Hi, 

As the title suggested, I wonder if I can extract exon information (e.g. through exonsBy) wherein I'll have each exon genome coordinates, exon ID, and the gene ID of which they belong (by = "gene") and, on top of all that, the transcript ID each exon belong to?

Thank you very much!

Shin

> ex <- exonsBy(TxDb.Hsapiens.UCSC.hg19.knownGene, use.names = TRUE)

> exgr <- unlist(ex)

> mcols(exgr)$txid <- names(exgr)

> mcols(exgr)$geneid <- mapIds(TxDb.Hsapiens.UCSC.hg19.knownGene, names(exgr), "GENEID","TXNAME")
'select()' returned 1:1 mapping between keys and columns
> exgr
GRanges object with 742493 ranges and 5 metadata columns:
                   seqnames         ranges strand |   exon_id   exon_name
                      <Rle>      <IRanges>  <Rle> | <integer> <character>
  uc001aaa.3           chr1 [11874, 12227]      + |         1        <NA>
  uc001aaa.3           chr1 [12613, 12721]      + |         3        <NA>
  uc001aaa.3           chr1 [13221, 14409]      + |         5        <NA>
  uc010nxq.1           chr1 [11874, 12227]      + |         1        <NA>
  uc010nxq.1           chr1 [12595, 12721]      + |         2        <NA>
         ...            ...            ...    ... .       ...         ...
  uc011mgv.2 chrUn_gl000241 [22732, 22846]      - |    289961        <NA>
  uc011mgv.2 chrUn_gl000241 [20433, 20481]      - |    289960        <NA>
  uc011mgw.1 chrUn_gl000243 [11501, 11530]      + |    289967        <NA>
  uc022brq.1 chrUn_gl000243 [13608, 13637]      + |    289968        <NA>
  uc022brr.1 chrUn_gl000247 [ 5787,  5816]      - |    289969        <NA>
             exon_rank        txid      geneid
             <integer> <character> <character>
  uc001aaa.3         1  uc001aaa.3   100287102
  uc001aaa.3         2  uc001aaa.3   100287102
  uc001aaa.3         3  uc001aaa.3   100287102
  uc010nxq.1         1  uc010nxq.1   100287102
  uc010nxq.1         2  uc010nxq.1   100287102
         ...       ...         ...         ...
  uc011mgv.2         6  uc011mgv.2        <NA>
  uc011mgv.2         7  uc011mgv.2        <NA>
  uc011mgw.1         1  uc011mgw.1        <NA>
  uc022brq.1         1  uc022brq.1        <NA>
  uc022brr.1         1  uc022brr.1        <NA>
  -------
  seqinfo: 93 sequences (1 circular) from hg19 genome
>