[Bioperl-l] UCSC database backend
cdavis at bcm.tmc.edu
Thu Aug 31 19:53:51 EDT 2006
Hi folks, first time caller here. Love the show!
I just started going through the archive and saw this thread. I vote in
favor of this interface, for what it's worth. What about doing it this
$objSeqIO = Bio::SeqIO->new(-file => '~/seq/myseqCustomTrack.bed',
-format => 'bed',
-assembly => 'hg18',
-track => 'hg18_myfavgenes'); #see example below
If this worked you could have any genomic sequence from any assembly at
your fingertips. The custom track format is a common way to specify
arbitrary genomic coordinates and region identifiers. There are a few
different formats, but BED is my current favorite
nice thing about custom tracks is that you can use them as hooks to
retrieve assembly sequence, as well as to visualize the regions of
interest directly in the browser.
A brief tutorial for using the table browser to retrieve
sequence...Here's an example of a plausible myCustomTrack.bed. In this
example the coordinates happen to correspond to genes, but they could
point to arbitrary genomic segments:
browser position chr1:1940702-1952050
track name=hg18_myfavgenes description="my favorite genes"
chr1 1940702 1952050 GABRD|NM_000815 1000 + 1940722
1951581 0,0,0 9 88,113,68,221,83,138,156,212,769
chr1 6008966 6083110 KCNAB2|NM_003636 1000 + 6023215
6081221 0,0,0 16
track name=hg18_othergenes description="some other genes"
chr1 11788880 11825772 CLCN6|NM_001286 1000 +
11788906 11822867 0,0,0 23
chr1 16221696 16233131 CLCNKA|NM_004070 1000 +
16221701 16232740 0,0,0 19
Submit the example into the form here:
To retrieve the sequence you go to the table browser, select the custom
track, and select sequence as the output format:
Maybe assemblies are interesting enough that they would get their own
objects, with a custom track query to an objAssembly generating an
objSeqIO. You folks rock!
>Sean Davis wrote:
>> Before we get too far down this line of thought, keep in mind that
>> be dozens of Gb of sequence and database tables. See here for details:
>> The sequences include all of genbank, essentially. The mysql tables
>> (no sequence) for only ONE human assembly is on the order of
>> kind of thing you can download in a few minutes (or even hours).
>> keep in mind....
>I think if someone needs heavy-duty access to genomic data, they'll find
>the discspace. That wouldn't be the problem. The problem would be
>finding an easy way of getting the data, which is where I hoped
>something like a UCSC frontend would come in.
>> On another point, the strength of UCSC is not in obtaining sequence,
>> mapping to the genome. I think getting actual sequence should be
>> here, if for no other reason than there are trivially easy ways of
>> sequence information from elsewhere given an accession or ID. There is
>> simply too much information to be stored locally for most people and
>> the data remotely from UCSC doesn't seem possible currently.
>The work would certainly be highly valuable even if it didn't allow for
>sequence retrieval, but from my own point of view my main interest was
>exactly the retrieval of arbitrary bits of genomic sequence - for which
>there is no accession or ID that can be used to query some other database.
>How does the website table browser frontend allow retrieval of sequence
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