgz",
 package = "ORFik")
 reassignTxDbByCage(txdbFile, cagePath)
 
## End(Not run)

[Package ORFik version 1.4.0 Index]