run_coverageQC: Quality control on read coverage over gene bodies and 3UTRs

In haibol2016/InPAS: Identify Novel Alternative PolyAdenylation Sites (PAS) from RNA-seq data

Quality control on read coverage over gene bodies and 3UTRs

Description

Calculate coverage over gene bodies and 3UTRs. This function is used for quality control of the coverage.The coverage rate can show the complexity of RNA-seq library.

Usage

run_coverageQC(
  sqlite_db,
  TxDb = getInPASTxDb(),
  edb = getInPASEnsDb(),
  genome = getInPASGenome(),
  cutoff_readsNum = 1,
  cutoff_expdGene_cvgRate = 0.1,
  cutoff_expdGene_sampleRate = 0.5,
  chr2exclude = getChr2Exclude(),
  which = NULL,
  future.chunk.size = 1,
  ...
)

Arguments

sqlite_db	A path to the SQLite database for InPAS, i.e. the output of setup_sqlitedb().
TxDb	An object of GenomicFeatures::TxDb
edb	An object of ensembldb::EnsDb
genome	An object of BSgenome::BSgenome
cutoff_readsNum	cutoff reads number. If the coverage in the location is greater than cutoff_readsNum,the location will be treated as covered by signal
cutoff_expdGene_cvgRate	cutoff_expdGene_cvgRate and cutoff_expdGene_sampleRate are the parameters used to calculate which gene is expressed in all input dataset. cutoff_expdGene_cvgRateset the cutoff value for the coverage rate of each gene; cutoff_expdGene_sampleRateset the cutoff value for ratio of numbers of expressed and all samples for each gene. for example, by default, cutoff_expdGene_cvgRate=0.1 and cutoff_expdGene_sampleRate=0.5,suppose there are 4 samples, for one gene, if the coverage rates by base are:0.05, 0.12, 0.2, 0.17, this gene will be count as expressed gene because mean(c(0.05,0.12, 0.2, 0.17) > cutoff_expdGene_cvgRate) > cutoff_expdGene_sampleRate if the coverage rates by base are: 0.05, 0.12, 0.07, 0.17, this gene will be count as un-expressed gene because mean(c(0.05, 0.12, 0.07, 0.17) > cutoff_expdGene_cvgRate)<= cutoff_expdGene_sampleRate
cutoff_expdGene_sampleRate	See cutoff_expdGene_cvgRate
chr2exclude	A character vector, NA or NULL, specifying chromosomes or scaffolds to be excluded for InPAS analysis. chrM and alternative scaffolds representing different haplotypes should be excluded.
which	an object of GenomicRanges::GRanges or NULL. If it is not NULL, only the exons overlapping the given ranges are used. For fast data quality control, set which to Granges for one or a few large chromosomes.
future.chunk.size	The average number of elements per future ("chunk"). If Inf, then all elements are processed in a single future. If NULL, then argument future.scheduling = 1 is used by default. Users can set future.chunk.size = total number of elements/number of cores set for the backend. See the future.apply package for details.
...	Not used yet

Value

A data frame as described below.

gene.coverage.rate

overage per base for all genes

expressed.gene.coverage.rate

coverage per base for expressed genes

UTR3.coverage.rate

coverage per base for all 3' UTRs

UTR3.expressed.gene.subset.coverage.rate

coverage per base for 3' UTRs of expressed genes

rownames

the names of coverage

Author(s)

Jianhong Ou, Haibo Liu

Examples

if (interactive()) {
  library("BSgenome.Mmusculus.UCSC.mm10")
  library("TxDb.Mmusculus.UCSC.mm10.knownGene")
  library("EnsDb.Mmusculus.v79")

  genome <- BSgenome.Mmusculus.UCSC.mm10
  TxDb <- TxDb.Mmusculus.UCSC.mm10.knownGene
  edb <- EnsDb.Mmusculus.v79

  bedgraphs <- system.file("extdata", c(
    "Baf3.extract.bedgraph",
    "UM15.extract.bedgraph"
  ),
  package = "InPAS"
  )
  tags <- c("Baf3", "UM15")
  metadata <- data.frame(
    tag = tags,
    condition = c("Baf3", "UM15"),
    bedgraph_file = bedgraphs
  )
  outdir <- tempdir()
  write.table(metadata,
    file = file.path(outdir, "metadata.txt"),
    sep = "\t", quote = FALSE, row.names = FALSE
  )

  sqlite_db <- setup_sqlitedb(
    metadata = file.path(
      outdir,
      "metadata.txt"
    ),
    outdir
  )
  tx <- parse_TxDb(
    sqlite_db = sqlite_db,
    TxDb = TxDb,
    edb = edb,
    genome = genome,
    outdir = outdir,
    chr2exclude = "chrM"
  )
  addLockName(filename = tempfile())
  coverage <- list()
  for (i in seq_along(bedgraphs)) {
    coverage[[tags[i]]] <- get_ssRleCov(
      bedgraph = bedgraphs[i],
      tag = tags[i],
      genome = genome,
      sqlite_db = sqlite_db,
      outdir = outdir,
      chr2exclude = "chrM"
    )
  }
  chr_coverage <- assemble_allCov(sqlite_db,
    seqname = "chr6",
    outdir,
    genome
  )
  run_coverageQC(sqlite_db, TxDb, edb, genome,
    chr2exclude = "chrM",
    which = GRanges("chr6",
      ranges = IRanges(98013000, 140678000)
    )
  )
}

haibol2016/InPAS documentation built on March 30, 2022, 10:30 a.m.