Hi,

I have a list of genes in a genomicRanges object. I'd like to resize the genes so that the range starts 500bp downstream from the current TSS without changing the end location. I've been looking at the resize and related functions, but can't figure out how to only change the start and not change the end. Is this possible?

Thanks

Hi Jake,

Here is one way to do this, using resize() (the genes are resized so that the range starts 5bp downstream from the current TSS):

## 2 fake genes
gr <- GRanges("chr1", IRanges(11:12, 30), c("+", "-"))
gr
# GRanges object with 2 ranges and 0 metadata columns:
#       seqnames    ranges strand
#          <Rle> <IRanges>  <Rle>
#   [1]     chr1  [11, 30]      +
#   [2]     chr1  [12, 30]      -
#   -------
#   seqinfo: 1 sequence from an unspecified genome; no seqlengths

resize(gr, width(gr) - 5, fix="end")
# GRanges object with 2 ranges and 0 metadata columns:
#       seqnames    ranges strand
#          <Rle> <IRanges>  <Rle>
#   [1]     chr1  [16, 30]      +
#   [2]     chr1  [12, 25]      -
#   -------
#   seqinfo: 1 sequence from an unspecified genome; no seqlengths

Maybe not as straightforward as one might hope though...

H.